Contour Lines 4 : Parallel lines used on topographic maps to show the shape and elevation of the land. They connect points of equal elevations. (Teacher's Packet)
U.S. Department of the Interior, U.S. Geological Survey, US Geological Society (USGS), Glossary of Volcano and Related Terminology, USGS/Cascades Volcano Observatory, Vancouver, Washington, USA 2006. http://vulcan.wr.usgs.gov/Glossary/volcano_termino logy.html, (ND/ Volc Sci - Amer) {493}