A seismograph in Pennsylvania picked up 6.4-magnitude earthquake in SoCal

This image shows that there were people who reported to the United States Geological Survey that they felt the 6.4-magnitude earthquake in the San Francisco Bay Area as well as throughout the state of California. less This image shows that there were people who reported to the United States Geological Survey that they felt the 6.4-magnitude earthquake in the San Francisco Bay Area as well as throughout the state of ... more Photo: Courtesy Of The United States Geological Survey Photo: Courtesy Of The United States Geological Survey Image 1 of / 7 Caption Close A seismograph in Pennsylvania picked up 6.4-magnitude earthquake in SoCal 1 / 7 Back to Gallery

The 6.4-magnitude earthquake that struck near Ridgecrest on July 4 was picked up by a seismograph in the San Francisco Bay Area, according to a tweet from the National Weather Service's Bay Area office.

"Seismograph near Morgan Hill in Santa Clara County picked up the #Ridgecrest #Earthquake this morning," reads a tweet from the NWS from late Thursday morning.

There's an image of a reading from the United States Geological Survey seismograph in Morgan Hill that accompanies the tweet; it shows activity right when the quake struck at 10:33 a.m.

"It doesn't necessarily mean that people felt that earthquake," said Scott Rowe, a meteorologist with the Bay Area NWS office in Monterey. He said his office, which is closer to the epicenter of the earthquake than the seismograph that picked up the shakes, didn't feel anything.

Seismograph near Morgan Hill in Santa Clara County picked up the #Ridgecrest #Earthquake this morning. pic.twitter.com/eWDic57WX8 — NWS Bay Area (@NWSBayArea) July 4, 2019

He said that the seismograph likely picked up the earthquake because it's an "incredibly sensitive instrument" and sometimes can pick up earthquakes from far away.

One Bay Area resident, Michael Dearing, commented on the NWS Twitter post that "My light fixtures at home [in Silicon Valley/Peninsula] were swinging."

The USGS Did You Feel It? map for the earthquake shows that there were several reports of people feeling the earthquake with "weak" or "light" intensity throughout the Bay Area. The closest NWS office to the Bay Area one that reported feeling the earthquake was in Hanford, which is the office for the Fresno area.

The Bay Area seismograph isn't even the one furthest from the quake that felt it. Brian Lada, a meteorologist and journalist for Accuweather in Pennsylvania tweeted out an image of a seismograph in Lancaster that picked up the earthquake over 2,000 miles away from the quake's epicenter.

Drew Costley is an SFGATE editorial assistant. Email: drew.costley@sfgate.com | Twitter: @drewcostley