ABSTRACT: Submarine Landslides at the Mouth of the Fraser River, Canada

G. T. McKenna, J. L. Luternauer, R. A. Kostaschuk

The Fraser River delta front, Canada, supports a variety of coastal structures but the stability of the submarine delta is poorly understood. Five large, shallow failures at the mouth of the Fraser River have been detected by comparing 105 successive bathymetric surveys conducted between 1970 and 1986. These failures, which can involve more than 1 million m³ of silty-sand, are thought to result from liquefaction of sand leading to sediment flow. The liquefaction is triggered primarily by deposition at the river mouth, but cyclic wave loading, tidal fluctuations, tidal currents, and earthquake loading may be contributory factors. These results have important implications for the stability of a lighthouse and jetty and indicate that the area is unsuitable for oth r engineering works.

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