On Tuesday morning, San Jose residents were shaken by a 5.1 magnitude earthquake at 11:42 a.m. with the epicenter at Joseph D. Grant County Park, about 13.8 miles east of San Jose State.
The earthquake reached a minimum depth of 8.4 kilometers on the Calaveras Fault, a major branch of the San Andreas fault which runs through the San Francisco Bay Area, according to the U.S. Geological Survey report.
Kimberly Blisniuk, earthquake geologist and SJSU associate professor, said she was in her office when she felt the main shock and left her building.
“That's pretty shallow for an earthquake and as a result, the energy that radiated from that earthquake propagated and we were able to feel it,” Blisniuk said.
At 11:47 a.m., five minutes after the first earthquake, U.S. Geological Survey reported a 3.1 magnitude aftershock and at 3:08 p.m., a 3.8 magnitude quake, according to a Tuesday ABC7 News article.
Although the number of aftershocks will decrease over time, larger magnitude shakes can temporarily increase the number of aftershocks, according to the U.S. Geological Survey Aftershock Forecast.
There is also a 1% chance of one or more aftershocks being larger than 5.0 magnitude, which can cause damages within the next week, according to the aftershock forecast.
“Oftentimes, we don't feel these aftershocks because they are quite small,” Blisniuk said. “But we do have the chance of a main shock still happening on the Calaveras Fault related to this earthquake, but the likelihood of a main shock occurring and this being the foreshock decreases quite a bit.”
The U.S. Geological Survey Community reports show that San Jose experienced a mild and light earthquake intensity.
Computer science freshman Aayush Kumar said he was in the Student Union when the earthquake hit.
“I was sitting on a chair and I thought, at first, someone was shaking the table with their leg,” Kumar said. “But then I realized I wasn't touching the table and I just felt myself going back and forth.”
He said other people in the Student Union were looking around trying to understand what was going on, but since the earthquake lacked intensity, the majority of people only realized what happened a few moments later.
“It was pretty mild, so I didn't feel too worried,” Kumar said. “I felt I could get out of the building safely, but honestly, it was just kind of cool to feel it.”
Engineering junior Ahmed Mohammed said he was at home sleeping when the earthquake began and at first, he was not sure about leaving his place.
“I just woke up and I was kind of naked,” Mohammed said. “But when I realized it was an earthquake, I dressed up and then I used the stairs.”
He also said he was not scared because the earthquake was not the first one he experienced.
“I am from Egypt and I experienced one like this when I was 15 years old,” Mohammed said.
Many Californians are accustomed to earthquakes as the state gets “two or three earthquakes large enough to cause moderate damage,” according to California’s Department of Conservation Earthquakes webpage.
Kimberly Blisniuk said she suggests certain measures, including earthquake kits, to minimize injuries for future quakes.
“Depending on where you are, if you have access to go outside and not be in an enclosed building, you should go outside so that nothing can fall on you,” Blisniuk said. “But if there's just not enough time to do that, you should duck and cover.”
She also recommended that people download the ShakeAlert app, which is “an earthquake early warning system that detects significant earthquakes so quickly that alerts can reach many people before shaking arrives,” according to ShakeAlert’s official website.
Blisniuk said this is a great example of Californians coming together to prepare for an earthquake, especially because the state is more prone to them.
“A lot of people felt the earthquake [and] got the notification that an earthquake may be coming,” she said. “It shows that with our advances in technology, we can really save lives.”
