SEISMIC CRUSTAL STUDY IN THE CHUKCHI SEA

Abstract

Abstract : During the period from June 22 to September 12, 1961, a seismic refraction study of the emerged and submerged coastal plain of northern Alaska was started in an attempt to determine the structure of the earth's crust in that area. This seismic study is part of a broad program of gravity, magnetic, and seismic investigations of the Arctic Ocean basin. Thirty shots were successfully recorded on a seismograph located at Point Barrow. Sixteen of these shots were fired in the Chukchi Sea and 14 on land. Eleven shots were fired from the U.S.S. Staten Island for a reversed profile extending 320 Km. northwest of Point Barrow. Using a weasel or small motor boat for transportation, 14 shots for two reversed profiles were set off within 30 Km. at the recording seismograph. One shot was fired from the U.S.S. Burton Island 16 Km. to the north. The offshore end of the long refraction profile at sea was recorded on ice island Arlis II by personnel from the Lamont Geological Observatory. A series of shots were attempted along a line between Point Barrow and Umiat, 250 Km. to the southwest using pontoon equipped Cesna 180 aircraft. These shots were not successfully recorded because of the difficulty in burying shots deep enough in the tundra or shallow lakes to provide sufficient energy coupling from the explosives into the earth.