Giant Quake Reveals Japan's Other Unstable Faults The March 11
earthquake just off the coast of Japan surprised many experts.
Geologists say they didn't expect that big a quake in that spot.
But they do fear that more big quakes may be in the offing in or
near Japan. Scientists can't tell when, but they're trying to
narrow down where. The answers lie amidst the huge plates that
make up the Earth's crust. Think of them as like floating ice
sheets on a lake. Where plates meet edge to edge, sometimes one
shoves itself under the other. The plate may just creep smoothly
underneath or get stuck. In that case, stress builds up until
the edges snap free like an overstretched rubber band. Distorted
Tectonic Plates Japan is smack in the middle of a bevy of plate
edges. "In Japan," says geologist Ross Stein of the U.S.
Geological Survey, "we have the junction of three different
tectonic plates, and some of them near Tokyo are highly
distorted." Distortions create stress. But Stein says geologists
didn't view the site of