A 4.0 magnitude aftershock rattled the northeast on Friday night only hours after the region experienced a rare 4.8 magnitude quake, and officials are warning that more could be coming soon.
The aftershock hit Gladstone, New Jersey, just before 6:00 p.m. ET on Friday, prompting many in the New York metro area to voice their disbelief over experiencing “another earthquake” on social media.
The U.S. Geological Survey (USGS) said that the larger earthquake—which centered on Whitehouse Station, New Jersey, at 10:23 a.m.—was the strongest felt in the area since 1950.
While some expressed confusion about the second earthquake, a USGS spokesperson told Newsweek via email on Friday night that it was “considered an aftershock to the M4.8 mainshock from earlier today.”
“Aftershocks are earthquakes,” the spokesperson said. “They are just smaller magnitude quakes that follow the largest quake, which is referred to as the ‘mainshock.’ The M4.8 this morning would be considered the ‘mainshock’ since it was the largest, while the M4.0 and others occurring after are called ‘aftershocks.'”
“If a larger earthquake were to occur after the mainshock, then that new quake becomes the mainshock, and the earlier quakes become ‘foreshocks,'” the USGS representative added. “Then things start again as subsequent smaller quakes following that new quake become aftershocks.”
USGS officials have forecasted that there is a 78 percent chance of additional 3.0 magnitude or larger aftershocks striking the area within the next week. The chances of additional 4.0 or larger aftershocks are 16 percent.
This is a developing story and will be updated as more information becomes available.
Photo by Eduardo Munoz Alvarez/Getty Images
Uncommon Knowledge
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.