B K Galloway and S L Klemperer (Both at: Department of Geophysics, Stanford University, Stanford, CA 94305; 415-725- 9907; e-mail: galloway@pangea.stanford.edu); J R Childs (Mail Stop 999, 345 Middlefield Road, Menlo Park, CA 94025; 415-354-3175; e-mail: jchilds@octopus.wr.usgs.gov); Bering-Chukchi Working Group (Institute of the Lithosphere and Insitute of Oceanology, Russian Academy of Sciences, Western Washington University; Lamont-Doherty Earth Observatory, Columbia University)
Stanford University, in conjunction with the USGS, conducted deep seismic investigations of the continental crust beneath the Bering and Chuckchi Seas, Alaska, during the month of August, 1994. The data was recorded to two-way travel-times of 15 to 23 seconds, with 50 to 75 meter shot spacing.
Two north-south transects were profiled. The eastern transect extended from 58d 50m N, 169d 32m W, well within the continental shelf of the Bering Sea, north of the Pribilof Islands, to just south of the shelf edge north of Barrow, Alaska, at 71d 49m N, 154d 33m W. Ice prevented continuation of the line beyond the shelf edge. The western transect extended from the central Chukchi Sea, within the shelf at 71d 30m N, 163d 00m W, into the Aleutian basin at 58d 00m N, 178d 30m W, near the Navarinsky Canyon. An additional short line crossing over the Beringian margin a second time was recorded near Zemchug Canyon east of the western transect. Constant-offset sections were plotted on board the ship during acquisition. These plots exhibit large differences in lower crustal reflectivity across the breadth of the continental crust.
The profiles cross important strike-slip faults, possible terrane boundaries, two continental margins, and several Cretaceous/Tertiary sedimentary basins (Norton, Hope, Chuckchi, Navarin Basins). Together with the preceding cruise EW94-09, led by Sue McGeary, the profiles provide a continuous transect across the North American continent, from the Pacific to the Arctic Ocean.
Most of the multi-channel seismic data is generally of high quality. Gravity, magnetic, and sonobuoy data were also recorded along the profiles. Wide-angle recording was done in conjunction with the seismic profiling, at recording sites located along the central west coast of Alaska and the Chukchi Peninsula, as well as on islands in the Bering Strait and Bering Sea.