TRENTON, NJ — Several months after a significant 4.8 magnitude earthquake struck near Tewksbury Township in New Jersey, residents continue to experience a series of smaller aftershocks that are keeping the region on alert. The initial quake, which occurred on April 5, 2024, was the largest the area had witnessed in over two centuries and was felt across a broad swath of the northeastern United States.
Since the main shock, multiple smaller tremors have been recorded, most notably near Califon and Whitehouse Station in New Jersey. Recent seismic activity includes:
- A 1.3 magnitude tremor 5 km ESE of Califon on June 12.
- A 1.7 magnitude quake 6 km N of Whitehouse Station on June 8.
- A 1.4 magnitude event 4 km NE of Whitehouse Station on the same day.
- Additional minor quakes ranging from 1.0 to 1.8 magnitude occurring sporadically throughout early June.
These ongoing tremors are part of a pattern of aftershocks that have been closely monitored by the U.S. Geological Survey. Although these aftershocks have been relatively mild, with magnitudes too low to cause significant damage, they serve as a persistent reminder of the region’s vulnerability to seismic events.
Residents have been advised to stay informed about earthquake preparedness and to remain vigilant. While the frequency and intensity of the aftershocks have gradually diminished, the possibility of more significant tremors cannot be entirely ruled out.
Initial report at the time of the 4.8 quake
A 4.8-magnitude earthquake struck near New York City on Friday morning, the U.S. Geological Survey said, shaking buildings up and down the East Coast and surprising residents in an area that rarely experiences notable seismic activity.
The quake’s epicenter was in Tewksbury in central New Jersey, about 40 miles (64 kilometers) west of New York City. It occurred just after 10:20 a.m. ET (1420 GMT) at a depth of 4.7 kilometers (2.9 miles), the USGS said.
At 5:59 p.m. there was a small but noticeable aftershock, which had a magnitude of 4.0, according to the USGS.
No major damage was reported, but engineering teams were inspecting roads and bridges.
“This is one of the largest earthquakes on the East Coast in the last century,” New York Governor Kathy Hochul said at a news conference.
New York City Mayor Eric Adams said that no injuries had been reported but urged city residents to take cover under furniture, in a doorway or next to an interior wall if they felt aftershocks.
“New Yorkers should go about their normal day,” he said at a news conference.
People from Baltimore to Boston reported feeling rumbling and shaking, with some running outside to try to detect the source.
Charita Walcott, a 38-year-old resident in the Bronx borough of New York, said the quake felt “like a violent rumble that lasted about 30 seconds or so.”
“It was kind of like being in a drum circle, that vibration,” she said.
James Pittinger, mayor of Lebanon, New Jersey, near the quake’s epicenter, said there were no reports of injuries or significant damage but that people were unnerved.
Feds Deploy Earthquake Sensors in New Jersey After 4.8 Quake
A team from the U.S. Geological Survey has initiated the installation of seismic sensors in New Jersey to monitor aftershocks following a recent earthquake.
After a 4.8 magnitude earthquake struck on April 5, 2024, the USGS team started setting up eight “aftershock kits” in Whitehouse Station. These kits are designed to record data on aftershocks’ origins, durations, and magnitudes, according to USGS electronics technician Greg Tanner.
The project involves collaboration with several academic institutions, including the Lamont Doherty Earth Observatory, the Texas Seismological Network, Rutgers University, and Yale University.
To date, the USGS has detected 50 aftershocks with magnitudes ranging from 1.3 to 3.8. There is a predicted 12 percent chance of a magnitude 3 or greater aftershock occurring within the next week, and a one percent chance of one reaching magnitude 4 or greater. This seismic activity is occurring in a region known for its ancient, inactive faults which can still occasionally reactivate due to ongoing tectonic pressures.
The newly deployed kits include sensors for recording strong motion and high frequency, digital transmission devices via cellular networks, and solar panels.
Data collected will be transmitted in real-time to the USGS National Earthquake Information Center in Colorado for immediate analysis. Some sensors are being placed alongside existing USGS stream gages in the state for enhanced monitoring capabilities.
