In surveillance video outside the center, you can just barely see the camera shake during the quake, which began around 2 a.m., but people near the epicenter definitely felt it.
"My husband thought it was a gas main explosion or something like that," said Jennifer Gerstenberg of Freehold.
"When I woke up, my friend called me and said that she felt an earthquake and stuff fell off of her shelf," said sixth-grade Sarah Gerstenberg.
"Our operators actually in our 911 center located just across the way has experienced what they describe as a jet engine kind of explosion," said Monmouth County Sheriff Shaun Golden.
Within 30 minutes of the 3.1 magnitude earthquake, the Monmouth County 911 Center received around 125 calls.
"I heard something," said one worried caller.
"Like your house shook? Yeah. So did half the state I guess," answered the dispatcher.
Some were asking if an explosion had happened.
"Our whole building just shook. And a big boom happened," one caller said.
"Just get yourself into a safe place, OK? We're not sure what it was, but we do have officers out investigating the area, OK?" the dispatcher replied.
Researchers at Princeton University are spent the day looking at data collected from campus, 30 miles from the epicenter.
"This is just part of the normal process of the earth's cycle of plate tectonics. The slow building up stress and a sudden release of elastic energy," said Frederik Simons, professor of seismology at Princeton University.
He said these small earthquakes are normal, we just don't feel them very often.
"Feeling one in New Jersey is extremely rare," said Simons.
Professor Simons estimated this earthquake could be felt within a radius of 30-50 miles from Freehold.
The USGS is reporting that a magnitude 3.1 earthquake has struck near the town of East Freehold, New Jersey early this morning. There have been numerous reports of shaking across the state. The latest information from the USGS here: https://t.co/7Oqrj9y05X pic.twitter.com/I62vRqkuo3— AccuWeather (@breakingweather) September 9, 2020
The earthquake, although small, is also relatively uncommon in the region. A 2.7 earthquake was reported in Bernardsville, New Jersey in 2015.
The Greater Delaware Valley region felt tremors after a 4.1 magnitude quake struck near Dover, Delaware back in December 2017.
And on Aug 23, 2011, a 5.8 magnitude earthquake in central Virginia shook buildings in the tri-state area.