Is There a Paleotsunami Record in the San Elijo Lagoon, San Diego?

Nadimi, Khadija; Kirby, Mathew E.; and Rhodes, Brady
[email protected]

Based upon projected tsunami undulation models, Southern California has many distal and local tsunami sources capable of producing run up heights >7m. Run up heights vary depending on source mechanisms, bathymetry and coastal plain topography. However, Southern California coastal line has no geologic records of paleotsunami. This project is one of the first efforts to search for paleotsunami deposits in low-lying coastal areas along the Southern California coastal line. This study mainly focus on San Elijo Lagoon, San Diego, for the paleotsunami research due to: (1) undulation models showing potential high tsunami run-up heights and large inundation distances from local and teletsunamis; (2) occurrence of undisturbed wetlands capable of trapping and preserving paleotsunami deposits; and (3) reconnaissance surveys indicating potential paleotsunami deposits. In this study, we are using multiple proxies to verify tsunamigenic origin of the buried sand and timing of those tsunami events is constrained with radiocarbon age determinations. The results of this study will be compared with the other paleotsunami studies along Southern California coastal line and will help with the California State’s tsunami assessment hazard programs.

AAPG Search and Discovery Article #90162©2013 Pacific Section AAPG, SPE and SEPM Joint Technical Conference, Monterey, California, April 19-25, 2013