Hydrosphere

Science / Weather / Hydrosphere: Considered as the water portion of the earth's surface. Part of the geosphere.
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Geosphere

Science / Weather / Geosphere: Considered the solid portions of the earth, including the hydrosphere and the lithosphere, as opposed to the atmosphere, which lies above it. At their conjunction is the biosphere. MORE

Gaia

Science / Biology / Gaia: A hypothetical superorganism composed of the Earths four spheres: the biosphere, hydrosphere, lithosphere, and atmosphere. MORE