SCEC Award Number 14013 View PDF
Proposal Category Individual Proposal (Special Fault Study Area)
Proposal Title Earthquake Rupture and Tsunami Simulations: Ventura-Pitas Point Fault System
Name Organization
Steven Ward University of California, Santa Cruz
Other Participants
SCEC Priorities 2e, 4e SCEC Groups Simulators, CS, Geology
Report Due Date 03/15/2015 Date Report Submitted N/A
Project Abstract
In the past several years, geologists have presented new evidence that the South San Cay-etano, Ventura and Pitas Point thrust faults may ‘link together’ and rupture simultaneously in earthquakes far larger than had been previously believed. Paleo-seismic evidence onshore east of the Ventura Anticline suggests that coseismic vertical uplift in certain quakes on this linked fault reach at least seven meters. Because for much of their length, these faults lie under the Santa Barbara Channel, a thrust event of this size on the linked system could pose a serious and previ-ously unrecognized hazard in the form of tsunami.

In 2014 I have been modeling rupture scenarios that arise from applications of ‘ALLCAL–style’ physics-based earthquake simulations. The idea is to see what types of ruptures might oc-cur on this fault and what is required to generate the seven meter uplifts seen in the field. Con-currently the plan is to input certain of the simulated ruptures into calculations of tsunami and inundation.

Rupture simulations reveal that 1000 bar strengths are required on the Ventura-Pitas Point Fault to produce the seven meter uplifts observed by paleo-seismologists. It remains to be seen whether such large coseismic stress drops could be acceptable to seismologists who infer the quantity from analysis of seismograms.
Intellectual Merit This proposal applies earthquake simulators to evaluate the likelihood and circumstances needed to reproduce certain paleoseismic observations. It also uses the simulators to evaluate the related tsunami hazards in the Santa Barbara Channel.

Using physics based earthquake simulators to provide feed back and direction to other disciplines with in SCEC is totally in accord with the Center's mission to create system level science.
Broader Impacts I continue to contribute to the 'outreach' goals of SCEC largely through the
production of short YouTube-style science videos. Recent videos discuss a wide range of topics related to SCEC including earthquake effects, turbidites,
shaking induced landslides and tsunami. Nearly 1.5 million people of viewed my movies. I can't imagine a more effective method to bring science to the broader world.
Exemplary Figure Figure 3.