The Regional Economic Cost of a Tsunami Wave Generated by the Palos Verdes Slide

Recent developments in modeling of tsunami waves and economic impact analysis are combined with data from recent offshore mapping of the Santa Barbara channel and other locations to model the mechanism and economic impact of a tsunamigenic undersea landslide in the vicinity of Los Angeles. Introduction The seismic sensitivity of the Los Angeles metropolitan region is well recognized, Fortunately, the densely populated regions of coastal Southern California, including the Los Angeles Basin, and the Santa Barbara -Ventura regions have been relatively free of severely damaging earthquakes during most of the past 200 years. See Figure 1. Several recent moderate earthquakes however, such as the 1994 Mw 6.7 Northridge earthquake and the 1987 Mw 6.0 Whittier Narrows earthquake, have brought to light the hazard associated with thrust and reverse faulting beneath Southern California (Dolan et al. 1995). There have been several smaller, less damaging thrust and reverse earthquakes in the near shore region that illustrate the possibility of a larger earthquake offshore. The shaking from an earthquake of magnitude 7 or greater on an offshore thrust or reverse fault would undoubtedly be damaging to coastal communities, and its effect would be enhanced by its potential for generating a damaging tsunami. 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 following the unusually large waves associated with the July 17, 1998 Papua New Guinea (PNG) tsunami. As a result of this increasing scientific scrutiny, Southern California’s susceptibility to tsunami damage is only recently becoming understood. Several locally generated tsunamis have been recorded in the region during the past 200 years. One of the first large earthquakes to be recorded in Southern 1 Research Assistant Professor of Civil Engineering, University of Southern California, KAP 210 MC2531, Los Angeles, CA, 90089-2531; phone 213-740-5129; jborrero@usc.edu. 2 PhD Candidate, Urban Planning, School of Policy, Planning, and Development, University of Southern California; and ImageCat, Inc., 400 Oceangate, Suite. 1050, Long Beach, CA 90802; phone 562-628-1675; sungbinc@rcf.usc.edu, sc@imagecatinc.com. 3 Professor of Civil Engineering; Public Policy and Management; and Industrial and Systems Engineering, University of Southern California, KAP 210 MC-2531, Los Angeles, CA, 90089-2531; phone 213-740-0595; jmoore@usc.edu. 4 Professor of Civil Engineering; University of Southern California, KAP 210 MC-2531, Los Angeles, CA, 90089-2531; phone 213-740-0613; costas@usc.edu. The Regional Economic Cost of a Tsunami Wave Generated by the Palos Verdes Slide 34 N 35 N 120 W 119 W 118 W