Officials said the megaquake advisory is not a prediction and the probability of a magnitude 8 or larger quake is only about 1%, but there's hope it will serve as a wake-up call.

Follow Newsweek for live coverage after a large earthquake strikes off the coast of Japan.

Lori Dengler is an emeritus professor of geology at Cal Poly Humboldt, an expert in tsunami and earthquake hazards. Questions or comments about this column, or want a free copy of the preparedness magazine “Living on Shaky Ground”? Leave a message at 707-826-6019 or email [email protected].