Scripps Institution of Oceanography

• Tectonics controlonshore and offshoremorphology

• How does tectonicsinfluence thickness ofsands offshore?

Scripps Institution of Oceanography

• Tectonics play arole in controllingsand thickness anddistribution

• How does tectonicsinfluence biology?

Scripps Institution of Oceanography

• Tectonic deformationcontrols habitats andbiodiversity

• Are there otherassociated hazardswith tectonics?

Slump scarSlump Block

Results from Multibeam Data

N

Slide Motion

Failure area broken into separate pistons

Each piston can move vertically, horizontallyor a combination of the two

Slide would besouth towards thebottom of thecanyon

N

Modeling Results Time

This

Corresponds to this

Maximum wave height

Tsunami Run Up & Effects

Streets that are below 5m: Camino Del Oro, Vallecitos, Avenida de la Playa, ElPaseo Grande, Paseo del Ocaso

Property value range: $275,000 – $1.37 million. Average cost: $700,000

During the summer months 17,000 people/day visit La Jolla Shores Beach

Tsunami Date Runup Source Type Region

December 21, 1812 3.4 m Earthquake/landslide Santa Barbara

7.7?

August 31, 1930 3 m Earthquake/landslide Redondo Beach

5.2 Santa Monica

Venice

October 18, 1989 1.0 m Earthquake/landslide Monterey

7.2 Moss Landing

April 25, 1992 0.9 m Earthquake Humboldt Bay region

7.2

September 1, 1994 0.1 m Earthquake Crescent City

7.0

Threat from Distant Sources: Large earthquakes of distant or local origincan cause tsunamis which can be very damaging in California. Of these,tsunamis generated from distant earthquakes pose the greatest threat forCalifornia, particularly those generated in the Aleutian Islands and Alaska.The frequency of occurrence for such events is considered relatively high.Northern California is particulary susceptible to such distantly - generatedtsunamis, while Southern California is affected to a much lesser extent.the bay.

Threat from Local Earthquakes: The relative tsunami threat for localtsunamis in California can be considered as being relatively low because ofthe low recurrence frequencies from these disasters. The recurrencefrequency of large tsunamis in California has been estimated to be once every100 years. Between 1812 and 1988, thirteen possible tsunamis have beenobserved or recorded from local earthquakes. These events were poorlydocumented and some are questionable. There is no doubt that earthquakesoccurring on submarine faults, off Santa Barbara, could generate largedestructive local tsunamis. Perhaps the size of the 1812 tsunami wasexaggerated in the historical records, but one and possibly two large tsunamisdid occur in the area.