Trembling with anticipation

Bay Area residents shrugged off the state's latest "strong" earthquake Tuesday morning, feeling little more than rumbling tremors from the 6.0 quake and its aftershocks that hit the Central Valley.

The shake-up missed peak commuting hours. And although most transit agencies were unaffected by the shifting tectonic plates, the seismic activity triggered BART's ultra-sensitive alarms, prompting a system-wide shutdown affecting about 12,000 passengers for a few minutes.

The quake, which hit near Parkfield, Monterey County, around 10:15 a.m., left little physical damage compared to a similarly large earthquake that shook the area in December and left two people dead.

Parkfield, with a population of 37, has more earthquake monitoring equipment than people. The town has seen 6.0 earthquakes with such frequency in the past two centuries that government scientists carpeted the area with all sorts of seismic monitors in 1985, anticipating that the data gathered from the next temblor would provide insight into what happens during a major quake.

"In a way, this is exciting," said U.S. Geological Survey Geophysicist Jeanne Hardebeck. "We did take a gamble in the '80s to start putting out all this instrumentation. This is a day we've been waiting for for a long time."

Near Parkfield, residents reported that trees were shaking like brooms and that standing on solid ground felt more like catching a wave on a surfboard. But in the Bay Area, few felt little more than a wobble.

"People felt it, but we didn't get any calls for damage," said San Mateo County Sheriff's Lt. Lisa Williams.

In Redwood Shores, which sits on about 14,000 acres of landfill east of U.S. Highway 101, the shaker interrupted a meeting of the Sequoia Union High School District administration when the conference room lights began swaying back and forth.

Earthquake preparedness

The latest earthquake was benign by most standards, and Bay Area residents live with the constant threat of natural disaster. Here are a few tips to better roll with the rumblings.

• Preparation is key: You should know how to easily shut off utilities such as water, electricity and gas. Don't store flammable liquids, such as spare gas, near stoves, furnaces or other sources of flame.
• You'll need some supplies: Portable radios, flashlights and extra batteries become particularly useful when the power is out. Remember your medications too, and try and keep a two-week supply handy.
• Don't wander around: During an earthquake, if you're inside, stay there. If you're in the kitchen, turn off the stove. If you're outside, stay away from potential hazards such as power lines, trees and tall buildings.
• Pull over: If you're in your car, steer clear of any overpasses, power lines and street signs. Pull to the side of the road, and don't leave your car until the quake has passed.

Source: Pacific Gas and Electric Co.