This term describes the entire land area that drains into a single river, lake, or other body of water.
What is a watershed?
These tiny, often microscopic organisms that drift in ocean water form the base of nearly every marine food chain.
What is plankton?
This is the standard metric unit used to measure volumes of liquid.
What is a liter?
This term describes rising sea levels and changing precipitation patterns caused by global warming, which threaten coastal freshwater supplies with saltwater intrusion.
What is climate change?
This word is typically used to describe the response to a question.
What is the answer?
This underground layer of rock, sand, or gravel stores and transmits groundwater.
What is an aquifer?
This diverse marine ecosystem, sometimes called the "rainforest of the sea," is built by colonies of tiny living organisms that secrete calcium carbonate skeletons.
What is a coral reef?
Water quality scientists use this unit, abbreviated ppm, to measure very small concentrations of a substance, like chlorine or lead, in water.
What is parts per million?
This type of pollution, made of tiny plastic fragments less than 5mm long, has been found in oceans, rivers, and even drinking water
What is microplastic (pollution)?
The common pencil does not contain lead, instead being made up of this element.
What is carbon?
This continuous process of evaporation, condensation, and precipitation moves water through Earth's atmosphere, land, and oceans.
What is the water cycle?
This ocean zone, found below about 1,000 meters, receives no sunlight at all and is home to bioluminescent creatures.
What is the midnight zone (bathypelagic zone)?
Farmers and water managers often measure large volumes of water using this unit, equal to the amount of water needed to cover one acre to a depth of one foot.
What is an acre-foot?
This large-scale structure, while useful for power and irrigation, can block fish migration, alter river ecosystems, and change downstream sediment flow.
What is a dam?
This non-negative whole number is less than the number of stars in the solar system.
What is 0?
This is the underground boundary between the soil surface and the area where groundwater saturates all spaces between sediments and rocks.
What is the water table?
These marine mammals, including whales and dolphins, must surface periodically to breathe air despite living in water.
What are cetaceans?
This unit, abbreviated as psi, measures water pressure and is often used in plumbing and irrigation systems.
What is pounds per square inch?
This phenomenon, caused by rising ocean temperatures and stress, occurs when corals expel the colorful algae living in their tissues, turning white.
What is coral bleaching?
This is the second most popular drink (second to water) in the world.
What is tea?
This large artificial lake, created by damming a river, is used for water storage, irrigation, flood control, and recreation.
What is a reservoir?
This term describes species that are not native to an ecosystem and often outcompete native species for resources, such as zebra mussels in the Great Lakes.
What is an invasive species?
This the unit permeability, named after a person whose first name is Henry.
What is the Darcy?
This ancient civilization built famous aqueducts to transport water over long distances to cities and farms using gravity alone.
What is the Roman Empire?
The Hoover Dam is named after the 31st US president Herbert Hoover and generate this many kilowatt-hours of energy after subtracting the year of his birth.
4 billion