Wind Erosion

Wind erosion happens when soils that have been cleared of plants are exposed to high-velocity wind. When wind speed is greater than the soil's gravitational and cohesive forces, it will shift soil and carry it away in suspension. Wind erosion is caused by the movement and deposition of soil particles by the wind. Wind moves soil particles between 0.1 and 0.5 mm in size by a bouncing movement and greater than 0.5 mm by rolling. The smallest particles (less than 0.1 mm) separate into suspension....

Pressure

Bakers that live in the mountains have to consider the pressure of air when creating light cakes and souffl s. The decrease in pressure at high altitudes (over 6,000 meters) changes the baking process from that of sea-level baking. That is why some cake mixes give different directions for high-altitude baking, to make up for the difference of pressure on the rising cake. Air pressure is the force applied on you by the weight of air molecules. Although air is invisible, it still has weight and...

Water Use and Quality

Land use and soil types are linked with human activity. Pesticide and fertilizer use on crops affects water purity if runoff joins with surface water or ground-water. Industrial use and land storage are related to the processing or disposal of hazardous chemicals. This may also present a hazard to streams or underground aquifers. Unfortunately, most water quality problems come from populated areas and improper land use. A variety of land uses brings pollutants into the overall water cycle. The...

Water Treatment

Whenever water is used for humans, it must be treated from two different angles. First, any surface water from rivers that is used in cities is treated for drinking, usually by chlorination. After water is used for drinking, washing, lawns, toilets, and so on, it has to be treated at a wastewater treatment plant before it can be released back into the environment. Fig. 8-1 illustrates the path that water takes from initial water treatment (chlorination) to urban use, and then wastewater...

Chemicals

Many pollution sources come from sewage and fertilizers containing nutrients like nitrates and phosphates. In high levels, nutrients overstimulate the growth of water plants and algae. Uncontrolled growth of these organisms clogs waterways that use up dissolved oxygen and as they decompose, keeps sunlight from penetrating into deeper water. When this happens, the photosynthetic cycle of good water plants and organisms is affected. This hurts fish and shellfish that live in the affected water....

Part Three Test

The difference between mass wasting and erosion is that erosion happens (a) over much greater distances 2. The slow or sudden movement of rock down slope as a result of gravity is called 3. When rock disintegrates and is removed from the surface of continents, it's called 4. Slower, long-term soil or rock movement with a series of sliding surfaces and plasticity is known as (d) a rolling stone gathers no moss 5. The repeated freeze-thaw cycle of water in extreme climates causes 6. The popular...

Common Uses

Photovoltaic systems are practical for beach, remote cabins, or vacation homes that don't have access to the electricity grid. These systems can be set up to meet power needs for less money. The fact that solar energy is highly reliable and needs little maintenance makes it a great choice for hard-to-reach locations with ample sunlight. Polar research stations are a good example. Remote mountain or desert homes in sunny locations can get reliable electricity from solar generation for lighting,...

Wind Energy

The fact that wind energy is natural is obvious, but did you know that its created by the sun Wind energy is created by the Earth's atmospheric circulation patterns, which are heated and influenced by the Sun's heat. Ancient people used wind power directly to power ships for travel, trade, and to discover new lands. Long before electricity, windmills provided energy for stone mills to grind grain into flour and or pump water. Think of the beautiful windmills that dot the countryside in the...

Acid Rain

Rain, naturally acidic because of the carbon dioxide in the earth's atmosphere, reacts with water to form carbonic acid. While regular rain has a pH of 5.6 to 5.7, most pH readings depend upon the type and amount of other gases like sulfur and nitrogen oxides present in the air. We learned in Chapter 4 that the most important natural acid is carbonic acid, formed when carbon dioxide dissolves in water (CO2 + H2O H2CO3). Rocks, like limestone and marble, are particularly sensitive to this type...

Part Two Test

Ith more and more people on the planet, a positive environmental step would include more (d) fertilizers used to increase crop yields 2. Pounding reefs with heavy weights to scare fish out of their hiding places is called 3. What percentage of runoff from the land surface eventually drains into the sea 4. Continental glaciers are large, U-shaped glaciers with the deepest ice found 5. The study of the occurrence, distribution, and movement of water on, in, and above the earth is called 6. All of...

Water Erosion

Water is heavy and when it's moving quickly, it can easily knock you off your feet. This is why people are warned against trying to cross a raging stream during a heavy rain or flash flood. Entire cars, trucks, and homes can be washed away as easily as a leaf into a sewer drain. Water impacts soil in a variety of ways. Most of them are good, like watering plants and filling lakes and rivers, but some are destructive. Rills are formed when water first washes soil...

Disadvantages Of Geothermal

Geothermal energy has few polluting problems itself, but there are some drawbacks in its processing. For example, steam can sometimes bring up toxic heavy metals, sulfur, minerals, salts, radon, and toxic gases. If water or steam is vented above ground as in an open-loop system, it can pollute. Scrubbers can filter out toxic components, but they produce hazardous sludge that has to be disposed of later. As we learned in Chapter 12, hazardous waste contaminates soil and potentially groundwater....

Our Planet Earth

Native peoples, completely dependent on nature for everything in their lives, worshipped Earth as a nurturing mother. The soil sprouted plants and trees that provided food, clothing, and shelter. The rivers and seas gave up fish and shellfish for food, trade articles, and tools. From the atmosphere came rain, snow, and wind to water crops and adjust the seasons. Earth, never stagnant or dull, provided abundantly for early stewards of her resources. Ancient peoples thought that Mother Earth...

Permafrost

In the frozen areas of the North and South Poles, in arctic and alpine areas, and at high elevations, there are areas where the winter freeze is so deep that the soil is forever frozen and doesn't ever get warm enough to thaw out. This frozen soil is called permafrost. Fig. 7-4 shows the permafrost layer. Some geologists think that as much as 25 of the land's surface is frozen as per- Fig. 7-4 Permafrost is the ground layer that never thaws, even in the summer. Fig. 7-4 Permafrost is the ground...

Tar Balls

When crude oil drifts on the ocean's surface, its physical properties change. During the first few hours of a spill, the oil spreads into a thin slick. Winds and waves tear the slick into smaller patches that get scattered over a much wider area. Various physical, chemical, and biological processes change the appearance of the oil. These changes are known as oil weathering. Winds and waves continue to pull and rip the spilled oil into smaller bits or tar balls. While some tar balls are as large...

The Hydrologie Cycle

We can't escape our need for water, even if we wanted to. Our bodies are made up of 66 water and require water daily We developed in amniotic fluid we can't last more than two or three days without water we wash ourselves and nearly everything else in water we get much of our food from water oceans and, we travel on water. Water is king Hydrology is the study of the occurrence, distribution, and movement of water on, in, and above the earth. If water is king, then the hydrologic cycle is queen....

Hydrologie Cycle

Hydrologic Cycle Molecule

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

Latitudes Hot Dry Deserts

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...

Nuclear Energy

When people think of nuclear energy, they think of bombs and weapons-grade uranium U235 . However, nuclear energy has its geological roots, as well. Uranium is present in minute amounts in the Earth's crust, with only a 0.00016 chance that an average continental rock sample will contain the ele- ment. Natural uranium is 99.3 U and 0.7 U . The type of uranium that undergoes fission and releases huge amounts of energy is U235. This accounts for only 1 in every 139 atoms of mined uranium. It is...

4 Types Of Sand Dunes

Sand Dunes Movement And Wind Slope

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

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...

Coastal Deserts

Mountains Desert One Side

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...

Atmosphere

Four Main Layers The Atmosphere

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

Aurographic Clouds

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...

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...

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...

Mass Movement

Shear Stress Shear Strength Slope

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...

Ecosystems and Biodiversity

Redwood National Park Animals

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...