HR: 1330h
AN: OS22B-1160    [PDF]
TI: Boussinesq Modeling of the 1975 Kitimat, British Columbia Landslide Tsunami
AU: Murty, T
EM: tmurty@baird.com
AF: Baird & Associates, 1145 Hunt Club Road Suite 500, Ottawa, ON K1V 0Y3
AU: * Watts, P
EM: phil.watts@appliedfluids.com
AF: Applied Fluids Engineering Inc., Private Mailbox #237 5710 E. 7th Street, Long Beach, CA 90803 United States
AU: Fullarton, M
EM: mfullarton@baird.com
AF: Baird & Associates, 1145 Hunt Club Road Suite 500, Ottawa, ON K1V 0Y3
AU: Grilli, S T
EM: grilli@oce.uri.edu
AF: Department of Ocean Engineering, University of Rhode Island, Narragansett, RI 02882 United States
AU: Kirby, J T
EM: kirby@udel.edu
AF: Centre for Applied Coastal Research, University of Delaware, Newark, DE 19716 United States
AB: Mass failures near the head of Kitimat fjord in British Columbia produced water waves that caused severe destruction of waterfront facilities. We revisit this event with the latest numerical models in order to better understand the geological and tsunamigenic processes involved. Mass failure began around low tide near Moon Bay, possibly on account of construction activities taking place there. Retrogressive failure along the fjord floor proceeded over the next several minutes, until it reached the steep fjord head just underneath the Kitimat River. A mass on the steep slope then failed during a single event that is best characterized as an underwater slide in glacial sediments, resulting in an observed depression of the water within the middle of the fjord. This slide was much larger in volume than the initial mass failure, and consequently much more tsunamigenic. The Kitimat event presents many processes that appear to apply to tsunamis in fjords elsewhere. We examine the larger slide volume and linear dimensions based on the available bathymetry. The slide scar is relatively well discerned and extends along the entire slope, in what can be termed a typical fashion. We reproduce tsunami generation of the larger slide with TOPICS and simulate tsunami propagation and inundation with the Boussinesq model FUNWAVE. Our simulation results reproduce the tsunami runup observations, as well as the regions of damage incurred along the shoreline. We also reproduce far-field wave amplitude observations from fishing boats located further south. The agreement between the modeling results and observations suggests that landslide tsunamis in fjords are becoming well-studied events that can yield consistent processes and that can be accurately modeled.
DE: 4564 Tsunamis and storm surges
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting