USGS to use Cal State East Bay building demolition to study Hayward Fault

  • July 19, 2013

By Rebecca Parr
Staff Writer, Bay Area News Group and Daily Review

HAYWARD -- Scientists are taking advantage of next month's implosion of a 13-story Cal State East Bay building to study a portion of the Hayward Fault using seismic monitors they will place throughout nearby neighborhoods.

The implosion of Warren Hall will produce energy similar to a very small earthquake and because scientists know when and where the quakelike event will occur, they can closely monitor the event, said Leslie Gordon, U.S. Geological Survey communications specialist. The data collected will help them better understand the Hayward Fault zone, which lies a little more than 750 yards west of the building.

USGS scientists and volunteers will fan out through neighborhoods within a couple of miles of the building beginning Monday, contacting residents to see if they are willing to have the monitors placed temporarily on their property.

"We can learn a lot," Gordon said. "How deep does the Hayward Fault go? Is it splintered? Is it connected to other faults?"

Using satellite images, USGS scientists have pinpointed where they would like to place the seismometers, instruments about the size of soda cans that measure shaking, Gordon said. Almost 600 seismometers will be positioned on both private and public property beginning Aug. 12 and retrieved after the implosion in mid-August.

The exact date that the building will come down has not been set, said Barry Zepel, Cal State spokesman. "It all depends on the contractor," he said.

Warren Hall, a Hayward hills landmark visible for miles and used by pilots as a visual reference point, has been declared the most seismically unsafe building in the California State University system by a review board. The former administration building has sat empty since 2011.

Earlier this year, regents authorized demolishing the 42-year-old building and constructing a new five-story administration building on the east side of campus.

Cal State geology department employees contacted USGS scientists, who decided to take advantage of the unique opportunity, said geophysicist Rufus Catchings, the lead scientist on what they have named the East Bay Seismic Experiment.

The seismometers will measure how fast the energy from the quake travels, Gordon said.

When seismic waves emanate from an earthquake, they are amplified in some areas, such as in soft sediment or on the fault itself. That makes the shaking there much more violent, Catchings said. The data will help scientists better map what kind of geological layers lie underground.

"If we can look at these things in detail and study it, we can extrapolate on what may happen on the greater fault zone and other fault zones, such as San Andreas," he said.

Scientists also plan to use the implosion to calibrate their permanent seismographs that are spread throughout the Bay Area, Catchings said.

"We can check to see how well our seismographic network is locating earthquakes," he said. "If a seismograph locates this implosion a kilometer off, for example, we can then say, oh, we know we have some errors and try to calibrate our network more precisely."

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