This pitcher fell and broke from a sturdy shelf in the home of Meriel Medrano on Saturday night. (Courtesy photo)

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5/6/2003

3.65 'quake hits Anderson Springs
By Margaret Gan-Garrison - Record-Bee staff
Tue May 6 03:00:08 2003 -- ANDERSON SPRINGS - Residents of Anderson Springs and Cobb were jolted from their regular routine Saturday night, when an earthquake measuring 3.65 on the Richter scale, struck the area.

The tremor struck 9:23 p.m. with the epicenter just four miles east of the Geysers and three miles from Anderson springs.

It rattled the nerves of local residents who said the tremors lasted longer this time and several reported damages.

"Normally it feels as if a truck has backed into the back of your house," said Jeffrey Gospe, president of Anderson Springs Com-munity Alliance. "This time, it felt like the truck struck the back of the house and went right through the house. It scared my three-year old."

"The tremors threw a vase I had for Christmas from the shelf and shattered it into 100 pieces," said Meriel Medrano, local resident and manager at Anderson Springs Community Service District.

"I am really concerned about our water source. This time, the epicenter was very close to the springs and the water flows through the creek to Lake Berryessa and Solano County," said Medrano. "Our water master went over to check it today. I am glad there was nothing unusual."

Joan Clay and her husband had guests over for dinner when the earthquake happened. "The tremors felt really bad. Things fell from the wall, but we did not have any breakage."

Connie Dethlefson, who has been coming to Anderson Springs since the 1940s and now lives there permanently, had some pictures coming off the wall. "Drawers became opened and the clothes rod in one big closet broke off" dumping the clothes on the floor

Dethlefson said she has just spent $600 to refinish the outside of the chimney, "The rocks fell off after the last earthquake. I had things breaking from the last quake. I am getting really sick of it."

The area has been experiencing increases in seismic activity, which residents say are man-made and related to the geothermal power plant that has been in operation since the 1980s and the injection of the county's wastewater into the Geysers over the past five years. Under Basin 2000, wastewater from various parts of the county is routed into the Geysers.

"This is the strongest earthquake we have ever experienced since we have been going up there for the last three years," said Gospe, concerned with the increased frequency and intensity of the tremors. He has been analyzing raw data on the earthquakes in the Southeast Geysers available on the website of the United States of Geological Survey (www.usgs.gov).

"In the 32-year period (1970-2002), there were 3,030 earthquakes with a magnitude of 1.2. About 57 percent took place in the last five years and three months," said Gospe.

Charles Watson, chief geologist with Seismo-Watch said there have been nine earthquakes of the magnitude of 3.0. so far this year. Seven of them happened over the last six weeks. Last year, there were 18 earthquakes with a magnitude of 3.

"Since geothermal activity started in the 1980s, the number of earthquakes within the range of three, have increased proportionately," said Watson. "There is a very strong indirect relationship between steam production up at the Geysers and the seismic activity (in the area)."

Watson said there is a need for more studies, "The Geysers is the most active seismic spot in the U.S. It is a valuable laboratory to see how industry can co-exist with its neighbors. There is a need to do long-term study in the area."

David Oppenheimer, project chief of USGS' Northern California Sesimic Network said it has been documented in the past that earthquakes can result if the steam fields expand in size.

"What we are asking is for the county to have a systematic and responsible program for the injection of wastewaters in the Geysers," said Gospe. He estimated that about 14 billion gallons of water have been injected into the Geysers between Sept. 1997 and Dec. 2002. The level of injection is expected to double and eventually triple with the addition of Sonoma County treated waste water and the Full Circle project in Lake County.

The Seismic Monitoring Task Force meets at 9:30 a.m. on May 19 at the Board of Supervisors chambers in Lakeport.