Last week a series of 10 mini-earthquakes struck Monterey County in the US state, raising fears a monster tremor could devastate the region.
A powerful, 4.6 magnitude quake 13 miles northeast of Gonzales, along the San Andreas Fault, was the largest to strike the region.
The San Andreas Fault – a 750-mile fissure that runs the length of California – is thought to be long overdue a “Big One” earthquake measuring magnitude 7 or greater.
Since last week, a whopping 134 earthquakes within three miles of that 4.6 tremor were recorded, USGS said.
Ole Kaven, a USGS seismologist, said he expects more aftershocks in the coming weeks.
“This one has been a quite productive aftershock sequence,” said Kaven.
“We suspect there will be aftershocks in the 2 to 3 [magnitude] range for at least a few more weeks.”
He said smaller earthquakes could rattle the region for even longer.
“This one has been a quite productive aftershock sequence.”
Ole Kaven, a USGS seismologist
There were no reports of injuries or significant damage as a result of the earthquake swarm.
Yet, a 4.6 tremor is at the “higher end of what we expect in terms of magnitude” for that area, Kaven said.
In the short term, this swarm has dramatically increased the chances of a colossal earthquake rattling the region, according to experts.
Over the past 150 years, pressure has been building up along the San Andreas Fault that experts believe could unleash the next major earthquake.
Seismologist Lucy Jones, of the US Geological Survey, said the fault is the most likely of California’s 300 to produce a major earthquake.