Caves are cavities that form in hillsides, in cliff walls, and underground, and are accessible at Earth's surface. Typically, they form in soft, fractured, or soluble rock as a result of natural mechanical and chemical processes that continue over thousands of years. This interactive activity from NOVAoffers animated explanations for how ocean waves, lava, slightly acidic groundwater, and, in a supporting role, microbes account for the variety of cave formations on Earth.
Visit the program page here.
© 2014 PBS & WGBH Educational Foundation. All rights reserved.