The study of how the component parts of a system interact and contribute to the functioning of the system. …
A curve that describes logistic growth in a population, so‐called because of its shape. Contrast J‐curve. …
A type of seismic wave, created by an earthquake, that causes shear stress in the material it moves through. Also known as a secondary wave or shear wave . Contrast p‐wave. …
A specialized group of segments in the body of an arthropod. …
The fusion of individual segments to form a body wall, which occurs in some insects. …
Rock and other waste materials that are separated from crushed ore in the mining process. …
The exhaust pipe through which gases from an engine (for example in a motor vehicle) are released into the air. …
Emission gas limitations that are applicable to the exhausts of mobile source engines. …
The surface water that drains from the lower end of an irrigated field. …
1 The abstraction of water from surface water or groundwater. 2 A North American term meaning to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect any wild species. …
A North American term for government appropriation of private property or property rights, without compensation. …
The name of a katabatic wind in southeastern Alaska. …
A North American prairiegrassland vegetation dominated by grasses (such as big bluestem, Andropogon gerardii ) that are tall and that flourish with abundant moisture. This type of grassland originally covered portions of 14 states from Texas to Minnesota, but more than 90% of it has been lost to urban sprawl and converted to cropland. …
A type of prairie that grows in areas that receive more than 50 centimetres of precipitation per year and have loamy or clay‐based soils. …
A North American approach to the reduction of air pollution, by using tall stacks (chimneys) which release gas emissions into the atmosphere, from which they are dispersed by wind. …
Angular rock debris (scree) at the base of a cliff. …
A naturally occurring substance that is found in the skins, seeds, and stems of grapes, or sometimes in oak barrels, that gives red wine its dry, slightly bitter taste. …
The main root of a plant that grows vertically downwards into the soil until it reaches either an impenetrable layer or a layer that lacks oxygen or moisture. …
Drinking water that comes directly from a tap, usually in a home. See also potable water. …
The area at which an application of agrochemicals (such as an insecticide or pesticide) is targeted. …
The desired or threshold value of an environmental indicator, defined in terms of human health, safety, and environmental quality. …
The intended catch of a fishery. Contrast bycatch. …
A sedimentary deposit that consists of a mixture of clay, sand, water, and a tar‐like heavy oil (bitumen), which can be extracted by heating, and can then be refined to produce synthetic crude oil. …
A group of organisms that are regarded as distinct enough to be treated as a separate unit. The plural of taxon is taxa. …
The science of naming and classifying organisms into systematic groups (taxa) based on shared characteristics and natural relationships. There are seven levels of classification in a hierarchy, with kingdom at the top, followed by phylum, class, order, family, genus, and species. A branch of systematics. See also Linnaean classification. …
US legislation that authorized the Secretary of the Interior to establish grazing districts from unreserved public domain lands, and to make rules and regulations for their occupancy and use. …
See Transportation Equity Act for the 21st Century. …
A type of insecticide that works by accelerating the moulting process, and is used to control larval insects (butterflies and moths) in apple orchards. …
Based on technology and science, or reflecting trust in science. Contrast anthropocentric, ecocentric. …
The control or strong influence of society and government by people with well‐developed technical skills, particularly scientists and engineers. …
A disaster that is caused by non‐natural causes, including biological, chemical, nuclear and transport disasters, and terrorism. Also known as man‐made disaster . Contrast natural disaster. …
A hazard created by people, as opposed to a natural hazard. Examples include the release of air pollutants such as CFCs, serious industrial accidents such as oil spills at sea and explosions at nuclear power stations and toxic chemical plants, and the creation of waste materials (such as nuclear wastes) that are toxic and persistent and which natural environmental systems are incapable of breaking…
The view that if we can do something, we should do it, such as generating energy from nuclear power, even if it has many risks and unknowns associated with it …
The application of scientific processes, methods, or knowledge to produce goods and services that people consider useful. …
The process of transferring scientific findings from research laboratories into useful products by the commercial sector. …
Reliance on engineering and technology to find solutions to major human problems, including environmental problems. …
Relating to the deformation of rocks in the Earth's crust. …
Geological forces that buckle, distort, and fracture the Earth's crust, including warping, folding, faulting, and volcanic activity. …
The study of the large‐scale movements of rocks in the Earth's crust, including diastrophism, orogenesis, and plate tectonics. …
A linkage between changes in ocean and atmosphere circulations in widely separated parts of the globe, through which weather patterns in one region influence the weather patterns in a distant place. The best known example is the El Ni?o/Southern Oscillation. See also butterfly effect. …
Sending and receiving data over long distance communication links, such as satellite or telephone. …
Relating to the mid‐latitude area of the Earth's surface, between the tropics (23.5?) and the polar circles (66.5?) in both hemispheres. …
A mid‐latitudeclimate with mild temperatures and moderate levels of rainfall, both of which vary from season to season. …
A mid‐latitudedesertbiome that is hot in the summer and cool in the winter, such as the Mojave Desert in the USA. …
A biome that is characterized by deciduousbroadleaved trees, which includes humid continental mixed forest and marine west coast forest. …
A grasslandbiome that is found in the warm climates of the continental interiors, such as the prairie of North America, pampas of South America, veld of South Africa, and steppe of Eurasia. …
A type of rainforestbiome that is found in the mid‐latitude zone, such as the cool, dense, rainy forest of the northern Pacific coast of North America, which is dominated by large coniferous trees. …
A measure of the heat content of an object or substance, described using a number of different scales, particularly the commonly used Fahrenheit and Celsius scales, and the Kelvin scale (which is used by scientists). …
A layer of the atmosphere in which air temperature increases with height, a reversal of the normal pattern. …
An agency established by the US Congress in 1933 to assist in the development of the Tennessee River and adjacent areas. …
A force or stress that causes stretching, for example of glacier ice as it passes over a rock step, or of crustal rocks stretched by tectonic activity. Contrast compression, shear. …
Volcanic ash and dust that is thrown out into the air during an explosive volcanic eruption. …
The study of layers of volcanic ash (tephra) to determine their relative ages or absolute ages. …
A chemical substance or other factor (such as radiation) that alters the formation of cells, tissues, and organs, which causes abnormal development of an embryo and thus birth defects. See also carcinogen, mutagen. …
1 The period of time in which a mammal completes gestation; from conception to birth. 2 The period of time during which a contract (such as the Kyoto Protocol) is in force. …
The genetic engineering of plants to produce sterile seeds, which makes it impossible for farmers to save and replant seeds from their harvest and makes them reliant on the commercial seed market. See also traitor technology. …
A satelliteremote sensing system that was launched by NASA in 1999 , which circled the Earth 16 times a day for the following six years in a polar orbit, and sent back information on how the oceans, continents, and atmosphere interact. Its sensors could scan the entire planet every one to two days. …
1 A relatively flat, natural surface along a river valley, above the level of the floodplain. 2 An artificial flat surface constructed on sloping ground in order to produce land for growing crops and to reduce soil erosion. …
Construction of a series of horizontal levels built on a hillside, in order to retain water and reduce soil erosion. …
The natural surface features of an area of land, particularly the landforms. …
The collection, analysis, evaluation, and interpretation of information on the features of the terrain in a particular place, such as slope, aspect, and relief. …
A region of the Earth's crust, usually defined by major fault systems, in which the geology differs significantly from that of surrounding regions. …
A box, usually made of glass, which is used for the keeping and observation of small animals or plants. …
Any land‐based ecosystem, such as a forest, desert, grassland, or cropland. …
Longwave electromagneticradiation that is emitted by the Earth back into the atmosphere, in contrast to the shortwave radiation that is emitted by the Sun. …
The behaviour of an animal defending its territory against others of its own kind. …
The defence of a given area (territory), in order to partially or totally exclude others from it. …
A zone of the high seas adjacent to each coastal state, that is generally either 5.6 or 22 kilometres wide, was established by the Convention on the Territorial Sea and Contiguous Zone, and within which the state has sovereignty over air space, water, and the sea‐bed. …
1 A specific area of the Earth's surface over which a state exercises sovereignty. 2 The area in which an animal lives and which it defends against intruders, which is usually smaller than its home range. …
Using acts or threats of violence to civilians, for example as a political weapon to draw attention to a group's goals or to gain those goals through fear and intimidation. …
The top carnivore, which occupies the top of a food chain because it eats herbivores and carnivores. …
Service activities, such as trade and transport. Contrast primary economic activities, secondary economic activities. …
In geological history, the first period of the Cenozoic era, which began 65 million years ago and ended 2.5 million years ago. It is subdivided into the Palaeocene, Eocene, Oligocene, Miocene, and Pliocene. During the Tertiary period the continents, climatic zones, and vegetation zones assumed their present positions and animal life began to assume forms (particularly mammals) that were similar to…
The amount of new biomass (weight) that is produced by meat‐eating animals (carnivores) in a given period of time. Contrast primary productivity, secondary productivity. …
That part of the economy that produces services and information. …
The sea that geologists believe lay between Laurasia and Gondwanaland in the original landmass Pangaea, probably between 200 and 250 million years ago. See also continental drift. …
The characteristics of the particles of an individual rock, including grain size, size variability, degree of rounding or angularity, and preferred orientation. …
The line of deepest water in a stream channel as seen from above, where the water usually flows fastest. …
Plant stalks (straw, reeds, or even living grass) that are used as roofing material. …
A remote sensing device that is found on Landsatsatellites, which scans images of the Earth's surface in seven spectral bands from visible to thermal infrared, with a spatial resolution of about 30 metres. …
Based on theory or speculation, rather than on observation, experiment, or empirical testing. …
A coherent explanation or description, reasoned from known facts. See also hypothesis. …
1 Relating to or caused by heat. 2 A small rising column of air occurring as a result of surface heating, which allows a glider to rise and fly in the sky. …
A measure of the capacity of a material (such as a rock) to transfer heat by direct contact. …
Cover (such as shade beneath trees) that is used by animals to lessen the adverse effects of weather. …
In climate change, the potential long time lag before ocean warming affects global warming. …
A condition that exists between two objects when they have reached the same temperature, so that heat energy ceases to flow between them. …
Expansion (for example of the volume of air) caused by an increase in temperature. …
A plume of hot water that is discharged into a stream or lake by a source of heat, such as a power plant. …
Artificially raising or lowering the temperature of a waterbody in a way that damages aquatic organisms or water quality. Also known as thermal enrichment . …
A nuclear reactor in which the fissionchain reaction is sustained mainly by slow (thermal) neutrons. …
The stratification of layers of water of different temperature and density within a deep waterbody. …
The use of heat to treat hazardous waste by changing its chemical, physical, or biological character or composition, for example by incineration. …
A resistor with a resistance that changes with temperature, and which can be used as a temperature sensor. …
The study of heat and energy flow in chemical reactions. …
A physical law that states that energy is conserved; it is neither created nor destroyed under normal conditions. Also known as the law of conservation of energy . See also thermodynamics, second law of. …
A physical law that states that less energy is available to do work with each successive energy transfer or transformation in a system. See also thermodynamics, first law. …
An instrument that measures and records variations in air temperature through time. See also thermometer. …
Relating to density currents in the ocean, associated with the combined effects of temperature and salinity. …
Large‐scale vertical motions of water in the ocean which are driven by density differences caused by variations in temperature and salinity. …
A low‐relief landscape dominated by irregular shallow depressions caused by selective thawing of ground ice (permafrost). …
An instrument that is used to measure temperature, using either the Fahrenheit or Celsius scale. See also thermograph. …
A nuclear reaction that is self‐sustaining and is triggered by the fusion of light nuclei under very high temperatures, which releases a large amount of heat. The basis of a nuclear bomb. …
The top of the atmosphere; a transitional layer between the thermosphere (where temperature increases with height) and the exosphere. Its height above the ground varies between about 200 and 500 kilometres depending on solar activity. …
The top layer within the upper atmosphere that lies above the mesosphere and extends to about 350 kilometres above the ground, where the air is very thin, temperature increases with altitude, and temperature may be as high as 1100?C. …
A dense growth of bushes or trees. See also brush. …
A group of individuals who seek collectively to generate new ideas or approaches to solving particular problems. Examples of US environmental think‐tanks include the Cato Institute, the Heartland Institute, and the Heritage Foundation. …
The act of removing some of the plants from a crop, or immature trees from a forest, in order to improve the growth of the remainder. Also known as thinning out . See also line thinning, mechanical thinning, selective thinning. …
A group of countries that committed themselves to reduce their emissions of sulphur dioxide by 30% between 1980 and 1993 in order to reduce the problem of acid deposition. …
US writer and social critic ( 1817 ? 62 ) who is best known for the book Walden ( 1854 ), an account of his experiment in simple living, and for the essay Civil Disobedience ( 1849 ), which outlined a doctrine of passive resistance that was subsequently to influence the views of Mahatma Gandhi and Martin Luther King Jr. …
A naturally occurring radioactive metal that is found at very low levels in soil, rocks, and water. It is a soft, ductile, silver‐grey, heavy metallic element which has a radioactiveisotope, thorium‐232, with a half‐life of 14 million years. …
A deciduous forest of small thorny trees which grows in a tropicalsemi‐arid climate. …
A dry, open woodland or shrubland that is dominated by sparse, spiny shrubs. …
A species or community that is likely to become endangered if limiting factors are not reversed. Contrast endangered, extinct, extirpation, vulnerable species. …
A category of species under threat, developed as IUCN (Red Data Book) Conservation Categories, and widely used around the world. The categories within this group are extinct, endangered, vulnerable, rare, and indeterminate. …
A major engineering project along the Yangtze River in China to build the world's largest hydroelectricdam. The dam was designed as part of a large multipurpose water resource project, designed to achieve four main goals, namely flood control (to prevent flooding along the densely populated middle and lower reaches of the Yangtze), energy generation (to generate the large amounts of electricity ne…
A narrow island in the middle of the Susquehanna River near Harrisburg, Pennsylvania, USA, which is also the site of a nuclear accident at the Three Mile Island Nuclear Generating Station on 28 March 1979 , when one of the nuclear reactors suffered a partial core meltdown. …
Common term for three methods of waste management, which are reduce, reuse, and recycle. …
A fixed value (such as the concentration of a particular pollutant) at which an abrupt change in the behaviour of a system is observed. …
The minimum dose of a substance that will produce a measurable effect. …
The concentration or amount of a particular substance or condition below which it cannot be detected, or below which a significant adverse effect is not expected. …
The concentration of a particular substance (such as an air pollutant) to which most workers can be exposed without adverse health effects. …
The flow velocity (of wind or water) that is needed to cause sediment to start to move. …
The precipitation that falls directly through vegetation to the ground surface below, and that which falls off leaves after interception. …
Water (soil moisture) that moves downslope within a soil, along impermeablesoil horizons. Contrast interflow. …
Output relative to input; the amount that passes through a system from input to output. …
A vertical displacement fault associated with low‐angle fault planes. …
The loud cracking or deep rumbling noise that is usually heard a short time after a lightning strike within a thunderstorm, and is generated by a shock wave caused by the rapid and violent expansion of atmospheric gases when they are suddenly heated (to perhaps 15?000?C) by lightning. The delay between seeing the lightning and hearing the thunder increases with distance, generally by about one sec…
The dark, towering, thick, flat‐topped cumulonimbus clouds associated with thunderstorms, caused by strong updraft. …
A storm that results from strong rising air currents, which brings heavy rain or hail, and thunder and lightning. See also air mass thunderstorm, frontal thunderstorm. …
The cyclical rise and fall of the water level in confined coastal areas (such as estuaries and inlets) that is caused by the tide. Each tidal current lasts for about six hours 12 minutes, which corresponds to the two phases of high water and low water each lunar day. Also known as tidal stream . See also flood current, ebb current, slack water. …
The 14 day period from one spring tide to the next spring tide, or from one neap tide to the next neap tide. Also known as the tidal period . …
A broad, flat coastal wetland of muddy, marshy, or sandy sediment, which is covered and uncovered in each tidal cycle. Also known as tidal marsh . …
Energy that is generated by using the motion of the tides to drive water turbines that run electricity generators. Most tidal power schemes are based on barrages, usually across natural inlets. The reservoir is filled with water as the tide rises and the sluice gates are shut at high tide. As the tide falls water drains out from the reservoir. In traditional systems as the water rushed out it turn…
A hydroelectric plant that exploits the rise and fall of tides to drive turbines to generate electricity using tidal power. Also known as tidal station . …
The difference in height between successive high and low tides at a particular place, which varies through time because of the solar tides. …
An unusually high destructive water level along the shore, usually caused by a storm surge. The term is often, but incorrectly, applied to a tsunami. …
Any saltwater or freshwaterwetland that is influenced by the cyclical movements of tidal waters. …
The cyclical rising and falling of the water of the oceans that occurs twice each day and results from the gravitational attraction of the Moon and Sun acting on the rotating Earth. See also tidal current, tidal cycle, tidal range. …
A perforated pipe (often made of plastic, concrete, or pottery) that is buried in soil in order to drain off excess water. …
The cultivation of land, particularly through ploughing, preparing the soil for sowing and raising crops, and weeding. See also conservation tillage. …
The alignment of elongated pebbles within boulder clay, which gives an indication of the direction in which the ice was moving when the sediment was deposited. …
An extensive, relatively flat or gently undulating land surface covered by boulder clay, which was deposited by a retreating glacier. …
The physical condition of a soil that determines its suitability for plant growth, and depends upon texture, structure, consistency, and the amount of pore space. …
1 A general term for forests or other clusters of trees. 2 Wood or wood products that are used for construction. Also known as lumber . …
Forestland that produces or is capable of producing crops of industrial wood. Previously known as commercial forestland. …
A community (stand) of trees of similar species, size, and age. …
The time it takes for groundwater to move a given horizontal distance. …
The division of geological history into eras, periods, and epochs, usually on the basis of stratigraphy and palaeontology. …
A region across which clocks are set to the same time. The 360? circumference of the Earth is divided into 24 time zones on the basis of longitude, each one roughly 15? wide and defined as one hour different from the adjacent time zone. The International Date Line marks the cross‐over from one day to the next. …
A particular form of land use zoning that allowing a particular activity in a particular place only for a defined period of time, after which it becomes illegal. …
A technique that is used to grow body tissue of a plant or animal outside the body ( in vitro ) in a culture medium, for example in test tubes. …
A lightweight non‐ferrous metal element that is very strong, non‐reactive and does not cause allergic reactions in humans. …
Any of various semiaquatic and terrestrial amphibians that have stout bodies, dry skin, no tail, and long back limbs for leaping. Contrast frog. …
The amount of soil that can be lost by accelerated erosion over 100 years without significant or permanent reduction of soil productivity. …
The ability of an organism to survive exposure to potentially harmful amounts of a substance without showing an adverse effect. …
The limit to which an organism can withstand changes in the environment (such as exposure to a potentially harmful pollutant). See also limiting factor. …
Not sensitive to adverse environmental conditions (such as shade or drought) and thus able to withstand them. Contrast intolerant. …
A colourless, flammable liquid that is derived from petroleum or coal tar, and is used as a solvent for gums and lacquers and in high‐octane fuels. See also trinitrotoluene. …
A coastal depositional landform (bar) that grows by longshore drift to join a small island with another island, or with the mainland. …
The creature occupying the highest trophic level in a food web (such as a lion). It is generally not consumed by other organisms whilst it is alive. …
A map that shows the topography of an area, usually by means of contour lines. …
The character of the surface of an area, particularly its relief and the position of its features. …
The upper layer within a soil profile (comprising the A‐horizon and B‐horizon), which normally contains organic matter, in which plants grow. …
A rocky outcrop or hill. The distinctive granite tors on Dartmoor in Devon, England are believed to have been formed by the chemical decomposition of granite under tropical climates during the Tertiary period. …
A ten‐point scale for assessing the risk of an asteroid or comet hitting the Earth; the higher the Torino value the greater the risk. The scale is given in Appendix 6. …
A violent storm with extremely high wind speeds in the form of a rapidly rotating column of air. Tornadoes can form when warm, humid air is sucked into a low pressure cell, where it comes into contact with a cold front moving towards it from the opposite direction. Also known as cyclone or twister . …
A news bulletin (warning) that is issued to warn the public and emergency and other agencies when a tornado is forecast or is occurring. …
A news bulletin (watch) announcing that atmospheric conditions are favourable for producing tornadoes. Contrast tornado warning. …
1 A very fast‐moving stream of water. 2 A heavy downpour of rain that may cause flooding. …
A large oil tanker that sank and broke apart off southwest England in 1967 and caused a large oil spill that polluted the sea, coastline, and marine food chain. …
The amount of dissolved substances (such as salts or minerals) in a sample of water, which reflects salinity and is measured by electrical conductivity. Also known as dissolved solids . …
The overall economic value of a particular natural resource, taking into account both use and non‐use values. …
A measure of fertility, based on the average number of children in a family. See also replacement‐level fertility. …
The net rate of growth of a particular population, which results from births, deaths, immigration, and emigration. …
A North American term for the amount of a particular pollutant that a waterbody can receive and still meet water quality standards. …
A small NASA spacecraft that makes global measurements of atmospheric ozone on a daily basis. …
An approach to management that focuses on achieving a high quality product and customer satisfaction. …
An approach to natural resource management in which all resources are managed as a whole, responsibly, and on a sustainable basis. Also known as stewardship management . …
All of the organic and inorganic matter that is suspended or dissolved in water. …
The particulate matter that is present in the air at a given place and time. …
A measure of the amount of suspended solids that is present in wastewater, effluent, or a waterbody, which can usually be removed by filtration. …
A tall cumulus cloud that extends through low and middle cloud levels, but lacks the characteristic anvil‐shaped top of a cumulonimbus. …
An urban settlement with a fixed boundary that is smaller than a city. The threshold size for distinguishing between a town and a city varies from country to country. …
An insecticide that was developed as a substitute for DDT. It causes adverse health effects their presenting in domestic water supplies, and is toxic to freshwater and marine aquatic life. It is a critical pollutant whose use is now restricted in North America. …
Any poison or toxic substance that may injure an organism exposed to it. See also toxin. …
A chemical that can cause severe illness, poisoning, birth defects, disease, or death when ingested, inhaled, or absorbed by living organisms, even at low doses. …
A plume of gases, vapours, fumes, or aerosols in the air, which contains toxic materials. …
General name for the export, usually by shipping, of toxic wastes to a weaker or poorer nation. …
The concentration at which a particular substance produces a toxic effect. …
The dose level at which a particular substance produces a toxic effect. …
The release of toxic materials into the air or water or onto the land. …
The degree to which a particular substance is harmful or poisonous. See also acute toxicity, chronic toxicity. …
The process of defining the nature of injuries that may be caused to an organism by exposure to a given toxic substance, and how these are affected by the time and concentration of exposure. …
A controlled laboratory test to determine the toxicity of a substance, using living organisms. …
An environmental disaster caused by the large‐scale, accidental release of a toxic substance into the air, soil, or water, which damages organisms and environmental systems. …
The detailed analysis and description of a toxic substance in order to determine safe levels of exposure. …
The study of the effects of poisons or toxic substances on living organisms. …
Any pollutant that is listed as toxic by a national agency, usually because it can cause death, disease, or birth defects in organisms that ingest or absorb it. …
A database of toxic releases in the USA which is compiled from SARA reports. …
