Contents

11 April 1986
Vol 232, Issue 4747

About The Cover

Cover image expansion

The combined red and blue beams from the two-color laser geodimeter travel across the south moat of the Long Valley caldera (California) during measurements of geodetic baselines established to monitor crustal deformation. The city of Mammoth Lakes lies in the foreground with the Ritter Range of the Sierra Nevada forming the skyline. See page 213. [Peter Bozek, U.S. Geological Survey, Menlo Park, CA 94025]