How far inland of Santa Monica California can a tsunami go?

Answer 1

A good way to get a feel for this is to go to Google maps, pull up Santa Monica, and then switch to "Terrain" view.

What you'll see is that west Los Angeles is relatively flat. While places like the San Fernando Valley would be protected by the Santa Monica mountains, a megatsunami like the one that struck Lituya Bay, Alaska in 1958 could conceivably reach downtown LA. There is evidence that past megatsunamis have gone over thirty miles inland, therefore it is possible that one could traverse all of LA and even make it through the same gap in the hills that the 605 freeway takes, roll right over El Monte, and not be stopped until reaching the San Bernardino mountains neat Duarte.