WELLS - Earthquake fluctuations in wells UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY Water Resources Division Washington 25, D.C. In reply refer to: April 24, 1958 Code 4054 0001 GROUND WATER BRANCH MEMORANDUM NO. 58.47 To: District Chiefs and Staff Officials (GW) From: Chief, Ground Water Branch, Washington, D.C. Subject: WELLS - Earthquake fluctuations in wells The United States Atomic Energy Commission has recently declassified and released certain data on nuclear explosions resulting from U.S. tests of nuclear weapons in the period March 1954 to August 1957. These data have been made available by the Division of Earth Sciences, National Academy of Sciences - National Research Council and in turn are forwarded to you as an attachment to this memorandum. The dates of nuclear tests by other nations were not made public. Those offices having recorder installations near the test sites may wish to check the water-stage recorder charts for the indicated test dates and times. Any evidence of abnormal water- level fluctuations, correlating with the nuclear tests, may be sent to this office attention code 4051 5402, in accord with the procedures followed in reporting earthquake fluctuations. (s) A. N. Sayre Attachment Distribution: A, B, GS, GFO