--> ABSTRACT: GLORIA Imagery of the Alaskan Exclusive Economic Zone, by H. A. Karl; #90097 (1990).

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ABSTRACT: GLORIA Imagery of the Alaskan Exclusive Economic Zone

H. A. Karl

About 2.2 × 106 km2 of the U.S. Exclusive Economic Zone of the Bering Sea and the North Pacific Ocean have been mapped using the GLORIA long-range side-scan sonar system as part of the EEZ-SCAN program of the U.S. Geological Survey. The areas surveyed include: (1) all of the Aleutian basin and Bowers basin deeper than 200 m east of the U.S.-U.S.S.R. Convention Line of 1867 and (2) the seafloor deeper than 200 m seaward 200 nautical miles from the Aleutian Islands and the Alaskan coastline between the 1867 Convention Line and the Canadian border. The GLORIA imagery is mosaicked to provide an unprecedented view of the regional geologic and geomorphic provinces that characterize backarc, arc, subduction zone, and transform boundary settings.

Some of the more significant or prominent geologic features seen on the GLORIA imagery include the following. Products of mass wasting characterize the slopes of the Bering Sea. The most striking evidence of the morphological effects of mass wasting are submarine canyons that are among the world's largest, incising the Beringian margin. Near the Aleutian Arc the imagery documents the impressive linear and continuous nature of major shear zones associated with oblique convergence tectonics. South of the Aleutian Arc, Stalemate fracture zone has collided with the western end of the Aleutian trench raising the trench floor 750 m and producing elongate, crescent-shaped ridges in the forearc thereby affecting both sediment transport and subduction tectonism. Imagery in the Gulf of Alaska r veals a spectacular system of recent and abandoned deep-sea channels and the prominent and linear morphologic expression of the Queen Charlotte fault system.

AAPG Search and Discovery Article #90097©1990 Fifth Circum-Pacific Energy and Mineral Resources Conference, Honolulu, Hawaii, July 29-August 3, 1990