Page 1 Two slabs of the earth's crust suddenly slide past one another, releasing huge amounts of energy in the form of vibrations, which pass through the deep crust and along the surface as waves. And when the shaking stops, some structures are heaps of rubble, while others still stand.
Traffic still streams on a freeway nearby, yet an elevated highway a mile away lies collapsed.
The example of Loma Prieta. RealVideo with Seismologist Robert Uhrhammer of the UC Berkeley Seismological Laboratory and Robert Reitherman. RealVideo with Seismologist Lind Gee of the UC Berkeley Seismological Laboratory. How old buildings are retrofitted.