Human Effects On Polar Bears
Humans kill polar bears for aboriginal subsistence, sport, and defense of human life and property. In some areas, monitoring of polar bear kills is effective (in Norway and the United States), but in other areas there is little reliable information (Russia and Greenland). Concerns have recently been expressed about the threat posed by trophy hunting (currently allowed only in Canada and Greenland). Quotas are often based on poor population data. Approximately 80 trophies are imported into the...
Supercontinents and Climate
The motion of the tectonic plates periodically causes most of the continental landmasses of the planet to collide with each other, forming giant continents known as supercontinents. For much of the past several billion years, these supercontinents have alternately formed and broken up in a process called the supercontinent cycle. The last supercontinent was known as Pangaea, which broke up about 160 million years ago to form the present-day plates on the planet.
Origins Of Earthquakes
Earthquakes can originate from sudden motion along a fault, from a volcanic eruption, bomb blasts, landslides, or anything else that suddenly releases energy on or in the Earth. Not every fault is associated with active earthquakes. Most faults are in fact no longer active but were active at some time in the geologic past. of the active faults, only some are particularly prone to earthquakes.
NASA Shock News : Manhattan Has Been Underwater For Four Years!
While doing research 12 or 13 years ago, I met Jim Hansen, the scientist who in 1988 predicted the greenhouse effect before Congress. I went over to the window with him and looked out on Broadway in New York City and said, If what you're saying about the greenhouse effect is true, is anything going to look different down there in 20 years He looked for a while and was quiet and didn't say anything for a couple seconds. Then he said, Well, there will be more traffic.
Why Does Climate Vary From One Place To Another
Essentially, there arc two main reasons that climate varies from place to place first, the amount of energy arriving from the sun, and second the circulation of the atmosphere and oceans which carry heat and moisture from one placc to another. One of the major factors determining the relative warmth of a climate is the angle of the sun in the sky. The sun shines almost straight at the earth's equator, because the equator sits in the direct plane of the sun within the solar system.
Gross Primary Production
Terrestrial gross primary productivity (GPP) is a collection of complex processes performed by photosynthetic organisms that result in the conversion of light energy and water into chemical energy and the subsequent biochemical fixation of carbon dioxide into sugars. Because the supply of organic carbon exerts a dominant control on the activity of heterotrophic organisms, from bacteria to ungulates, GPP is a central process regulating the structure and functioning of ecosystems. Further, during...
Faultblock mountains
Fault-block mountains generally form by extension of the continental crust. The best examples include the Basin and Range Province of the western United States, and parts of the East African Rift System, including the Ethiopian Afar. These mountain belts are formed by the extension or pulling apart of the continental crust, forming basins between individual tilted fault-block mountains. These types of ranges are associated with thinning of the continental crust, and some have active volcanism...
Global warming myths and facts
And other venues. It receives a lot of attention because it is more than a scientific issue it also affects economics, sociology, and people's lifestyles and standards of living. It is one of the most passionate political issues, not only in the United States, but worldwide as public demands for a solution have intensified. Myth The Earth has warmed up before. Maybe what is happening today is natural. Fact The global warming of today is not natural. Scientists have already considered and ruled...
Driving Forces Of Mass Wasting
Gravity is the main driving force behind mass-wasting processes, as it is constantly attempting to force material downhill. On a slope, gravity can be resolved into two components, one perpendicular to the slope, and one parallel to the slope. The steeper the angle of the slope, the greater the influence of gravity. The effect of gravity reaches a maximum along vertical or overhanging cliffs. The tangential component of gravity tends to pull material downhill, resulting in mass wasting. When gt...
Peruvian current
ORIGINATING IN THE frigid waters offthe coast of Antarctica, the Peruvian Current moves north along the western coast of South America. When in reaches the continental shelf along South America, the current rises, carrying cold water with it to the surface of the Pacific Ocean. The prevailing winds of the South Pacific and Earth's rotation cause the Peruvian Current to rotate the Coriolis Force causes the current to rotate clockwise. The Peruvian Current extends 125 mi. (201 km.) west from the...
Cold tolerance in plants
If you are a gardener in an area with cold winters, you will know that most plants do not grow over the winter and survive the conditions in a dormant state. The first cold snap will kill off flowering annuals, which then overwinter as seeds. Early growth in the spring will be destroyed by a late frost and so careful gardeners will cover the emerging shoots of their early potatoes with earth to protect them. Plants are subjected to chilling stress at temperatures in the range 0-15 C and to...
Global Climate In Cretaceous
THE CRETACEOuS Era spanned the time period from 144 to 65 million years ago. It was the final epoch of the dinosaurs. It ended when the dinosaurs became extinct. At its height, the Cretaceous was a period of great warmth. The poles were ice-free, and warm ocean currents spread from the equator to the poles. The concentration of carbon dioxide was higher than it is today, causing a greenhouse effect. The abundance of plants was not enough to lower the amount of carbon dioxide in the atmosphere....
Chlorine Dioxide
Chlorine dioxide, discovered in 1811 by Davy, was prepared from the reaction of potassium chlorate with hydrochloric acid. Early experimentation showed that chlorine dioxide exhibited strong oxidizing and bleaching properties. In the 1930s, the Mathieson Alkali Works developed the first commercial process for preparing chlorine dioxide from sodium chlorate. By 1939, sodium chlorite was established as a commercial product for the generation of chlorine dioxide. Chlorine dioxide uses expanded...
The Mesopotamians Southwest Asia 3700 bce to 1600 bce
The first known case of ecological collapse of a civilization occurred during the Bronze Age, several thousand years ago, in the valley of the Tigris and Euphrates rivers in what is now Iraq and part of Syria. This Mesopotamian culture, known as the Sumerian civilization (3500-1600 bce), was one of the first human societies to have produced what some archaeologists refer to as big tradition.47 Mesopotamian civilizations utterly depended on irrigation from the two great rivers. With an assured...
Features of Agriculture and Forestry in the Humid and SubHumid Tropics
Agriculture is very important for most countries in the humid and the sub-humid tropics. Take tropical Asia as an example. In tropical Asia, agriculture is a key economic sector. In 1993, ithad employed more than half of the labor force, accounting for 10-63 of the GDP in most countries of the region (IPCC, 1998). Substantial foreign exchange earnings also are derived from exports of agricultural products. Climate-sensitive crops - such as rice, other grains and cereals, vegetables, and spices...
Advocacy and Operational NGOs
The World Bank differentiates between operational and advocacy NGOs, where an operational NGO focuses on the design and implementation of development-related projects, such as service delivery, and an advocacy NGO defends or promotes a specific cause. A good example of an operational NGO is that of the work of the International Medicine Corps (IMC) in Afghanistan. In this case, the IMC instituted a vaccination campaign against measles, a disease that was identified by the World Health.
Ural Mountains
The boundary between Europe and Asia is typically taken to be the Ural Mountains, a particularly straight mountain range that stretches 1,500 miles (2,400 km) from the Arctic tundra to the deserts north of the Caspian Sea. Naroda (6,212 feet 1,894 m) and Telpos-Iz (meaning nest of winds, 5,304 feet 1,617 m) are the highest peaks, found in the barren rocky and tundra-covered northern parts of the range. Southern parts of the mountain range rise to 5,377 feet (1,639 m) at Yaman-Tau, in the...
The Warming Effects of the Industrial Revolution
Until recently, humans did not significantly affect the much larger forces of climate and atmosphere. Many scientists believe, however, that with the dawn of the industrial age and the burning of fossil fuels such as coal, natural gas, and oil humans began to significantly add to the amounts of carbon dioxide and other greenhouse gases in the atmosphere, enhancing the planet's natural greenhouse effect and causing higher temperatures.
Two layers of the atmosphere
Based on chemical composition, the atmosphere is divided into two broad layers the homosphere and the heterosphere. The homosphere extends up to the height of 56 mi. (90 km.) and is characterised by uniformity in chemical composition. It consists of three thermal layers, namely, the troposphere, the stratosphere, and the mesosphere. Each sub-layer is separated from the adjoining layer by a shallow transitional zone.
Absorption Cross Section
Determining the absorption coefficient of liquids and solids from the absorption properties of their individual molecules is not an easy task because they are sufficiently close together that they interact strongly. This is evident from Figs. 1.11 and 1.12, which show that the spectral emissivity of liquid water bears little resemblance to that of water vapor. Beginning with the latter it is not an easy step to the former. Interactions between water molecules in the liquid phase all but destroy...
NOAA: Beluga whales in danger of extinction
Tagging a beluga in Cook Inlet near AnchorageCredit NMML The isolated and ever dwindling beluga whales of Cook Inlet one of the smallest distinct populations of marine mammals on the planet should be listed as endangered under the federal Endangered Species Act, NOAA Fisheries announced Thursday (April 19).
Himalaya Mountains
The Himalaya Mountains were formed during the Tertiary continent-continent collision between India and Asia and contain the tallest mountains, as well as those exhibiting the greatest vertical relief over short distances, in the world. The range extends for more than 1,800 miles (3,000 km) from the Kara-koram near Kabul, Afghanistan, past Lhasa, Tibet, to Arunachal Pradesh in the remote Assam Province of India. Ten of the world's 14 peaks that rise to more than 26,000 feet (8,000 m) are located...
Natural sources
Major natural sources include wetlands, termites and release from onshore and offshore geological sources. Recently, living vegetation has also been suggested as an important natural source of CH4. Of the globally significant sources of CH4 to the atmosphere, natural sources are currently outweighed by anthropogenic sources. Together they emit some 582Tg CH4 each year, with 200Tg arising from natural sources (Denman et al, 2007). Given the estimated global CH4 sink of 581Tg per year, the...
Western Boundary Currents
WESTERN BOUNDARY CURRENTS are intense jet currents at the western periphery of large-scale oceanic gyres in the World Ocean. As was shown in the pioneer paper of Henry Stommel in 1948, they are the result of two causes the so-called p-effect (this term has arisen from traditional representation of Corio-lis force, f, in the following form f f + py, where f is a Coriolis parameter at a definite latitude in other words, the p-effect is to the result of the spherical form of the Earth turning...
Oxygen Cycle
THE OXYGEN CYCLE allows for the regeneration of freely available diatomic oxygen (O2) in the atmosphere. Oxygen accounts by volume for approximately 21 percent of the atmosphere, is reactive with myriad inorganic and organic substances, and is vital to living organisms for aerobic respiration and energy production. The cycle involves any source of oxygen within the world, and is not limited to the oxygen animals must breathe to sustain life any compound containing an atom of oxygen is...
Recent Nearcollisions Of Asteroids With Earth
Collisions between asteroids can alter their orbits and cause them to head into an Earth orbit-crossing path. At this point, the asteroid becomes hazardous to life on Earth and is known as an Apollo object. NASA and the United States Air Force estimate that approximately 20,000 objects in space could be on Earth orbit-crossing trajectories. Presently, about 150 Apollo asteroids with diameters of greater than half a mile (1 km) are known, and a couple of thousand objects this size are known in...
Collapsing Interstellar Cloud Fragment
As the huge interstellar cloud collapses into many fragments, it is useful to consider the processes inside one of the individual cloud fragments as it continues to develop into a star. Most of these fragments are about one to two solar masses but can be about 100 times the size of the Earth's present solar system. The temperature of the cloud is about the same as when it started to condense, but it would have an increased density of about 1012 particles per cubic meter in the center of the...
Explain Strata And Gravitational Eruption
One of the deadliest natural disasters in history unfolded on December 26, 2004, when a great undersea earthquake with a magnitude between 9.0-9.3 triggered a tsunami that devastated many coastal areas of the Indian ocean, killing an estimated 283,000 people. The tsunami devastated large parts of coastal Indonesia such as Banda Aceh, then swept across islands in the Indian ocean to strike Sri Lanka, India, and east Africa. The tsunami propagated into all of the world's oceans where it was...
Hawaiian Hot Spot
The most famous hot spot in the world consists of the chain of the Hawaiian Islands, extending northwest to the Emperor Seamount chain. Hawaii is a group of eight major and about 130 smaller islands in the central Pacific Ocean. The islands are volcanic in origin, having formed over a magmatically active hot spot that has melted magmatic channels through the Pacific plate as it moves over the hot spot, forming a chain of southeastward younging volcanoes over the hot spot. Kilauea volcano on the...
Unfrozen water and ice in ground
The phase composition of moisture, i.e. the content of vapour, unfrozen water and ice in the frozen ground, predetermines its specific physical and mechanical properties and the pattern of occurrence of cryogenic-geological processes. The liquid phase of water in the frozen sediments can be in different energetic and structural states ranging from the state of free water to the substantially modified structure in the immediate vicinity of the surface of mineral particles. A triangle is formed...
Early Agriculture And Civilization
Agriculture originated independently in several regions within the last 12,000 years. The two earliest developments, in the Fertile Crescent region of Mesopotamia at the eastern end of the Mediterranean and in the Yellow River Valley in northern China fig. 7.1 , were to have the largest impact on early civilization. Agricultural discoveries began thousands of years later in other regions, including the Central American lowlands, the high terrain around the Peruvian Andes, and the tropics of...
The Hydrologic Cycle
The hydrologic (water) cycle, like other cycles, plays a direct role in the function of healthy ecosystems. The hydrologic cycle describes the movement of all the water on Earth. It has no starting point and involves the existence and movement of water on, in, and above the Earth. The Earth's water is always moving and changing states from liquid to vapor to ice and back again. This cycle has been in operation for billions of years, and all life depends on its existence. Many scientists are...
Erosional Landforms
A number of landforms result from the movement of glaciers across Earth's surface. Such features in present-day glaciers range from rock polish and glacial grooves on smaller scales to hanging valleys and drumlins on larger ones. Most recently during the Pleistocene Epoch (about 2.6 million to 11,700 years ago), vast continental ice sheets reached into the middle latitudes. Most scientists maintain that these ice sheets carved out many of the world's present-day freshwater basins. Small-Scale...
Supernovas And The Formation Of The Heavy Elements
Supernovas are fundamentally important for life and the state of the universe, since nearly all of the elements heavier than carbon are formed in massive stars, and the elements heavier than bismuth 209 are all formed in supernova explosions. Only the elements hydrogen and helium are primordial in the universe, meaning that they have been in existence since the earliest moments of the universe. All of the other elements have been produced by nucleosynthesis, or the combination of large atomic...
Monsoon Winds Over The Indian Ocean
As discussed in Section 2.1, the winds over the Indian Ocean change dramatically with the seasons. In the northern winter (Figure 2.3(b)), the air over southern Asia is cooler and denser than air over the ocean, and so the surface atmospheric pressure is greater over the continent than over the ocean. The resulting pressure gradient leads to a low-level northerly or north-easterly flow of air from the Asian landmass to south of the Equator. This flow of air is the North-East Monsoon. After...
Sulphur hexafluoride
Sulphur hexafluoride (SF6) is the most powerful of all the greenhouse gases recognized by the Kyoto Protocol and evaluated by the Intergovernmental Panel on Climate Change. Although its concentration in the atmosphere is low, the combination of a high global warming potential and a very long lifetime make emissions of SF a considerable concern. It is primarily used as an electrical insulator in the high-voltage distribution network, and major industrial users are beginning to restrict the use...
Littoral Zone
J A Peters and D M Lodge, University of Notre Dame, Notre Dame, IN, USA 2009 Elsevier Inc. All rights reserved. The littoral zone of a lake is the nearshore interface between the terrestrial ecosystem and the deeper pelagic zone of the lake. It is the area where at least one percent of the photosynthetically active light 400-700 nm entering the water reaches the sediment, allowing primary producers macrophytes and algae to flourish. The littoral zone is structurally and functionally an...
Kinds Of metamorphic ROCKS
The names of metamorphic rocks are derived from their original rock type, their texture, and mineral assemblages. shales and mudstones have an initial mineral assemblage of quartz, clays, calcite, and feldspar. slate is the low grade metamorphic equivalent of shale and, with recrystallization, is made of quartz and micas. At intermediate grades of metamorphism, the mica grains grow larger so that individual grains become visible to the naked eye and the rock is called a phyllite. At high grades...
Clouds Cirrus
Cirrus clouds ARE the thin and wisp-like clouds seen at high altitudes (higher than 20,000 to 26,000 ft., or 6,000 to 8,000 m.). The name cirrus comes from the Latin word for curl. They are composed predominantly of tiny ice crystals, because they form in the cold region of the troposphere. If cirrus clouds drop their ice crystals, these crystals evaporate before they arrive at the ground. Cirrus clouds can take on a variety of formations, including a more tuft-like characteristic called...
Zagros And Makran Mountains
The Zagros are a system of folded mountains in western and southern Iran, extending about 1,100 miles (177 km) from the Turkish-Russian-Iranian border, to Zendam fault north of the Strait of Hormuz. The Makran Mountains extend east from the Zagros, through the Baluchistan region of Iran, Pakistan, and Afghanistan. The mountains form the southern and western borders of the Iranian Plateau and Dasgt-e Kavir and Lut Deserts. The northwestern Zagros are forested and snow-capped, and include many...
Cenozoic Tectonics And Climate
Cenozoic global tectonic patterns are dominated by the opening of the Atlantic ocean, closure of the Tethys Ocean and formation of the Alpine-Himalayan Mountain System, and mountain building in western North America. Uplift of mountains and plateaus and the movement of continents severely changed oceanic and atmospheric circulation patterns, altering global climate patterns. As the North and South Atlantic Oceans opened in the Cretaceous, western North America was experiencing contractional...
Nitrogen Cycle
Nitrogen is an essential element required by all organisms. In animals, nitrogen is a component of crucial organic molecules, such as proteins and DNA, and it constitutes 1 to 3 dry weight of cells. Our atmosphere contains 78 by volume of nitrogen, yet it is not a common element on Earth. Although nitrogen is an essential ingredient for plant growth, it is chemically very inactive, and it must be fixed before the vast majority of the biomass can incorporate it. Special nitrogen-fixing bacteria...
The Force That Drives The Tectonic Plates
Tectonic plates do not randomly drift or wander about the Earth's surface definite, yet unseen, forces drive them. Scientists believe that the relatively shallow forces driving lithospheric plates are also working with forces that originate much deeper in the Earth. From seismic and other geographical evidence and laboratory experiments, scientists generally agree with Harry Hess's theory that the plate-driving force is the slow movement of the hot, softened mantle that lies below the rigid...
Hydroelectric Power Pros and Cons
Whereas wave and tidal power are still in development, a kind of water power known as hydroelectricity is already widespread. Hydroelectricity refers to power generated by hydroelectric dams. These dams are placed across rivers, creating huge lakes or reservoirs of water behind the dams. The water can then be released as needed, pouring over turbines that generate power. Hydroelectricity already generates massive amounts of electricity. Hydroelectric dams accounted for about 20 percent of total...
Clouds Stratus
Stratus clouds are those clouds that resemble a sheet across the atmosphere. These clouds typically rest at a low altitude, found below 6,000 ft. (2,000 m.). Their color can vary between white to dark gray. A stratus cloud that rests at ground level is known more commonly as fog. Stratus clouds a bit higher than fog block the sun from view and cause a cloudy day' The name stratus is the Latin word to spread out. The formation of stratus clouds occurs when a sheet of cool air passes under a...
Internal Energy Sources Heat Transfer And Flow From Deep In The Earth
In geology crustal heat flow is a measure of the amount of heat energy leaving the Earth from internal energy sources, measured in calories per square centimeter per second. Typical heat-flow values are about 1.5 microcalories per centimeter squared per second, commonly stated as 1.5 heat flow units. most crustal heat flow is due to heat production in the crust by radioactive decay of uranium, thorium, and potassium. heat flow shows a linear relationship with heat production in granitic rocks....
Ocean Circulation
At the surface, ocean currents are driven by the winds, which make the surface water move parallel to the predominant wind direction, except The surface ocean circulation transports heat globally, maintaining temperatures and supporting marine life. The principal warm and cool currents control climate locally, regionally, and globally. where continental landmasses exist and block its movement. Water also moves vertically in the ocean depths. There are two factors that make water more dense...
Clouds Cumulus
Cumulus clouds are puffy and usually have well-defined boundaries. They form from the condensation or deposition of moisture in particles known as cloud nuclei present in the moist updrafts of convective plumes. The cloud particles can be composed of liquid water, supercooled water, or ice. These cloud particles are denser than air therefore they increase the density of cumulus updrafts. However, water vapor is lighter than dry air, and therefore, except for the effects of the cloud particles,...
Seismograph
Seismographs are sensitive instruments that can detect, amplify, and record ground vibrations, especially earthquakes, producing a seismogram. Numerous seismographs have been installed in the ground throughout the world and form a seismograph network, monitoring earthquakes, explosions, and other ground-shaking events. The first very crude seismograph was constructed in 1890. While the seismograph could tell that an earthquake was occurring, it was unable to actually record the earthquake....
Chemical Weathering
Minerals that form in igneous and metamorphic rocks at high temperatures and pressures may be unstable at temperatures and pressures at the Earth's surface, so they react with the water and atmosphere to produce new minerals. This process is known as chemical weathering. The most effective chemical agents are weakly acidic solutions in water. Therefore, chemical weathering is most effective in hot and wet climates. Rainwater mixes with Co2 from the atmosphere and from decaying organic matter,...
The Great Lakes Region
Although it is common to speak of five Great lakes (Superior, Michigan, Huron, Erie, and Ontario) several more are part of the same group based on physiographic setting and origins. Among these are Great Kilometers Data from the North American Atlas Figure 1 Major lakes and reservoirs of North America. Bear Lake, Lake Winnipeg, Lake Athabaska, Great Slave Lake, and Reindeer Lake. These ten total about 340 000 km2 in area, and all are among the 25 largest lakes in the world (Table 1). They lie...
Subduction subduction zone
Principal axes remain perpendicular, but some other lines will be lengthening with each increment, and others will be shortening. There are some orientations that experience shortening first, and then lengthening. This leads to some complicated structures in rocks deformed by simple shear for instance, folds produced by the shortening, and then exten-sional structures, such as faults or pull-apart structures known as boudens, superimposed on the early contractional structures. Natural strains...
Natural Lakes
Commensurate with its long eventful geological history and complex geomorphology, Asia has a large diversity of natural lakes that vary in their age, area, depth, hydrology, water quality, and biodiversity. Asia has the world's largest (Caspian Sea), oldest and deepest (Lake Baikal) lakes as well as those lying at the highest ( 6000 m) and lowest elevation (Dead Sea, > 400 m below sea level), and with highest salinity (> 400 ). Lakes larger than 1000km2 and those more than 100 m deep are...
The importance of sun angle
Just as sun angle makes the difference overall between temperatures at different latitudes of the earth, it makes a significant difference on a local scale too. If a slope is angled towards the sun when the sun is low in the sky, it gets more of a full beam and so the surface temperature of soil or leaves (and the air just above) will be warmer. On a slope that is in the wrong direction relative to the sun, much of the day is spent in shadow or being sunlit at an angle, so it will be colder...
Polar Bears
THE POLAR BEAR (order Carnivora, family Ursi-dae) is the largest bear species and is thought to have evolved from brown bears, Ursus arctos, approximately one million years ago. There are 19 recognized populations, distributed in Canada, the United States (Alaska), Norway (Svalbard Islands), Denmark (Greenland), and Russia. The current estimated worldwide population is 20,000-25,000. Polar bear territories can cover tens of thousands of sq. km. They live solitarily, but often congregate around...
Groundwater Contamination
Natural groundwater is typically rich in dissolved elements and compounds derived from the soil, regolith, and bedrock through which the water has migrated. Some of these dissolved elements and compounds are poisonous, whereas others are tolerable in small concentrations but harmful in high concentrations. Human and industrial waste contamination of the groundwater is increasing, and the overuse of groundwater resources has caused groundwater levels to drop and has led to other problems,...
Ecological Zonation in Lakes
W M Lewis, University of Colorado, Boulder, CO, USA 2009 Elsevier Inc. All rights reserved. Lakes show many kinds of spatial variation in both vertical and horizontal dimensions. Variation can be chemical, physical, or biotic, and is important to the understanding of ecosystem functions. Although some types of variation are unique to specific classes of lakes, others are common to most lakes, and correspond to an obvious spatial organization of the biota in lakes. The existence of certain...
Life without water
Most animals and plants have only a limited ability to survive water loss. Humans may die if they lose 14 per cent of the water from their bodies. Some frogs can lose 50 per cent and some earthworms 83 per cent of their water and still recover. Some organisms, however, can lose more than 95 per cent, or even more than 99 per cent, of their water and enter into a state of anhydrobiosis (life without water) in which their metabolism comes, reversibly, to a standstill. There is a problem, however,...
Main Asteroid Belt
By far the largest number of asteroids in the inner solar system are located in the main asteroid belt between the orbits of Mars and Jupiter. There are estimated to be between 1.1 and 2 million asteroids in this belt with diameters greater than half a mile (1 km), comprising about 95 percent of the known asteroids. There are probably billions of objects in this belt with diameters of less than half a mile (1 km). Despite the large number of objects in the main asteroid belt, the total mass of...
THE DiScovery And Use A Of RadiOACTiVe Decay
Natural radioactive decay was discovered by Henri Becquerel, a french physicist, in 1896. shortly afterward, ernest Rutherford, a British physicist, described the structure of an atom. These two discoveries are what prompted the idea of using radioactivity as a tool with which to measure geologic time. Then, in 1907, Professor B. B. Boltwood, a radiochemist at Yale university, published the first list of geologic ages of formations based on the use of radioactivity as a true laboratory dating...
The Chaco Anasazi Northwestern New Mexico 700 ce to 1300 ce
The ancient Anasazi civilization in the American southwest was a farming society that created one of the grandest regional and social political systems in prehistoric North America. Anasazi is a Navajo name that is usually, and romantically, translated as the ancient ones, also ancient strangers. A better translation, according to anthropologist team David Stuart and Susan Moczygemba-McKinsey, would be ancestors of our enemies, a frank description of the social relationships that once prevailed...
Lime Types Uses Composition And Treatment
Acidic industrial wastewater can be neutralized with slaked lime Ca(OH)2 , caustic soda (NaOH), or soda ash (Na2C03). Since slaked lime is less expensive than other bases, it is the most commonly used chemical for acidic neutralization 5 . Two types of commercial lime with their associated hydrates are high calcium quicklime, otherwise known as calcium oxide (CaO), and dolomitic quicklime (CaO and MgO). The composition of these will depend on the source of the parent limestone and the method of...
Troposphere
On THE BAsis of thermal characteristics, the atmosphere is normally subdivided into four major vertical layers the troposphere, stratosphere, mesosphere, and thermosphere. The troposphere makes up the lowest of these layers, extending from the surface to a global average height of 7.5 mi. (12 km.). Coined in 1908 by French scientist Leon Philippe Teisserenc de Bort, the name troposphere is derived from the Greek word tropos, meaning to turn, mix, or change. The term aptly describes the...
Tropical Deforestation And Climate
Tropical forests cover a large portion of the globe's land surface running along the equator, roughly between the Tropic of Cancer and the Tropic of Capricorn. The largest expanse of tropical forest is found in the South American equatorial region, predominantly in the Amazon Basin, but extending up into Central America and down into northern Argentina. Large tropical forests are also found in the equatorial regions of Africa and West Africa and in Southeast Asia, running from India to...
December 26 2004 Indian Ocean Tsunami
One of the deadliest natural disasters in history unfolded on December 26, 2004, when a great undersea earthquake with a magnitude of 9.0 triggered a tsunami that devastated many coastal areas of the Indian Ocean, killing an estimated 283,000 people. The Sumatra-Andaman earthquake had an epicenter located 100 miles (160 km) off the west coast of Sumatra, and struck at 7 58 a.m. local time. This was a very unusual earthquake, in that the rupture (and quake) lasted between eight and 10 minutes,...
Microclimates and vegetation
Climate on the broad scale, across hundreds of kilometers, brings about the broad-scalc distribution of vegetation types (Chapters 1 and 2). However, even looking at the world much more locally, wc see that there arc also very substantial differences in the average climatc. For example, a south-facing slope has a different climate from a north-facing one. The year-round temperature and rainfall conditions under a tree will be different from those just a few meters away in the open. The...
Garbage Challenges in Developing Countries
The problems of waste management are different for the developing world. Because the economies of developing countries are usually not as robust as the economies of countries such as the United States, people in these poorer countries tend to buy fewer products with less packaging, and they produce less waste than Americans or residents of other industrialized nations. On the A child scavenges on a dump in Manila, in the Philippines.
Stratigraphic Principles And The Rock Record As Indicators Of Earth History
Stratigraphy is the study of rock strata or layers and is concerned with aspects of the rock layers such as their succession, age relationships, lithologic composition, geometry, distribution, correlation, fossil content, and environments of deposition. The main aim of stratigraphy is to understand and interpret the rock record in terms of paleoenvironments, mode of origin of the rocks, and the causes of similarities and differences between different stratigraphic units. These units can then be...
Burning the Forests
Climate change is being caused by a combination of factors, but the most important is the increase of greenhouse gases in the atmosphere, and especially carbon dioxide. Most of this extra carbon dioxide is being released by burning carbon-rich fuels. This is the same process that turns sugar into energy in our bodies, but it is more violent, releasing the energy as searing heat. The most basic of all fuels is wood, which people have been burning for thousands of years to keep warm and to cook...
Scientific Inquiry And The Limits Of Technology
Scientists are always asking and answering questions. In order to get answers, they must follow steps through discovery and analysis. Formulating a hypothesis and designing an experiment to test the hypothesis are the first steps in all scientific inquiry. Once a test has been designed, data must be collected. When collecting data, it is important to maintain data integrity and obtain a representative sample of what is being measured. Then data needs to be interpreted or analyzed. The results...
Water transfer and ice formation in freezing and thawing soils
There are basically two different ways that soils freeze with and without water migration. Soil freezing without water migration occurs either in the case of soils of low moisture content or a sufficiently rapid advance of the freezing boundary. For example, when a soil sample is frozen through quickly at temperatures of 60 C, 70 C, water freezes in situ, since the temperature field is by a factor of 10 more active than the moisture content field. Usually freezing in nature proceeds slowly...
Large igneous province flood basalt A
Large igneous province, also known as a continental flood basalt, plateau basalt, and trap, is deposits that include vast plateaus of basalts, covering large areas of some continents. They have a tholeiitic basalt composition, but some show chemical evidence of minor contamination by continental crust. They are similar to anomalously thick and topographically high seafloor known as oceanic plateaus and to some volcanic rifted passive margins. In numerous instances over the past several hundred...
History of Levee Building on the Mississippi River
The Mississippi River is the longest river in the world and encompasses the third-largest watershed, draining 41 percent of the continental United States including an area of 1,245,000 square miles (3,224,550 km2). The river transports 230 million tons of sediment, including the sixth-largest silt load in the world. Before the Europeans came and began altering the river, this silt used to cover the flood-plains with this fertile material during the semiannual floods and carry more downriver.
What Was The Climate Like In The Jurassic Period
THE JURASSIC PERIOD extended from about 199 million years ago to 145 million years ago. This geological time period constitutes the middle of the Mesozoic era, also known as the Age of Dinosaurs. The start of the period is marked by the major Triassic-Jurassic extinction event. This period was named by Alexandre Brogniart for the extensive marine limestone exposures of the Jura Mountains, in the region where Germany, France and Switzerland meet. During the early Jurassic, the supercontinent...
The Carbon Cyclenatural V Human Amplification
Thus, the carbon cycle is extremely important. It also plays a critical role in global warming. Carbon dioxide enters the air during the carbon cycle. Because of its abundance, it enters from several sources. Vast amounts of carbon are stored in the Earth's soils, oceans, and sediments at the bottoms of oceans. Carbon is stored in the Earth's rocks and released when they erode. It exists in all living matter. Every time animals and plants breathe, they exhale CO2. When examining the Earth's...
Carbon Cycle
The carbon cycle preserves a record of many processes on the Earth throughout the planet's history and includes many geologic, biologic, ocean, and atmospheric systems. Many volatile substances including water and carbon dioxide were degassed from the deep interior of the Earth during the early Archean, and some has been added by cometary and meteorite impact. The early atmosphere of the Earth was rich in carbon dioxide (C02), and since the Archean this C02 has been progressively removed by the...
Ratio Of Lime To Drinking Water
Lime is among a family of chemicals which are alkaline in nature and contain principally calcium, oxygen and, in some cases, magnesium. In this grouping are included quicklime, dolomitic lime, hydrated lime, dolomitic hydrated lime, limestone, and dolomite. The most commonly used additives are quicklime and hydrated lime, but the dolomitic counterparts of these chemicals (i.e., the high-magnesium forms) are also widely used in wastewater treatment and are generally similar in physical...
Aurora aurora borealis aurora australis
Auroras Borealis and Aurora Australis are glows in the sky sometimes visible in the Northern and Southern Hemispheres, respectively. They are informally known as the northern lights and the southern lights. The glows are strongest near the poles, and originate in the Van Allen radiation belts, regions where high-energy charged particles of the solar wind that travel outward from the Sun are captured by the Earth's magnetic field. The outer Van Allen radiation belt consists mainly of protons,...
Advantages and Disadvantages of Composting
The main advantages of sludge composting are the following Compost has an abundance of nutrients and is suitable for a wide variety of end uses, such as landscaping, topsoil blending, and growth media. Compost has less nitrogen than biosolids from other stabilization processes, due to the loss of ammonia during composting. However, nitrogen in compost is released more slowly and is available to plants over a long period of time, which is more consistent with plant uptake needs.
Atmospheric Absorption of solar Radiation
Solar radiation is radiant energy emitted by the Sun. The process begins at the Sun's core, where hydrogen atoms are fused to helium atoms via nuclear fusion. For each second of nuclear fusion, the Sun converts 700 million tons of hydrogen into 695 million tons of helium, with 5 million tons of electromagnetic energy radiating out into space. Some of this energy travels the approximately 92.89 million mi. (149.5 million km.) across the solar system to Earth. The importance of the Sun to Earth...
Introduction climate and agriculture in Russia
When analyzing the development of Soviet agriculture it should be borne in mind that Russia is comparatively poorly endowed in terms of agricultural land and climate and that, under any system of farming, agricultural productivity would be appreciably lower than, for example, that of the United States or Western Europe. Russian farming is characterized by its extreme northerly location. The center of Russia lies at roughly the same latitude as Hudson Bay, and St. Petersburg is actually at the...
Southwest Monsoon
The southwesterly monsoon is a prevailing wind that blows during the wet seasons of April to October. Very heavy rains are brought to India and to countries surrounding the Indian Ocean. These include Pakistan, Bangladesh, Burma, Thailand, the Arabian Peninsula (Oman, Saudi Arabia, the United Arab Republic, and Yemen) and neighboring African countries that border the Indian Ocean and the Arabian Sea. The rains are very heavy and bring the majority of the rainfall to the region each year. There...
Age size and growth in tropical rainforest trees
The growth rates of tropical trees are usually estimated by repeat measurements of dimensions, most often that of stem girth or diameter. If tropical trees could be aged easily and accurately then estimates of average growth rates would be possible from one-off measurements. The age of trees in the temperate zone can generally be estimated precisely from counting annual rings on cores taken from the trunk base. Tree rings are caused by periodic variation in the nature of the wood laid down at...
The dark reactions
The pathway by which, in the stroma of the chloroplast, the NADPH2 and ATP produced in the light reactions are used to convert CO2 to carbohydrate was elucidated largely by the work of Calvin and Benson, and is outlined in Fig. 8.18. The cycle is somewhat involved and needs Fig. 8.18 The photosynthetic CO2 fixation cycle. P phosphate group Pi inorganic phosphate. The enzymes involved in each step are (1) Rubisco (2) 3-phosphoglyceric acid kinase (3) glyceraldehyde-3-phosphate dehydrogenase (4)...
Agricultural Hazardous Wastes
Industrial manufacturing is not the only industry that generates hazardous wastes, however. Enormous amounts of hazardous chemical pesticides and herbicides are used on crops by U.S. agriculture producers each year. Many of these chemicals run off into the soil and groundwater, and any materials left over are considered hazardous wastes. In some cases, too, the application of phosphate fertilizer produces fluoride wastes. Even animal manure produces concentrated nitrates that can leach into...
Proposal Of Seafloor Spreading
Hess contemplated these many unexpected discoveries in relation to the theory of continental drift proposed by the German meteorologist and geophysicist Alfred Wegener in 1912. After noticing that the east coast of south America and the west coast of Africa fit together like pieces of a jigsaw puzzle and collecting additional fossil evidence, Wegener concluded that the continents had once been connected, but split and drifted thousands of miles apart. Wegener offered no explanation for the...
Interhalogen Compounds And Their Properties
Interhalogen compounds are formed from two different halogens. These compounds resemble the halogens themselves in both their physical and chemical properties. Principal differences show up in their electronegativities. This is clearly shown by the polar compound IC1, which has a boiling point almost 40 C above that of bromine, although both have the same molecular weights. Interhalogens have bond energies that are lower than halogens and therefore in most cases they are more reactive. These...
Baalbek Temple and Human Sacrifice worship to Baal
Human Sacrifice including child Sacrifice as worship to the God Baal at the Baalbek Temple When we turn to mythology to help understand these calamities we find some puzzling insights. The Greek writer Homer told how the mighty sky god Zeus cast thunderbolts on the earth and tumbled the walls of Troy with his earthquakes. The inhabitants of Baalbek feared Baal. This God was their name for Zeus also known as Jupiter and Amon.
Iceland Hot Spot
The mid-Atlantic ridge rises above sea level on the North Atlantic island of Iceland, lying 178 miles (287 km) off the coast of Greenland and 495 miles (800 km) from the coast of Scotland. Iceland has an average elevation of more than 1,600 feet (500 m), and owes its elevation to a hot spot interacting with the midocean ridge system beneath the island. The mid-Atlantic ridge crosses the island from southwest to northeast and has a spreading rate 1.2 inches per year (3 cm yr), with the mean...
First Studies in Microbiology
Antoni van Leeuwenhoek (1632-1723) was the first person able to grind simple lenses and who built the first microscopes (Fig. 1.9). The biconvex lens (L) was fastened between two thin metal plates and the object was mounted up on the pin at (P), which was adjustable by moving two screws. He constructed many of these microscopes and all the necessary lenses he ground himself. The best of them magnified about 200 times (Burdon and Williams 1969). With these instruments, he patiently examined...
Processes of Decomposition of Refuse in Landfills
Landfilled material will gradually change in form and will exhibit different engineering and physical properties as a result of various environmental factors. Witmer and coworkers 7,8 reported the garbage decomposition process for a 10-year period as reflected on a particle size distribution curve. The aging process from fresh trash to aged trash along with the environmental and mechanical factors are illustrated in Figure 1. Mechanical processes do not directly contribute to the decomposition...
Thermosphere
THE EARTH is surrounded by a blanket of air, called the atmosphere. The atmosphere is a thin layer of gases that envelope the Earth. The gases are held close to the earth by gravity and the thermal movement of air molecules. Life on Earth is supported by the atmosphere, solar energy, and the magnetic fields. Five layers have been identified in the atmosphere, using thermal characteristics, chemical composition, movement, and density. The atmosphere is divided into the troposphere, the...
Romanticism And Conservation
Researchers and other intellectuals, including artists, began to recognize the local impacts of environmental degradation around the turn of the 19th century in the United States and Europe. For scientists, powers of observation were based on empiricism and the scientific method that were honed during the Enlightenment. Artists and intellectuals observed natural beauty and captured it in the painting, music, and literature of the Romantic period. Romanticism emerged along with the Industrial...
The Theory Of Continental Drift
At one point in geologic time, the world was made up of a single continent called Pangaea. Over time, this supercontinent separated and drifted apart, forming the different continents that exist today. The process is always in motion the plates always moving, as they will continue to do far into the geologic future. In fact, the configuration of the Earth's landmasses may change drastically from the way they are today. The Earth's plates have shifted over geologic time. In 1912, Alfred Wegener,...
Trade Winds
The Trade WINDs are a large-scale component of Earth circulation, occupying most of the tropics straddling the equator between approximately latitude 30 degrees N and latitude 30 degrees S, with a seasonal shift of the entire trade wind belt system about 5 degrees of latitude northward during summer (July) and southward during winter (December). In the Northern Hemisphere, warm equatorial air rises and flows north toward the pole, the Coriolis Effect (caused by the Earth's rotation) deflects...
History of gondwana
Gondwana is the name given to the southern continents that amalgamated before they joined, as a group, to the northern continents of Laurentia to form Pangaea. Most of Gondwana was assembled in the period between 600 million and 400 million years ago, when many Archean cratons were joined together by suturing during closure of several ocean basins that lay between them, forming a series of orogenic belts across Africa, India, South America, Madagascar, Antarctica, and Australia known as the...
Hazards of Pyroclastic Flows
While some volcanoes spew massive amounts of lava in relatively nonthreatening flows, other volcanoes are extremely explosive and send huge eruption clouds tens of thousands of feet into the air. Violent pyroclastic flows present one of the most severe hazards associated with volcanism. Unlike slow-moving lava flows, pyroclastic flows may move at hundreds of miles (km) per hour by riding on a cushion of air, burying entire villages or cities before anyone has a chance to escape. There are...
Alaska: Daylight Stealing Time
Along with most other Americans, Alaskans moved to Daylight Savings Time on Sunday. The shift came a month earlier than last year, a change estimated to save energy consumption across the United States by up to 1 percent and reduce carbon emissions. Arctic Sunrise 1950 But there are reasons to doubt this savings will really happen in Alaska.
Vermont Law School
VERMONT LAW SCHOOL'S (VLS's) environmental law program is ranked number one in the nation by U.S. News & World Report. Students at VLS participate in a variety of legal and environmental study programs, many of which focus on climate change and related policies. The Environmental Law Center at VLS includes several specialized institutes and clinics that are involved in various aspects of climate change research and litigation. At present, VLS is home to 612 students, participating in four...
Dynamics Of Stream Flow
Streams are dynamic systems and constantly change their channel patterns and the amount of water (discharge) and sediment being transported in the system. streams may transport orders of magnitude more water and sediment in times of spring floods, as compared with low-flow times of winter or drought. since streams are dynamic systems, as the amount of water flowing through the channel changes, the channel responds by changing its size and shape to accommodate the extra flow. For instance, in a...
Upper Chattahoochee River Case Study
The Southeast Basin (Hydrologic Region 3), covering a drainage area of 278,523 square miles, includes the Chattahoochee-Flint-Apalachicola River, which has a length of 524 miles and a drainage area of 19,600 square miles (Iseri and Langbein, 1974). On the basis of a mean annual discharge (1941-1970) of 24,700 cfs, the Chat-tahoochee-Flint-Apalachicola River ranks twenty-third of the large rivers of the United States (Iseri and Langbein, 1974). Figure 10-1 highlights the location of the Upper...
Bending Of Rocks
The bending or warping of rocks is called folding. Monoclines are folds in which both sides are horizontal, which often form over deeper faults. Anticlines are upward-pointing arches that have the oldest rocks in the center, and synclines are downward-pointing arches, with the oldest rocks on the outside edges of the structure. Though many other geometric varieties of folds exist, most are variations of these basic types. The fold hinge is the region of maximum curvature on the fold, whereas...
Unconformities And Gaps In The HistonCal Geological record
Unconformities are regional surfaces that extend for large distances and represent periods of time missing from the geological record at that location. To interpret unconformities and understand what each means for the history of the region and Earth, it is important to determine how much of a time gap is represented, and what caused the stratum that would have been deposited in that interval to not be preserved. In some cases the stratum was once there and has since been eroded, and in other...
Sunspots Flares And The Solar Cycle
The Sun produces a steady stream of electromagnetic radiation from the photosphere, essentially unchanging with time. Superimposed on this steady, quiet process are several dynamic, active, or changing events and cycles that show the Sun also has some unpredictable and explosive behavioral traits. These features are not significant in terms of total solar energy output but do influence the electromagnetic radiation received on Earth. They include sunspots, solar flares, magnetic storms, the...
The Influence of pH on the Nitrification Rate
In the literature, the optimum pH value forthe nitrification process varies between 8 and 9. Figure 3.7 summarizes investigations of pH effects on the nitrification rate. Usually the nitrification rate decreases, as the pH decreases. By measuring the nitrification rates Meyerhof (1916) found the pH optimum for Nitrosomonas to be between 8,5 and 8,8, and for Nitrobacter to be 8,3 to 9,3. Hofman et al. (1973) made similar investigations, and found for both organisms an optimum pH of 8.3, and that...
Geostrophic And Hydrostatic Balance
On the large-scale, water obeys the same fluid dynamics as air so we have already derived the equations we will need Eq. 6-44 applies just as well to the ocean as to the atmosphere. One simplification we can make in application of these equations to the ocean is to recognize that the density varies rather little in the ocean (by only a few see Fig. 9.2), so we can rewrite the horizontal momentum equations Eq. 6-44a,b thus (using our local Cartesian coordinate system see Fig. 6.19) without...
VE 4rkxrs1111
Where the wiggly overbar denotes the vertical average. Assuming constant values of p* and diffusivity uv in Eq. (11.7), the Ekman depth e can be shown to be proportional to *Jvs f, typically attaining a value of about 50 m. It is implied by Eq. (11.11) that the flow in this layer is to the right of the surface wind stress in the Northern Hemisphere and to the left in the Southern Hemisphere. Taking the horizontal divergence of Eq. (11.7), and applying the mass continuity Eq. (11.3) with the...
Hydrodynamic escape
Hydrodynamic escape is basically a more efficient means of deploying the energy available to the atmosphere in order to assist escape. The energy involved still comes from EUV absorption or the general thermal energy of the atmosphere, but instead of this accumulating in a more or less random set of motions, in some circumstances the energy can sustain a mean outward escaping flow which carries fluid to space without wasting energy on motions directed toward the planet or on a population of...
Static Stability of the Atmosphere and Ocean
In Chapter 1, we considered hydrostatic equilibrium in the atmosphere and ocean, whereby the gravitational acceleration is balanced by the vertical pressure gradient force. Here we examine vertical displacements in a fluid that is in hydrostatic balance. A parcel moving vertically within the fluid is subject to adiabatic expansion or compression, and hence its temperature will change. As the parcel moves vertically, it may become warmer or cooler than the surrounding fluid at a particular...