Jose Carlos Borrero

Modeling of the November 3, 1994 Skagway, Alaska Tsunami

In the evening of November 3, 1994, a series of submarine landslides and associated waves destroyed the Pacific Arctic Railway Company (PARN) dock at Skagway, Alaska, killing one construction worker. Numerous geologic and hydrodynamic studies followed, in an effort to prove or disprove that construction failure was responsible for initiating the slide. We model the slide using two inundation models, the model known as TUNAMI--N2 (not TSUNAMI) developed at Tohoku University and the model VTCS--3 developed at the University of Southern California and now in use by NOAA and known as MOST. Both models when run under the same initial conditions and bathymetry provided consistent results about the hydrodynamic motions close to the PARN dock. The results qualitatively fit the eyewitness observations, using a combination of three slides, and suggest that the sliding started offshore along the fjord wall off the southern end of the dock and undermined the southern two thirds of the dock.

The Regional Economic Impacts of a Tsunami Wave

The hazard to metropolitan Southern California posed by locally generated tsunamis has received considerably less study than the hazards posed by onshore earthquakes. This is likely to change. The mechanisms that generate tsunamis have received considerable study as have major tsunamis in the past two decades such as in Papua New Guinea in July 1998, the Indian Ocean in December 2004 (with about 250,000 deaths in 14 countries), and Tohoku, Japan, in May 2011 (followed by the Fukushima nuclear disaster). As a result of this increasing scientific scrutiny, Southern California’s susceptibility to tsunami damage has only recently become understood.

Tsunami Inundation from Great Earthquakes on the Cascadia Subduction Zone along the Northern California Coast

We model tsunami runup and inundation along the Northern California Coast caused by hypothetical earthquakes on the Cascadia Subduction Zone (CSZ). The CSZ forms the boundary between the Pacific and North American tectonic plates and extends from Northern California to Southern British Columbia and is believed capable of producing great earthquakes with moment magnitudes (M w ) 9.0 or greater. A suite of CSZ rupture scenarios based on the geological characteristics of the southern part of the CSZ were simulated with the tsunami propagation and inundation model MOST. CSZ inundation projections were compared and related to historical accounts and modeled data for two teletsunamis at Crescent City: the tsunami of 1 April 1964 that caused 12 deaths and more than 17 million in damages to Northern California, and the 15 November 2006 Kuril Islands tsunami that caused nearly 10 million in damages to the Crescent City harbor. Our modeling suggests that near field tsunamis from the CSZ present a hazard greater than the 1964 event for the northernmost part of the State. However, south of Shelter Cove tsunamis generated by great earthquakes along the Alaska — Aleutians subduction zone are potentially more damaging.