The San Francisco & California quakes look like text book for-shocks for something big.
I have the gut feeling a limit has been reached somewhere.
Stay safe east coast people!
Quoting: Anonymous Coward 70442455 The area around San Ramon, in the San Francisco Bay area has been hit by a large swarm of earthquakes over the last 24 hours. Early Wednesday morning, authorities reported that the small town in the East Bay area had experienced 20 or so small earthquakes.
USGS said that while the quakes were all small, the largest only reached a magnitude of 3.0, that many were centered in a small area located near the Crow Canyon Country Club. Officials said that five of the quakes ranked as 2.0 or higher.
A senior research geologist for the US Geological Survey, David Schwartz, said such swarms are not that unusual. He went on to say that the San Ramon Valley is the “center of earthquake activity” in the Bay Area. He said that as recently as 2003, a swarm of 120 earthquakes over 31 days hit the area in and around San Ramon. That time the largest quake registered a magnitude of 4.2.
Schwartz, who lives in nearby Danville, said he was shaving when the largest quake in this swarm struck. “I thought at first a truck was passing by,” he said.
But even that swarm pales in comparison to the biggest one recorded back in 1990, when a swarm in Alamo, struck with over 350 earthquakes over a period of just 42 days. That time the largest was measured at magnitude 4.4.
Schwartz said that they are still not sure why such swarms occur. “We just don’t understand the structural geology of the swarms, why they turn on and shut off quickly,” he said. “We just don’t understand.”
sorry glp wont let me post link.....