Annemarie Baltay, a seismologist with the USGS, said the location of the epicenter suggests the quake occurred within the Calaveras Fault zone.
There is a one-in-100 chance of an aftershock greater than a magnitude 5.0 happening in the next day, according to Baltay. There could be 10 to 15 aftershocks of magnitude 3.0 or greater over the next week.
"Aftershocks of this magnitude and duration are totally normal for an event of this type," Baltay said.
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Here's a look at earthquakes above 2.0 magnitude reported near the Seven Trees and Alum Rock epicenter after Tuesday's M5.1 temblor:
- M2.8 reported at 5:20 p.m. Tuesday
- M3.5 reported at 3:08 p.m. Tuesday
- M2.4 reported at 2:49 p.m. Tuesday
- M2.9 reported at 11:47 a.m. Tuesday
There were also several smaller tremors overnight Wednesday in the same general area along the Calaveras Fault.
You can track other earthquakes in the Bay Area using our Earthquake Tracker.