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.

In the latest report prepared by a Japanese government earthquake task force, it was estimated that up to 298,000 people could be killed in a Nankai Trough megaquake with a magnitude of 8-9. The casualties would include 215,000 deaths caused by tsunami waves, the report said.

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].