La Jolla, San DiegoLa Jolla, San Diego

Small faults in San Diego & La Jolla yellow -> gen. fault trend red -> small faults

Mt. Soledad formed by tectonic uplift

N

La Jolla and Scripps CanyonLa Jolla and Scripps Canyon

Submarine canyon

Proximal to LJ Shores and SIO

Associated w/ regional faults

Terraces along N&S faces of

Scripps Canyon

Scripps Canyon

LJ Canyon

Bathymetry of Scripps Bathymetry of Scripps CanyonCanyon

Bulletin of the Geological Society of America 60:1597-1612, 1949

Results from Multibeam Data

N

SeismicsSeismics

Examination of sub-Examination of sub-bottom structurebottom structure

Origin of terraces and Origin of terraces and associated blocksassociated blocks

Explain asymmetric Explain asymmetric profile canyonprofile canyon

Seismic SurveyingSeismic SurveyingKennedy, 1980

R/V Ellen B. Scripps in 1977 and R/V Polaris in 1970

Yield:

2,000 km medium and high resolution sub-bottom reflection profiles

Portions used marked in red

Seismic DataSeismic Data

Concepts of Ward’s Tsunami Concepts of Ward’s Tsunami ModelModel

Determine perturbation of sea floor shape and project Determine perturbation of sea floor shape and project perturbation onto sea surface over time and spaceperturbation onto sea surface over time and space

Classical Tsunami Theory:

Rigid sea floor

Sea water is “incompressible, homogenous, and non-viscous”

Linear wave theory:

Ratio of a wave’s amplitude to wavelength much less than 1

Allows modeling of complex events through the superposition of simpler ones

Slide MotionSlide Motion

Failure area broken into separate pistons

Each piston can move vertically, horizontally or a combination of the two

Slide would be south towards the bottom of the canyon

N

Modeling ResultsModeling Results Time

This

Corresponds to this

Maximum wave height

Tsunami Run Up & EffectsTsunami Run Up & Effects

Streets that are below 5m: Camino Del Oro, Vallecitos, Avenida de la Playa, El Paseo 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

Extras