Md.'s first earthquake monitoring station planned in Howard Co.

January 11, 1995|By Howard Libit | Howard Libit,Sun Staff Writer

The shakiest ground in Maryland soon will have its own earthquake sensor, two years after the Columbia area came through 21 small quakes with nothing worse than the jitters.

The $28,000 earthquake monitoring station, the state's first, could be operating at the University of Maryland Central Farm in Ellicott City by April. An agreement is expected to be signed this month by county and state officials.

The automated sensor will alert Maryland Geological Survey officials to all but the tiniest earthquakes anywhere in the state, said James P. Reger, chief of the survey's environmental geology and mineral resources program.

"We're trying to get this station so that the state of Maryland will have its own independent seismograph, giving us a quicker response to confirm earthquakes," Dr. Reger said. "The need to get more data is a concern that grew out of the earthquake activity in the spring and summer of 1993."

The 21 small earthquakes prompted County Executive Charles I. Ecker to offer up to $25,000 for an earthquake monitoring station in the county -- provided that the state and federal governments matched the funds.

"The earthquake people told me that there was no recording place in the entire state and no readings on the earthquakes we were having, so I said I'd be willing to pay up to half of it to get some data," Mr. Ecker said.

Funding for the station's equipment -- including a digital seismograph -- will come from a $10,000 grant from the U.S. Nuclear Regulatory Commission (NRC) and $13,000 from Howard County. The state will pay about $5,000, Dr. Reger said.

The state, which is coordinating the project, turned to the NRC for a federal contribution after being rejected by the U.S. Geological Survey. The NRC, which is in the midst of phasing out its seismic studies, had some unclaimed grant money that it contributed, Dr. Reger said.

The Lamont-Doherty Earth Observatory of Columbia University will lend sensors worth about $6,000 to the monitoring station and provide technical expertise for their setup and operation, said . Doug Johnson, the observatory's technical manager.

Seismologists from the observatory had flocked to Columbia in 1993 to study the county's strange series of earthquakes. The tremors nearly doubled the total number of earthquakes in Maryland's recorded history, a total of about 25 up to that time, Dr. Reger said.

Seismologists told Howard County residents that they were not living on top of a major fault line. They instead theorized that the earthquakes were related to shallow fractures in the Earth's crust that are filled with once-molten rock that has hardened. The tremors could have been caused by the crust shifting to adjust around those fractures.

Dr. Leonardo Seeber, a seismologist at the observatory, said there is little -- but not zero -- risk of a major temblor.

The strongest recorded earthquake to hit Columbia registered 2.7 on the Richter scale. By contrast, the January 1994 earthquake that devastated Los Angeles' San Fernando Valley and killed 61 people registered 6.7.

Nevertheless, the series of Columbia-area earthquakes created fear and curiosity among residents who had never before experienced such an event and also prompted the county's fire and rescue service to modify its emergency disaster plans.

Residents of the Allview Estates development near U.S. 29 and Route 32 -- the area where the earthquakes were felt the strongest -- flooded the county's 911 system with phone calls during the first few earthquakes, said Sgt. Robert Wiseman, a spokesman for the county's fire and rescue service.

Since then, the county has received phone calls several times from residents suspecting they had felt a tremor. But because the nearest earthquake monitoring station is in Delaware, the county has been unable to confirm any earthquakes below 1.5 on the Richter scale, Sergeant Wiseman said.

"This will help fill in a gap in the regional network of seismographs," Dr. Reger said.

The Howard County station will be equipped with a seismograph that automatically alerts local officials to any tremors, enabling them to release information more quickly and accurately, he said.

Seismologists at the observatory also will use data from the seismograph to continue their studies of the Earth's movement along the East Coast, Dr. Johnson said.

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