CES210: Chapter 14 Notes
CES210: Chapter 14 Notes CES 210
Popular in Introduction to Conservation and Environmental Science
Popular in GN Natural Science
verified elite notetaker
This 5 page Class Notes was uploaded by Emma Eiden on Sunday October 16, 2016. The Class Notes belongs to CES 210 at University of Wisconsin - Milwaukee taught by Mai Phillips in Fall 2016. Since its upload, it has received 128 views. For similar materials see Introduction to Conservation and Environmental Science in GN Natural Science at University of Wisconsin - Milwaukee.
Reviews for CES210: Chapter 14 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 10/16/16
CES210: Conservation and Environmental Science Chapter 14: Geology and Earth Resources Case Study: Moving Mountains for Coal - Mountaintop removal mining (MTR) is the term used for this approach in the mountains of Appalachia. As the term suggests, entire ridge tops are removed, and the overburden often is pushed downhill, where it fills valleys and buries streams EARTH PROCESSES AND MINERAL Convection in the earth’s mantle causes tectonic plate movement, earthquakes, and volcanoes Oceanic crust is thinner, denser, and younger than continental crust The rock cycle involves formation of three general rock types Earth is a dynamic planet - The earth is a layered sphere - The oceanic crust consists of rocks rich in iron, silicon, and magnesium, such as basalt. Continental crust is thinker (25-75km), less dense, and older, some of it 3.8 billion years old. Rocks in the continental crust, such as granite or sandstone, generally are composed of lighter elements, such as oxygen, silicon, and aluminum compared to the rest of the Earth Tectonic processes move continents - The convection currents in the mantle provide the force to move the overlaying crust, a mosaic of huge blocks called tectonic plates. These plates slide slowly across the Earth’s surface like ice sheets on water, in some places breaking up into smaller pieces, and in other places crashing ponderously into each other to create new, larger landmasses - Magma (molten rock) forced up through the cracks forms new oceanic crust that piles up underwater in mid-ocean ridges - When an oceanic plate converges with a continental landmass, the continental plate usually rides up over the seafloor, while the oceanic plate is subducted, or pushed into the mantle Tectonic plate movement: where thin, oceanic plates diverge, upwelling magma forms mid-ocean ridges. A chain of volcanoes, like the Hawaiian Islands, may form as plates pass over a “hot spot”. Where plates converge, melting can cause volcanoes, such as the Cascades - Trenches and volcanic mountains ring the Pacific Ocean rim from Indonesia to Japan to Alaska and down the west coast of the Americas, forming a “ring of fire” where oceanic plates are being subducted under the continental plates - The redistribution of continents has profound effects on the earth’s climate and may help explain the periodic mass extinction of organisms that mark the divisions between many major geological periods Rocks are composed of minerals - A mineral is a naturally occurring, inorganic, solid element or compound with a specific chemical composition and crystal structure - A rock is a solid, cohesive, aggregate of one or more minerals - Fine-grained crystalline rocks indicate a relatively rapid cooling environment near the surface. Large-grained rocks crystallized and solidified slowly, deep underground Rocks and minerals are recycled constantly - Heat, pressure, erosion, deposition, and other processes create new minerals and rocks. We call this cycle of creation, destruction, and metamorphosis the rock cycle - The most common rock-type in the Earth’s crust Is solidified from magma, welling up from the Earth’s interior. These rocks are classed as igneous rocks - Extreme heat and pressure can transform mineral structures to create new forms called metamorphic rock. Metamorphism generally happens as buried layers of rocks are squeezed, folded, and heated by tectonic processes Weathering breaks down rocks - Sedimentary rocks, the third type, are accumulation of sand, mud, or other material deposited over time from another source - Mechanical weathering is the physical breakup of rocks into smaller particles without a change in chemical composition of the constituent minerals - Particles of rock are transported by wind, water, ice, and gravity until they come to rest again in a new location. The deposition of these materials is called sedimentation - Sedimentary “evaporate” minerals also form as salt layers accumulate in shallow, evaporating water bodies - Humans have become a major force in shaping landscapes EARTH RESOURCES Metals are valuable because they are strong and easily shaped Metals derive from ores, which often include sulfur Nonmetal resources are diverse and valuable Conservation reduces energy consumption as well as pollution - The Earth is unusually rich in mineral variety. Mineralogists have identified some 4,400 different mineral species – far more, we believe, than on any out neighboring planets. What makes the difference Metals are especially valuable resources - The mining, processing, and distribution of these materials have broad implications for both our culture and over environment. Metals are useful because they are light, strong, and malleable (easily shaped). Unlike stone, metals can hold a sharp edge. Most metals also conduct electricity well - A new class of metals, knowns as rare earth metals, has become key to the production of small electronics, lightweight motors, as in wind turbines, and batteries for electric or hybrid cars. Because they are sparsely distributed, extracting them causes considerable environmental disturbance Fossil fuels originated as peat and plankton - Oil, in contrast, derives from the remains of tiny plankton and algae. Also growing in generally warm, coastal, environments, these microscopic organisms accumulated on the sea floor over millions of years China, Russia, and the United States possess more than 68% of the world’s knowns reserves of these materials China produces about 97% of all rare earth metals Conserving resources saves energy and materials - Conversation can also help reduce the effects of mining and processing, including water use and contamination, air pollution, and energy use Resource substitution reduces demand - Consumption of minerals, metals, and fuels can be reduced by substituting traditional materials and technologies with new ones ENVIRONMENTAL EFFECTS OF RESOURCE EXTRACTION Mining produces dust, acids, and toxic metals pollutants Metal is extracted by smelting or chemical extraction The value of minerals and the cost of cleanup lead to conflict over these resources - The most obvious effect of mining is often the disturbance or removal of the land surface. Farther-reaching effects, though, include air and water pollution - Gold, copper, and other metals are often found in sulfide ores. When these minerals are exposed to air and water, they produce sulfuric acid, which is highly mobile and strongly acidic Different mining techniques pose different risks to water and air - One mine fire in Centralia, Pennsylvania, has been burning since 1962; control efforts have cost at least $40 million, but the fire continues to expand. China, which depends on coal for much of its heating and electricity, has hundreds of smoldering mine fires; one has been burning for 400 years Processing also produces acids and metals - The acids, metals, and cyanide in the heap between threaten the nearby Salmon River and its $2 billion annual tourism and fishing industry - Ore washing and leaching consume a great deal of water - Worldwide, mine closing and rehabilitation costs are estimated in the trillions of dollars. Because of the volatile prices of metals and coal, many mining companies have gone bankrupt because restoring mine sites, leaving the public responsible for cleanup High-value minerals can support corruption - Although international agreements often ban trade that finances war and genocides, illegal trade continues. Much of the “blood diamond” trade ends up in $100-billion-per-year global jewelry trade, 2/3 of which sells in the United States - In the United States, where legal controls often are in place for environmental and public protection, mining also reminds controversial. Often the public bears the cost of cleanup, as well as providing the resources nearly free of change. On the other hand, public policy in the United States encourages mining on public lands as a way of boosting the economy and utilizing natural resources GEOLOGICAL HAZARDS Earthquakes result from sudden shifts of tectonic plates Earthquakes and floods causes the greatest damage and mortality of all geological hazards Erosion and landslides frequently cause property damage Earthquakes occur on plate margins - Earthquakes are sudden movements in the Earth’s crust that occur along faults (planes of weakness) where one plate slides past another - The San Andreas fault in California is one of the most notorious and highly visible faults in the world. It runs about 1,300 km (810mi) from the Salton Sea in southern California to Point Reyes, just north of Dan Francisco, were it veers offshore to follow the coast north nearly to Oregon. The fault occurs where the Pacific plate is moving to the northwest, past the North American plate, which is moving south. - When movement along faults occurs gradually and relatively smoothly, it is called creep or seismic slip and may be undetectable to the casual observer. When friction prevent rocks from slipping easily, stress builds up until it is finally released with a sudden jerk, which can cause the ground to shake like jelly - Most earthquake deaths result from the collapse of weakly constructed buildings - Increasingly builders in earthquake zones are designing buildings to withstand tremors Tsunamis can be more damaging than the earthquakes that trigger them - Tsunamis are powerful waves triggered by earthquakes or landslides. The name is derived from the Japanese word for “harbor wave” because the waves often are noticed only when they approach shore - Elevated radiation levels were detected in milk, vegetables, seafood, and some water supplies from regions surrounding the damaged nuclear plants. Two years later, officials still were uncertain how to contain leaks of radioactive cooling water. The government has estimated economic losses of as much as $300 billion, not including costs such as the cleanup of the nuclear reactors, several of which will probably have to be entombed in concrete forever Volcanoes eject gas and ash, as well as lava - Volcanoes and undersea magma vents produce much of the Earth’s crust. Over hundreds of millions of years, gaseous emissions from these sources formed the Earth’s earlier oceans and atmosphere. Many of the world’s fertile soils are weathered volcanic materials - Nuess ardentes (French for “glowing clouds”) are deadly, denser-than-air mixtures of hot gases and ash like those that inundated Pompeii and Herculaneum Landslides and mass wasting can bury villages - Gravity constantly pull downward on every material everywhere on Earth, causing a variety of phenomena collectively termed mass wasting or mass movement, in which geological materials are moved downslope from one place to another - Activities such as road construction, forest clearing, agricultural cultivation, and building house on steep, unstable slopes increase both the frequency and the damage done by landslides. In some cases people are unaware of the risks they face by locating on or under unstable hillsides Floods are the greatest geological hazard - As rivers carve and shape the landscape, they build broad floodplains and level expanse that are periodically inundated. Many cities have been built on these flat, fertile plains, which are both good for agriculture and convenient to the river. When floods occur irregularly, people develop a false sense of security - A flood on the Yangtze River in China in 1931 killed 3.7 million people, making it the most deadly natural disaster in recorded history - Rather than spend money on levees and floodwalls, many people think would be better to restore wetlands, replace groundcover on water courses, build check dams on small streams, move buildings off the floodplain, and undertake other nonstructural ways of reducing flood danger Beaches erode easily, especially in storms - Beach erosion occurs on all sandy shorelines because the motion of the waves is constantly redistributing sand and other sediments - Construction directly on beaches and barrier islands can cause irreparable damage to the whole ecosystem. Under normal circumstances, fragile vegetative cover holds the shifting sand in place. Damaging this vegetation and breaching dunes with roads can destabilize barrier islands - Subsidies for road building and bridges, support for water and sewer projects, tax exemptions for seconds homes, flood insurance, and disaster relief are all good for the real estate and construction businesses but invite people to build in risky places Vocab words to review… Core Mantle Magma Crust Tectonic plates Mid-ocean ridges Subducted Mineral Rock Rock cycle Igneous rock Metamorphic rock Sedimentary rock Weathering Sedimentation Earthquakes Tsunamis Volcanoes Mass wasting