The Potential of Silent Tsunamis Along the Central California Margin
Abstract
Government and industry concerns about the impacts of tsunamis on critical infrastructures have resulted in an extensive assessment of mass movement events along the central California margin. Part of this study includes the evaluation of potential mass movements along the coastline and in the heads of submarine canyons that may have locally generated tsunamis in the past and may have the potential to generate tsunamis in the future. We report upon landslides concentrated within the Arquello-Conception and Partington canyon systems and adjacent slopes, estimate time of movement of the features, model potential tsunami inundation and runups, and speculate on future failures. Landslide deposits from trans-terrestrial failures in the Partington Canyon area are well imaged in recently collected multibeam bathymetric data sets. In this area faulting controls the head of the canyon and landslide movement has deflected the present day channel. In contrast, mass movement of the Arquello-Conception canyon system are concentrated at the canyon heads and appear to result from retrogressive erosional activity initiated by fluid flow and expulsion of gases from hydrocarbon reservoirs at depth. Examination of these two canyon systems and their adjacent areas provide insight into the mechanisms, loci and amount of submarine mass movement in the central California region and their ability to direct tsunami waves to critical coastal areas. Since most of the sites of failures are close to shore, little time is required for the waves to arrive at the shoreline and their generation may occur silently, without a seismic trigger. Therefore, locating areas where potential silent tsunamis may generate is critical to emergency preparation processes. We use the results of this work to determine where the likelihood of tsunamis deposits on land may be found.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFMOS34C..03G
- Keywords:
-
- 3070 Submarine landslides