This video segment adapted from NOVA chronicles the discoveries that led to a radical new theory in which living organisms, not just geological processes, play an active role in cave formation. [5:42]

Students investigate ocean chemistry. The article discusses Jim Bishop, ocean cycle, the biology of the sea, and carbon in the sea. The resource consists of pictures, quotes, and links to additional resources.

This site from USGS provides several activities to help understand the interrelationships among earth surface processes, ecological systems, and human activities. Also included are links to new findings and programs concerning Earth...