Encyclopedia of Global Resources part 26 pot

presence of which would ordinarily cause decay of the plant tissue. Under such near-stagnant conditions plant remains are preserved, while the presence of hy- drogen sulfide discourages the presence of organisms that feed on dead vegetation. Analog environments under which coal is presently forming are found within the Atchafalaya swamp of coastal Louisiana and the many peat-producing regions of Ireland. A layer of peat inexcessof2metersinthicknessandcov- ering more than 5,000 square kilometers is present in the Dismal Swamp of coastal North Carolina and Vir- ginia. The sapropelic class of coal, relatively uncommon in distribution and composed of fossil algae and spores, is formed through partial decomposition of organic matter by organisms within oxygen-deficient lakes and ponds. Sapropelic coals are subdivided into boghead (algae origin) and cannel (spore origin) de- posits. The vegetable origin of coal has been accepted since 1825 and is convincingly evidenced by the iden- tification of more than three thousand freshwater plant species in coal beds of Carboniferous (360 to 286 million years ago) age. The common association of root structures and even upright stumps with layers of coal indicates that the parent plant material grew and accumulated in place. Detailed geologic studies of rock sequences that lie immediately above and below coal deposits indicate that most coals were formed in coastal regions af- fected by long-term sea-level cycles characterized by transgressing (advancing) and regressing (retreating) shorelines. Such a sequence of rock deposited during a single advance and retreat of the shoreline, termed a “cyclothem,” typically contains nonmarine strata separated from overlying marine strata by a single layer of coal. In sections of the Interior coal province, a minimum of fifty cyclothems have been recognized, some of which can be traced across thousands of square kilometers. Such repetition in a rock sequence is most advantageous to the economics of a coal re- gion, creating a situation in which a vertical mine shaft could penetrate scores of layers of coal. The formation of coal is a long-term geologic pro- cess. Coal cannot therefore be considered a renew- able resource, even though it is formed from renew- able resource plant matter. Studies have suggested that 1 meter of low-rank coal requires approximately ten thousand years of plant growth, accumulation, bi - ologic reduction, and compaction to develop. Using these time lines, the 3-meter-thick Pittsburgh coal bed, underlying 39,000 square kilometers of Pennsyl- vania, developed over a period of thirty thousand years, while the 26-meter-thick bed of coal found at Adaville, Wyoming, required approximately one- quarter of a million years to develop. Coal formation favors climate conditions under which plant growth is abundant andconditionsforor- ganic preservation are favorable. Such climates range from subtropical to cold, with the ideal being classed as temperate. Tropical swamps produce an abun- dance of plant matter but very high bacterial activity, resulting in low production of peat. Modern peats are developing in temperate to cold climate regions, such as Canada and Ireland, where abundant precipitation ensures fast plant growth while relatively cool temper- atures diminish the effectiveness of decay-promoting bacteria. The first coal provinces began to form with the evo- lution of cellulose-rich land plants. One of the earliest known coaldeposits,of Upper Devonianage(approx- imately 365 million years ago), is found on Buren Is- land, Norway. Between the Devonian period and to- day every geologic period is represented by at least some coal somewhere in the world. Certain periods of time, however, are significant coal-forming ages. During the Carboniferous and Permian periods (360 to 245 million years ago) widespread develop- ment of fern and scale tree growthsetthe stage for the formation of the Appalachian coal province and the coal districts of the United Kingdom, Russia, and Manchuria. Coal volumes formed during these pe- riods of geologic time constitute approximately 65 percent of present world reserves. The remaining re- serves, developed mainly over the past 200 million years, formed in swamps consisting of angiosperm (flowering) plants. The reserves of the Rocky Moun- tain province and those of central Europe are repre- sentative of these younger coals. After dead land-plant matter has accumulated and slowly begun to compact, biochemical decomposi- tion, rising temperature, and rising pressure all con- tribute to the lengthy process of altering visible plant debris into various ranks of coal. With the advent of the Industrial Revolution there was a need for a sys- tem of classification defining in detail the various types of coals. Up to the beginning of the nineteenth century, coal was divided into three rudimentary classes, determined by appearance: bright coal, black coal, and brown coal. Through the decades, other 220 • Coal Global Resources schemes involving various parameters were intro - duced, including oxygen content, percent of residue remaining after the burning of coal, ratio of carbon to volatile matter content, or analysis of fixed carbon content and calorific value (heat-generating ability). In 1937, a classification of coal rank using fixed car- bon and Btu content was adopted by the American Standards Association. Adaptationsofthis scheme are still in use, listing the steps of progressive increase in coal rank as lignite (brown coal), subbituminous, bi- tuminous (soft coal), subanthracite, and anthracite (hard coal). Some classification schemes also list peat as the lowest rank of coal. (Technically speaking, peat is nota coal; rather, itis a fuel anda precursor tocoal.) Coalification is the geologic process whereby plant material is altered into differing ranks of coal by geo- chemical and diagenetic change. With an increase in rank, chemical changes involve an increase in carbon content accompanied by a decrease in hydrogen and oxygen. Correspondingly, diagenesis involves an in- crease in density and calorific value, and a progressive decrease in moisture. At all ranks, common impuri- ties include sulfur, silt and clay particles, and silica. U.S. reserves are found mainly in eleven northeast- ern counties in Pennsylvania. Subanthracite coal has characteristics intermediate between bituminous and anthracite. Bedded and compacted coal layers are geologically considered to be rocks. Lignite and bituminous ranks are classed as organic sedimentary rocks. Anthracite, formed when bituminous beds of coal are subjected to the folding and regional deformation affiliated with mountain building processes, is listed as a meta- morphic rock. Because peat is not consolidated or compacted, it is classed as an organic sediment. Graph- ite, a naturally occurring crystalline form of almost pure carbon, is occasionally associated with anthra- cite. While it can occur as the result of high-tempera- ture alteration of anthracite, its chemical purity and common association with crystalline rock causes it to be listed as a mineral. History Considering the importance of coal to modern soci- ety, it is somewhat surprising that the production of this commodity played only a minor role in pre- Industrial Revolution (that is, prior to the middle eighteenth century) history. The origins of coal use date back at least several thousands of years, as evi - denced by the discovery of flint axes embedded in layered coal in central England. These primitive tools have been attributed to Neolithic (New Stone Age, c. 6000-2000 b.c.e.) open-pit mining. The Chi- nese were acquainted early with the value of coal, us- ing it in the making of porcelain. Coal cinders found in Roman-era walls in association with implements of similar age suggest the use of coal for heating purposes prior to the colonization of England by the Saxons. The philosopher Theophrastus (c. 372-287 b.c.e.), noted as the academic successor to Aristotle and the author of many studies on plants, called coal anthrax, a Greek word later used in the naming of anthracite coal. Later, the Anglo-Saxon term col, probably de- rived from the Latin caulis, meaning plant stalk, evolved into “cole” prior to the emergence of the modern spelling some three centuries ago. With the decline of forests in England by the thir- teenth century, coal began to assume a significant role. The first coal-mining charter was granted the freemen of Newcastle in 1239. This early burning of coal, however, because of its propensity to befoul the atmosphere, was banned in 1306 by King Edward I. King Edward III reversed this ban and again granted the Newcastle freemen a coal-mining license, whereby this town soon became the center of the first impor- tant coal-mining district. Coal mining was initiated in North America near Richmond, Virginia, in 1748. A decade later, coal- mining activities had moved to the rich deposits around Pittsburgh, Pennsylvania. The spread of the Industrial Revolution, invention of the iron-smelting process, and improvement of the steam engine guar- anteed the classification of coal as an industrial staple. With the development of the steam-driven electric generator in the last decade of the nineteenth cen- tury, coal became the dominant fuel. A century later, world coal production exceeded 4.5 billion metric tons and constituted some 26 percent of world energy production ona Btu basis. Intheearly twenty-first cen- tury, with the rapid growth of the Chinese economy, China passed the United States as the top producer of coal. Obtaining Coal Coal has been produced by two common methods: underground (or deep) mining and surface(or strip) mining. Underground mining requires the digging of extensive systems of tunnels and passages within and along the coal layers. These openings are connected Global Resources Coal • 221 to the surface so the coal can be removed. Prior to the development of the gigantic machinery necessary to open-pit mining, deep mining was the industrynorm. This early period was characterized by labor-intensive pick-and-shovel work in cramped mine passages. Con- stant dangers included the collapse of ceilings and methane gas explosions. Today, augers and drilling machinery supplement manpower to a large extent, and mine safety and health regulations have greatly reduced the annual death toll. The common method of underground ex- traction involves initialremoval of about 50 percentof the coal, leaving a series of pillars to support the mine roof. As reserves are exhausted, the mine is gradually abandoned after removal of some or all of the pillars. Another modern underground-mining technique, with a coal removal rate approaching 100 percent, in- volves the use of an integrated rotary cutting machine and conveyer belt. Surface mining of coal, accounting for about 40 percent of global production, is a multiple-step pro- cess. First, the overburden material must be removed, allowing exposure of the coal. The coal is then mined by means of various types of surface machinery, rang- ing from bulldozers to gigantic power shovels. Finally, after removal of all the coal, the overburden is used to fill in the excavated trench and the area is restored to its natural topography and vegetation. Economics usually determine whether underground or open-pit techniques are preferable in a given situation. Gen- erally, if the ratio of overburden to coal thickness does not exceed twenty to one, surface mining is more profitable. In the Appalachian coal province, coal-mining tech- nique is closely related to geology. In tightly folded re- gions of West Virginia, the steeply dipping coal beds are mostly mined underground. To the northwest, folds become gentler, and both deep- and surface- mining methods are used. In the Interior province, strip mining is the most common process. In the Rocky Mountain area, where many thick coal beds lie close to the surface, strip mining again predominates, although a few underground mines are present. With increased concern regarding the state of the natural Earth environment, and with federal passage of the Coal Mine Health and Safety Act (1969) and the Clean Air Acts (U.S.), the mining of coal in the United States has undergone both geographic and extraction-technology changes. Because the Rocky Mountain province coals, while lower grade than east - ern coals, contain lower percentages of sulfur, the center of U.S. production has gradually shifted west- ward. The burning of high-sulfur coals releases sulfur dioxide intotheatmosphere; it isasignificant contrib- utor to acid rain. Western coals are often contained within layers thicker than those found in the east, are shallow in depth, and can be found under large areas—all con- ditions amenable to surface mining. As a result, the state of Wyoming, with a 1995 production of 240 mil- lion metric tons of low-sulfur coal that is burned in more than twenty-four statesinthegeneration of elec- tricity, became the leading U.S. coal producer. Coal mining has played an integral role in the de- velopment of the industrialized world, and this role should continue well into the future. Reserve addi- tions continue to closely equal losses due to mining, and at current levels of production estimates indicate that there is enough recoverable coal globally for some 130 to 150 years of future production. Uses of Coal Historically, coal has been industry’s fuel of choice. Those countries in possession of sufficient coal reserves have risen commercially, while those less endowed with this resource—or lacking it altogether—have turned to agriculture or stagnated in development. The top exporters of coal are Australia, Indonesia, Russia, Colombia, South Africa, China, and the United States. The top importers are Japan, South Korea, Taiwan, India, the United Kingdom, China, and Ger- many. Different ranks of coal are employed for different purposes. In the middle of the twentieth century, it was common to see separate listings of coking, gas, steam, fuel, and domestic coals. Each had its specific uses. Domestic coal could not yield excessive smoke, while coal for locomotives had to raise steam quickly and not produce too high an ash content. Immedi- ately after World War II, fuel coal use in the United States, representing 78 percentofannualproduction, was divided into steam raising (29 percent), railway transportation (23 percent), domestic consumption (17 percent), electric generation (6 percent), and bunker coal (3 percent). The remaining 22 percent was employed in the production of pig iron (10 per- cent), steel (7 percent), and gas (5 percent). Fifty years later, more than 80 percent of the approxi - mately 900 million metric tons of coal produced an - nually in the United States was used in the generation 222 • Coal Global Resources of electricity. Industrial consumption of coal, particularly in the produc- tion of coke for the steel and iron manufacturing industry, is the sec- ond most important use. Globally, 13 percent of hard coal production is used by the steel industry. Some 70 percent of global steel production depends on coal. Additional indus- trial groups that use coal include food processing, paper, glass, ce- ment, and stone. Coal produces more energy than any other fuel, more than natural gas, crude oil, nu- clear, and renewable fuels. The drying of malted barley by peat fires has long beenimportant in giving Scotch whiskey its smoky fla- vor. Peat has also been increasingly employed as a soil conditioner. While expensive to produce, the conver- sion of intermediate ranks of coal into liquid (coal oil) and gaseous (coal gas) forms of hydrocarbon fu- els will become more economically viable, especially during times of in- crease in the value of crude oil and natural gas reserves. New uses ofcoal are constantly be- ing explored and tested. Two prom- ising techniques are the mixing of water with powdered coal to make a slurry that can be burned as a liq- uid fuel and the underground extraction of coal-bed methane (firedamp). Interest in the latter by-product as an accessible and clean-burning fuel is especially high in Appalachian province localities distant from conventional gas resources. Albert B. Dickas Further Reading Berkowitz, Norbert. An Introduction to Coal Technology. 2d ed. San Diego, Calif.: Academic Press, 1994. Freese, Barbara. Coal: A Human History. Cambridge, Mass.: Perseus, 2003. Goodell, Jeff. Big Coal: The Dirty Secret Behind America’s Energy Future. Boston: Houghton Mifflin, 2006. Schobert, Harold H. Coal: The Energy Source of the Past and Future. Washington, D.C.: American Chemical Society, 1987. Speight, James G. The Chemistry and Technology of Coal. 2d ed., rev. and expanded. New York: M. Dekker, 1994. Thomas, Larry. Coal Geology. Hoboken, N.J.: Wiley, 2002. _______. Handbook of Practical Coal Geology. New York: Wiley, 1992. Web Sites American Coal Foundation All About Coal http://www.teachcoal.org/aboutcoal/index.html Natural Resources Canada About Coal http://www.nrcan.gc.ca/eneene/sources/coacha- eng.php Global Resources Coal • 223 History: U.S. Energy Information Administration (EIA), (June-December, 2008). Projections: EIA, World Energy Projections Plus (2009). Source: International Energy Annual, 2006 2025 2010 2005 2000 1995 1990 2015 2020 2030 1985 1980 89.2 88.5 93.6 121.7 140.6 150.7 161.7 175.2 190.2 82.4 70.0 Quadrillion British Thermal Units (Btus) 20015010050 World Coal Consumption and Projections U.S. Department of Energy Coal http://www.energy.gov/energysources/coal.htm U.S. Geological Survey Coal Resources: Over One Hundred Years of USGS Research http://energy.usgs.gov/coal.html World Coal Institute Gas and Liquids http://www.worldcoal.org/ See also: American Mining Congress; Asbestos; Car- bon; Coal gasification and liquefaction; Environmen- tal degradation, resource exploitation and; Industrial Revolution and industrialization; Mining safety and health issues; Mining wastes and mine reclamation; Open-pit mining; Peat; Strip mining; Surface Mining ControlandReclamation Act; Undergroundmining. Coal gasification and liquefaction Categories: Energy resources; obtaining and using resources Synthetic fuels offer alternatives for systems, such as vehicles, designed to operate on liquid or gaseous fuels. Historically, these fuels have been used when imports of petroleum or natural gas are restricted by boycotts or warfare. The conversion of coal to synthetic fuels can reduce the amounts of sulfur and ash released into the environment, providing a cleaner fuel. Background Coal is one of the most abundant fossil fuel resources in the world. The worldwide reserves of coal are likely to last substantially longer than reserves of petroleum and natural gas. Several factors can create shortages of liquid or gaseous fuels, including international trade embargoes (as occurred during the 1970’s), wars, and, in the long run,the depletion of petroleum and gas reserves. Gaseous or liquid fuels are easier to handle and transport than are solids, and they are eas- ier to treat for removal of potential pollutants, such as sulfur. Worldwide there is an immense investment in combustion devices of many kinds designed to oper - ate onliquidsor gases. Alarge-scalereplacement ofall these units, or retrofitting them to burn solid coal, is not practically or economically feasible. Solid coal is not a practical alternative for many applications of liquid or gaseous fuels, such as automobile en- gines. Conversion of coal to synthetic gaseous or liq- uid fuels offers opportunities for providing alterna- tive fuel supplies, for removing sulfur and ash from the fuel before combustion, and for providing strate- gic security against the possible interruption of im- ports. Coal Gasification The simplest approach to producing gaseous fuel from coalisheating in closed vesselsunderconditions that would not allow combustion to occur. In such a process, the coal decomposes to a variety of products, including gases, liquids (coal tar), and a solid residue. Depending on the quality of the coal used, the gas can have excellent fuel qualities, because it is rich in hy- drogen and methane and has a calorific value of about two-thirds that ofnaturalgas. The product has a variety of names: town gas, illuminating gas, or coal gas. The process itself also has various names, includ- ing pyrolysis, destructive distillation, and carboniza- tion. If the primary objective is to produce a gaseous fuel, then simple carbonization is very wasteful of the coal, because only about 20 percent is converted to gas. Much of the original coal still remains a solid, and some converts to a liquid. However, if the gas is col- lected as a by-product, for example from the conver- sion of coal to metallurgical coke, then sale of the gas can provide extra revenue; it can also be used as a fuel inside the plant. Carbonization is not useful when the intent is to convert the maximum amount of coal to a gaseous fuel. The principal method for converting coal com- pletely to a gaseous fuel is the reaction of coal with steam. When steam is passed over a bed of red-hot coal, the product is water gas, which consists mainly of hydrogen and carbon monoxide. The reaction of steam with coal is endothermic (it requires a sourceof heat in order to proceed). Consequently, some por- tion of the coal must be burned to provide the heat to “drive” the reaction of coal with steam. This is usually accomplished by allowing the combustion reaction and the reaction with steam to proceed simultaneously in the same vessel. Initially this was accomplished by feeding coal, air, and steam together into a reactor. The heat-releasing combustion reaction effectively balances the heat-consuming reaction with steam, 224 • Coal gasification and liquefaction Global Resources and the process can operate continuously. When air is used for the combustion reaction, the product gas will inevitably be diluted with large amounts of nitrogen. Consequently, its calorific value will be very low, about 10 to 20 percent of the value of natural gas. For this reason, modern approaches to coal gasification use coal, steam, and oxygen as the feedstocks. Though this addstothecost and complex- ity of separating oxygen from air for the gasification process, it is more than recompensed by a much higher quality product. Gasifier Designs Early designs of gasifiers were so-called moving bed gasifiers, in which a bed of solid coal slowly descended through a tall cylindrical vessel to react with a steam- oxygen (or steam-air) mixture at the bottom. Such gasifiers, such as the Lurgi gasifier, developed in Ger- many in the 1930’s, have a disadvantage in that the heating drives out any moisture that may be in the coal and generates some liquids or tars. Some of the compounds driven out of the coal will dissolve in the water, producing a wastewater that must be treated before discharge into the environment. The tars represent a by-product for which uses must be found or which must be disposed of in environmen- tally acceptable ways. Despite these apparent disad- vantages, the Lurgi is one of the most successful gasifier designsinthe world: Thegasifieris used in the synthetic fuels plants in South Africa as well as in the Dakota gasification plant in Beulah, North Dakota, the primary coal gasification facility in the United States. Alternative approaches to gasification rely on the so-called entrained flow method, in which finely pul- verized coal is blown into the gasifier or injected as a coal-water slurry. In these gasifiers, the coal is heated and reacted sorapidlythatthe formationofby-product tars is avoided. One such gasifier is the Koppers- Totzek, which is used in many places around the world, mainly to produce hydrogen for ammonia syn- thesis (for eventual production of fertilizers). The Koppers-Totzek unit uses pulverized solid coal. The Texaco gasifier injects coal in the form of a slurry. Synthesis Gas The composition of the gas depends on the specific gasification process used. Generally, the main compo - nents are hydrogen and carbon monoxide, the mix - ture of which makes synthesis gas. One application of synthesis gas is the production of methane, which can then be sold as substitute for natural gas. Synthesis gas can be converted to liquid fuels, as discussed below. The gas can also be burned, particularly in gas tur- bines that are part of combined-cycle plants for elec- tricity generation. Other uses include production of methanol as a liquid fuel, acetic anhydride for chemi- cals production, or hydrogen (by removing the car- bon monoxide). Coal Liquefaction There are two major routes for production of syn- thetic liquid fuelsfrom coal. The firstiscalled indirect liquefaction, because the coal itself is actually con- verted to synthesis gas by gasification. In a subsequent step, the synthesis gas is converted to liquid fuels. The dominant technology for this process was developed by Franz Fischer and Hans Tropsch in Germany in the 1920’s. Synthesis gas is reacted over a catalyst at high temperatures and pressures. Depending on the spe- cific choice of catalyst, the pressure and temperature of the reaction, and the relative amounts of hydrogen and carbon monoxide, it is possible to produce a vari- ety of liquid fuels, ranging from gasoline to heating oils. The Fischer-Tropsch process, coupled with coal gasification, produced about 757 million liters per year of synthetic liquid fuels used by Germany during World War II. Subsequently, it was commercialized on a large scale in South Africa, which was barred from international trade in oil during the apartheid years but possesses large reserves of coal. The alternative approach is direct liquefaction. Di- rect liquefactionis based on theobservation thatmost desirable petroleum products contain about two at- oms of hydrogen per atom of carbon. Coal has on av- erage less than one hydrogen atom per carbon atom. The direct conversion of coal to synthetic petroleum- like liquids therefore requires adding hydrogen chemically to the coal. Direct liquefaction is some- times also called coal hydrogenation. The methods for performing direct liquefaction were developed by Friedrich Bergius, who received the Nobel Prize in Chemistry in 1931. The Bergius process requires ex- tremely high temperatures (500° Celsius) and pres- sures (up to 4,500 kilograms per six square centime- ters), a situation which poses difficult engineering challenges for large-scale operation. Nevertheless, the Bergius process provided three billion liters of synthetic fuels per year to the German war effort in World War II. A metric ton of coal will yield approxi - Global Resources Coal gasification and liquefaction • 225 mately 150 to 170 liters of gasoline, 200 liters of diesel fuel, and 130 liters of fuel oil. During the 1970’s and 1980’s, much ingenious re- search in chemistry and process engineering was di- rected toward reducing the severe conditions of the Bergius process in order to make the eventual prod- uct more economically competitive with petroleum. Despite substantial progress, a synthetic crude oil from coal is likely to cost about $30 to $40 per barrel. There are no direct liquefaction plants operating in the world, though China had plans to open one by 2007, which did not happen. Harold H. Schobert Further Reading Berkowitz, Norbert. An Introduction to Coal Technology. 2d ed. San Diego, Calif.: Academic Press, 1994. Freese, Barbara. Coal: A Human History. Cambridge, Mass.: Perseus, 2003. Goodell, Jeff. Big Coal: The Dirty Secret Behind America’s Energy Future. Boston: Houghton Mifflin, 2006. Higman, Chris, and Maarten van der Burgt. Gasifica- tion. 2d ed. Boston: Elsevier/Gulf Professional, 2008. Probstein, Ronald F., and R. Edwin Hicks. Synthetic Fuels. New York: McGraw-Hill, 1982. Schobert, Harold H. Coal: The Energy Source of the Past and Future. Washington, D.C.: American Chemical Society, 1987. Speight, James G. The Chemistry and Technology of Coal. 2d ed., rev. and expanded. New York: M. Dekker, 1994. Thomas, Larry. Coal Geology. Hoboken, N.J.: Wiley, 2002. _______. Handbook of Practical Coal Geology. New York: Wiley, 1992. Williams, A., M. Pourkashanian, J. M. Jones, and N. Skorupska. Combustion and Gasification of Coal. New York: Taylor & Francis, 2000. Web Sites American Coal Foundation All About Coal http://www.teachcoal.org/aboutcoal/index.html Natural Resources Canada About Coal http://www.nrcan.gc.ca/eneene/sources/coacha- eng.php U.S. Department of Energy Coal http://www.energy.gov/energysources/coal.htm U.S. Department of Energy Gasification Technology R&D (Research and Development) http://www.fossil.energy.gov/programs/ powersystems/gasification/index.html U.S. Geological Survey Coal Resources: Over One Hundred Years of USGS Research http://energy.usgs.gov/coal.html World Coal Institute Gas and Liquids http://www.worldcoal.org/pages/content/ index.asp?PageID=415 See also: Carbon; Coal; Electrical power; energy poli- tics; Synthetic Fuels Corporation. Coast and Geodetic Survey, U.S. Category: Organizations, agencies, and programs Date: Established as Coast Survey in 1807; reestablished in 1832; renamed Coast and Geodetic Survey in 1878; abolished in early 1970’s The Coast and Geodetic Survey, moving far beyond its original assignment of making coastal navigation charts, was a research agency that became a world leader in geodesy. It developed and refined navigation and measurement techniques and did research in hy- drography and coastal geology. Background The U.S. Congress created the Coast and Geodetic Survey,initially known astheCoast Survey,early in the nineteenth century to survey the Atlantic coast of the United States and develop accurate charts for naviga- tion and shipping. Legislation in 1807, the Coast Sur- vey Act, first provided for surveying and mapping the nation’s coastline, but Congress failed to allocate ade- quate funding. As a result, little progress was made. In 1832, Congress authorized reestablishment of the Coast Survey. Lawmakers at the time intended for the Coast Survey to be a temporary agency: Funding 226 • Coast and Geodetic Survey, U.S. Global Resources would be provided only until the charts needed for safe navigation were completed, and then the Coast Survey would be dissolved. Under the leadershipofits early superintendents, however, the Coast Survey ex- panded its mission to include basic research into hydrography, topography, cartography, meteorology, coastal geology, and a wide range of other topics relat- ing to the physics of the Earth. By the time the Coast Survey completed charts of the Atlantic and, after the acquisition of Western territories, Pacific coastlines, the organization was so thoroughly established as a scientific agency that it became difficultforlegislators to argue against continued funding. In 1878, the agency’s name was changed to the Coast and Geo- detic Survey. Impact on Resource Use Over the course of the more than 150 years of the Coast and Geodetic Survey’s existence, the agency achieved numerous scientific and technical break- throughs. In the process of completing its original mission of creating navigation charts, the organiza- tion evolved into a scientific research agency that be- came a world leader in geodesy. It developed methods for use in triangulation, arc measurement, geodetic astronomy, determining longitude and latitude, and other aspects of measuring the Earth. The Coast and Geodetic Survey improved instruments used in sur- veying and navigation for determining position, dis- tance, angles,directions, andelevations,and it investi- gated the best methods to be used in reproducing maps. As part of its research in geodesy, the survey conducted methodical observations of solar eclipses. For the solar eclipse of August 7, 1869, for example, the survey stationed observation teams in Tennessee, Kentucky, Illinois, Iowa, and Alaska. Other astronomi- cal observations made atvarioustimes included study- ing the transit of theplanetsMercury and Venus. Mea- surements of the great arcs of the thirty-ninth parallel and the ninety-eighth meridian both provided a basis for the government surveys of the interior of the United States and suggested a more refined model of the shape of the Earth. In addition, the Coast and Geodetic Survey pio- neered research in tidal flows, hydrography, and oceanography. The organizationdetermined the best sites for lighthouses and navigation buoys and re- searched the history of names of prominent geo - graphic features for use on maps and charts. Minor functions of the Coast and Geodetic Survey included serving as the keeper of the nation’s standard weights and measures. Though the Coast and Geodetic Survey was even- tually dismantled, its research traditions continued in other agencies, such as the National Oceanic and Atmospheric Administration (NOAA), a scientific agency created as part of President Richard Nixon’s reorganization of the Department of Commerce in 1970. NOAA’s National Ocean Service, for example, prepares charts and monitors tidal activity. Nancy Farm Männikkö Web Sites U.S. Coast and Geodetic Survey National Geodetic Survey http://www.ngs.noaa.gov/ U.S. Coast and Geodetic Survey Office of Coast Survey http://www.nauticalcharts.noaa.gov/ See also: Landsat satellites and satellitetechnologies; National Oceanic and Atmospheric Administration; U.S. Geological Survey. Coastal engineering Category: Environment, conservation, and resource management Coastal engineering is the discipline that studies the natural and human-induced changes of the geomor- phology of the coastal zone. It also develops methods and techniques for protecting and enhancing the coastal environment. Definition Coastal engineering focuses on the special engineer- ing needs of the coastal environment. The discipline studies bothnaturaland anthropogenic effects (those caused by human activity) on the geometry and other physical characteristics of the coastal zone, which in- cludes riverine deltas, inlets, estuaries, bays, and la- goons. In the offshore direction, the activities of the coastal engineer are limited to the relatively shallow waters of the continental shelf. Global Resources Coastal engineering • 227 Overview Since the coastline serves as the boundary between the land and the ocean, the coastal engineer must un- derstand the dynamic interaction between water and sediments. Water dynamics involves the action of as- tronomical tides, tsunamis, storm surges, wind waves, and longshore currents. Water forces continuously change the shape of the coastline through sediment erosion and deposition. Episodic events such as hurri- canes may have a significant effect on the stability and integrity of a coastal system. Coastal engineers are mostly interested in sandy or muddy beaches, which are readily subject to sediment erosion. The weather- ing of rocky beaches to wave action is a slow process and is not of direct interest to coastal engineers. The coastline is an extremely dynamic system, sub - ject to short-term and long-term changes. Spatially these changes may be localized or may extend for great distances. Generally, if left undisturbed, the coast tends to develop its own defense systems against wave action through barrier islands and sand dunes. Any attempts by humans to regulate the shape of the coastline at a particular site may have adverse ef- fects on another site on the same coastline. Coastal engineers investigate wave and current forces and their impact on the shape of the coastline. For that purpose, coastal engineers collect and analyze field data and use physical models (applying determinis- tic or probabilistic analytical techniques) and com- puter models to simulate the wave and current cli- mate. These procedures can lead to predictions of the amount and fate of the transported sediments that cause accretion or erosion of the coastline. Coastal engineers also investigate techniques for protecting residential and industrial developments along the coast, maintaining recreational facilities 228 • Coastal engineering Global Resources One aspect of coastal engineering is the development and protection of coastal environments like this beach at Point Lobos, California. (©Joseph Salonis/Dreamstime.com) and beaches, and providing safe navigation through inlets and coastal waterways. Therefore, constructing structures such as jetties, breakwaters, groins, bulk- heads, marinas, and harbors falls within the domain of the coastal engineer. Beach nourishment and inlet dredging are also projectsundertaken by coastal engi- neers. In order to assess the prevailing hydrodynamic and sedimentological conditions of the coastal zone effi- ciently and effectively, engineers develop equipment and instrumentation for data collection of wave and current characteristics, suspended and bottom sedi- ments, and other supplementary information such as salinity andtemperature ofthe ambient water. Coastal engineers are also involved in the environmental as- pects of coastal waters. Estimation of the spread of an oil spill; the flashing capacity of a lagoon, finger ca- nals, oranyother protected waterbody;dissolved con- taminant advection and dispersion; and sediment contamination are all topics of interest to the coastal engineer. Panagiotis D. Scarlatos See also: Coastal Zone Management Act; Deltas; Ocean current energy; Ocean wave energy; Oceans; Salt; Sand and gravel; Tidal energy. Coastal Zone Management Act Categories: Laws and conventions; government and resources Date: Enacted October 27, 1972 The Coastal Zone Management Act provides a frame- work for protecting and developing the U.S. coastal zones. Achieving both protection and development de- pends on land management accompanied by land-use planning and land-use regulation and control. Background The Coastal Zone Management Act of 1972 was passed by Congress in order to establish “a national policy and develop a nationalprogram for the management, beneficial use, protection, and development of the land and water resources of the nation’s coastal zones, and for other purposes.” The coastal zones included in the act are those of the Atlantic and Pacific Oceans, the Gulf of Mexico, and the Great Lakes. The length of coastline involved is about 153,000 kilometers. The extensive nature of the coastal area of the United States means that thirty states and four territories— Puerto Rico, the Virgin Islands, Guam, and American Samoa—are eligible for coastal zone management as- sistance. The Coastal Zone Management Act was passed as a result of concern for the vulnerable nature of the coastal zones and their exposure to intensive develop- ment pressures. These pressures include recreation, fishing, agriculture, housing, transportation, and in- dustrial development. With more than half oftheU.S. population living within eighty kilometers of a coastal area, the pressuresare considerable. The act is admin- istered by the National Oceanic and Atmospheric Ad- ministration’s Office of Coastal Zone Management. The federal role consists of providing assistance to states asthey develop programstomanage the coastin a manner sufficient to deal with the problems arising from competing land uses. Provisions Federal assistance takes the form of both financial and technical aid. Paragraph (h) of section 302 of the act emphasizes the importance of a state’s role in ex- ercising its authority over the land and water re- sources of the coastal zone. Especially important in this exercise of authority is the encouragement of citizen involvement in the overall planning process. From the state perspective, such citizen participation has helped in the development of land-use planning guidelines relating to designation of the coastal zone areas, determination of land uses within the coastal zone, the identification of areas of particular con- cern, the identification of the ways by which the state will control land and water uses, and guidelines for es- tablishing the priority of uses. Impact on Resource Use Over the years, the Coastal Zone Management Act has been amended several times. In 1976, the states were given additional time and money for program devel- opment. Energy-related coastal development, provi- sions for access to public beaches, and increased agency cooperation were also part of the 1976 amend- ments. According to the Congressional Quarterly Alma- nac (1985), the reauthorization of the Coastal Zone Management Act in 1985 lowered the federal share of costs to be paid. Changes in 1990 gave the states more say over federal activities in offshore areas, espe - Global Resources Coastal Zone Management Act • 229 . Coal Global Resources of electricity. Industrial consumption of coal, particularly in the produc- tion of coke for the steel and iron manufacturing industry, is the sec- ond most important use. Globally,. relating to designation of the coastal zone areas, determination of land uses within the coastal zone, the identification of areas of particular con- cern, the identification of the ways by which. other 220 • Coal Global Resources schemes involving various parameters were intro - duced, including oxygen content, percent of residue remaining after the burning of coal, ratio of carbon to volatile