Tsunami Hazards Associated with the Catalina Fault in Southern California

Abstract

We investigate the tsunami hazard associated with the Catalina Fault off-shore of southern California. Realistic faulting parameters are used to match coseismic displacements to existing sea floor topography. Several earthquake scenarios with moment magnitudes ranging between 7.0 and 7.6 are used as initial conditions for tsunami simulations, which predict runup of up to 4 m. Normalizing runup with the maximum uplift identifies areas susceptible to tsunami focusing and amplification. Several harbors and ports in southern California lie in areas where models predict tsunami amplification. Return periods are estimated by dividing the modeled seafloor uplift per event by the observed total uplift of the Santa Catalina Island platform multiplied by the time since the uplift began. The analysis yields return periods between 2,000 to 5,000 years for the Catalina Fault alone, and 200 to 500 years when all offshore faults are considered. [DOI: 10.1193/1.1773592

Preliminary estimation of the tsunami hazards associated with the Makran subduction zone at the northwestern Indian Ocean

“…In cases where deterministic scenarios are not based on historic events, there may be a tendency to use maximum credible tsunami for a given region (Geist and Parsons 2006). Further examples of application of DTHA can be found in Tinti and Armigliato (2003), Yalciner et al (2004), Legg et al (2004), Okal et al (2006b).…”

“…Most studies of tectonic tsunamis use Mansinha and Smylie's (1971) formula or Okada's (1985) analytical formula to predict seafloor displacement due to an earthquake and to model initial water displacement (Legg et al 2004). Here, the algorithm of Mansinha and Smylie (1971) is used to calculate the seafloor deformation.…”

Tsunami hazard assessment in the Ionian Sea due to potential tsunamogenic sources – results from numerical simulations

“…Most studies of earthquake generated tsunamis use Mansinha and Smylie's (1971) formula or Okada's (1985) analytical formula based on elastic dislocation theory to predict seafloor displacement due to an earthquake and to model initial water displacement (e.g. Legg et al, 2004;Tselentis et al, 2006). This approach is being adopted in the present investigation.…”

A Second Generation of Tsunami Inundation Maps for the State of California

“…These maps cover the most significant ports, harbors, coastal urban centers, and popular recreational areas in California. The tsunami modeling took advantage of updated bathymetric and topographic datasets, and included additional tsunami source information and descriptions published or identified since 1998 (i.e., BARDET et al, 2003;LEGG et al, 2004;BORRERO et al, 2004).…”

“…It also contains the list of tsunami scenarios used and the important disclaimer that the map is solely for the purpose of emergency and evacuation planning. Each county will use a similar map for determining evacuation routes and locating tsunami signage BORRERO et al, 2004;LEGG et al, 2004) and nearfield effects of ruptures along the CSZ (USLU, 2008) were modeled from the epicenter to the maximum inundation point, without using precomputed data.…”