Cover-Clockwise from top left:

Reeds and duckweed on the Milwaukee River,
Campbellsport, Wis. (Mark A. Hardy; see articles
p. 19-26).

Mount Redoubt volcano eruption on the morning of
April 21, 1990 (copyright 1990, Robert J. Clucas,
reprinted by permission; see articles p. 12 and 18).
Brooks Falls, Wyo. (Mark A. Hardy; see articles
p. 19-26).

Major roads lead to Atlantic City on this portion of the
newly digitized New Jersey State base map (see
article p. 66).

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
J. Bennett; see article p. 3).

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