UPDATE: More earthquakes Saturday night centered in Lake Tahoe
UPDATE: There have been a few more earthquakes centered in the middle of Lake Tahoe on Saturday evening. According to USGS, there was a 3.4 magnitude just after 8 p.m., followed by 1.5 at 8:05 p.m., and a 2.8 at 8:19 p.m. The University of Nevada reports several small ones during the day, all under 1.0 magnitude.
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Two small earthquakes happened in the middle of Lake Tahoe on Saturday at 7:19 a.m. and 7:49 a.m. The University of Nevada Seismology Lab measured them at 2.34 and 1.9, but the United States Geological Survey (USGS) measured them at 2.8 and 2.5 magnitude.
Each department's measuring systems look at different depths and conditions. Both quakes were east of Glenbrook, south of Tahoe City. Numerous smaller quakes have been reported since.
The Sierra Nevada is no stranger to seismic activity and Lake Tahoe is on the western rim of the Basin and Range Province, one of the most seismically active regions in the United States.
There are three faults under Lake Tahoe.
West Tahoe Fault
The largest of the three faults, running parallel to the west shore of the lake from Emerald Bay in the south to Tahoe City in the north. It's submerged from Emerald Bay to McKinney Bay, where it becomes the Dollar Point Fault. Scientists believe that these two faults may rupture together.
Stateline Fault
Runs north to south through Incline and into the lake. Scientists believe that the two North Shore faults, including the Stateline Fault, are part of one system and may rupture together.
Incline Village Fault
Runs parallel to the east shore of the lake. In the past, this fault has caused large earthquakes, including one about 500 years ago.