Apparently Catalina Island was created and uplifted by earthquakes at a bend in an offshore strike-slip fault. Studies estimate that every 200 to 500 years another quake could occur that would generate a tidal wave to the coast of up to 6 to 9 feet. The tidal wave would be concentrated to 9 to 12 feet in San Pedro in the Los Angeles harbor. That is not very often compared to quakes on the San Andreas fault. With respect to the San Onofre nuclear plant, they are protected by beach and a tsunami wall that rises 30 feet over the average low tide level. A source for this 2004 study is www.physorg.com/print1288.html. The study also shows that there would be a 15 to 20 minute warning before it his the harbors, which is time to set up an early warning system and have walking evacuation to higher ground.
Places like the Newport peninsula could build raised safety platforms every few blocks, or require some evacuation residences or businesses to have ground level garages and upper floor safety zones.
