Japan Earthquake Not the "Big One"?

Megaquake long predicted—but in totally different region

Though Friday's Japanearthquake—which spawned atsunami and damaged a nuclear power plant—was the largest to strike the country since the dawn of modern seismology, it wasn't the long dreaded "big one," experts say.

Not because the magnitude 9 earthquake wasn't big, but because it was in the wrong place. (See Japan earthquake and tsunami pictures.)

Seismologists have long predicted that the big one would probably be a repeat of the 1923 Kanto earthquake, which occurred in a dangerous fault zone close toTokyo and killed an estimated 142,000 people.