(CBS News) SAN DIEGO - Chile was shaken by a 6.7 magnitude earthquake Monday night. It was one of 13 powerful quakes around the world so far this month.
Structural engineers and researchers at the University of California have begun tests to determine what would happen when a series of massive earthquakes strikes a large medical building.
CBS News correspondent Ben Tracy reports on the experimental man-made earthquakes.
Over the next two weeks, they will be shaking an 80-foot-high building.
It's hard to tell from the outside, but on Monday the five-story building experienced an 8.8 earthquake, moving just inches in each direction.
Inside things barely moved, thanks to giant shock absorbers which protected the building from most of the shaking. It was an unprecedented test of so-called base isolators.
"The ground is moving a lot but the building is staying put," said Jose Restrepo, an engineer at the University of California, San Diego." It's like being hung from the air while the ground moves."
Base isolators have been placed under the Bay Bridge in San Francisco in order to absorb the shock of a major quake.
"This is utterly unique; it has not been done," said Mike Gardner, head of the California Seismic Commission.
He said Monday's building test near San Diego is one of the most realistic ever done.
"We have lots of data on buildings that have been shaken in real earthquakes and how they have failed," said Gardner. "But we have not been able to measure during the course of the shaking what happens to the building and that's a real key."
The point of this test is to see how engineers can improve buildings such as hospitals and schools to keep them functional after being struck by a major quake.
So while from the outside this doesn't look like much, inside it's very realistic. There is a mock operating room and intensive care, heating and cooling systems and even elevators. The building sits on top of powerful hydraulics that can simulate nearly any earthquake.
One test simulated the 6.7 magnitude quake that hit Northridge, California in 1994.
57 people died and the quake caused $20 billion in damage. Since then thousands of structures in California have been retrofitted to withstand even stronger quakes.
Researchers will be running more quake tests next week and will remove the shock absorbers so they can see what happens without them. Likely, a lot more damage.