The 1975 Kitimat Landslide Tsunami: Validation and Comparative Testing of Modeling Strategies

摘要

We present numerical simulations of the April 27, 1975 landslide event in Kitimat Arm, British Columbia. The event caused a tsunami with an estimated wave height of 8.2 m and 6.1 m at the northern and southern ends of Kitimat Arm, respectively. We use the non-hydrostatic model NHWAVE to perform a series of numerical experiments with different slide configurations and with two approaches to modeling the slide motion: a solid slide with motion controlled by a basal Coulomb friction, and a depth-integrated numerical slide based on Newtonian viscous flow. Both models are capable of reproducing observations of the event if an adequate representation of slide geometry is used. Comparable results are obtained using estimates of either Coulomb friction angle or slide viscosity that are within reasonable ranges of values found in previous literature. Preliminary results are presented for an alternate model based on a granular debris flow slide layer.