The sum total of our surroundings, including all of the living things and non-living things with which we interact.
The study of how the natural world functions and how humans and the environment interact.
Any of the various substances and energy sources we need in order to survive.
Renewable natural resources
A natural resource that is virtually unlimited or that is replenished by the environment over relatively short periods of hours to weeks to years.
Nonrenewable natural resources
A natural resource that is in limited supply and is formed much more slowly than we use it.
An essential service an ecosystem provides that supports life and makes economic activity possible. For example, ecosystems naturally purify air and water, cycle nutrients, provide for plants to be pollinated by animals, and serve as receptacles and recycling systems for the waste generated by our economic activity.
The shift around 10,000 years ago from a hunter-gatherer lifestyle to an agricultural way of life in which people began to grow their own crops and raise domestic animals.
The shift in the mid-1700s from rural life, animal-powered agriculture, and manufacturing by craftsmen to an urban society powered by fossil fuels such as coal and crude oil.
A nonrenewable natural resource such as crude oil, natural gas, or coal, produces by the decomposition and compression of organic matter from ancient life.
Tragedy of the commons
Because no single person owns a common area, no one has incentive to expend effort taking are of it, and everyone takes what he or she can until the resource is depleted.
The cumulative amount of land and water required to provide the raw materials a person or population consumes and to dispose of or recycle the waste that is produced.
The amount by which humanity has surpassed Earth’s long-term carrying capacity for our species.
An academic environmental science program that heavily incorporates the social sciences as well as the natural sciences.
A social movement dedicated to protecting the natural world.
A formalized method for testing ideas with observations that involves several assumptions and a more or less consisten series of interrelated steps.
A statement that attempts to explain a phenomenon or answer a scientific question.
A specific statement, generally arising from a hypothesis, that can be tested directly and unequivocally.
An activity designed to test the validity of a hypothesis by manipulating variables.
In an experiment, a condition that can change.
The variable that the scientist manipulates in a manipulative experiment.
The variable that is affected by manipulation of the independent variable.
An experiment in which the effects of all variables are held constant, except the one whose effect is being tested by comparison of treatment and control conditions.
The portion of an experiment in which a variable has been left unmanipulated to serve as a point of comparison with the treatment.
The portion of an experiment in which a variable has been manipulated in order to test its effect.
Information, generally qualitative information
An experiment in which the researcher actively chooses and manipulates the independent variable.
An experiment in which the researcher cannot directly manipulate the variables and therefore must observe nature, comparing conditions in which variables differ, and interpret the results.
A relationship among variables
The process by which a manuscript submitted for publication in an academic journal is examined by other specialists in the field, who provide comments and criticism generally anonymously and judge whether the work merits publication in the journal.
A widely accepted, well-tested explanation of one or more cause-and-effect relationships that has been extensively validated by a great amount of research.
A dominant philosophical and theoretical framework within a scientific discipline.
A guiding principle of environmental science that requires us to live in such a way as to maintain Earth’s systems and its natural resources for the foreseeable future.
The variety of life across all levels of biological organization, including the diversity of species, their genes, their populations, and their communities.
Millenium Ecosystem Assessment
The most comprehensive scientific assessment of the present condition of the world’s ecological systems and their ability to continue supporting our civilization. Prepared by over 2,000 of the world’s leading environmental scientists from nearly 100 nations, and completed in 2005
A worldview that we will find ways to make Earth’s natural resoureces meet all of our needs indefinitely and that human ingenuity will see us through any difficulty. In Greek mythology, cornucopia — literally “horn of plenty” — is the name for a magical goat’s horn that overflowed with grain, fruit, and flowers.
A worldview that predicts doom and disaster as a result of our environmental impacts. In Greek mythology, Cassandra was the princess of Troy with the gift of prophecy, whose dire predictions were not believed.
Development that satisfies our current needs without compromising the future availability of natural resources or our future quality of life.
Triple bottom line
An approach to sustainability that attempts to meet environmental, economic, and social goals simultaneously.
Renewable energy that is generated deep within Earth. The radioactive decay of elements amid the extremely high pressures and temperatures at depth generate heat that rises to the surface in magma and through fissures and cracks. Where this energy heats groundwater, natural eruptions of heated water and steam are sent up from below.
All material in the universe that has mass and occupies space.
The chemical element with eight protons and eight neutrons. A key element in the atmosphere that is produced by photosynthesis.
Law of conservation of matter
Physical law stating that matter may be transformed from one type of substance into others, but that it cannot be created or destroyed.
Hydrogen: The chemical element with 1 proton. The most abundant element in the universe. Also a possible fuel for our future economy.
A fundamental type of matter; a chemical substance with a given set of properties which cannot be broken down into substances with other properties. Chemists currently recognize 92 elements that occur in nature, as well as more than 20 others that have been artificially created.
The chemical element with seven protons and seven neutrons. The most abundant element in the atmosphere, a key element in macromolecules, and a crucial plant nutrient.
The chemical element with six protons and six neutrons. A key element in organic compounds.
The smallest component of an element that maintains the chemical properties of that element.
A positively charged particle in the nucleus of an atom.
An electrically neutral (uncharged) particle in the nucleus of an atom.
A negatively charged particle that surrounds the nucleus of an atom.
One of several forms of an element having differing numbers of neutrons in the nucleus of its atoms. Chemically, isotopes of an element behave almost identically, but they have different physical properties because they differ in mass.
The quality by which some isotopes “decay,” changing their chemical identity as they shed atomic particles and emit high-energy radiation.
The amount of time it takes for one half the atoms of a radioisotope to emit radiation and decay. Different radioisotopes have different half-lives, ranging from fractions of a second to billions of years.
An electrically charged atom or combination of atoms.
A combination of two or more atoms.
A molecule whose atoms are composed of two or more elements.
A colorless gas used by plants for photosynthesis, given off by respiration, and released by burning fossil fuels. A primary greenhouse gas whose buildup contributes to global climate change
A colorless gas produced primarily by anaerobic decomposition. The major constituent of natural gas, and a greenhouse gas that is molecule-for-molecule more potent than carbon dioxide.
A molecule consisting of three atoms of oxygen. Absorbs ultraviolet radiation in the stratosphere. Ozone layer.
The property of a solution in which the concentration of hydrogen ions is greater than the concentration of hydroxide (OH-) ions.
The property of a solution in which the concentration of hydroxide (OH-) ions is greater than the concentration of hydrogen ions.
A measure of the concentration of hydrogen ions in a solution. The pH scale ranges from 0 to 14: a solution with a pH of 7 is neutral, below 7 is acidic and above 7 is basic. Because the pH scale is logarithmic, each step on the scale represents a tenfold difference in hydrogen ion concentration.
A compound made up of carbon atoms ( and, generally, hydrogen atoms), joined by covalent bonds and sometimes including other elements, such as nitrogen, oxygen, sulfur, or phosphorus. The unusual ability of carbon to build elaborate molecules has resulted in millions of different organic compounds showing various degrees of complexity.
A chemical compound or mixture of compounds consisting of long chains of repeated molecules. Some polymers play key roles in the building blocks of life.
An organic compound consisting solely of hydrogen and carbon atoms.
A very large molecule, such as a protein, nucleic acid, carbohydrate, or lipid.
A macromolecule made up of long chains of amino acids.
A macromolecule that directs the production of proteins. Includes DNA and RNA.
Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)
DNA: A double-stranded nucleic acid composed of four nucleotides, each of which contains a sugar (deoxyribose), a phosphate group, and a nitrogenous base. DNA carries the hereditary information for living organisms and is responsible for passing traits. RNA: A single-stranded nucleic acid composed of four nucleotides, each contains a sugar (ribose) a phosphate group, and a nitrogenous base.
A stretch of DNA that represents a unit of hereditary information.
An organic compound consisting of atoms of carbon, hydrogen, and oxygen.
Synthetic human-made polymers used in numerous manufactured products.
the capacity to change the position, physical composition, or temperature of matter; a force that can accomplish work.
Energy of position.
Energy of motion.
First law of thermodynamics
Physical law stating that energy can change from one form to another but cannot be created or lost. The total energy in the universe remains constant and is said to be conserved.
Second law of thermodynamics
Physical law stating that the nature of energy tends to change from a more-ordered state to a less-ordered state; that is, entropy increases.
Energy conversion efficiency
Ratio of useful output of energy to the amount that we need to input
An organism that can use the energy from sunlight to produce its own food. Includes green plants, algae and cyanobacteria.
The process by which autotrophs produce their own food. Sunlight powers a series of chemical reactions that convert carbon dioxide and water into sugar (glucose) thus transforming low-quality energy from the sun into high-quality energy the organism can use.
The process by which a cell uses the chemical reactivity of oxygen to split glucose into its constituent parts, water and carbon dioxide, and thereby release chemical energy that can be used to form chemical bonds or to perform other tasks within the cell.
An organism that consumes other organisms. Includes most animals, as well as fungi and microbes that decompose organic matter.
Location in the deep ocean where heated water spurts from the sea-floor, carrying minerals that precipitate to form rocky structures. Unique and recently discovered ecosystems cluster around these vents; tubeworms, shrimp, and other creatures here use symbiotic bacteria to derive their energy from chemicals in the heated water rather than from sunlight.
The process by which bacteria in hydrothermal vents use the chemical energy of hydrogen sulfide to transform inorganic carbon into organic compounds.
The innermost part of the Earth, made up mostly of iron, that lies beneath the crust and mantle.
The malleable layer of rock that lies beneath Earth’s crust and surrounds a mostly iron core.
Especially soft rock, melted in some areas
The outer layer of Earth, consisting of crust and uppermost mantle, and located just above the asthenosphere. More generally, the solid part of the Earth, including the rocks, sediment, and soil at the surface and extending down many miles underground.
The lightweight outer layer of the Earth, consisting of rock that floats atop the malleable mantle, which in turn surrounds a mostly iron core.
The process by which Earth’s surface is shaped by the extremely slow movement of tectonic plates, or sections of crust. Earth’s surface includes about 15 major tectonic plates. Their interaction gives rise to processes that build mountains, cause earthquakes, and otherwise influence the landscape.
Divergent plate boundary
Area where tectonic plates push apart from one another as magma rises upward to the surface, creating new lithosphere as it cools and spreads. A prime example is the Mid-Atlantic Ridge.
Molten, liquid rock.
Transform plate boundary
Area where two tectonic plates meet and slip and grind alongside one another, creating earthquakes. For example, the Pacific Plate and the North American Plate rub against each other along California’s San Andreas Fault.
Convergent plate boundary
Area where tectonic plates converge or come together. Can result in subduction or continental collision.
The plate tectonic process by which denser crust slides beneath lighter crust at a convergent plate boundary. Often results in volcanism.
The meeting of two tectonic plates of continental lithosphere at a convergent plate boundary, wherein the continental crust on both sides resists subduction and instead crushes together, bending, buckling, and deforming layers of rock and forcing portions of the buckled crust upward, often creating mountain ranges.
The very slow process in which rocks and the minerals that make them up are heated, melted, cooled, broken, and reassembled, forming igneous, sedimentary, and metamorphic rocks.
A solid aggregation of minerals.
A naturally occurring solid element or inorganic compound with a crystal structure, a specific chemical composition, and distinct physical properties.
Magma that is released from the lithosphere and flows or spatters across Earth’s surface.
One of the three main categories of rock. Formed from cooling magma. Granite and basalt are examples of igneous rock.
Extrusive igneous rock
When molten rock is ejected from a volcano, it cools quickly so minerals have little time to grow into coarse crystals. Ex: basalt
The eroded remains of rock.
One of the three main categories of rock. Formed when dissolved minerals seep through sediment layers and act as a kind of glue, crystallizing and binding sediment particles together. Sandstones and shale are examples. Compaction, cementation, lithification
One of the three main categories of rock. Formed by great heat and/or pressure that reshapes crystals within the rock and changes its appearance and physical properties. Marble and slate.
A release of energy occurring as Earth relieves accumulated pressure between masses of lithosphere and which results in shaking at the surface.
A site where molten rock, hot gas, or ash erupt through Earth’s surface, often creating a mountain over time as cooled laval accumulates.
The collapse and down hill flow of large amounts of rock or soil. A severe and sudden form of mass wasting.
The downslope movement of soil and rock due to gravity.
An immense swell, or wave, of ocean water triggered by an earthquake, volcano, or landslide, that can travel long distances across oceans and inundate coasts.
A network of relationships among a group of parts, elements, or components that interact with and influence one another though the exchange of energy, matter and/or information.
A circular process in which a system’s output serves as input to that same system.
Negative feedback loop
A feedback loop in which output of one type acts as input that moves the system in the opposite direction. The input and output essentially neutralize each other’s effects, stabilizing the system.
Positive feedback loop
A feedback loop in which output of one type acts as input that moves the system in the same direction. The input and output drive the system further toward one extreme or another.
The tendency of a system to maintain constant or stable internal conditions.
A characteristic that is not evident in a system’s components.
The entire area of land from which water drains into a given river.
The process of nutrient enrichment, increased production of organic matter, and subsequent ecosystem degradation in a water body.
The thin layer of gases surrounding planet Earth.
All water — salt or fresh, liquid, ice, or vapor — in surface bodies, underground, and in the atmosphere.
The sum total of all the planet’s living organisms and the abiotic portions of the environment with which they interact.
All organisms and nonliving entities that occur and interact in a particular area at the same time.
Gross primary production
The enerfy that results when autotrophs convert solar energy to energy of chemical bonds in sugars through photosynthesis. Autotrophs use a portion of this production to power their own metabolism, which entails oxidizing organic compounds by cellular respiration.
Net primary production
The energy or biomass that remains in an ecosystem after autotrophs have metabolized enough for their own maintenance through cellular respiration. Net primary production is the energy or biomass available for consumption by heterotrophs.
The rate at which plants convert solar energy to biomass. Ecosystems whose plants convert solar energy to biomass rapidly are said to have high productivity.
Net primary productivity
The rate at which net primary production is produced.
An element or compound that organisms consume and require for survival. Macro and micro
Geographic information system
GIS — Computer software that take multiple types of data and overlays them on a common set of geographic coordinates. The idea is to create a complete picture of a landscape and to analyze how elements of the different datasets are arrayed spatially and how they may be correlated. A common took of geographers, landscape ecologists, etc.
A simplified representation of a complex natural process, designed by scientists to understand how the process occurs and to make predictions.
The practice of constructing and testing models that aim to explain and predict how ecological systems function.
An essential service an ecosystem provides that suports life and makes economic activity possible. For example, ecosystems naturally purify air and water, cycle nutrients, provide for plants to be pollinated by animals, and serve as receptacles and recycling systems for the waste generated by our economic activity.
The comprehensive set of cyclical pathways by which a given nutrient moves through the environment. Biogeochemical cycles
Pool or reservoir
A location in which nutrients in a biogeochemical cycle remain for a period of time before moving to another pool. Can be living or nonliving entities. Synonymous with reservoir.
In a biogeochemical cycle, the amount of time a nutrient remains in a given pool or reservoir before moving to another.
The movement of nutrients among pools or reservoirs in a nutrient cycle.
In a nutrient cycle, a pool that releases more nutrients than it accepts.
In a nutrient cycle, a pool that accepts more nutrients than it releases.
Hydrologic cycle, Water cycle
The flow of water — in liquid, solid, or gaseous forms — through our biotic and abiotic environment.
The conversion of a substance forma liquid to a gaseous form.
The release of water vapor by plants through their leaves.
Water that condenses out of the atmosphere and falls to Earth in droplets or crystals.
The water from precipitation that flows into streams, rivers, lakes, and ponds, and in many cases eventually into the ocean.
An underground water reservoir
Water held in aquifers underground.
The upper limit of groundwater held in an aquifer.
A major nutrient cycle consisting of the routes that carbon atoms take through the nested networks of environmental systems.
A major nutrient cycle consisting of the routes that nitrogen atoms take through the nested networks of environmental systems.
The process by which inert nitrogen gas combines with hydrogen to form ammonium ions which are chemically and biologically active and can be taken up by plants.
Bacteria that convert the nitrates in soil or water to gaseous nitrogen and release it back into the atmosphere.
A process to synthesize ammonia on an industrial scale. Developed by German chemists Haber and Bosch, the process has enable humans to double the natural rate of nitrogen fixation on Earth and thereby increase agricultural productivity, but it has also dramatically altered the nitrogen cycle.
Capitalist market economy
Centrally planned economies
Gross Domestic Product
Genuine Progress Indicator
A party that fails to invest in controlling pollution or carrying out other environmentally responsible activities and instead relies on the efforts of other parties to do so. A factory fails to control its emissions gets a free ride on the efforts of other factories that do make the sacrifices necessary to reduce emissions.
Principle specifying that the party responsible for producing pollution should pay the costs of cleaning up the pollution or mitigating its impacts.
A specific rule issued by an administrative agency, based on the more broadly written statutory law passed by Congress and enacted by the President.
The deprivation of a property’s owner, by means of a law or regulation, of most or all economic uses of that property.
National Environmental Policy Act
NEPA — A U.S. law enacted on January 1, 1970, that created an agency called the Council on Environmental Quality and required that an environmental impact statement be prepared for any major federal action.
Environmental Impact Statement
A report of results from detailed studies that assess the potential effects on the environment that would likely result from development projects or other actions undertaken by the government.
Environmental Protection Agency
An administrative agency created by executive order in 1970. The EPA is charged with conducting and evaluating research, monitoring environmental quality, setting standards, and enforcing those standards, assisting the states in meeting standards and goals, and educating the public.
A system of law addressing harm cause by one entity to another which operates primarily through lawsuits.
A levy on environmentally harmful activities and products aimed at providing a market-based incentive to correct for market failure.
The practice of buying and selling government issued marketable emissions permits to conduct environmentally harmful activities. Under a cap-and-trade system, the government determines an acceptable level of pollution and then issues permits to pollute. A company receives credit for amounts it does not emit and can then sell this credit to another company.
A permit-trading system for emissions in which a gov’t issues marketable emissions permits to conduct environmentally harmful activities. A company receives credit for amounts it does not emit and can sell this credit to other companies.
A permit trading system in which govt determines an acceptable level of pollution and then issues polluting parties permits to pollute. A company receives credit for amounts it does not emit and can then sell this credit to other companies.
A combined effort of government and a for-profit entity, generally intended to use the efficiency of the private sector to help achieve a public policy goal.
The expenditure of time or money in an attempt to influence an elected official.
The movement of powerful officials between the private sector and government agencies.
International law that arises from long-standing practices, or customs, held in common by most cultures.
International law that arises from conventions, or treaties, that nations agree to enter into.
Conventions or treaties
A treaty or binding agreement among national governments.
North American Free Trade Agreement
an agreement signed by the governments of Canada, Mexico, and the United States, creating a trilateral trade bloc in North America
Organization founded in 1945 to promote international peace and to cooperate in solving international economic, social, cultural, and humanitarian problems.
Institution founded in 1944 that serves as one of the globe’s largest sources of funding for economic development, including such major projects as dams, irrigation infrastructure, and other undertakings.
Political and economic organization formed after WWII to promote Europe’s economic and social progress. As of 2007 the EU consisted of 28 member nations.
World Trade Organization
Organization based in Geneva, Switzerland, that represents multinational corporations and promotes free trade by reducing obstacles to international commerce and enforcing fairness among nations in trading practices.
Water that is relatively pure, holding very few dissolved salts.
Water located atop Earth’s surface.
The region of land over which a river has historically wandered and periodically floods.
Littoral: The region ringing the edge of a water body. — Benthic: The bottom layer of a water body. — Limnetic: In a water body, the layer of open water through which sunlight penetrates
A system in which the soil is saturated with water and which generally features shallow standing water with amble vegetation. These biologically productive systems include freshwater marshes, swamps, bogs, and seasonal wetlands such as vernal pools.
Confined aquifer, Artesian aquifer
A water-bearing porous layer of rock, sand, or gravel that is trapped between an upper and lower layer of less permeable substrate, such as clay, The water in a confined aquifer is under pressure because it is trapped between to impermeable layers.
A water-bearing, porous layer of rock, sand, or gravel that lies atop a less-permeable substrate. Th water in an unconfined aquifer is not under pressure because there is no impermeable upper layer to confine it.
Shelf: The gently sloping underwater edge of a continent, varying in width from 100 m to 1,300 km with an average slope of 1.9 m/km. Continental slope; the portion of the ocean floor that angles somewhat steeply downward connecting the continental shelf to the deep ocean basin below. Then Shelf slope break, continental slope, continental rise, oceanic ridge
The zone of the ocean beneath the surface in which density increases rapidly with depth. Temperature decreases.
The flow of a liquid or gas in a certain direction.
In the ocean, the flow of cold, deep water toward the surface. Upwelling occurs in areas where surface currents diverge.
In the ocean, the flow of warm surface water toward the ocean floor. Downwelling occurs where surface currents converge.
A worldwide system of ocean currents in which warmer, fresher water moves along the surface and colder, saltier water (which is more dense) moves deep beneath the surface.
El Nino-Southern Oscillation
A systematic shift in atmospheric pressure, sea surface temperature, and ocean circulation in the tropical Pacific ocean. ENSO cycles give rise to El Nino and La Nina conditions.
El Nino/La Nina
El Nino – The exceptionally strong warming of the Eastern Pacific Ocean that occurs every 2-7 years and depresses local fish and bird populations by altering the marine food web in the area. La Nina – An exceptionally strong cooling of surface water in the equatorial Pacific Ocean that occurs every 2-7 years and has widespread climatic consequences,
The process by which today’s oceans are becoming more acidic as a result of increased carbon dioxide concentrations in the atmosphere. Occurs as ocean water absorbs CO2 form the air and forms carbonic acid. Threatens to dissolve coral reefs.
In the ocean or a freshwater body, the well-lit top layer of water where photosynthesis occurs.
Of, relating to, or living between the surface and floor of the ocean.
Of, relating to, or living on the bottom of a water body.
A mass of calcium carbonate composed of the skeletons of tiny colonial marine organisms called corals.
Intertidal, or littoral
Of, relating to, or living along shorelines between the highest reach of the highest tide and the lowest reach of the lowest tide.
The periodic rise and fall of the ocean’s height at a given location, caused by the gravitational pull of the moon and sun.
Flat land that is intermittently flooded by the ocean where the tide reaches inland. Salt marshes occur along temperate coastlines and are thickly vegetated with grasses, rushes, shrubs, and other herbaceous plants.
A tree with a unique type of roots that curve upward to obtain oxygen, which is lacking in the mud in which they grow, and that serve as stilts to support the tree in changing water levels. Grow on the coastlines of tropics and subtropics.
An area where a river flows into the ocean, mixing fresh water with salt water.
The bottommost layer of the atmosphere; it extends to 11 km above sea level.
The layer of the atmosphere above the troposphere and below the mesosphere. Extends from 11 km – 50 km above sea level.
A portion of the stratosphere roughly 17-30 km above sea level, that contains most of the ozone in the atmosphere.
The atmospheric layer above the stratosphere, extending 50-80 km above sea level.
The atmosphere’s top layer, extending upward to an altitude of 500 km
The weight per unit area produced by a column of air.
The ratio of the water vapor contained in a given volume of air to the maximum amount the air could contain, for a given temperature.
A circular current (of air, water, magma, etc.) driven by temperature differences. In the atmosphere, warm air rises into regions of lower atmospheric pressure, where it expands and cools and then descends and becomes denser, replacing warm air that is rising. The air picks up heat and moisture near ground level and prepares to rise again, continuing the process.
The local physical properties of the troposphere, such as temperature, pressure, humidity, cloudiness, and wind, over relatively short time periods.
The pattern of atmospheric conditions found across large geographic regions over long periods of time.
The boundary between air masses that differ in temperature and moisture (and therefore density).
The boundary where a mass of warm air displaces a mass of colder air.
The boundary where a mass of cold air displaces a mass of warmer air.
An air mass with elevated atmospheric pressure, containing air that descends, typically bringing fair weather.
An air mass in which the air moves toward the low atmospheric pressure at the center of the system and spirals upward, typically bringing clouds and precipitation.
Temperature (thermal) inversion
A departure from the normal temperature distribution in the atmosphere in which a pocket of relatively cold air occurs near the ground, with warmer air above it. The cold air, denser than the air above it, traps pollutants near the ground and causes a buildup of smog.
In a temperature inversion, the band of air in which temperature rises with altitude (instead of falling with altitude, as temperature does normally).
One of a pair of cells of convective circulation between the equator and 30 degrees north and south latitude that influence global climate patterns.
One of a pair of cells of convective circulation between 30-60 degrees north and south latitude that influence global climate patterns.
One of a pair of cells of convective circulation between the poles and 60 degrees north and south latitude that influence global climate patterns.
The apparent deflection of north-south air currents to a partly east-west direction, caused by the faster spin of regions near the equator than of regions near the poles as a result of Earth’s rotation.
A cyclonic storm that forms over the ocean but can do damage upon its arrival on land. A type of cyclone or typhoon that usually forms over the Atlantic Ocean.
A type of cyclonic storm in which funnel clouds pick up soil and objects and can do great damage to structures.