
Image Credit: Map courtesy of U.S. Geological Survey, “Exploring Caves,” http://interactive2.usgs.gov/learningweb/teachers/explorecaves.htm.
Originally published at http://www.sciencecases.org/abyss/map1.asp
Copyright © 1999–2010 by the National Center for Case Study Teaching in Science. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.