Jet stream: High-speed winds that race around the planet at about five miles above the Earth.
Jetty: Structure built out into the sea, a lake, or a river to protect the harbor or shore against waves or tides.
Karst: Landscape with caverns, sinkholes, underground streams, and springs created by erosion of limestone rock layers by groundwater.
Kayak: Boat that is pointed at both ends and has a closed deck except for a small hole where the paddler sits.
Kettle: Round depression left in glacial sediment after melting of a buried block of ice; it forms lakes and ponds when filled with water.
Kettle pond: Small round pond that forms when a melting glacier leaves chunks of ice buried in its deposits.
Lagoon: A shallow body of water that is separated from the sea by a reef or narrow island.
Lake overturn: Mixing of lake waters from temperatures causing changes in the water layers’ density.
Land bridge: Strip of dry land that connects islands or continents when it is exposed by lowered sea level during glacial periods.
Latitude: Imaginary lines that tell how far north or south a place is from the equator.
Lava: Hot, liquid rock that reaches the Earth’s surface through a volcano or opening in Earth’s crust.
Leachate: An acidic wastewater that contains contaminants from decomposed materials in a landfill.
Lentic: Relating to waters that are moving, like in rivers and streams.
Levee: A natural or man-made wall along the banks of a stream channel that helps confine floodwaters within the channel.
Limnology: Study of the ecology of continental surface waters including lakes, rivers, wetlands, and estuaries.
Liner: A sheet of plastic or other material that is put on top of clay on the inside of a landfill to prevent material from leaking out of the landfill.
Lithosphere: Rocky outer shell of Earth that is broken into large, rigid pieces called plates.
Littoral zone: Shallow, sunlit zone along lake shores where rooted plants grow.
Lock: One in a series of gates that allows boats or ships to pass through multiple water levels.
Longshore current: Near-shore current that runs parallel to a coastline.
Lotic: Relating to waters that are stationary, like in ponds and lakes.
Macroplankton: Plankton large enough to be seen by the naked eye, including larval forms of jellyfish and some species of crustaceans.
Magnetometer: Used in marine archaeology to locate shipwrecks by finding metal objects used in the ship’s construction such as nails, brackets, decorative ironwork, or artillery.
Malacostraca: A class of marine invertebrates that includes shrimp, lobsters, crabs, and euphausids.
Mammal: A vertebrate that nurses its young with milk, breathes air, has hair at some point in its life, and is warmblooded.
Mariculture: Farming of marine animals and aquatic plants in a controlled marine environment.
Marine biology: Study of life in the ocean.
Marine geology: Study of the formation and structure of underwater land and rock formation.
Marine Mammal Protection Act: Law that seeks to increase the population of marine mammal species by prohibiting the hunting, capture, or killing of marine mammals.
Marsh: Wetland dominated by grasses, reeds, and sedges.
Meandering stream: A stream with a channel that follows a twisting path of curves and bends.
Mesopelagic zone: The layer of the ocean below the epipelag-ic zone and above the bathypelagic zone; generally it extends from about 500 feet (150 meters) to about 3,250 feet (1,000 meters).
Metabolic rate: The rate at which the biochemical processes occur in an organism.
Metal: Substance that is a conductor of electricity and heat.
Meteorology: The science of atmospheric conditions and phenomena.
Mid-ocean ridge: A continuous chain of low, symmetrical volcanoes that extends through all the ocean basins.
Milankovitch cycles: Predictable changes in Earth’s average temperature that are caused by changes in Earth’s position relative to the Sun.
Mines: Explosive devices that usually explode when an object makes contact with them; sea mines usually float on or just below the surface.
Molecule: A group of atoms arranged to interact in a particular way; the smallest part of a substance that has the qualities of that substance.
Mollusk: A member of a group of invertebrates that includes the snails, clams, oysters, scallops, mussels, squid, and octopuses.
Monsoon: A wind from the southwest that brings heavy rainfall to India and other parts of southern Asia during the summer.
Moraine: A ridge formed by the unsorted gravel, sand, and rock pushed by a glacier and deposited at the outer edge, or front, of the glacier.
Mousse: A water-in-oil emulsion that is formed by turbulence of the surface water after a petroleum spill to the aquatic environment.
Municipality: A village, town, or city with its own local government that provides services for its residents.
National Weather Service: Government agency that predicts the weather and warns the public of dangerous weather situations and their consequences, including severe weather and flood warnings.
Native species: A species naturally occurring in an environment.
Natural gas: Naturally occurring hydrocarbon gas.
Natural resources: Economically valuable materials that humans extract from the Earth; water is one of humans’ most essential natural resource.
Navigable: Describes a body of water wide and deep enough for boats or ships to travel.
Navigation: The ability to determine the correct position of a ship in the ocean and the direction to sail in order to reach the desired destination.
Navigation channel: Passage in a waterway that is naturally deep or dredged to permit the passage of ships, or a defined, well-marked passage that leads from the docks to open waters; also called ship channel.
Navigation rights: The right of the ships from one nation to pass through certain waters, particularly the territorial waters of another nation.
Neap tide: Lowest tides of the month that occur at the second and fourth quarters of the Moon.
Neutron: A particle found in the nucleus of an atom that has no electric charge.
Non-point source pollution: Water pollution that comes from several unidentified sources, such as contaminated rain, runoff, or groundwater.
Nor’easter: A gale or storm blowing from the northeast, particularly common in New England and eastern Canada.
Nutrient: Chemical such as phosphate and nitrate needed by organisms in order to grow.
Ocean currents: The circulation of ocean waters that produce a steady flow of water in a prevailing direction.
Oligotrophic: Describing a body of water in which nutrients are in low supply.
Open-pit mine: Large craters dug into the earth to extract ore that is near the surface.
Ore: Naturally occurring source of minerals.
Organic: Of or relating to or derived from living organisms.
Overfishing: Catching a species of fish faster than it can naturally reproduce resulting in a decline in the overall population of that species.
Ozone layer: Region in the outer atmosphere that absorbs the Sun’s harmful ultraviolet radiation.
Pangea: A super-continent that existed about two hundred million years ago when all of Earth’s continental land masses were joined.
Parts per million (ppm): The number of particles in a solution per million particles of the solution.
Pathogen: Organisms (such as bacteria, protozoa, and viruses) that can cause disease.
Peat: Compressed organic material found in bogs.
Permafrost: Frozen layer of soil beneath the top layer of soil that has remained frozen for two or more years.
Permeability: The ability of fluid to move through a material.
Pesticides: Substances used to kill or harm unwanted plants, insects, or rodents.
Petroleum: A naturally occurring liquid mixture of hydrocarbons that is mined and refined for energy and the manufacturing of chemicals, especially plastics. Also known as crude oil.
Phase change: Transformation of a substance between one phase of matter (solid, liquid, or gas) to another.
Phosphorus: An element used as a food source by a variety of plants and microorganisms.
Photosynthesis: The process where plants use sunlight, water, and carbon dioxide to produce their food.
Physical oceanography: Study of the physical properties of the ocean including temperature, salinity and density, the ability to transmit light and sound, and the flow of currents and tides.
Phytoplankton: Plankton composed of plants and plant-like bacteria, such as algae.
Pinniped: A member of the group of marine mammals that include seals, sea lions, fur seals, and walruses.
Placer deposit: Water-deposited mineral source, such as gold nuggets in streams.
Plankton: Small, often microscopic, organisms that float in the ocean.
Plate tectonics: The theory that Earth’s lithospheric plates move over time. It explains geological patterns of earthquakes, mountain chains, volcanoes, and rock types.
Platform: Large buildings, attached to the sea floor or floating, that house workers and machinery needed to drill for oil or gas.
Playa: Flat areas at the bottom of desert basins that occasionally fill with water.
Pleistocene Epoch: Division of geologic time from 10,000 to 2 million years ago; also known as the Ice Age.
Point-source pollution: Water pollution that enters the water body from a particular site.
Point-source wastewater: Wastewater that enters natural waters from defined locations.
Polar: A molecule that has a positively charged part and a negatively charged part.
Polychaeta: The largest class of segmented worms that live in the ocean.
Population: Group of organisms all belonging to the same species that live in a specific location.
Porosity: Amount of empty space within a rock or soil body.
Port: City or town on a harbor where ships dock and cargo is loaded or unloaded.
Potable: Water that is safe to drink.
Precipitation: Transfer of water as rain, snow, sleet, or hail from the atmosphere to the surface of Earth. In chemistry or geochemistry: The process in which ions dissolved in a solution bond to reform a solid.
Proton: A positively charged particle that is located in the nucleus of an atom.
Purification: Process by which pollutants, mud, salt, and other substances are removed from the wastewater.
Rainshadow: An area that has decreased precipitation because a barrier mountain range causes prevailing winds to lose their moisture before reaching it.
Recharge zone: Area where water enters groundwater reservoirs by infiltrating through soils, stream beds, and ponds.
Reclamation: Draining submerged or wetter land to form dry, usable land.
Reef: An underwater ridge of rock or coral near the surface of the ocean.
Remote sensing: The use of devices to collect and interpret data; in marine archaeology, remote sensing is used to locate, map, and study underwater sites.
Remotely operated vehicle (ROV): Motorized crafts designed to withstand the increased pressure of the deep ocean.
Reservoir: Natural or man-made lake or body of water, often constructed to control a body of water.
Reservoir rocks: Rocks where petroleum collects.
Residence time: Time an average water molecule spends in one of the reservoirs of the hydrologic cycle.
Respiration: Process in which an organism uses oxygen for its life processes.
Ring of fire: A zone of large volcanoes and earthquakes that surrounds the Pacific Ocean.
Riparian zone: Narrow strip of vegetation that is found bounding the edge of a natural water body such as a stream or river.
River system: A river and its network of headwater streams and tributaries. All the streams that contribute water to the main river.
Runoff: Excess water when the amount of precipitation (water falling to Earth’s surface) is greater than the ability of the land to soak up the water.
Sailing: Moving across the water in a boat powered by wind energy harnessed by sails.
Saline lake: Saltwater lake that contains high concentrations of dissolved salts.
Salinity: A measure of the salt concentration of seawater.
Sanctuary: A habitat where killing animals or plants is prohibited.
Sanitation: Maintaining clean, hygienic conditions that help prevent disease through the use of clean water and wastewater disposal.
Saprotroph: Organism that decomposes another organism into inorganic substances and in the process obtains energy for itself.
Scuba diving: "Scuba" is the acronym for self-contained underwater breathing apparatus, referring to the air tanks and mouthpieces used by divers.
Sea ice: Frozen seawater floating on the ocean surface.
Seafloor spreading: The process by which a new oceanic seafloor is created by small volcanic eruptions at mid-ocean ridges.
Seamount: An underwater mountain.
Sedge: Grass-like plants.
Sediment: Particles of gravel, sand, and silt.
Seismic waves: Vibrations emitted by earthquakes and large explosions that travel as waves through the Earth.
Semipermeable: Descriptive of a material that allows the passage of some molecules and prevents the passage of others.
Sensor: Device that can detect the waves that have bounced back from the object they contacted.
Sewer system: Network of channels or pipes that carry wastewater to a treatment facility for purification.
Shoreline: A strip of land within a coastal zone that is submerged by high tide; also called shore zone.
Sidescan sonar: Type of sonar that emits sound energy over a wide path, tens or hundreds of miles (kilometers) across, allowing scientists to map large areas of the ocean.
Silt: Sedimentary particles smaller than sand particles, but larger than clay particles.
Sinkhole: A crater that forms when the roof of a cavern collapses; usually found in limestone rock.
Sludge: A semisolid residue, containing microorganisms and their products, from any water treatment process.
Snorkel: A hollow tube attached to a mouthpiece that can jut out above the surface of the ocean to allow a diver to breath.
Snorkeling: Form of diving in which the diver swims at or near the surface of the water using a snorkel to breathe surface air.
Snow line: The lowest elevation where snow stays on the ground or glacier surface without melting.
Solar salt production: A process that yields sea salt by allowing the sun to evaporate saltwater.
Solution: A liquid that contains dissolved substances.
Solution mining: Producing table salt by pumping water underground where it dissolves halite, then returning the solution to the surface where the salt is recovered through evaporation.
Solvent: A substance, most often a liquid, into which other compounds can dissolve.
Sonar: Derived from "Sound Navigation and Ranging," sonar uses sound waves to locate underwater objects.
Source rocks: Mud layers rich with plant and animal material that become rocks where temperature and pressure transform the plant and animal material into petroleum.
Species: Group of organisms that have a unique set of characteristics, such as body shape and behavior, and are capable of reproducing with each other and producing offspring.
Sponge: One of the least complex multicellular animals; a member of the phylum Porifera.
Spring tide: Highest tides of the month that occur at the new and full Moon.
Stratified: Layered.
Stream: Moving surface fresh water driven towards sea level by gravity.
Stromata: Holes on the surface of leaves that can let water vapor pass out of the plant into the air.
Subarctic: Region just below the Arctic Circle, to the edge of the northern forests in North America, Europe, and Asia.
Subduction: Process by which oceanic seafloor is recycled into Earth’s interior at deep ocean trenches.
Submersible: A craft designed to carry a pilot and scientists for underwater study of the deep ocean.
Superfund: A program managed by the Environmental Protection Agency that identifies, investigates, and cleans up the worst hazardous waste sites in the United States.
Surface mixed layer: The surface of the ocean where wind acts as a mixer, dissolving gases such as oxygen into the water.
Surface water: Water that is located on the surface, naturally in the form of streams, rivers, lakes, and other waterways, or in reservoirs, swimming pools, and other containers that have been built.
Sustainability: The use of a natural resource in a manner where it can be maintained and renewed for future generations.
Swamp: Wetland dominated by trees.
Swash: The forward and backward motion of water where waves break upon the shore.
Synecology: Ecological study of groups of organisms and how they work together.
Tanker: A ship that transports liquid cargo, usually oil or chemicals.
Tectonic plate: Moving plates of Earth’s crust.
Temperate zone: Region characterized by moderate temperatures, rainfall, and weather and overall climate that is neither hot nor cold, wet nor dry.
Tentacles: Long appendages on sea organisms that contain suckers or stinging cells and are used to grasp food and move around.
Terra cotta: Ceramic materials made from baked clay used in Ancient Rome for aqueduct pipes, dishes, and some tools.
Territorial water: Ocean waters governed by a nation; most territorial waters extend for 12 miles (19.3 kilometers) from a nation’s coastline.
Thermal spring: Natural spring of water at a temperature of 70°F (21°C) or above; commonly called a hot spring.
Thermocline: The part of the ocean below the epipelagic zone where the temperature changes very quickly with depth.
Threatened: Descriptive of a species that is likely to become endangered in the foreseeable future.
Tidal fence: Device installed in an area with highly-changing tides that makes electricity by harnessing tidal energy.
Tidal flat: A broad, flat area of coastline alternately covered and exposed by the tides.
Tidal wave: The swell or crest of surface ocean water created by the tides. Also refers to an unusual water rise along a coastline as created by a storm or undersea earthquake.
Tide: Periodic rise and fall of sea level along coastlines caused by gravitational and rotational forces between the Sun, Moon, and Earth.
Tornado: A violently rotating column of air that is in contact with the ground.
Trade winds: Strong winds that blow from east to west in the subtropics on either side of the equator; named for their part in propelling European sailing ships to the East and West Indies to conduct trade.
Transpiration: The process where water is absorbed by a plant through its roots and passes into the air from the leaves as water vapor.
Treaty: An international agreement between two or more nations in written form and governed by international law.
Tributary: Smaller streams that flow into a larger stream or river.
Tropical storm: A low pressure storm system formed in tropical latitudes with sustained winds between 39 and 74 miles per hour (63 and 119 kilometers per hour).
Tropics: Warm, humid region lying north and south of the equator.
Trough: The lowest point in a wave; occurs between the crests.
Tsunami: Very large ocean wave created by an undersea earthquake or volcanic eruption.
Tundra: Treeless plains of the arctic and subarctic between the northern forests and the coastline of the Arctic Ocean.
Turbine: Device that converts the flow of a fluid (air, steam, water, or hot gases) into mechanical motion for generating electricity.
Twister: Common name for a tornado.
Typhoon: Tropical cyclone in the western Pacific or Indian oceans.
United Nations: An association of countries founded in 1945 that is devoted to the promotion of peace, security, and cooperation between nations.
United Nations Law of the Sea: International law that governs the rights and responsibilities of nations and their approach to the oceans.
Upwelling: An area where cold, often nutrient-rich water rises from the deep ocean to the surface.
U.S. Department of the Interior: Department in the U.S. government that is responsible for the conservation of natural resources and the administration of government-owned land.
U.S. Geological Survey: Division of the U.S. Department of the Interior that is responsible for the scientific analysis of natural resources, the environment, and natural disasters.
Vertebrate: An animal that has a bony spine that contains a nerve (spinal) chord.
Wall cloud: An area of clouds that extends beneath a severe thunderstorm and sometimes produces a tornado.
Wastewater: Water left over after it has been used, such as any water that empties into a drain or sewer.
Water allotment: An individual portion of water granted by a water right.
Water chemistry: The balance of nutrients, chemicals, and minerals in water.
Water footprint: The amount of water used by an individual, business, community, or nation.
Water right: Grants a right to use water but not ownership of the waterway.
Water table: The zone above which the spaces in the soil and rocks are not completely filled with water and below which the soil and rock spaces are completely filled with water.
Water treatment: A series of steps that makes water potable and removes chemicals and microoganisms that could be harmful to the natural environment.
Watershed: The land area that drains water into a river or other body of water.
Waterspout: A column of rotating air, similar to a tornado, over a body of water.
Wave base: Water depth at which water is undisturbed by a passing wave. Wave base is at a depth equal to half the horizontal distance between two neighboring wave crests (one-half wavelength).
Wave refraction: Wave fronts bending when they approach a coastline at an angle.
Wavelength: Distance of one full wave; can be measured from crest to crest or trough to trough.
Weir: A low dam built across a stream or any flowing body of water, usually with rocks, to raise its level or divert its flow.
Wet deposition: Precipitation that has become acidic as a result of air pollution.
Wetlands: Areas of land where water covers the surface for at least part of the year and controls the development of soil.
Zone of infiltration: Shallow soil and rock layers with pore space that are at least partially filled with air; water table is the bottom of this zone.
Zone of saturation: Soil and rock layers with pore spaces that are completely filled with fluid; water table is the top of this zone.
Zooplankton: Small, often microscopic, animals that float in the ocean.
