Assuming your name SLO is a location reference, it might help to reassure your DS that earthquakes along the San Andreas (where a "big one" is most likely to occur) would happen below land anywhere south of San Francisco, so those won't trigger a tsunami.
Yes and no. EQ and Tsunami geek reporting.
Tsunami risk along the CA coast is real. Great maps are here:
http://www.conservation.ca.gov/cgs/...nundation_Maps/Pages/Statewide_Maps.aspxThe source of those tsunami are either from off shore vertical faults, off shore faults that trigger landslides, or from distant earthquakes. The Japanese EQ in 2013 hit CA and did quite a bit of damage in some places, and killed one. Not that I'd tell a kid already anxious about such things about this.
However, being prepared means that a kid will almost assuredly be out of harms way: If you in one of the inundation zones, then if you feel shaking, get to high ground. If the earthquake is in Alaska or Japan, then there will be p.l.e.n.t.y of time to communicate to everyone how to be safe.
The SAF is actually quite a bit inland from SLO, and the local geology means that the shaking hazard is lower. This is also getting into the zone where the fault slips more continuously than catastrophically. That's not to say that EQs aren't a concern there, but not as bas as other parts of CA. One thing that would be good to know as coming online is an Earthquake Early Warning system (
http://www.shakealert.org) for CA. It's something that performed extremely well in the Tohoku earthquake. If he wants to take action on this, he can write letters to Congress to help get the project fully funded.
