Cover-Clockwise from top left: Reeds and duckweed on the Milwaukee River, Mount Redoubt volcano eruption on the morning of Major roads lead to Atlantic City on this portion of the Close up of sand boils (from underlying loose, saturated sand deposits) at eastern end of Marina Green, San Francisco, Calif., caused by the October 17, 1989, Loma Prieta earthquake (Michael Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government United States Geological Survey Yearbook ISSN 0892-3442 UNITED STATES GOVERNMENT PRINTING OFFICE: 1991 For sale by the Books and Open-File Reports Section, U.S. Geological Survey Federal Center, Box 25425, Denver, CO 80225 |