Gus Woltmann » Earth & Climate

Volcanoes

admin — Fri, 25 Sep 2009 11:39:28 +0000

Shield volcano
A shield volcano is a wide volcano with shallowly-sloping sides.
Shield volcanoes are formed by lava flows of low viscosity – lava that flows easily.
Consequently, a volcanic mountain having a broad profile is built up over time by flow after flow of relatively fluid basaltic lava issuing from vents or fissures on the surface of the volcano.
Many of the largest volcanoes on Earth are shield volcanoes.
The largest is Mauna Loa on the Big Island of Hawaii; all the volcanoes in the Hawaiian Islands are shield volcanoes.
There are also shield volcanoes, for example, in Washington, Oregon, and the Galapagos Islands.
The Piton de la Fournaise, on Reunion Island, is one of the more active shield volcanoes on earth, with one eruption per year on average..
Volcanic cone
Volcanic cones are among the simplest volcano formations.
They are built by fragments (called ejecta) thrown up (ejected) from a volcanic vent, piling up around the vent in the shape of a cone with a central crater.
Volcanic cones are of different types, depending upon the nature and size of the fragments ejected during the eruption.
Types typically differentiated are spatter cone, cinder cone, ash cone, and tuff cone..
Pyroclastic flow from volcanoes
Pyroclastic flows are a common and devastating result of some volcanic eruptions.
They are fast-moving fluidized bodies of hot gas, ash and rock (collectively known as tephra) which can travel away from the vent at up to 150 km/h.
The gas is usually at a temperature of 100-800 degrees Celsius.
The flows normally hug the ground and travel downhill under gravity, their speed depending upon the gradient of the slope and the size of the flow. Volumes range from a few hundred cubic metres to more than a thousand cubic kilometres, and the larger ones can travel for hundreds of kilometres although none on that scale have occurred for several hundred thousand years.
Most flows are around one to ten cubic kilometres and travel for several kilometres.
Flows usually consist of two parts: the basal flow hugs the ground and contains larger, coarse boulders and rock fragments, while an ash cloud rises above it because of the turbulence between the flow and the overlying air..
Stratovolcano
A stratovolcano is a tall, conical volcano composed of one layer of hardened lava, tephra, and volcanic ash.
These volcanoes are characterized by a steep profile and periodic, explosive eruptions.
The lava that flows from them is highly viscous, and cools and hardens before spreading very far.
The source magma of this rock is classified as acidic, or high in silica to intermediate (rhyolite, dacite, or andesite.
or basalt).
This is in contrast to less viscous basic magma that forms shield volcanoes (such as Mauna Loa in Hawaii), which have a wide base and more gently sloping profile.
Many stratovolcanoes exceed a height of 2500 m..

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Hurricanes and Cyclones

admin — Fri, 25 Sep 2009 11:28:48 +0000

List of major natural disasters in the United States
This is a list of major natural disasters in the United States..
National Hurricane Center
The U.S.
National Hurricane Center is the division of National Weather Service’s Tropical Prediction Center responsible for tracking and predicting the likely behavior of tropical depressions, tropical storms and hurricanes.
When tropical storm or hurricane conditions are expected within 36 hours, the center issues the appropriate watches and warnings via the news media and NOAA Weather Radio..
Saffir-Simpson Hurricane Scale
The Saffir-Simpson Hurricane Scale is a scale classifying most Western Hemisphere tropical cyclones that exceed the levels of “tropical depression” and “tropical storm” and thereby become hurricanes..
Cyclone Gafilo
Cyclone Gafilo was a powerful tropical cyclone which struck Madagascar in March 2004, causing devastating damage.
At least 250 people were listed dead, with more missing, and 300,000 people were left homeless.
The greatest single loss of life came on March 7 when the ferry ‘Le Samson’ sank in heavy seas off Comoros carrying 112 people; only two survived.
The storm also caused significant crop losses..

“This article is brought to you by Gus Woltmann”.

Floods

admin — Fri, 25 Sep 2009 11:25:41 +0000

Flood
A flood is an overflow of water, an expanse of water submerging land, a deluge.
Since prehistoric times people have lived by the seas and rivers for the access to cheap and quick transportation and access to food sources and trade; without human populations near natural bodies of water, there would be no concern for floods.
However fertile soil in a river delta is subject to regular inundation from normal variation in precipitation.
Floods from the sea can cause overflow or overtopping of flood-defenses like dikes as well as flattening of dunes or bluffs.
Land behind the coastal defence may be inundated or experience damage.
A flood from sea may be caused by a heavy storm (storm surge), a high tide, a tsunami, or a combination thereof.
As many urban communities are located near the coast this is a major threat around the world.
In western countries, rivers prone to flooding are often carefully managed.
Defenses such as levees, bunds, reservoirs, and weirs are used to prevent rivers from bursting their banks.
Coastal flooding has been addressed in Europe with coastal defenses, such as sea walls and beach nourishment..
Levee
A levee, floodbank or stopbank is a natural or artificial embankment or dike, usually earthen, which parallels the course of a river.
The main purpose of an artificial levee is to prevent flooding of the adjoining countryside; however, they also confine the flow of the river resulting in higher and faster water flow. Levees are usually built by piling earth on a cleared, level surface.
Broad at the base, they taper to a level top, where temporary embankments or sandbags can be placed.
Because flood discharge intensity increases in levees on both river banks, and because silt deposits raise the level of riverbeds, planning and auxiliary measures are vital.
Sections are often set back from the river to form a wider channel, and flood valley basins are divided by multiple levees to prevent a single breach from flooding a large area..
Floodplain
A floodplain, or flood plain, is flat or nearly flat land adjacent to a stream or river that experiences occasional flooding.
It includes the floodway, which consists of the stream channel and adjacent areas that carry flood flows, and the flood fringe, which are areas covered by the flood, but which do not experience a strong current.
Floodplains are formed in two ways: by erosion; and by aggradation.
An erosional floodplain is created as a stream cuts deeper into its channel and laterally into its banks.
A stream with a steep gradient will tend to downcut faster than it causes lateral erosion, resulting in a deep, narrow channel with little or no floodplain at all..
List of major natural disasters in the United States
This is a list of major natural disasters in the United States..

“This article is brought to you by Gus Woltmann”.

El Nino and La Nina

admin — Fri, 25 Sep 2009 11:23:43 +0000

El Niño-Southern Oscillation
El Niño-Southern Oscillation (ENSO) is a global coupled ocean-atmosphere phenomenon.
The Pacific ocean signatures, El Niño and La Niña (also written in English as El Nino and La Nina) are major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean.
The names, from the Spanish for “the little boy” and “the little girl”, refer to the Christ child, because the phenomenon is usually noticed around Christmas time in the Pacific Ocean off the west coast of South America.
Their effect on climate in the southern hemisphere is profound.
These effects were first described in 1923 by Sir Gilbert Thomas Walker from whom the Walker circulation, an important aspect of the Pacific ENSO phenomenon, takes its name.
The atmospheric signature, the Southern Oscillation (SO) reflects the monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin.
El Nino affects Australia by drought..
Atmospheric circulation
Atmospheric circulation is the large-scale movement of air by which heat is distributed on the surface of the Earth.
The wind belts and the jet streams girdling the planet are steered by three convection cells: the Hadley cell, the Ferrel cell, and the Polar cell.
While the Hadley, Ferrel, and Polar cells are major players in global heat transport, they do not act alone.
Disparities in temperature also drive a set of longitudinal circulation cells, and the overall atmospheric motion is known as the zonal overturning circulation..
Meteorology
Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting.
Meteorological phenomena are observable weather events which illuminate and are explained by the science of meteorology.
Those events are bound by the variables that exist in Earth’s atmosphere.
They are temperature, pressure, water vapor, and the gradients and interactions of each variable, and how they change in time.
The majority of Earth’s observed weather is located in the troposphere.
Although meteorologists now rely heavily on computer models (numerical weather prediction), it is still relatively common to use techniques and conceptual models that were developed before computers were powerful enough to make predictions accurately or efficiently..
Instrumental temperature record
The instrumental temperature record shows the fluctuations of the temperature of the atmosphere and the oceans since the invention of thermometers..

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Near-Earth Object Impacts

admin — Fri, 25 Sep 2009 11:16:13 +0000

Meteorite
A meteorite is a small extraterrestrial body that impacts the Earth’s surface.
While in space they are called meteoroids, and while falling through Earth’s atmosphere they are called meteors.
These are small asteroids, approximately boulder-sized or less.
When it enters the atmosphere, air drag and friction cause the body to heat up and emit light, thus forming a fireball or shooting star..
Impact crater
An impact crater is a circular depression on a surface, usually referring to a planet, moon, asteroid, or other celestial body, caused by a collision of a smaller body (meteor) with the surface..
Impact event
Impact events are caused by the collision of large meteoroids, asteroids or comets (generically: bolides) with Earth and may sometimes be followed by mass extinctions of life..
Chicxulub Crater
Chicxulub Crater is an ancient impact crater buried underneath the Yucatan peninsula, with its center located approximately underneath the town of Chicxulub, Yucatan, Mexico.
Investigations suggest that this impact structure is dated from the late Cretaceous, about 65 million years ago..

“This article is brought to you by Gus Woltmann”.

Natural Disasters

admin — Fri, 25 Sep 2009 11:13:58 +0000

Great Chilean Earthquake
The Great Chilean Earthquake or Valdivia Earthquake (Terremoto de Valdivia in Spanish) of May 22, 1960 is the largest magnitude earthquake recorded since seismographic monitoring began..
North Anatolian Fault
The North Anatolian Fault is one of the most energetic earthquake zones in the world.
Turkey is set on a minor tectonic plate which is being squeezed westwards as the Arabian and the Eurasian plates move together..
Earthquake liquefaction
Earthquake liquefaction, often referred to simply as liquefaction, is the process by which saturated, unconsolidated soil or sand is converted into a suspension during an earthquake.
The effect on structures and buildings can be devastating, and is a major contributor to urban seismic risk.
Ancient earthquakes have caused liquefaction, leaving a record in the sediments (paleoseismology)..
Engineering geology
Engineering Geology is the application of the science of geology to the understanding of geologic phenomena and the engineering solution of geologic hazards and other geologic problems for society..

“This article is brought to you by Gus Woltmann”.

Landslides

admin — Fri, 25 Sep 2009 11:12:13 +0000

Landslide
A landslide is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes, and shallow debris flows..
Earthquake liquefaction
Earthquake liquefaction, often referred to simply as liquefaction, is the process by which saturated, unconsolidated soil or sand is converted into a suspension during an earthquake.
The effect on structures and buildings can be devastating, and is a major contributor to urban seismic risk.
Ancient earthquakes have caused liquefaction, leaving a record in the sediments (paleoseismology)..
Geotechnical engineering
Geotechnical engineering is concerned with the engineering properties of earth materials.
Geotechnical engineers investigate the soil and bedrock below a site to confirm their engineering properties as they will relate to the proposed costruction..
Engineering geology
Engineering Geology is the application of the science of geology to the understanding of geologic phenomena and the engineering solution of geologic hazards and other geologic problems for society..

“This article is brought to you by Gus Woltmann”.

Earthquakes

admin — Fri, 25 Sep 2009 11:09:42 +0000

North Anatolian Fault
The North Anatolian Fault is one of the most energetic earthquake zones in the world.
Turkey is set on a minor tectonic plate which is being squeezed westwards as the Arabian and the Eurasian plates move together..
Earthquake liquefaction
Earthquake liquefaction, often referred to simply as liquefaction, is the process by which saturated, unconsolidated soil or sand is converted into a suspension during an earthquake.
The effect on structures and buildings can be devastating, and is a major contributor to urban seismic risk.
Ancient earthquakes have caused liquefaction, leaving a record in the sediments (paleoseismology)..
Elastic-rebound theory of earthquakes
In geology, the elastic rebound theory was the first theory to satisfactorily explain earthquakes.
Previously it was thought that ruptures of the surface were the result of strong ground shaking rather than the converse suggested by this theory.
Following the great 1906 San Francisco earthquake, Henry Feilding Reid examined the displacement of the ground surface around the San Andreas Fault.
From his observations he concluded that the earthquake must have been the result of the elastic rebound of previously stored elastic strain energy in the rocks on either side of the fault..
Richter magnitude scale
The Richter magnitude test scale (or more correctly local magnitude ML scale) assigns a single number to quantify the size of an earthquake.
It is a base-10 logarithmic scale obtained by calculating the logarithm of the combined horizontal amplitude of the largest displacement from zero on a seismometer output..

“This article is brought to you by Gus Woltmann”.

Wildfires

admin — Fri, 25 Sep 2009 11:07:44 +0000

Wildland fire suppression
Wildland fire suppression is a unique aspect of firefighting.
Wildland firefighting requires different tactics, equipment, and training from the normal structure fire fighting found in populated areas.
Working in conjunction with specially designed firefighting aircraft, these wildfire trained crews knock down flames, construct a fireline, and mop up hot spots to protect watershed, wildlands, and the populated areas within the wilds.
Wildland fire suppression also addresses the issues of the “urban interface” where populated areas border wildland areas..
Controlled burn
Prescribed or controlled burning is a technique sometimes used in forest management, farming, or prairie restoration.
Fire is a natural part of both forest and grassland ecology and controlled fire can be a tool for foresters.
Controlled burning stimulates the germination of some desirable forest trees, thus renewing the forest.
Some seeds, such as sequoia, remain dormant until fire breaks down the seed coating.
Another consideration is the issue of fire prevention.
In Florida, during the drought in 1998, catastrophic wildfires burned numerous homes.
But forestry managers note that the underlying problem was prior cessation of controlled burning, due to complaints by homeowners.
Each year additional leaf litter and dropped branches increased the likelihood of a hot and uncontrollable fire.
In industrialized counties, controlled burning is usually overseen by fire control authorities for regulations and permits.
The party responsible must delineate the intended time and place.
Obtaining a permit may not limit liability if the fire burns out of control..
Smoke
Smoke is a suspension in air (aerosol) of small particles resulting from incomplete combustion of a fuel.
It is commonly an unwanted by-product of fires (including stoves and lamps) and fireplaces, but may also be used for pest control (fumigation), communication (smoke signals), defense (smoke-screen) or inhalation of tobacco or other drugs.
Smoke is sometimes used as a flavouring agent and preservative for various foodstuffs.
Smoke is also sometimes a component of internal combustion engine exhaust gas, particularly diesel exhaust. Smoke inhalation is the primary cause of death in victims of indoor fires.
The smoke kills by a combination of thermal damage, poisoning and pulmonary irritation caused by carbon monoxide, hydrogen cyanide and other combustion products..
Bushfire
A bushfire is a wildfire that occurs in the bush (collective term for forest, scrub, woodland or grassland of Australia, New Zealand, New Caledonia).
In southeast Australia, bushfires tend to be most common and most severe during summer and autumn, in drought years, and particularly in El Nino years.
In the north of Australia, bushfires usually occur during winter (the dry season), and fire severity tends to be more associated with seasonal growth patterns.
In the southwest, similarly, bushfires occur in the summer dry season and severity is usually related to seasonal growth.
Fire frequency in the north is difficult to assess, as the vast majority of fires are deliberately started by humans.
Plants have evolved a variety of strategies to survive fires, (possessing reserve shoots that sprout after a fire, or developing fire-resistant or fire-triggered seeds) or even encourage fire (eucalypts contain flammable oils in the leaves) as a way to eliminate competition from less fire-tolerant species.
It is also a method of reproduction for eucalypts as their seed pods explode in the intense heat.
Many native animals are also adept at surviving bushfires..

“This article is brought to you by Gus Woltmann”.

Water

admin — Fri, 25 Sep 2009 11:04:36 +0000

Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of geologic formations.
A formation of rock/soil is called an aquifer when it can yield a useable quantity of water.
The depth at which soil pore spaces become saturated with water is called the water table..
Water resources
Water resources are sources of water that are useful or potentially useful to humans.
It is important because it is needed for life to exist.
Many uses of water include agricultural, industrial, household, recreational and environmental activities.
Virtually all of these human uses require fresh water.
Only 2.5% of water on the Earth is fresh water, and over two thirds of this is frozen in glaciers and polar ice caps.
Water demand already exceeds supply in many parts of the world, and many more areas are expected to experience this imbalance in the near future.
It is estimated that 70% of world-wide water use is for irrigation in agriculture.
Climate change will have significant impacts on water resources around the world because of the close connections between the climate and hydrologic cycle.
Due to the expanding human population competition for water is growing such that many of the worlds major aquifers are becoming depleted.
Many pollutants threaten water supplies, but the most widespread, especially in underdeveloped countries, is the discharge of raw sewage into natural waters..
Septic tank
A septic tank is part of a small scale sewage treatment system often referred to as a septic system, which consists of the tank itself and a septic drain field..
Surface runoff
Surface runoff is water, from rain, snowmelt, or other sources, that flows over the land surface, and is a major component of the water cycle.
Runoff that occurs on surfaces before reaching a channel is also called overland flow.
A land area which produces runoff draining to a common point is called a watershed.
When runoff flows along the ground, it can pick up soil contaminants such as petroleum, pesticides, or fertilizers that become discharge or overland flow.
Urbanization increases surface runoff, by creating more impervious surfaces such as pavement and buildings do not allow percolation of the water down through the soil to the aquifer.
It is instead forced directly into streams, where erosion and siltation can be major problems, even when flooding is not.
Increased runoff reduces groundwater recharge, thus lowering the water table and making droughts worse, especially for farmers and others who depend on water wells..

“This article is brought to you by Gus Woltmann”.

Tundra

admin — Fri, 25 Sep 2009 11:02:55 +0000

Tundra
In physical geography, tundra is an area where the tree growth is hindered by low temperatures and short growing seasons.
There are three types of tundra: Arctic tundra, Antarctic tundra, and alpine tundra.
In all of these types, the dominant vegetation is grasses, mosses, and lichens.
Trees grow in some of the tundra.
The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree-line or timberline.
The word “tundra” usually refers only to the areas where the subsoil is permafrost, or permanently frozen soil.
The arctic tundra is a vast area of stark landscape, which is frozen for much of the year.
The soil there is frozen from 25-90 cm (9.8-35.4 inches) down, and it is impossible for trees to grow.
Instead, bare and sometimes rocky land can only support low growing plants such as moss, heath, and lichen.
There are two main seasons, winter and summer, in the polar Tundra areas.
The biodiversity of the tundras is low: 1,700 species of flora and only 48 land mammals can be found, although thousands of insects and birds migrate there each year for the marshes.
There are few species with large populations.
Notable animals in the arctic tundra include caribou (reindeer), musk ox, arctic hare, arctic fox, snowy owl, lemmings, and polar bears (only the extreme north)..

Arctic fox
The Arctic fox, also known as the polar fox, is a small fox native to cold Arctic regions of the Northern Hemisphere.
It is common in all three tundra biomes.
The Arctic fox has evolved to live in the most frigid extremes on the planet.
Among its adaptations for cold survival are its deep, thick fur, a system of countercurrent heat exchange in the circulation of paws to keep them from freezing, and a good supply of body fat.
Arctic foxes will eat pretty much anything.
Their prey includes voles, lemmings, hares, ground squirrels, and bird eggs.
Foxes living on the coast also eat shellfish, sea urchins, dead seals and fish, beached whales, and nesting seabirds.
In winter when food is scarce, they may follow a polar bear and after the bear makes a kill, eats and leaves, they will steal what ever scraps of meat are left..
Taiga
Taiga is a biome characterized by coniferous forests.
Covering most of inland Alaska, Canada, Sweden, Finland, inland Norway, northern Kazakhstan and Russia (especially Siberia), as well as parts of the extreme northern continental United States, the taiga is the world’s largest terrestrial biome.
In Canada, boreal forest is the term used to refer to the southern part of this biome, while “taiga” is used to describe the more barren northern areas south of the Arctic tree-line. Since North America and Eurasia were recently connected by the Bering land bridge, a number of animal and plant species (more animals than plants) were able to colonise both continents and are distributed throughout the taiga biome.
Others differ regionally, typically with each genus having several distinct species, each occupying different regions of the taiga.
Taigas also have some small-leaved deciduous trees like birch, alder, willow and aspen; mostly in areas escaping the most extreme winter cold.
However, the deciduous Larch is coping with the coldest winters on the northern hemisphere in eastern Siberia.
The southernmost part of the taiga also have trees like oak, maple and elm scattered among the conifers..
Snowy Owl
The Snowy Owl is a large owl of the typical owl family Strigidae.
It is also known in North America as the Arctic Owl or the Great White Owl.
This huge yellow-eyed white bird is unmistakable.
It is 53-65 cm long with a 125-150 cm wingspan.
The adult male is virtually pure white, but females and young birds have some dark scalloping; the young are heavily barred, and dark spotting may even predominate.
Its thick plumage, heavily-feathered feet, and coloration render the Snowy Owl well-adapted for life north of the Arctic Circle.
This powerful bird relies primarily on lemmings and other rodents for food, but at times when these prey are not available, or during the ptarmigan nesting period, they may switch to ptarmigan young.
As opportunistic hunters, they feed on a wide variety of small mammals and birds, and will take advantage of larger prey, frequently following traplines to find food..

“This article is brought to you by Gus Woltmann”.

Rainforests

admin — Fri, 25 Sep 2009 11:00:19 +0000

Forest
A forest is an area with a high density of trees (or, historically, a wooded area set aside for hunting).
These plant communities cover large areas of the globe and function as animal habitats, hydrologic flow modulators, and soil conservers, constituting one of the most important aspects of the Earth’s biosphere.
Although often thought of as as carbon dioxide sinks, mature forests are approximately carbon neutral with only disturbed and young forests acting as carbon sinks.
Nonetheless mature forests do play an important role in the global carbon cycle as stable carbon pools, and clearance of forests leads to an increase of atmospheric carbon dioxide levels..
Slash and burn
Slash and burn (a specific practice that may be part of shifting cultivation or swidden-fallow agriculture) is an agricultural procedure widely used in forested areas.
Although it was practised historically in temperate regions, where it was termed assarting, it is most widely associated with tropical agriculture today.
Slash and burn is a specific functional element of certain farming practices, often shifting cultivation systems.
In some cases such as parts of Madagascar, slash and burn may have no cyclical aspects (e.g some slash and burn activities can render soils incapable of further yields for generations), or may be practiced on its own as a single cycle farming activity with no follow on cropping cycle.
Shifting cultivation normally implies the existence of a cropping cycle component, whereas slash-and-burn actions may or may not be followed by cropping.
Slash-and-burn agriculture is usually labeled as ecologically destructive, but it may be workable when practiced by small populations in large forests, where fields have sufficient time to recover before again being slashed, burned, and cultivated.
Tropical forests are habitats for extremely biologically diverse ecosystems, typically containing large numbers of endemic and endangered species which can be threatened by slash-and-burn actions..
Savanna
A savanna or savannah is a grassland with widely spaced trees, and occurs in several types of biomes.
In savannas, grasses and trees are co-dominant vegetation types, with trees and grasses often alternating in dominance over time.
The herbaceous layer is usually a mixture of grasses and herbs with trees and shrubs scattered individually or in small clumps.
Savannas are frequently seen as a transitional zone, occurring between forest or woodland regions and grassland or desert regions.
Savannas are targets of regular fires.
Most savannas experience fire at least twice a decade and annual fires are common in many savanna types..
Old growth forest
Old growth forest, sometimes called late seral forest or ancient forest or primary forest is an area of forest that has attained great age and exhibits unique biological features.
Old growth forests typically contain large live trees, large dead trees (sometimes called “snags”), and large logs..

“This article is brought to you by Gus Woltmann”.

Mining

admin — Fri, 25 Sep 2009 10:58:20 +0000

Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, usually (but not always) from an ore body, vein, or (coal) seam..
Engineering geology
Engineering Geology is the application of the science of geology to the understanding of geologic phenomena and the engineering solution of geologic hazards and other geologic problems for society..
Smoulder
Smouldering (or smoldering in American spelling) combustion is a flameless form of combustion, deriving its heat from oxidations occurring on the surface of a solid fuel.
Common examples are the initiation of fires on upholstered furniture by weak heat sources (e.g.
a cigarette, a short-circuited wire), and the persistent combustion of biomass behind the flaming front of wildland fires.
Many materials can sustain a smouldering reaction, including coal, tobacco, wood, biomass fuels on the forest surface (duff) and subsurface (peat), cotton clothing and string, and polymeric foams (e.g.
upholstery and bedding materials)..
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of geologic formations.
A formation of rock/soil is called an aquifer when it can yield a useable quantity of water.
The depth at which soil pore spaces become saturated with water is called the water table..

“This article is brought to you by Gus Woltmann”.

Invasive Species

admin — Fri, 25 Sep 2009 10:55:47 +0000

Introduced species
An introduced species (also known as an exotic species) is an organism that is not native to the place or area where it is considered introduced and instead has been accidentally or deliberately transported to the new location by human activity.
Perhaps the most common motivation for introducing a species into a new place is that of economic gain..
Zebra mussel
The Zebra mussel (Dreissena polymorpha) is a bivalve mussel native to freshwater lakes of southeast Russia.
Zebra mussels are currently causing serious problems in North America and Sweden, where they are considered an invasive species.
Zebra mussels are voracious filter-feeding organisms.
They remove particles from the water column, increasing water clarity..
Purple loosestrife
Purple loosestrife is a semi-aquatic herbaceous plant belonging to the loosestrife family, Lythraceae, native to the wetlands of Eurasia.
It is a herbaceous perennial plant, growing 1-2 m tall, forming clonal colonies 1.5 m or more in width with numerous erect stems growing from a single woody root mass.
Purple loosestrife has become an invasive species since its introduction into temperate New Zealand and North America where it is now considered a noxious weed..
Pest (animal)
A pest is an animal which has characteristics which people regard as injurious or unwanted.
An example of serious pests are those organisms which vector human disease, such as rats and fleas which carry the plague disease, or mosquitoes which vector malaria..

“This article is brought to you by Gus Woltmann”.

Grasslands

admin — Fri, 25 Sep 2009 10:53:13 +0000

Savanna
A savanna or savannah is a grassland with widely spaced trees, and occurs in several types of biomes.
In savannas, grasses and trees are co-dominant vegetation types, with trees and grasses often alternating in dominance over time.
The herbaceous layer is usually a mixture of grasses and herbs with trees and shrubs scattered individually or in small clumps.
Savannas are frequently seen as a transitional zone, occurring between forest or woodland regions and grassland or desert regions.
Savannas are targets of regular fires.
Most savannas experience fire at least twice a decade and annual fires are common in many savanna types..
Prairie Restoration
Prairie Restoration is an ecologically friendly way to restore some of the prairie land that was lost to industry, farming and commerce.
Ecologically, prairie restoration aids in conservation of our earth’s topsoil, which disappears along with the prairie grasses and plants to make way for new commerce.
Conversely, much more of the prairie lands have become the fertile fields on which we grow our cereal crops of corn, barley and wheat on.
The restoration project of prairie lands can be large or small.
You can create a backyard prairie restoration that will enrich your soil, help with erosion and take up extra water in excessive rainfalls.
Prairie flowers are a big attraction to native butterflies and other pollinators which can further enhance your backyard as a low maintenance showplace.
On a larger scale, communities and even corporations are doing their part to create areas of restored prairies which in turn will store organic carbon in the soil and help maintain the biodiversity of 3000 plus species that count on the grasslands for food and shelter..
Controlled burn
Prescribed or controlled burning is a technique sometimes used in forest management, farming, or prairie restoration.
Fire is a natural part of both forest and grassland ecology and controlled fire can be a tool for foresters.
Controlled burning stimulates the germination of some desirable forest trees, thus renewing the forest.
Some seeds, such as sequoia, remain dormant until fire breaks down the seed coating.
Another consideration is the issue of fire prevention.
In Florida, during the drought in 1998, catastrophic wildfires burned numerous homes.
But forestry managers note that the underlying problem was prior cessation of controlled burning, due to complaints by homeowners.
Each year additional leaf litter and dropped branches increased the likelihood of a hot and uncontrollable fire.
In industrialized counties, controlled burning is usually overseen by fire control authorities for regulations and permits.
The party responsible must delineate the intended time and place.
Obtaining a permit may not limit liability if the fire burns out of control..
Japanese beetle
The Japanese Beetle (Popillia japonica) is a beetle about 1.5 cm (0.6 inches) long and 1 cm (0.4 inches) wide (smaller in Canada), with shiny copper-colored elytra and a shiny green top of the thorax and head.
It is not very destructive in Japan, where it is controlled by natural enemies, but in America it is a serious pest to rose bushes and other plants..

“This article is brought to you by Gus Woltmann”.

Forests

admin — Fri, 25 Sep 2009 10:50:50 +0000

Forest
A forest is an area with a high density of trees (or, historically, a wooded area set aside for hunting).
These plant communities cover large areas of the globe and function as animal habitats, hydrologic flow modulators, and soil conservers, constituting one of the most important aspects of the Earth’s biosphere.
Although often thought of as as carbon dioxide sinks, mature forests are approximately carbon neutral with only disturbed and young forests acting as carbon sinks.
Nonetheless mature forests do play an important role in the global carbon cycle as stable carbon pools, and clearance of forests leads to an increase of atmospheric carbon dioxide levels..
Savanna
A savanna or savannah is a grassland with widely spaced trees, and occurs in several types of biomes.
In savannas, grasses and trees are co-dominant vegetation types, with trees and grasses often alternating in dominance over time.
The herbaceous layer is usually a mixture of grasses and herbs with trees and shrubs scattered individually or in small clumps.
Savannas are frequently seen as a transitional zone, occurring between forest or woodland regions and grassland or desert regions.
Savannas are targets of regular fires.
Most savannas experience fire at least twice a decade and annual fires are common in many savanna types..
Slash and burn
Slash and burn (a specific practice that may be part of shifting cultivation or swidden-fallow agriculture) is an agricultural procedure widely used in forested areas.
Although it was practised historically in temperate regions, where it was termed assarting, it is most widely associated with tropical agriculture today.
Slash and burn is a specific functional element of certain farming practices, often shifting cultivation systems.
In some cases such as parts of Madagascar, slash and burn may have no cyclical aspects (e.g some slash and burn activities can render soils incapable of further yields for generations), or may be practiced on its own as a single cycle farming activity with no follow on cropping cycle.
Shifting cultivation normally implies the existence of a cropping cycle component, whereas slash-and-burn actions may or may not be followed by cropping.
Slash-and-burn agriculture is usually labeled as ecologically destructive, but it may be workable when practiced by small populations in large forests, where fields have sufficient time to recover before again being slashed, burned, and cultivated.
Tropical forests are habitats for extremely biologically diverse ecosystems, typically containing large numbers of endemic and endangered species which can be threatened by slash-and-burn actions..
Old growth forest
Old growth forest, sometimes called late seral forest or ancient forest or primary forest is an area of forest that has attained great age and exhibits unique biological features.
Old growth forests typically contain large live trees, large dead trees (sometimes called “snags”), and large logs..

“This article is brought to you by Gus Woltmann”.

Environmental Science

admin — Fri, 25 Sep 2009 10:48:34 +0000

Environmental engineering
Environmental engineering is the application of science and engineering principles to improve the environment (air, water, and/or land resources), to provide healthful water, air, and land for human habitation and for other organisms, and to remediate polluted sites.
Negative environmental effects can be decreased and controlled through public education, conservation, regulations, and the application of good engineering practices.
In the U.S., minimum education requirements for environmental engineers typically include a Bachelor’s Degree in environmental (or civil) engineering from an accredited college..
Hazardous waste
Hazardous waste is waste that poses substantial or potential threats to public health or the environment and generally exhibits one or more of the these characteristics: ignitability, corrosivity, reactivity or toxicity.
Examples of hazardous waste include waste pickle liquor from iron and steel manufacturing and certain electroplating sludges.
Many types of businesses generate hazardous waste.
Some are small companies that may be located in a community.
For example, the following types of businesses typically generate hazardous waste: dry cleaners, automobile repair shops, hospitals, exterminators, and photo processing centers.
Some hazardous waste generators are larger companies like chemical manufacturers, electroplating companies, and oil refineries..
Air pollution
Air pollution is a broad term applied to any chemical, physical (particulate matter), or biological agent that modifies the natural characteristics of the atmosphere.
The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet earth.
Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the earth’s ecosystems. Worldwide air pollution is responsible for large numbers of deaths and cases of respiratory disease.
Enforced air quality standards, like the Clean Air Act in the United States, have reduced the presence of some pollutants.
While major stationary sources are often identified with air pollution, the greatest source of emissions are actually mobile sources, principally the automobile.
There are many available air pollution control technologies and urban planning strategies available to reduce air pollution; however, worldwide costs of addressing the issue are high.
The most immediate method of improving air quality would be the use of bioethanol fuel, biodiesel, solar energy, and hybrid vehicle technologies.
The World Health Organization estimates that 4.6 million people die each year from causes directly attributable to air pollution.
Many of these mortalities are attributable to indoor air pollution.
Worldwide more deaths per year are linked to air pollution than to automobile accidents.
Research published in 2005 suggests that 310,000 Europeans die from air pollution annually.
Direct causes of air pollution related deaths include aggravated asthma, bronchitis, emphysema, lung and heart diseases, and respiratory allergies..
Waste
Waste, rubbish, or garbage is unwanted or undesired material.
Waste is something which has lost its apparent value to its owner.
It is a misplaced resource..

“This article is brought to you by Gus Woltmann”.

Energy

admin — Fri, 25 Sep 2009 10:46:23 +0000

Power station
A power station or power plant is a facility for the generation of electric power.
At the centre of nearly all power stations is a generator, a rotating machine that converts mechanical energy into electrical energy by creating relative motion between a magnetic field and a conductor..
Liquid nitrogen economy
A liquid nitrogen economy is a hypothetical proposal for a future economy in which the primary form of energy storage and transport is liquid nitrogen.
It is proposed as an alternative to liquid hydrogen in some transport modes and as a means of locally storing energy captured from renewable sources..
Renewable energy
Renewable energy (sources) or RES capture their energy from existing flows of energy, from on-going natural processes, such as sunshine, wind, flowing water, biological processes, and geothermal heat flows.
The most common definition is that renewable energy is from an energy resource that is replaced rapidly by a natural process such as power generated from the sun or from the wind..
Fossil fuel
Fossil fuels are hydrocarbons, primarily coal, fuel oil or natural gas, formed from the remains of dead plants and animals.
In common dialogue, the term fossil fuel also includes hydrocarbon-containing natural resources that are not derived from animal or plant sources.
These are sometimes known instead as mineral fuels.
The utilization of fossil fuels has enabled large-scale industrial development and largely supplanted water-driven mills, as well as the combustion of wood or peat for heat.
Fossil fuel is a general term for buried combustible geologic deposits of organic materials, formed from decayed plants and animals that have been converted to crude oil, coal, natural gas, or heavy oils by exposure to heat and pressure in the earth’s crust over hundreds of millions of years.
The burning of fossil fuels by humans is the largest source of emissions of carbon dioxide, which is one of the greenhouse gases that allows radiative forcing and contributes to global warming.
A small portion of hydrocarbon-based fuels are biofuels derived from atmospheric carbon dioxide, and thus do not increase the net amount of carbon dioxide in the atmosphere..

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Ecosystems

admin — Fri, 25 Sep 2009 10:44:09 +0000

“This article is brought to you by Gus Woltmann”.

Ecology

admin — Fri, 25 Sep 2009 10:42:10 +0000

Ecosystem
In ecology, the word ecosystem is an abbreviation of the term, ecological system.
Some consider this the basic unit in ecology.
Ecosystems are not to be confused with biomes because they are smaller than biomes.
They can be as big as the Sahara Desert, but as small as a pond.
The term microecosystem may be used to describe a very small (often closed)ecosystem..
cological niche
In ecology, a niche is a term describing the relational position of a species or population in an ecosystem.
More formally, the niche includes how a population responds to the abundance of its resources and enemies (e.
g., by growing when resources are abundant, and predators, parasites and pathogens are scarce) and how it affects those same factors (e.
g., by reducing the abundance of resources through consumption and contributing to the population growth of enemies by falling prey to them).
The abiotic or physical environment is also part of the niche because it influences how populations affect, and are affected by, resources and enemies. The description of a niche may include descriptions of the organism’s life history, habitat, and place in the food chain.
According to the competitive exclusion principle, no two species can occupy the same niche in the same environment for a long time..
Ecological succession
Ecological succession, a fundamental concept in ecology, refers to more-or-less predictable and orderly changes in the composition or structure of an ecological community.
Succession may be initiated either by formation of new, unoccupied habitat (e.g., a lava flow or a severe landslide) or by some form of disturbance (e.g.
fire, severe windthrow, logging) of an existing community.
The former case is often referred to as primary succession, the latter as secondary succession. The trajectory of ecological change can be influenced by site conditions, by the interactions of the species present, and by more stochastic factors such as availability of colonists or seeds, or weather conditions at the time of disturbance.
Some of these factors contribute to predictability of successional dynamics; others add more probabilistic elements.
In general, communities in early succession will be dominated by fast-growing, well-dispersed species (opportunist, fugitive, or r-selected life-histories).
As succession proceeds, these species will tend to be replaced by more competitive (k-selected) species..
Agroecology
Agroecology is the science of applying ecological concepts and principles to the design, development, and management of sustainable agricultural systems. Agroecology is the science of sustainable agriculture; the methods of agroecology have as their goal achieving sustainability of agricultural systems balanced in all spheres.
This includes the socio-economic and the ecological or environmental. While farming methods vary, traditional manipulated “agroecosystems” generally differ from natural ecosystems in six ways: maintenance at an early successional state, monoculture, crops generally planted in rows, simplification of biodiversity, plough which exposes soil to erosion, use of genetically modified organisms and artificially selected crops meanwhile agroecology tends to minimize the human impact.
The agroecologist views any farming system primarily with an ecologist’s eye; that is, it is not firstly economic (created for a commodity and profit), nor industrial (modeled after a factory)..

“This article is brought to you by Gus Woltmann”.

Coral Reefs

admin — Fri, 25 Sep 2009 10:37:54 +0000

Environmental effects of fishing
Environmental impacts of fishing are the ecological changes brought about on the wider environment of the growth in global demand for fish as a food source, and to a lesser extent, for the aquarium trade.
These impacts are brought about through choise of fishing practices and the selective properties of the fishing gears.
Fishing gears and fishing activities are said to be destructive when the environmental impacts of fishing is negative..
Artificial reef
An artificial reef is a man-made, underwater structure, typically built for the purpose of promoting marine life in areas of generally featureless bottom.
Artificial reefs may also serve to improve hydrodynamics for surfing or to control beach erosion. Artificial reefs can be built in a number of different methods.
Many reefs are built by deploying existing materials in order to create a reef.
This can be done by sinking oil rigs (through the Rigs-to-Reefs program), scuttling ships (such as the USS Oriskany), or by deploying rubble, tires, or construction debris.
Other artificial reefs are purpose built (e.g.
ASR or reef balls) from PVC and/or concrete.
Historic or modern shipwrecks become unintended artificial reefs when preserved on the sea floor.
Regardless of construction method, artificial reefs are generally designed to provide hard surfaces to which algae and invertebrates such as barnacles, corals, and oysters attach; the accumulation of attached marine life in turn provides intricate structure and food for assemblages of fish..
Coral
Corals are marine animals from the class Anthozoa and exist as small sea anemone-like polyps, typically in colonies of many identical individuals.
The group includes the important reef builders that are found in tropical oceans, which secrete calcium carbonate to form a hard skeleton. A coral “head”, commonly perceived to be a single organism, is actually formed of thousands of individual but genetically identical polyps, each polyp only a few millimeters in diameter.
Over thousands of generations, the polyps lay down a skeleton that is characteristic of their species.
A head of coral grows by asexual reproduction of the individual polyps.
Corals also breed sexually by spawning, with corals of the same species releasing gametes simultaneously over a period of one to several nights around a full moon. Although corals can catch plankton using stinging cells on their tentacles, these animals obtain most of their nutrients from symbiotic unicellular algae called zooxanthellae.
Consequently, most corals depend on sunlight and grow in clear and shallow water, typically at depths shallower than 60 m (200 ft).
These corals can be major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the enormous Great Barrier Reef off the coast of Queensland, Australia.
Other corals do not have associated algae and can live in much deeper water, such as in the Atlantic, with the cold-water genus Lophelia surviving as deep as 3000 m.
Corals have also been found off the coast of Washington State and the Aleutian Islands in Alaska. While a coral head appears to be a single organism, it is actually a head of many individual, yet genetically identical, polyps.
The polyps are multicellular organisms that feed on a variety of small organisms, from microscopic plankton to small fish. Polyps are usually a few millimeters in diameter, and are formed by a layer of outer epithelium and inner jellylike tissue known as the mesoglea.
They are radially symmetrical with tentacles surrounding a central mouth, the only opening to the stomach or coelenteron, through which both food is ingested and waste expelled..
Ocean acidification
Ocean acidification is the name given to the ongoing decrease in the pH of the Earth’s oceans, caused by their uptake of anthropogenic carbon dioxide from the atmosphere.
Between 1751 and 2004 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14.
In the natural carbon cycle, the atmospheric concentration of carbon dioxide (CO2) represents a balance of fluxes between the oceans, terrestrial biosphere and the atmosphere.
Human activities such as land-use changes and the combustion of fossil fuels have led to a new flux of CO2 into the atmosphere.
Some of this has remained in the atmosphere (where it is responsible for the rise in atmospheric concentrations), some is believed to have been taken up by terrestrial plants, and some has been absorbed by the oceans.
Although this oceanic absorption will help ameliorate the climatic effects of anthropogenic emissions of CO2, it is believed that it will have negative consequences for oceanic calcifying organisms.
These use the calcite or aragonite polymorphs of calcium carbonate to construct cell coverings or skeletons.
Calcifiers span the food chain from autotrophs to heterotrophs and include organisms such as coccolithophores, corals, foraminifera, echinoderms, crustaceans, and some mollusks, especially pteropods..

“This article is brought to you by Gus Woltmann”.

Caving

admin — Fri, 25 Sep 2009 10:35:40 +0000

Stalagmite
A stalagmite is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. The corresponding formation on the ceiling of a cave is known as a stalactite.
If these formations grow together, meeting in the middle, the result is known as a column or pillar..
Stalactite
A stalactite or dripstone, is a type of speleothem that hangs from the ceiling or wall of limestone caves.
Stalactites are formed from the deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions.
The corresponding formation on the floor underneath a stalactite is known as a stalagmite.
Given enough time, these formations can meet, resulting in a formation known as a column or pillar..
Cave
A cave is a natural underground void large enough for an adult human to enter.

Some scientists stipulate that it must be large enough that some portion of it will not receive daylight; however, in popular usage, the term includes smaller spaces like cliff cavities, rock shelters and sea caves..
Limestone
Limestone is a sedimentary rock composed largely of the mineral calcite (calcium carbonate: CaCO3).
Limestones often contain variable amounts of silica in the form of chert or flint, as well as varying amounts of clay, silt and sand as disseminations, nodules, or layers within the rock.
The primary source of the calcite in limestone is most commonly marine organisms.
These organisms secrete shells that settle out of the water column and are deposited on ocean floors as pelagic ooze or alternatively is conglomerated in a coral reef.
Secondary calcite may also be deposited by supersaturated meteoric waters (groundwater that precipitates the material in caves).
This produces speleothems such as stalagmites and stalactites.
Another form taken by calcite is that of oolites (oolitic limestone) which can be recognised by its granular appearance.
Limestone makes up about 10 percent of the total volume of all sedimentary rocks..

“This article is brought to you by Gus Woltmann”.

SustainabilityBiodiversity

admin — Fri, 25 Sep 2009 10:33:32 +0000

Biodiversity hotspot
A biodiversity hotspot is a biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction.
The term biodiversity hotspot specifically refers to 25 biologically rich areas around the world that have lost at least 70 percent of their original habitat.
The remaining natural habitat in these biodiversity hotspots amounts to just 1.4 percent of the land surface of the planet, yet supports nearly 60 percent of the world’s plant, bird, mammal, reptile, and amphibian species..
Conservation biology
Conservation biology is the protection and management of biodiversity that uses principles and experiences from the biological sciences, from natural resource management, and from the social sciences, including economics.
Put another way, conservation biology is the scientific study of the phenomena that affect the maintenance, loss, and restoration of biological diversity..
Seedbank
Seedbanks store seeds as a source for planting in case seed reserves elsewhere should be destroyed.
The seeds stored may be various in nature, such as those of food crops or those of rare species, to protect biodiversity.
Slash and burn
Slash and burn (a specific practice that may be part of shifting cultivation or swidden-fallow agriculture) is an agricultural procedure widely used in forested areas.
Although it was practised historically in temperate regions, where it was termed assarting, it is most widely associated with tropical agriculture today.
Slash and burn is a specific functional element of certain farming practices, often shifting cultivation systems.
In some cases such as parts of Madagascar, slash and burn may have no cyclical aspects (e.g some slash and burn activities can render soils incapable of further yields for generations), or may be practiced on its own as a single cycle farming activity with no follow on cropping cycle.
Shifting cultivation normally implies the existence of a cropping cycle component, whereas slash-and-burn actions may or may not be followed by cropping.
Slash-and-burn agriculture is usually labeled as ecologically destructive, but it may be workable when practiced by small populations in large forests, where fields have sufficient time to recover before again being slashed, burned, and cultivated.
Tropical forests are habitats for extremely biologically diverse ecosystems, typically containing large numbers of endemic and endangered species which can be threatened by slash-and-burn actions..

“This article is brought to you by Gus Woltmann”.

Sustainability

admin — Fri, 25 Sep 2009 10:30:58 +0000

Sustainable agriculture
Sustainable agriculture integrates three main goals: environmental stewardship, farm profitability, and prosperous farming communities.
Sustainable agriculture refers to the ability of a farm to produce perpetually..
Agroecology
Agroecology is the science of applying ecological concepts and principles to the design, development, and management of sustainable agricultural systems. Agroecology is the science of sustainable agriculture; the methods of agroecology have as their goal achieving sustainability of agricultural systems balanced in all spheres.
This includes the socio-economic and the ecological or environmental. While farming methods vary, traditional manipulated “agroecosystems” generally differ from natural ecosystems in six ways: maintenance at an early successional state, monoculture, crops generally planted in rows, simplification of biodiversity, plough which exposes soil to erosion, use of genetically modified organisms and artificially selected crops meanwhile agroecology tends to minimize the human impact.
The agroecologist views any farming system primarily with an ecologist’s eye; that is, it is not firstly economic (created for a commodity and profit), nor industrial (modeled after a factory)..
Infiltration (hydrology)
Infiltration is the process by which water on the ground surface enters the soil.
Infiltration is governed by two forces, gravity, and capillary action.
While smaller pores offer greater resistance to gravity, very small pores pull water through capillary action in addition to and even against the force of gravity. Infiltration rate in soil science is a measure of the rate at which a particular soil is able to absorb rainfall or irrigation.
It is measured in inches per hour or millimeters per hour.
The rate decreases as the soil becomes saturated.
If the precipitation rate exceeds the infiltration rate, runoff will usually occur unless there is some physical barrier.
It is related to the saturated hydraulic conductivity of the near-surface soil..
Forestry
Forestry is the art, science, and practice of studying and managing forests and plantations, and related natural resources.
Silviculture, a related science, involves the growing and tending of trees and forests.
Modern forestry generally concerns itself with assisting forests to provide timber as raw material for wood products; wildlife habitat; natural water quality regulation; recreation; landscape and community protection; employment; aesthetically appealing landscapes; and a ’sink’ for atmospheric carbon dioxide.
A practitioner of forestry is known as a forester. Forests have come to be seen as one of the most important components of the biosphere, and forestry has emerged as a vital field of science, applied art, and technology.
Foresters may be employed by industry, government agencies, conservation groups, urban parks boards, citizens’ associations, or private landowners.
Industrial foresters are predominantly involved in planning the timber harvests and forest regeneration..

“This article is brought to you by Gus Woltmann”.

Renewable Energy

admin — Fri, 25 Sep 2009 10:28:43 +0000

“This article is brought to you by Gus Woltmann”.

Pollution

admin — Fri, 25 Sep 2009 10:23:38 +0000

Automobile emissions control
Automobile emissions control covers all the technologies that are employed to reduce the air pollution-causing emissions produced by automobiles..
Tropospheric ozone
Ozone (O3) is a key constituent of the troposphere.
Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night.
At abnormally high concentrations brought about by man’s activities (largely the combustion of fossil fuel), it is a pollutant, a constituent of smog.
Many highly energetic reactions produce it, ranging from combustion to photocopying.
Often laser printers will have a smell of ozone, which in high concentrations is toxic.
Ozone is a powerful oxidizing agent readily reacting with other chemical compounds to make many possibly toxic oxides.
The majority of tropospheric ozone formation occurs when nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs), such as xylene, react in the atmosphere in the presence of sunlight.
NOx and VOCs are called ozone precursors.
Motor vehicle exhaust, industrial emissions, and chemical solvents are the major anthropogenic sources of these chemicals..
Smog
Smog is a kind of air pollution, originally named for the mixture of smoke and fog in the air.
Classic smog results from large amounts of coal burning in an area and is caused by a mixture of smoke and sulfur dioxide.
In the 1950s a new type of smog, known as Photochemical Smog, was first described.
Smog is a problem in a number of cities and continues to harm human health.
Ground-level ozone, sulfur dioxide, nitrogen dioxide carbon monoxide are especially harmful for senior citizens, children, and people with heart and lung conditions such as emphysema, bronchitis, and asthma.
It can inflame breathing passages, decreasing the lungs’ working capacity, and causing shortness of breath, pain when inhaling deeply, wheezing, and coughing.
It can cause eye and nose irritation and it dries out the protective membranes of the nose and throat and interferes with the body’s ability to fight infection, increasing susceptibility to illness.
Hospital admissions and respiratory deaths often increase during periods when ozone levels are high. The U.S.
EPA has developed an Air Quality index to help explain air pollution levels to the general public.
8 hour average ozone concentrations of 85 to 104 ppbv are described as “Unhealthy for Sensitive Groups”, 105 ppbv to 124 ppbv as “unhealthy” and 125 ppb to 404 ppb as “very unhealthy.” Smog can form in almost any climate where industries or cities release large amounts of air pollution.
However, it is worse during periods of warmer, sunnier weather when the upper air is warm enough to inhibit vertical circulation.
It is especially prevalent in geologic basins encircled by hills or mountains.
It often stays for an extended period of time over densely populated cities or urban areas, such as London, New York, Los Angeles, Mexico City, Houston, Toronto, Athens, Beijing, Hong Kong, the Randstad or Ruhr Area and can build up to dangerous levels..
Air pollution
Air pollution is a broad term applied to any chemical, physical (particulate matter), or biological agent that modifies the natural characteristics of the atmosphere.
The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet earth.
Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the earth’s ecosystems. Worldwide air pollution is responsible for large numbers of deaths and cases of respiratory disease.
Enforced air quality standards, like the Clean Air Act in the United States, have reduced the presence of some pollutants.
While major stationary sources are often identified with air pollution, the greatest source of emissions are actually mobile sources, principally the automobile.
There are many available air pollution control technologies and urban planning strategies available to reduce air pollution; however, worldwide costs of addressing the issue are high.
The most immediate method of improving air quality would be the use of bioethanol fuel, biodiesel, solar energy, and hybrid vehicle technologies.
The World Health Organization estimates that 4.6 million people die each year from causes directly attributable to air pollution.
Many of these mortalities are attributable to indoor air pollution.
Worldwide more deaths per year are linked to air pollution than to automobile accidents.
Research published in 2005 suggests that 310,000 Europeans die from air pollution annually.
Direct causes of air pollution related deaths include aggravated asthma, bronchitis, emphysema, lung and heart diseases, and respiratory allergies..

“This article is brought to you by Gus Woltmann”.

Ozone Holes

admin — Fri, 25 Sep 2009 10:21:12 +0000

Ozone layer
The ozone layer is the part of the Earth’s atmosphere which contains relatively high concentrations of ozone (O3).
“Relatively high” means a few parts per million – much higher than the concentrations in the lower atmosphere but still small compared to the main components of the atmosphere.
Although the concentration of ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation from the Sun.
The “thickness” of the ozone layer – that is, the total amount of ozone in a column overhead – varies by a large factor worldwide, being in general smaller near the equator and larger as one moves towards the poles.
It also varies with season, being in general thicker during the spring and thinner during the autumn..
Tropospheric ozone
Ozone (O3) is a key constituent of the troposphere.
Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night.
At abnormally high concentrations brought about by man’s activities (largely the combustion of fossil fuel), it is a pollutant, a constituent of smog.
Many highly energetic reactions produce it, ranging from combustion to photocopying.
Often laser printers will have a smell of ozone, which in high concentrations is toxic.
Ozone is a powerful oxidizing agent readily reacting with other chemical compounds to make many possibly toxic oxides.
The majority of tropospheric ozone formation occurs when nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs), such as xylene, react in the atmosphere in the presence of sunlight.
NOx and VOCs are called ozone precursors.
Motor vehicle exhaust, industrial emissions, and chemical solvents are the major anthropogenic sources of these chemicals..
Ozone depletion
Ozone depletion describes the observed loss of ozone in the stratosphere over the past 50 years.
It encompasses both a steady thinning of the ozone layer at mid-latitudes and its catastrophic springtime collapse at the poles, often called the ozone hole..
Refrigerant
A refrigerant is a compound used in a heat cycle that undergoes a phase change from a gas to a liquid and back.
The two main uses of refrigerants are refrigerators/freezers and air conditioners.
Cf.
coolant..

“This article is brought to you by Gus Woltmann”.

Ice Ages

admin — Fri, 25 Sep 2009 10:18:35 +0000

Temperature record
The temperature record shows the fluctuations of the temperature of the atmosphere and the oceans through various spans of time.
The most detailed information exists since 1850, when methodical thermometer-based records began..
Ice sheet
An Ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 square kilometers (19,305 square miles).
The only current ice sheets are Antarctic and Greenland; during the last ice age at Last Glacial Maximum (LGM) the Laurentide ice sheet covered much of Canada and North America, the Weichselian ice sheet covered northern Europe and the Patagonian Ice Sheet covered southern South America.
The Antarctic ice sheet is the largest single mass of ice on Earth.
The Greenland ice sheet occupies about 82% of the surface of Greenland, and if melted would cause sea levels to rise by 7.2 metres.
Estimated changes in the mass of Greenland’s ice sheet suggest it is melting at a rate of about 239 cubic kilometres (57.3 cubic miles) per year. Ice sheets are bigger than ice shelves or glaciers.
Masses of ice covering less than 50,000 square kilometers are termed an ice cap.
An ice cap will typically feed a series of glaciers around its periphery..
Greenland ice sheet
The Greenland Ice Sheet is a vast body of ice covering roughly 80% of the surface of Greenland.
It is the second largest ice body in the world, after the Antarctic Ice Sheet.
The ice sheet is almost 2,400 kilometres long in a north-south direction, and its greatest width is 1,100 kilometres at a latitude of 77° N, near its northern margin.
The ice sheet, consisting of layers of compressed snow from more than a hundred thousand years, contains in its ice today’s most valuable record of past climates.
In the past decades, scientists have drilled ice cores up to three kilometres deep.
With the ice cores, scientist have obtained information on (proxies for) temperature, ocean volume, precipitation, chemistry and gas composition of the lower atmosphere, volcanic eruptions, solar variability, sea-surface productivity, desert extent and forest fires.
This variety of climatic proxies is greater than in any other natural recorder of climate, such as tree rings or sediment layers.
The Greenland Ice Sheet has experienced record melting in recent years and is likely to contribute substantially to sea level rise as well as to possible changes in ocean circulation in the future..
Ice shelf
An ice shelf is a thick, floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface, typically in Antarctica or Greenland.
The boundary between floating ice shelf and the grounded (resting on bedrock) ice that feeds it is called the grounding line.
When the grounding line retreats inland, water is added to the ocean and sea level rises..

“This article is brought to you by Gus Woltmann”.

Hazardous Waste

admin — Fri, 25 Sep 2009 10:16:31 +0000

Hazardous waste
Hazardous waste is waste that poses substantial or potential threats to public health or the environment and generally exhibits one or more of the these characteristics: ignitability, corrosivity, reactivity or toxicity.
Examples of hazardous waste include waste pickle liquor from iron and steel manufacturing and certain electroplating sludges.
Many types of businesses generate hazardous waste.
Some are small companies that may be located in a community.
For example, the following types of businesses typically generate hazardous waste: dry cleaners, automobile repair shops, hospitals, exterminators, and photo processing centers.
Some hazardous waste generators are larger companies like chemical manufacturers, electroplating companies, and oil refineries..
Septic tank
A septic tank is part of a small scale sewage treatment system often referred to as a septic system, which consists of the tank itself and a septic drain field..
Waste
Waste, rubbish, or garbage is unwanted or undesired material.
Waste is something which has lost its apparent value to its owner.
It is a misplaced resource..
Landfill
Landfill is a waste disposal site for the deposit of the waste onto or into land.
Most modern landfills require a minimum of one containment liner..

“This article is brought to you by Gus Woltmann”.

Global Warming

admin — Fri, 25 Sep 2009 10:14:19 +0000

Antarctic ice sheet
The Antarctic ice sheet is the largest single mass of ice on Earth.
It covers an area of almost 14 million square km and contains 30 million cubic km of ice.
Around 90 percent of the fresh water on the Earth’s surface is held in the ice sheet, an amount equivalent to 70 m of water in the world’s oceans.
In East Antarctica, the ice sheet rests on a major land mass, but in West Antarctica the bed can extend to more than 2500m below sea level.
The land would be seabed if the ice sheet were not there. Ice enters the sheet through snow and frost and leaves by calving of icebergs and melting, usually at the base but also sometimes at the surface at warm sites..
Ice sheet
An Ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 square kilometers (19,305 square miles).
The only current ice sheets are Antarctic and Greenland; during the last ice age at Last Glacial Maximum (LGM) the Laurentide ice sheet covered much of Canada and North America, the Weichselian ice sheet covered northern Europe and the Patagonian Ice Sheet covered southern South America.
The Antarctic ice sheet is the largest single mass of ice on Earth.
The Greenland ice sheet occupies about 82% of the surface of Greenland, and if melted would cause sea levels to rise by 7.2 metres.
Estimated changes in the mass of Greenland’s ice sheet suggest it is melting at a rate of about 239 cubic kilometres (57.3 cubic miles) per year. Ice sheets are bigger than ice shelves or glaciers.
Masses of ice covering less than 50,000 square kilometers are termed an ice cap.
An ice cap will typically feed a series of glaciers around its periphery..
Greenland ice sheet
The Greenland Ice Sheet is a vast body of ice covering roughly 80% of the surface of Greenland.
It is the second largest ice body in the world, after the Antarctic Ice Sheet.
The ice sheet is almost 2,400 kilometres long in a north-south direction, and its greatest width is 1,100 kilometres at a latitude of 77° N, near its northern margin.
The ice sheet, consisting of layers of compressed snow from more than a hundred thousand years, contains in its ice today’s most valuable record of past climates.
In the past decades, scientists have drilled ice cores up to three kilometres deep.
With the ice cores, scientist have obtained information on (proxies for) temperature, ocean volume, precipitation, chemistry and gas composition of the lower atmosphere, volcanic eruptions, solar variability, sea-surface productivity, desert extent and forest fires.
This variety of climatic proxies is greater than in any other natural recorder of climate, such as tree rings or sediment layers.
The Greenland Ice Sheet has experienced record melting in recent years and is likely to contribute substantially to sea level rise as well as to possible changes in ocean circulation in the future..
Consensus of scientists regarding global warming
The IPCC Third Assessment Report is a product of the Intergovernmental Panel on Climate Change, which is based in Geneva Switzerland, and was established in 1988 by two United Nations organisations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP).
IPCC has been established to assess scientific, technical and socio-economic information relevant for the understanding of climate change, its potential impacts and options for adaptation and mitigation. A few of the main points of the third assessment report issued in 2001 include: An increasing body of observations gives a collective picture of a warming world and other changes in the climate system; emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate; confidence in the ability of models to project future climate has increased; and there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities..

“This article is brought to you by Gus Woltmann”.

Environmental Policy

admin — Fri, 25 Sep 2009 10:11:19 +0000

“This article is brought to you by Gus Woltmann”.

Environmental Issues

admin — Fri, 25 Sep 2009 10:08:57 +0000

Consensus of scientists regarding global warming
The IPCC Third Assessment Report is a product of the Intergovernmental Panel on Climate Change, which is based in Geneva Switzerland, and was established in 1988 by two United Nations organisations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP).
IPCC has been established to assess scientific, technical and socio-economic information relevant for the understanding of climate change, its potential impacts and options for adaptation and mitigation. A few of the main points of the third assessment report issued in 2001 include: An increasing body of observations gives a collective picture of a warming world and other changes in the climate system; emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate; confidence in the ability of models to project future climate has increased; and there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities..
Atmospheric chemistry
Atmospheric chemistry is a branch of atmospheric science in which the chemistry of the Earth’s atmosphere and that of other planets is studied.
It is a multidisciplinary field of research and draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology and other disciplines..
Tropospheric ozone
Ozone (O3) is a key constituent of the troposphere.
Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night.
At abnormally high concentrations brought about by man’s activities (largely the combustion of fossil fuel), it is a pollutant, a constituent of smog.
Many highly energetic reactions produce it, ranging from combustion to photocopying.
Often laser printers will have a smell of ozone, which in high concentrations is toxic.
Ozone is a powerful oxidizing agent readily reacting with other chemical compounds to make many possibly toxic oxides.
The majority of tropospheric ozone formation occurs when nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs), such as xylene, react in the atmosphere in the presence of sunlight.
NOx and VOCs are called ozone precursors.
Motor vehicle exhaust, industrial emissions, and chemical solvents are the major anthropogenic sources of these chemicals..
Fossil fuel
Fossil fuels are hydrocarbons, primarily coal, fuel oil or natural gas, formed from the remains of dead plants and animals.
In common dialogue, the term fossil fuel also includes hydrocarbon-containing natural resources that are not derived from animal or plant sources.
These are sometimes known instead as mineral fuels.
The utilization of fossil fuels has enabled large-scale industrial development and largely supplanted water-driven mills, as well as the combustion of wood or peat for heat.
Fossil fuel is a general term for buried combustible geologic deposits of organic materials, formed from decayed plants and animals that have been converted to crude oil, coal, natural gas, or heavy oils by exposure to heat and pressure in the earth’s crust over hundreds of millions of years.
The burning of fossil fuels by humans is the largest source of emissions of carbon dioxide, which is one of the greenhouse gases that allows radiative forcing and contributes to global warming.
A small portion of hydrocarbon-based fuels are biofuels derived from atmospheric carbon dioxide, and thus do not increase the net amount of carbon dioxide in the atmosphere..

“This article is brought to you by Gus Woltmann”.

Drought

admin — Fri, 25 Sep 2009 10:06:44 +0000

Dust storm
A dust storm (or sandstorm in some contexts) is a meteorological phenomenon.
Such a storm is usually the result of convection currents created by intense heating of the ground..
Organic lawn management
Organic lawn management is the practice of establishing and caring for a garden lawn without the use of chemical inputs such as pesticides or artificial fertilisers.
The garden lawn is a place where we can walk, play and relax, and is especially important for children, providing them with space to run around and enjoy themselves..
Bushfire
A bushfire is a wildfire that occurs in the bush (collective term for forest, scrub, woodland or grassland of Australia, New Zealand, New Caledonia).
In southeast Australia, bushfires tend to be most common and most severe during summer and autumn, in drought years, and particularly in El Nino years.
In the north of Australia, bushfires usually occur during winter (the dry season), and fire severity tends to be more associated with seasonal growth patterns.
In the southwest, similarly, bushfires occur in the summer dry season and severity is usually related to seasonal growth.
Fire frequency in the north is difficult to assess, as the vast majority of fires are deliberately started by humans.
Plants have evolved a variety of strategies to survive fires, (possessing reserve shoots that sprout after a fire, or developing fire-resistant or fire-triggered seeds) or even encourage fire (eucalypts contain flammable oils in the leaves) as a way to eliminate competition from less fire-tolerant species.
It is also a method of reproduction for eucalypts as their seed pods explode in the intense heat.
Many native animals are also adept at surviving bushfires..
Growth ring
Growth rings (or “tree rings” or “annular rings”) can be seen in a horizontal cross section cut through the trunk of a tree.
Visible rings result from the change in growth speed through the seasons of the year, thus one ring usually marks the passage of one year in the life of the tree..

“This article is brought to you by Gus Woltmann”.

Air Quality

admin — Fri, 25 Sep 2009 10:04:22 +0000

Tropospheric ozone
Ozone (O3) is a key constituent of the troposphere.
Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night.
At abnormally high concentrations brought about by man’s activities (largely the combustion of fossil fuel), it is a pollutant, a constituent of smog.
Many highly energetic reactions produce it, ranging from combustion to photocopying.
Often laser printers will have a smell of ozone, which in high concentrations is toxic.
Ozone is a powerful oxidizing agent readily reacting with other chemical compounds to make many possibly toxic oxides.
The majority of tropospheric ozone formation occurs when nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs), such as xylene, react in the atmosphere in the presence of sunlight.
NOx and VOCs are called ozone precursors.
Motor vehicle exhaust, industrial emissions, and chemical solvents are the major anthropogenic sources of these chemicals..
Automobile emissions control
Automobile emissions control covers all the technologies that are employed to reduce the air pollution-causing emissions produced by automobiles..
Air pollution
Air pollution is a broad term applied to any chemical, physical (particulate matter), or biological agent that modifies the natural characteristics of the atmosphere.
The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet earth.
Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the earth’s ecosystems. Worldwide air pollution is responsible for large numbers of deaths and cases of respiratory disease.
Enforced air quality standards, like the Clean Air Act in the United States, have reduced the presence of some pollutants.
While major stationary sources are often identified with air pollution, the greatest source of emissions are actually mobile sources, principally the automobile.
There are many available air pollution control technologies and urban planning strategies available to reduce air pollution; however, worldwide costs of addressing the issue are high.
The most immediate method of improving air quality would be the use of bioethanol fuel, biodiesel, solar energy, and hybrid vehicle technologies.
The World Health Organization estimates that 4.6 million people die each year from causes directly attributable to air pollution.
Many of these mortalities are attributable to indoor air pollution.
Worldwide more deaths per year are linked to air pollution than to automobile accidents.
Research published in 2005 suggests that 310,000 Europeans die from air pollution annually.
Direct causes of air pollution related deaths include aggravated asthma, bronchitis, emphysema, lung and heart diseases, and respiratory allergies..
Nitrogen oxide
NOx is a generic term for the various nitrogen oxides produced during combustion.
They are believed to aggravate asthmatic conditions, react with the oxygen in the air to produce ozone, which is also an irritant and eventually form nitric acid when dissolved in water.
When dissolved in atmospheric moisture the result can be acid rain which can damage both trees and entire forest ecosystems..

“This article is brought to you by Gus Woltmann”.

Air Pollution

admin — Fri, 25 Sep 2009 10:02:04 +0000

Nitrogen oxide
NOx is a generic term for the various nitrogen oxides produced during combustion.
They are believed to aggravate asthmatic conditions, react with the oxygen in the air to produce ozone, which is also an irritant and eventually form nitric acid when dissolved in water.
When dissolved in atmospheric moisture the result can be acid rain which can damage both trees and entire forest ecosystems..
Tropospheric ozone
Ozone (O3) is a key constituent of the troposphere.
Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night.
At abnormally high concentrations brought about by man’s activities (largely the combustion of fossil fuel), it is a pollutant, a constituent of smog.
Many highly energetic reactions produce it, ranging from combustion to photocopying.
Often laser printers will have a smell of ozone, which in high concentrations is toxic.
Ozone is a powerful oxidizing agent readily reacting with other chemical compounds to make many possibly toxic oxides.
The majority of tropospheric ozone formation occurs when nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs), such as xylene, react in the atmosphere in the presence of sunlight.
NOx and VOCs are called ozone precursors.
Motor vehicle exhaust, industrial emissions, and chemical solvents are the major anthropogenic sources of these chemicals..
Automobile emissions control
Automobile emissions control covers all the technologies that are employed to reduce the air pollution-causing emissions produced by automobiles..
Air pollution
Air pollution is a broad term applied to any chemical, physical (particulate matter), or biological agent that modifies the natural characteristics of the atmosphere.
The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet earth.
Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the earth’s ecosystems. Worldwide air pollution is responsible for large numbers of deaths and cases of respiratory disease.
Enforced air quality standards, like the Clean Air Act in the United States, have reduced the presence of some pollutants.
While major stationary sources are often identified with air pollution, the greatest source of emissions are actually mobile sources, principally the automobile.
There are many available air pollution control technologies and urban planning strategies available to reduce air pollution; however, worldwide costs of addressing the issue are high.
The most immediate method of improving air quality would be the use of bioethanol fuel, biodiesel, solar energy, and hybrid vehicle technologies.
The World Health Organization estimates that 4.6 million people die each year from causes directly attributable to air pollution.
Many of these mortalities are attributable to indoor air pollution.
Worldwide more deaths per year are linked to air pollution than to automobile accidents.
Research published in 2005 suggests that 310,000 Europeans die from air pollution annually.
Direct causes of air pollution related deaths include aggravated asthma, bronchitis, emphysema, lung and heart diseases, and respiratory allergies..

“This article is brought to you by Gus Woltmann”.

Acid Rain

admin — Fri, 25 Sep 2009 10:00:06 +0000

Acid rain
Acid rain is defined as any type of precipitation with a pH that is unusually low.
Dissolved carbon dioxide dissociates to form weak carbonic acid giving a pH of approximately 5.6 at typical atmospheric concentrations of CO2.
There is a strong relationship between lower pH values and the loss of populations of fish in lakes.
Below 4.5 virtually no fish survive, whereas levels of 6 or higher promote healthy populations..
Humus
Humus is a complex organic substance resulting from the breakdown of plant material in a process called humification.
This process can occur naturally in soil, or in the production of compost.
Humus is extremely important to the fertility of soils in both a physical and chemical sense..
Soil pH
Soil pH is an indication of the alkalinity or acidity of soil.
It is based on the measurement of pH, which is based in turn on the activity of hydrogen ions (H+) in a water or salt solution..
Nitrogen oxide
NOx is a generic term for the various nitrogen oxides produced during combustion.
They are believed to aggravate asthmatic conditions, react with the oxygen in the air to produce ozone, which is also an irritant and eventually form nitric acid when dissolved in water.
When dissolved in atmospheric moisture the result can be acid rain which can damage both trees and entire forest ecosystems..

“This article is brought to you by Gus Woltmann”.

Oceanography

admin — Fri, 25 Sep 2009 09:54:50 +0000

Sea level
Mean sea level (MSL) is the average (mean) height of the sea, with reference to a suitable reference surface.
Defining the reference level, however, involves complex measurement, and accurately determining MSL can prove difficult.
Sea level has changed over geologic time.
During the most recent ice age (at its maximum about 20,000 years ago) the world’s sea level was about 130 m lower than today, due to the large amount of sea water that had evaporated and been deposited as snow and ice in northern hemisphere glaciers..
Sea water
Seawater is water from a sea or ocean.
On average, seawater in the world’s oceans has a salinity of approximately 3.5%, or 35 parts per thousand.
This means that for every 1 litre (1000 mL) of seawater there are 35 grams of salts (mostly, but not entirely, sodium chloride) dissolved in it.
Although a vast majority of seawater is found in oceans with salinity around 3.5%, seawater is not uniformly saline throughout the world.
The planet’s freshest (least saline) sea water is in the eastern parts of Gulf of Finland and in the northern end of Gulf of Bothnia, both part of the Baltic Sea.
The most saline open sea is the Red Sea, where high temperatures and confined circulation result in high rates of surface evaporation and there is little fresh inflow from rivers.
The salinity in isolated seas and salt-water lakes (for example, the Dead Sea) can be considerably greater.
Seawater is more enriched in dissolved ions of all types compared to fresh water. Scientific theories behind the origins of sea salt started with Sir Edmond Halley in 1715, who proposed that salt and other minerals were carried into the sea by rivers, having been leached out of the ground by rainfall runoff.
Upon reaching the ocean, these salts would be retained and concentrated as the process of evaporation removed the water.
Halley noted that of the small number of lakes in the world without ocean outlets (such as the Dead Sea and the Caspian Sea), most have high salt content.
Halley termed this process “continental weathering”. Halley’s theory is partly correct.
In addition, sodium was leached out of the ocean floor when the oceans first formed..
Ocean current
An ocean current is any more or less permanent or continuous, directed movement of ocean water that flows in one of the Earth’s oceans.
The currents are generated from the forces acting upon the water like the earth’s rotation, the wind, the temperature and salinity differences and the gravitation of the moon.
The depth contours, the shoreline and other currents influence the current’s direction and strength.
Ocean currents can flow for thousands of kilometers.
They are very important in determining the climates of the continents, especially those regions bordering on the ocean.
Perhaps the most striking example is the Gulf Stream, which makes northwest Europe much more temperate than any other region at the same latitude.
Deep ocean currents are driven by density and temperature gradients.
Thermohaline circulation, also known as the ocean’s conveyor belt, refers to the deep ocean density-driven ocean basin currents.
These currents, which flow under the surface of the ocean and are thus hidden from immediate detection, are called submarine rivers..
Sediment
Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid.
Sedimentation is the deposition by settling of a suspended material..

“This article is brought to you by Gus Woltmann”.

Geology

admin — Fri, 25 Sep 2009 09:53:00 +0000

Continental crust
The continental crust is the layer of granitic, sedimentary and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves.
It is less dense than the material of the Earth’s mantle and thus “floats” on top of it.
Continental crust is also less dense than oceanic crust, though it is considerably thicker; mostly 35 to 40 km versus the average oceanic thickness of around 7-10 km.
About 40% of the Earth’s surface is now underlain by continental crust..
Lithosphere
The lithosphere is the solid outermost shell of a rocky planet.
On the Earth, the lithosphere includes the crust and the uppermost layer of the mantle (the upper mantle or lower lithosphere) which is joined to the crust.
The lithosphere is broken up into different plates..
Crust (geology)
In geology, a crust is the outermost layer of a planet. The crust of the Earth is composed of a great variety of igneous, metamorphic, and sedimentary rocks.
The crust is underlain by the mantle.
The upper part of the mantle is composed mostly of peridotite, a rock denser than rocks common in the overlying crust.
The boundary between the crust and mantle is conventionally placed at the Mohorovicic discontinuity, a boundary defined by a contrast in seismic velocity.
Earth’s crust occupies less than 1% of Earth’s volume. The oceanic crust of the Earth is different from its continental crust.
The oceanic crust is 5 km (3 mi) to 10 km (6 mi) thick and is composed primarily of basalt, diabase, and gabbro.
The continental crust is typically from 30 km (20 mi) to 50 km (30 mi) thick, and it is mostly composed of less dense rocks than is the oceanic crust.
Some of these less dense rocks, such as granite, are common in the continental crust but rare to absent in the oceanic crust. The temperature of the crust increases with depth, reaching values typically in the range from about 500 °C (900 °F) to 1,000 °C (1,800 °F) at the boundary with the underlying mantle.
The crust and underlying relatively rigid mantle make up the lithosphere.
Because of convection in the underlying plastic, although non-molten, upper mantle and asthenosphere, the lithosphere is broken into tectonic plates that move. The common rock constituents of the Earth’s crust are nearly all oxides; chlorine, sulfur and fluorine are the only important exceptions to this and their total amount in any rock is usually much less than 1%.
F.
W.
Clarke calculated that a little more than 47% of the Earth’s crust consists of oxygen.
It occurs principally in combination as oxides, of which the chief are silicon, aluminum, iron, calcium, magnesium, potassium and sodium oxides.
Silica is a major constituent of the crust occurring as the silicate minerals, which are the most common minerals of igneous and metamorphic rocks..
Earth science
Many scientists are now starting to use an approach known as Earth system science which treats the entire Earth as a system in its own right, which evolves as a result of positive and negative feedback between constituent systems.
The systems approach, enabled by the combined use of computer models as hypotheses tested by global satellite and ship-board data, is increasingly giving scientists the ability to explain the past and possible future behaviour of the Earth system..

“This article is brought to you by Gus Woltmann”.

Geography

admin — Fri, 25 Sep 2009 09:49:58 +0000

Engineering geology
Engineering Geology is the application of the science of geology to the understanding of geologic phenomena and the engineering solution of geologic hazards and other geologic problems for society..
Antarctic ice sheet
The Antarctic ice sheet is the largest single mass of ice on Earth.
It covers an area of almost 14 million square km and contains 30 million cubic km of ice.
Around 90 percent of the fresh water on the Earth’s surface is held in the ice sheet, an amount equivalent to 70 m of water in the world’s oceans.
In East Antarctica, the ice sheet rests on a major land mass, but in West Antarctica the bed can extend to more than 2500m below sea level.
The land would be seabed if the ice sheet were not there. Ice enters the sheet through snow and frost and leaves by calving of icebergs and melting, usually at the base but also sometimes at the surface at warm sites..
Circle of latitude
On the Earth, a circle of latitude or parallel is an imaginary east-west circle that connects all locations with a given latitude.
The position on the circle of latitude is given by the longitude.
Each is perpendicular to all meridians at the intersection points.
Those parallels closer to the poles are smaller than those at or near the Equator. For a low latitude a circle of latitude can be said to be a line around the Earth, while at a high latitude it is a circle around a pole.
Circles of latitude are often used as boundaries between countries or regions. The five major circles of latitude are, starting from the North Pole and finishing at the South Pole; the Arctic Circle, the Tropic of Cancer, the Equator, the Tropic of Capricorn and the Antarctic Circle..
Ocean current
An ocean current is any more or less permanent or continuous, directed movement of ocean water that flows in one of the Earth’s oceans.
The currents are generated from the forces acting upon the water like the earth’s rotation, the wind, the temperature and salinity differences and the gravitation of the moon.
The depth contours, the shoreline and other currents influence the current’s direction and strength.
Ocean currents can flow for thousands of kilometers.
They are very important in determining the climates of the continents, especially those regions bordering on the ocean.
Perhaps the most striking example is the Gulf Stream, which makes northwest Europe much more temperate than any other region at the same latitude.
Deep ocean currents are driven by density and temperature gradients.
Thermohaline circulation, also known as the ocean’s conveyor belt, refers to the deep ocean density-driven ocean basin currents.
These currents, which flow under the surface of the ocean and are thus hidden from immediate detection, are called submarine rivers..

“This article is brought to you by Gus Woltmann”.

Earth Science

admin — Fri, 25 Sep 2009 09:47:31 +0000

Geophysics
Geophysics, the study of the earth by quantitative physical methods, especially by seismic reflection and refraction, geodesy, gravity, magnetic, electrical, electromagnetic, and radioactivity methods.
The field of geophysics includes the branches of seismology (earthquakes and elastic waves), gravity and geodesy (the Earth’s gravitational field and the size and form of the earth) and the atmospheric sciences..
Earth science
Many scientists are now starting to use an approach known as Earth system science which treats the entire Earth as a system in its own right, which evolves as a result of positive and negative feedback between constituent systems.
The systems approach, enabled by the combined use of computer models as hypotheses tested by global satellite and ship-board data, is increasingly giving scientists the ability to explain the past and possible future behaviour of the Earth system..
Continental crust
The continental crust is the layer of granitic, sedimentary and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves.
It is less dense than the material of the Earth’s mantle and thus “floats” on top of it.
Continental crust is also less dense than oceanic crust, though it is considerably thicker; mostly 35 to 40 km versus the average oceanic thickness of around 7-10 km.
About 40% of the Earth’s surface is now underlain by continental crust..
Mid-ocean ridge
A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics.
This uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.
The mid-ocean ridges of the world are connected and form a single global mid-oceanic ridge system that is part of every ocean, making the mid-oceanic ridge system the longest mountain range in the world, with a total length of about 60,000 km.
There are two processes, ridge-push and slab-pull, thought to be responsible for the spreading seen at mid-ocean ridges, and there is some uncertainty as to which is dominant.
Ridge-push occurs when the weight of the ridge pushes the rest of the tectonic plate away from the ridge, often towards a subduction zone.
At the subduction zone, “slab-pull” comes into effect.
This is simply the weight of the tectonic plate being subducted (pulled) below the overlying plate dragging the rest of the plate along behind it. The other process proposed to contribute to the formation of new oceanic crust at mid-ocean ridges is the “mantle conveyor” (see image).
However, there have been some studies which have shown that the upper mantle (asthenosphere) is too plastic (flexible) to generate enough friction to pull the tectonic plate along..

“This article is brought to you by Gus Woltmann”.

Chemistry

admin — Fri, 25 Sep 2009 09:45:25 +0000

Carbon cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere and atmosphere of the Earth.
The cycle is usually thought of as four major reservoirs of carbon interconnected by pathways of exchange.
The reservoirs are the atmosphere, the terrestrial biosphere (which usually includes freshwater systems and non-living organic material, such as soil carbon), the oceans (which includes dissolved inorganic carbon and living and non-living marine biota), and the sediments (which includes fossil fuels).
The annual movements of carbon, the carbon exchanges between reservoirs, occur because of various chemical, physical, geological, and biological processes.
The ocean contains the largest active pool of carbon near the surface of the Earth, but the deep ocean part of this pool does not rapidly exchange with the atmosphere..
Atmospheric chemistry
Atmospheric chemistry is a branch of atmospheric science in which the chemistry of the Earth’s atmosphere and that of other planets is studied.
It is a multidisciplinary field of research and draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology and other disciplines..
Fertilizer
Fertilizers or fertilisers are compounds given to plants with the intention of promoting growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar spraying, for uptake through leaves.
Fertilizers can be organic (composed of organic matter, i.e.
carbon based), or inorganic (containing simple, inorganic chemicals)..
Phosphate
In inorganic chemistry, a phosphate is a salt of phosphoric acid.
Phosphates are also important in biochemistry.
Surface runoff of phosphates from excessively fertilized farmland can be a cause of phosphate pollution in surface waters, leading to eutrophication (algal bloom) and consequent oxygen deficit, leading to (anoxia) for fish and other aquatic life in the same manner as phosphate-based detergents..

“This article is brought to you by Gus Woltmann”.

Weather

admin — Fri, 25 Sep 2009 09:42:58 +0000

Numerical weather prediction
Numerical weather prediction is the science of predicting the weather using “models” of the atmosphere and computational techniques.
Manipulating the huge datasets and performing the complex calculations necessary to do this on a resolution small enough to make it accurate requires some of the most powerful supercomputers in the world..
Storm Prediction Center
The Storm Prediction Center is responsible for forecasting (identifying, describing, and quantifying) the risk of severe weather caused by severe convective storms (specifically, those producing tornadoes, hail 3/4″ or larger, and winds 58 MPH or greater), as well as winter and fire weather..
National Hurricane Center
The U.S.
National Hurricane Center is the division of National Weather Service’s Tropical Prediction Center responsible for tracking and predicting the likely behavior of tropical depressions, tropical storms and hurricanes.
When tropical storm or hurricane conditions are expected within 36 hours, the center issues the appropriate watches and warnings via the news media and NOAA Weather Radio..
Derecho
A derecho is a widespread and long-lived, violent convectively induced windstorm that is associated with a fast-moving band of severe thunderstorms usually taking the form of a bow echo.
Derechos are usually not associated with a cold front, but a stationary front..

“This article is brought to you by Gus Woltmann”.

Climate

admin — Fri, 25 Sep 2009 09:41:11 +0000

Consensus of scientists regarding global warming
The IPCC Third Assessment Report is a product of the Intergovernmental Panel on Climate Change, which is based in Geneva Switzerland, and was established in 1988 by two United Nations organisations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP).
IPCC has been established to assess scientific, technical and socio-economic information relevant for the understanding of climate change, its potential impacts and options for adaptation and mitigation. A few of the main points of the third assessment report issued in 2001 include: An increasing body of observations gives a collective picture of a warming world and other changes in the climate system; emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate; confidence in the ability of models to project future climate has increased; and there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities..
Temperature record
The temperature record shows the fluctuations of the temperature of the atmosphere and the oceans through various spans of time.
The most detailed information exists since 1850, when methodical thermometer-based records began..
Greenland ice sheet
The Greenland Ice Sheet is a vast body of ice covering roughly 80% of the surface of Greenland.
It is the second largest ice body in the world, after the Antarctic Ice Sheet.
The ice sheet is almost 2,400 kilometres long in a north-south direction, and its greatest width is 1,100 kilometres at a latitude of 77° N, near its northern margin.
The ice sheet, consisting of layers of compressed snow from more than a hundred thousand years, contains in its ice today’s most valuable record of past climates.
In the past decades, scientists have drilled ice cores up to three kilometres deep.
With the ice cores, scientist have obtained information on (proxies for) temperature, ocean volume, precipitation, chemistry and gas composition of the lower atmosphere, volcanic eruptions, solar variability, sea-surface productivity, desert extent and forest fires.
This variety of climatic proxies is greater than in any other natural recorder of climate, such as tree rings or sediment layers.
The Greenland Ice Sheet has experienced record melting in recent years and is likely to contribute substantially to sea level rise as well as to possible changes in ocean circulation in the future..
Climate
The climate is the weather averaged over a long period of time.
Weather is the combination of events in the atmosphere and climate is the overall accumulated weather in a certain location.
Over historic time spans there are a number of static variables that determine climate, including: latitude, altitude, proportion of land to water, and proximity to oceans and mountains.
Other climate determinants are more dynamic: The thermohaline circulation of the ocean distributes heat energy between the equatorial and polar regions; other ocean currents do the same between land and water on a more regional scale.
Degree of vegetation coverage affects solar heat absorption, water retention, and rainfall on a regional level.
Alterations in the quantity of atmospheric greenhouse gases determines the amount of solar energy retained by the planet, leading to global warming or global cooling.
The variables which determine climate are numerous and the interactions complex, but there is general agreement that the broad outlines are understood, at least in so far as the determinants of historical climate change are concerned..

“This article is brought to you by Gus Woltmann”.

Atmosphere

admin — Fri, 25 Sep 2009 09:39:19 +0000

Geophysics
Geophysics, the study of the earth by quantitative physical methods, especially by seismic reflection and refraction, geodesy, gravity, magnetic, electrical, electromagnetic, and radioactivity methods.
The field of geophysics includes the branches of seismology (earthquakes and elastic waves), gravity and geodesy (the Earth’s gravitational field and the size and form of the earth) and the atmospheric sciences..
Earth’s atmosphere
Earth’s atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth’s gravity.
It contains roughly 78% nitrogen and 21% oxygen 0.97% argon and carbon dioxide 0.04% trace amounts of other gases, and water vapor.
This mixture of gases is commonly known as air.
The atmosphere protects life on Earth by absorbing ultraviolet solar radiation and reducing temperature extremes between day and night. The atmosphere has no abrupt cut-off.
It slowly becomes thinner and fades away into space.
There is no definite boundary between the atmosphere and outer space.
Three-quarters of the atmosphere’s mass is within 11 km of the planetary surface…
Planetary boundary layer
The planetary boundary layer (PBL) is also known as the atmospheric boundary layer (ABL).
It is the lowest part of the atmosphere and its behavior is directly influenced by its contact with the ground.
It responds to surface forcings in a timescale of an hour or less.
In this layer physical quantities such as flow velocity, temperature, moisture etc., display rapid fluctuations (turbulence) and vertical mixing is strong.
Physical laws and equations of motions, which govern the planetary boundary layer dynamics and microphysics, are strongly non-linear and considerably influenced by properties of the earth’s surface and evolution of the processes in the free atmosphere.
Perhaps the most important processes, which are critically dependent on the correct representation of the PBL in the atmosperic models, are turbulent transport of moisture and pollutants.
Clouds in the boundary layer influence trade winds, the hydrological cycle, and energy exchange..
Ionosphere
The ionosphere is the part of the atmosphere that is ionized by solar radiation.

It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere.
It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
The lowest part of the Earth’s atmosphere is called the troposphere and it extends from the surface up to about 10 km (6 miles).
The atmosphere above 10 km is called the stratosphere, followed by the mesosphere.
It is in the stratosphere that incoming solar radiation creates the ozone layer.
At heights of above 80 km (50 miles), in the thermosphere, the atmosphere is so thin that free electrons can exist for short periods of time before they are captured by a nearby positive ion.
The number of these free electrons is sufficient to affect radio propagation.
This portion of the atmosphere is ionized and contains a plasma which is referred to as the ionosphere.
In a plasma, the negative free electrons and the positive ions are attracted to each other by the electromagnetic force, but they are too energetic to stay fixed together in an electrically neutral molecule.
The ionosphere has irregular patches of ionization..

“This article is brought to you by Gus Woltmann”.