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Welcome to the Science Topics page of the USGS Water Science School, where you can explore the many aspects of water. All of our science information is available by browsing the Themes below.
The water cycle, also known as the hydrologic cycle, describes the continuous movement of water as it makes a circuit from the oceans to the atmosphere to the Earth and on again.Most of Earth's water is in the oceans. The sun, which drives the water cycle, heats water in the oceans. Some of it evaporates as vapor into the air. Rising vapor cools and condenses into clouds. Cloud particles grow and...
About 2.1% of all of Earth's water is frozen in glaciers.97.2% is in the oceans and inland seas2.1% is in glaciers0.6% is in groundwater and soil moistureless than 1% is in the atmosphereless than 1% is in lakes and riversless than 1% is in all living plants and animals.About three-quarters of Earth's freshwater is stored in glaciers. Therefore, glacier ice is the second largest reservoir of water...
Groundwater, which is in aquifers below the surface of the Earth, is one of the Nation's most important natural resources. Groundwater is the source of about 37 percent of the water that county and city water departments supply to households and businesses (public supply). It provides drinking water for more than 90 percent of the rural population who do not get their water delivered to them from...
The USGS Water Science School offers many resources to teachers help teach students all about water.
This is the interactive section of our site where you can answer challenge questions, participate in opinion surveys about water issues, and take true/false quizzes.
An aquifer is a geologic formation, a group of formations, or a part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells and springs. This site explains the geology of aquifers and provides a general overview and maps of the principal aquifers of the United states.