As part of the General Chemistry Virtual Textbook, this site examines a variety of topics related to the hydrosphere and the oceans. Topics covered include where the water came from, the hydrologic cycle, Oceanic circulation, atmospheric...

Explains what the four spheres of the Earth are, and the interactions between them.

This site provides a comprehensive introduction to the water cycle. Students construct a model to simulate parts of the water cycle. Includes background information, links to standards, lesson plans, and assessment ideas.

Get a general grasp on the four spheres, five sub-fields, and two scales of physical geography.