Mass sediment failure and transport features revealed by acoustic techniques, Beringian margin, Bering Sea, Alaska

Abstract

Abstract GLORIA sidescan sonar imagery and seismic‐reflection profiles show pervasive evidence for a wide variety of slides and slumps associated with the large canyons of the 1400‐km‐long Beringian margin. Styles of failure include mud and debris flows, slumps, and massive block slides. A 100‐km‐long shelf‐edge segment on the northern margin is characterized by a series of scalloped slide scars and incipient scars associated with sedimentary blocks, 1–2 km across, that seem to be the initiators of a series of small canyons. Some of the largest single slide masses, including huge blocks tens of kilometers wide, occur on the rise of the central margin. Sliding of these blocks may have initiated the incision of some of the world's largest submarine canyons, a prime example of which is the massive Zhemchug Canyon. Mass movement along the southern margin is widespread at the edges of Umnak Plateau. One mass failure, particularly well defined by GLORIA, is 55 km long. This slide and others along the plateau ar...