Numerical simulation of tsunamigenic submarine slope failure in the Fraser River delta, British Columbia

Abstract

The Fraser River delta has been identified in previous studies as a potential site for a tsunamigenic submarine slide. A numerical model has been developed to simulate such events by representing the slide volume as a large number of independent slabs acting under the influence of a reduced gravitational acceleration and friction. The resulting movement of mass results in vertical displacement of the water's surface. Five simulations were performed using slide volumes from 2.5 to 7.5 km³, and with three different friction coefficients. Examination of resulting time series of calculated water elevation at 10 near‐shore loctions indicates that maximum surface displacements of greater than 4 m may occur at some sites near the source. Response characteristics were found to vary significantly over distances of 5 to 10 km. The period of waves generated in this way is typically 5 to 15 min.

Keywords:

• tsunami
• submarine slide
• Strait of Georgia