This is a tricky area, in plate tectonics terms. As I learn more, I'll straighten this out a bit. There are three graphs showing three different components of the ground motion at the site. Time Zero is one minute before the P-wave first arrival. Survivors began to emerge from the devastation, digging themselves out of the sand to seek help or grasping the hands of rescuers sorting among the bodies.
Survivors say that first their homes trembled as an earthquake shook the seabed.
Then they heard a roar like a jet fighter landing. Rescue officials estimate that at least 1,000 people died when the tidal waves struck in the darkness. The Australian Defense Force, which is helping in the rescue operation, estimates 6,000 people are homeless.