Carbon Dioxide
Carbon dioxide CO2 is a natural greenhouse gas and also the biggest humansupplied gas to the greenhouse effect about 70 . A heavy, colorless gas, carbon dioxide is the main gas we exhale during breathing. It dissolves in water to form carbonic acid, is formed in animal respiration, and comes from the decay or combustion of plant animal matter. Carbon dioxide is absorbed from the air by plants in photosynthesis and is also used to carbonate drinks. You may be thinking that the Earth's...
Geothermal Power Generation
In 1999, 8217 megawatts of electricity were being produced from around 250 geothermal power plants operating in 22 countries around the world. These plants provide reliable power for over 60 million people, mostly in developing countries. Today, geothermal power provides about 10 percent of the United States' energy supply. Table 15-5 provides a list of countries that use geothermal energy and the megawatts of electricity that each produced in 1999. Table 15-5 There are a number of different...
Hydrologie Cycle
Remember from Chapter 1 that the hydrosphere, crust, and atmosphere combined make up the biosphere. The hydrosphere includes all the water in the atmosphere and on the Earth's surface. When the sun heats the oceans, the cycle starts. Water evaporates and then falls as precipitation in the form of snow, hail, rain, or fog. While it's falling, some of the water evaporates or is sucked up by thirsty plants before soaking into the ground. The sun's heat also keeps the cycle going. The hydrologic...
Hot And Dry Desert
The major North American hot and dry deserts are the Chihuahuan, Mojave, Great Basin, and Sonoran. The Southern Asian, South and Central American, Ethiopian, and Australian deserts also fall into the hot and dry class. These deserts are almost always warm during the day year around and are searing hot in the summer. Winters bring little rainfall. Temperatures show daily extremes due to low humidity. Desert surfaces receive over twice as much solar radiation as humid areas and lose nearly twice...
Carbon
Carbon is the fourth most abundant element in the universe after hydrogen, helium, and oxygen. At last count, there were more than 2 million known organic compounds, nearly 20 times more than all the other known chemicals combined. Carbon is known as the building block of life and is the foundational element of all organic substances, from molds to mosquitoes to fossil fuels. Carbon cycles through the land, ocean, atmosphere, and the Earth's interior in a major biogeochemical cycle. Organic...
Chemical Added To Wastewater During Coagulation From Sticky Blobs That Sang
1. One of the most newsworthy chemical weathering types is known as 2. Radiopharmaceuticals are used b to lose weight without exercising c to study organ function and structure c good way to seal open manhole covers d way to remind people about the final destination of storm runoff a can kill off entire marine populations d can be prevented by outlawing the use of electric blankets 5. The best way to slow or stop acid deposition is to a keep people out of chemical labs d limit chemical...
Dunes
Most people think of sand dunes when they hear the word dune. However, a dune is any landmass created by deposited material that forms a low mound or ridge of sediment. Dunes can be formed by sediments of different sizes or even snow. They are formed when wind blows sediments, mostly from the same direction, until it encounters an obstruction of some sort. The wind slows and drops the heavier particles, which then build up and add to the size of the original obstruction. This becomes a cycle,...
Glacier Zones
Glaciers have two main zones, or sections. The first zone is known as the accumulation zone. This is just what it sounds like. It is the part of the glacier that is building up or accumulating, the area that gets bigger in size and depth. The second zone is called the ablation zone. This is the part of the glacier that is shrinking. Accumulation zone more snow and ice Ablation zone less snow and ice Glaciers increase in colder periods when lots of snow falls. That's easy to remember Glaciers...
Fisheries
The importance of marine resources to humans is obvious. Fish and shellfish give us a valuable source of food protein and a livelihood to many in the seafood industry. Other marine resources meet the needs of the general population and provide jobs. The question is the extent to which the oceans can continue to meet human needs. Scientific studies and marine management based upon current trends are the key to the future. Although some scientists suggest that there exists a climatic control...
Coastal Deserts
Coastal deserts are found on the western edges of continents between 15 and 30 latitudes near the Tropics of Cancer and Capricorn. These are also the largest of the climatic zones, covering nearly half of the Earth's area. They are located on both sides of the equator. The latitudes directly north and south of the equator are known as the Tropic of Cancer and Tropic of Capricorn respectively. Coastal deserts are affected by cold ocean currents that follow the coastline. Since regional winds...
Thermal Pollution
The final form of water pollution we will study is thermal pollution. At first glance, it seems like a fairly harmless form of water pollution, but it can have far-reaching and damaging effects on an ecosystem. Heat pollutes water through its impact on aquatic organisms and animal populations. The release of a substance, liquid or air, which increases heat in the surrounding area is known as thermal pollution. Water temperature is important to aquatic life. It controls metabolic and...
Runoff
We have seen that permeability is the measure of how easily something flows through a material. The higher the permeability of the soil, the more rain seeps into the ground. However, when rain falls faster than it can soak into the ground, it becomes runoff. Runoff is made up of rainfall or snow melt that has not had time to evaporate, transpire, or move into groundwater reserves. Water always takes the path of least resistance, flowing downhill from higher to lower elevations, eventually...
Atmosphere 1
Along the Texas Gulf Coast, the common saying is, If you don't like the weather, just wait 15 minutes and it will change True of many places, the weather can change suddenly, especially at the turn of the seasons. Temperature drops of 30 F in the two hours preceding a cold front are possible. What is the atmosphere made of Air Water Smoke The answer depends on what is happening at that moment. Most of the time you can't even see the atmosphere unless there is fog, rain, snow, clouds, wind, or...
Specialty Clouds
Some clouds are very specialized. They form when specific events take place. For example, some of these clouds are formed by aircraft, earlier storms, and the presence of mountain peaks. A few of these specialty clouds are shown in Fig. 3-7. Fig. 3-7 Contrails, mammatus, and orographic clouds are very distinct. Fig. 3-7 Contrails, mammatus, and orographic clouds are very distinct. A contrail, short for condensation trail, is a cirrus-like trail of condensed water vapor that looks like the tail...
Precipitation
Precipitation is the main way that water is transported from the atmosphere to the Earth's surface. There are different types of precipitation, but the most common is rain. Water moisture falls in the form of rain, snow, and hail from clouds circling the globe, propelled by air currents. Clouds are fairly active. For example, when clouds rise over mountain ranges, they cool, becoming so full of moisture that water falls as rain, snow, or hail, depending on local air temperatures. Rainfall...
Evaporation
The sun provides the energy that powers evaporation. When water is heated, its molecules get excited and vibrate so much that they break the bonds holding them together. When this happens, solar energy light and heat causes water to evaporate from oceans, lakes, rivers, and streams. Rising from the earth's surface, warm air currents sweep water vapor up into the atmosphere. When water changes its form from a liquid to a gas vapor , it is said to evaporate. Because of the huge amount of water in...
Condensation
This part of the hydrologic cycle begins with condensation, when water vapor condenses in the atmosphere to form clouds. Condensation takes place when the air or land temperature changes. Water shifts forms when temperatures rise and fall. You see this in the early morning when dew forms on plants. As water vapor rises, it gets cooler and eventually condenses, sticking to minute particles of dust in the air. Condensation describes water's change from its gaseous form vapor into liquid water....
Clouds
These visible wonders of the troposphere are found in a variety of shapes and sizes. While some clouds are happy just to be, others come with precipitation like mist, rain, sleet, hail, and snow. A cloud is a combination of tiny water droplets and or ice crystals suspended in the atmosphere. Clouds are classified and often named using Latin prefixes and suffixes to describe their appearance. Table 3-4 lists a few of these Latin root words. Additional detail is provided by measuring a cloud's...
Water Is King
In order to understand how water became king, let's take a look at some of water's unique properties. Of all the chemical formulas that are written, the one that most people remember is H2O, or the formula for water. Water is made up of two hydrogen atoms bonded to an oxygen atom. However, because of other bonding factors, water has a variety of special properties that make it universally important. Table 5-2 Fresh water is mainly found in glaciers. Table 5-2 Fresh water is mainly found in...
Air Pollution
The atmosphere has many faces. Polluting compounds present another area for concern. For the great majority of most industrialized nations, the very air we breathe is laced with smoke, particulates, and an array of toxic chemicals from human activities and industrial processes. This is a major problem. The most common air pollutants are Heavy metals arsenic, chromium, cadmium, lead, mercury, zinc Organic chemicals volatile organic compounds VOCs , dioxins Most of the time, people depend on...
Transpiration
Another type of evaporation that adds to the hydrologic cycle is transpiration. This is a little more complicated. During transpiration, plants and animals release moisture through their pores. This water rises into the atmosphere as vapor. Transpiration is most easily seen in the winter when you can see your breath. When exhaling carbon dioxide and used air, you also release water vapor and heat. Your warm, moist exhalation on a frosty winter morning becomes a small cloud of water vapor....
The Earths Water
Water covers over 70 of the Earth's surface, but it's hard to picture that much water. Standing on a beach and looking seaward, ocean water stretches to the horizon and seems to go on forever. The oceans hold 97 of the Earth's water, the land masses hold 3 , and the atmosphere holds less than 0.001 . The water on the land masses is stored as fresh water in glaciers and icecaps, groundwater, lakes, rivers, and soil. The annual precipitation for the Earth has been estimated at more than 30 times...
Desert Features
Sand covers only around 20 of the Earth's deserts. Most of the sand is in sand sheets and sand seas that look like huge areas of rising and falling dunes. The movement of sand and particles by the wind is called eolian movement after the Greek god of wind, Aeolus. Geologists have found that nearly 50 of desert surfaces are plains, where eolian movement of fine-grained material has uncovered loose gravels, pebbles, and stones. The remaining arid land surfaces are composed of exposed outcrops,...
Denudation
Most people use the word weathering as an overall term for erosion and all gradual land wasting, but it actually comes under a larger category called denudation. Denudation takes place when surface layers are removed from underlying rock. They are laid bare. When the wind blows constantly on a high mountain slope, there is hardly any soil left on the bare surfaces except for grains that fall into protected cracks and fissures. This is especially obvious in rock outcrops where very little soil...
Desertification
Deserts are formed from a variety of geological factors. Global temperatures, rainfall rates, and tectonic processes all contribute to the forming of the landmasses. Desertification is the downgrading of rich soil and land into dry barren lands. Today, a lot of desertification is influenced by human activities and climatic changes. Desertification takes place because dry land environments are vulnerable to overdevelopment and poor land use. The following factors, which ruin a land's richness,...
Geological Carbon Cycle
In the geological carbon cycle, carbon moves between rocks and minerals, sea-water and the atmosphere through weathering. Table 11-1 shows all the various rock forms that contain carbonate. Table 11-1 Carbonate is found in many different forms. Table 11-1 Carbonate is found in many different forms. Micrite microcrystalline limestone Very fine-grained light gray or tan to nearly black Fossil mash cemented together may resemble granola Microscopic planktonic organisms such as coccolithophores...
Thermosphere
The changeover from the mesosphere to the thermosphere layer begins at a height of approximately 80 km. The thermosphere is named because of the return to rising temperatures that can reach an amazing 1,982 C. The different temperature ranges in the thermosphere are affected by high or low sun spot and solar flare activity. The more active the sun is, the higher the heat generated in the thermosphere. Extreme thermospheric temperatures are a result of UV radiation absorption. This radiation...
Halocarbons
As we learned earlier, halocarbons levels dropped since being banned in the 1990s. The phasing out of chlorofluorocarbons has removed a lot of the ozone threat and is allowing the protective ozone layer to recover. However, other problem gases, like perfluorocarbons and sulfur hexafluoride, affect the atmosphere and are given off during aluminum smelting, production of electricity, magnesium processing, and semiconductor manufacturing. These can be limited through different manufacturing...
Paleodeserts
Information on ancient sand seas, changing lake basins, archaeology, and vegetation show that climatic conditions have changed drastically over vast areas of the Earth in the geologic past. During the last 12,500 years, parts of some deserts were drier than they are today. About 10 of the land between 30 N and 30 S is now covered by sand seas. Around 18,000 years ago, sand seas in these two vast belts occupied almost 50 of this land area. Just like today, tropical rain forests and savannahs...
Nonnative Alien Species
When plants and animals found in one part of the world, with their own natural predators, diseases, and ecosystem controls are transported to a far distant location, they are known as non-native species. In their new location, they flourish, die, or do something in between. Non-native alien species are transplanted geographically to a formerly unknown area. Many times, the new species is not suited to the new environment, and it fails to prosper there. However, in other cases, the new species...
Glacial Till and Moraines
Rock pulverized by shifting ice is gathered and carried downhill as the glacier moves. As temperatures increase and or a great distance is traveled, the glacial ice begins to melt. When this happens, rock is deposited as a sediment called glacial till. Large boulders picked up in one place and dropped in another by a glacier are called erratics since their composition doesn't usually match surrounding rock where they are found. When glacial till becomes rock lithifies , it is known as tillite,...
Mass Movement
In slides, slips, flows, and landslides, gravity is the main force acting upon soil and rock. When slope stability is changed, a variety of complex sliding movements takes place. Sudden movements of soil or rock that occur when the upper layers separate from the underlying rock and involve one distinct sliding surface are called landslides. There is little loose flow. The rock moves in a solid sheet downward. Slides take place because of a buildup of 1 internal stress along fractures 2...
Sinkholes
Karsts can be a big problem for homebuilders and business owners, especially in the Gulf Coast states of North America since they may form sinkholes. Sinkholes come in all sizes. Areas that are ripe for sinkholes can often be recognized by aerial or satellite photography. From these elevated views, characteristic karst circular patterns of ground cracks and depressions or lakes point to subsurface mineral dissolution. In karst regions, groundwater flow is speedy due to the high porosity and...
Convection
In atmospheric studies, convection refers to vertical atmospheric movement. As the earth is heated by the sun, different surfaces absorb different amounts of energy, convection occurs, and surfaces are quickly heated. Hot air rises. This is why it's warmer in the upper floors of a house or building in the summer. The same is true of the atmosphere. As the Earth's surface warms, it heats the overlying air, which gradually becomes less dense than the surrounding air and begins to rise. A thermal...
Plants
Nearly all desert plants are drought-resistant or salt-tolerant. Some store water in their leaves, roots, and stems, then use it during the long dry times. Other desert plants have long tap roots that enter the water table, hold soil, and resist erosion. When water evaporates and leaves minerals behind or minerals are washed from higher elevations, salt builds up in the soil. Chlorine is particularly retained and causes problems for plants. Halophytes are desert plants that adjust to high salt...
Ecosystems and Biodiversity
Although humans are primarily land dwellers, the Earth's surface is largely water. The world's oceans make up 99 of the planet's biosphere and contain the greatest diversity of life. Even the most biologically rich tropical rain forests cannot match the biodiversity measured by the number of species found in a coral reef community. Rain forests, deserts, coral reefs, grasslands, and a rotting log are all examples of ecosystems. An ecosystem is a complex community of plants, animals, and...
Land Overuse
Land overuse can come from economic circumstances, poor land laws, and cultural customs. Some people exploit land resources for their own gain with little thought for the land or neighboring areas. Some people in poverty have little choice but to overuse their meager resources, even to the extent of wearing out the land. Trade and exploitation of a country's natural resources often leaves the land restoration in the hands of local people without the funding to have much of an impact. In the...
Glacier Surge
Glaciers flow very slowly, with different layers flowing at different speeds. On average, glacial movement slips along at about 20 meters per year. However, during short periods of speedy movement or surge, they may flow up to 10 km per day. Glacial surging is not well understood, but seems to follow a cycle. The Variegated Glacier in southern Alaska is known to surge every 16 to 21 years. The Medvezhiy Glacier in the Soviet Pamirs surges approximately every 10 years. These glaciers are easier...
Nuclear Disadvantages
The serious problem with nuclear power is the storage of radioactive waste. Each year, about 30 metric tons of used fuel are created by every 1000-megawatt nuclear electric power plant. Most of this waste is stored at the power plants because of the lack of high-level radioactive waste disposal sites. Long-term storage is crucial now and will become even more important as additional radioactive waste accumulates. Although not much waste is created at any one plant, it is extremely dangerous. It...
Nonhazardous Waste
Municipal solid waste is the garbage generated by homes, businesses, and institutions. Other kinds of solid wastes include sludge from wastewater treatment plants, water treatment plants, and air pollution control facilities. Additional discarded materials includes solid, liquid, semisolid, or containerized gaseous materials from industrial, commercial, mining, and agricultural operations, and community activities. When solid waste does not pose a threat to the environment or human health, it...
References
Hambrey, M., and J. Alean, Glaciers, New York, NY Press Syndicate of the University of Cambridge, 1992. Holmes, G., et al., Handbook of Environmental Management and Technology, New York, NY John Wiley amp Sons, Inc., 1993. Jackson, J. L., ed., Dictionary of Geological Terms, 3rd ed., National Academy of Sciences for the American Geological Institute, New York, NY Knopf Group, 1984. Jensen, J., Remote Sensing of the Environment An Earth Resource Perspective, Upper Saddle River, NJ Prentice Hall,...
Physical Changes
Human activities can change the seabed directly by dredging, trawling, and boat groundings and indirectly by damming, construction of sea walls, and other things that increase sedimentation and or cut off the natural flow between land and sea . Coastal landscape changes that replace natural coastal ecosystems like the building of major urban centers, resorts, hotels, golf courses, ports, and factories can be huge. As coastal areas are developed, seabird habitats, marine mammals, and other...