Don, a slide the size of those know offshore southern California would not cause damage across the Pacific....they are a local, southern California hazard (or, same for M7.5 earthquake). On the other hand, mega landslides, with volumes of 100s or even 1000s of cubic km are known, and the associated tsunamis can cross oceans....interesting talk at AGU that the marine deposits at elevations of 21-28 m on Bermuda and 23 m in England were not due to high global sea levels at 400,000 years...they are due instead to a collapse of a volcanic island (Canary Islands?) and a mega-tsunami....

I'm interested in this because some of the best-developed wavecut platforms uplifted on the Islands south of Santa Barbara are inferred to be that age.....and we will be trying to core deposits of this age next August.....Chris