In San Ramon the last record number of earthquake swarms to rock the area was 120 back in 2003 and because the Bay Area has been hit with up to 30 earthquakes since Tuesday October 27th there’s good reason to wonder if something bigger is going to hit the Bay Area.
Before now, the biggest swarm on record in the same general area had been in 1990 in neighboring Alamo, about 30 miles east of San Francisco. That’s when 351 earthquakes struck over 42 days, with the largest recorded at a magnitude of 4.4.
According to the U.S. Geological Center the actual number of earthquake swarms to hit the Bay Area back in 1990 may have been more since the equipment back in the early 1990’s wouldn’t have been able to detect it.
The USGS noted that “based on the characteristics of historical earthquake swarms in this region, the current swarm may continue for several more weeks.
What Schwarts is more interested in is how large the earthquakes have been, not simply the number. And in that respect, the 1990 Alamo swarm beats the current San Ramon one. Back then, the largest Alamo quake was recorded at a magnitude of 4.4, and people reported having their chimneys knocked down. None of the current San Ramon quakes have risen to that level or caused any reported damage or injury. But some people – and pets – have felt the ground rumbling.
“I’ve not felt so many tremors in decades,” Mark Stone said outside a San Ramon Starbucks on Tuesday morning. “My dog, Gimmel, she’s the first one to know a couple of seconds before.” Gimmel might be a busy pet for a while. The USGS noted that “based on the characteristics of historical earthquake swarms in this region, the current swarm may continue for several more weeks.” Scientists, however, added that it is unlikely that the swarms are a foreshock to a large, damaging earthquake.
Source: The Extinction Protocol