A shallow double earthquake just four miles from Gilroy was reported early Monday morning according to the U.S. Geological Survey.
A 2.5 magnitude earthquake struck at 1:35 a.m about four miles south-southeast of Gilroy, followed by a 3.7 magnitude earthquake that hit at approximately 2:05 a.m. with an epicenter roughly five miles south-southeast of Gilroy.
The smaller quake had a depth of 3.7 miles, while the larger quake occurred at a depth of 2.2 miles.
According to user submitted reports on earthquake-report.com, some Gilroyans said the larger quake lasted for six seconds, shaking and creating a rumbling noise that woke many residents up. The temblor was even felt in Morgan Hill, as a few residents reported being woken up and said they felt the bed shake and doors rattle.
The most recent, largest earthquake to rock the Bay Area took place in May 2002, when a 5.2 magnitude temblor with an epicenter just three miles south of Gilroy damaged a water main in Gilroy.
About nearby earthquake faults
The areas of Gilroy, Morgan Hill and Hollister are something of a terrestrial intersection where a handful of earthquake fault lines converge like superhighways (namely, Sargent, Calaveras, Quien Sabe, San Andreas and Paicines).
The southern segment of the Calaveras Fault produced two 6.2 magnitude earthquakes in Morgan Hill – the first in 1911 and the second in 1984. It also caused the 5.9 quake at Coyote Lake in 1979.
The 2003 Working Group for California Earthquake Probability assigned an 11 percent probability that the Calaveras Fault will produce a magnitude 6.7 or larger earthquake in the next 30 years.
