How long could aftershocks last following New Jersey earthquake?
The 4.8-magnitude earthquake that hit New Jersey on Friday has produced more than three dozen aftershocks, and experts say more could be on the way within the next week.
As of late Monday morning, the United States Geological Survey website had recorded 41 measurable quakes in the state since 10:23 a.m. Friday, when New Jersey's strongest earthquake since 1783 was felt throughout the Northeast and mid-Atlantic regions.
The most significant aftershock, the map shows, was a magnitude-3.8 event with an epicenter near Gladstone that arrived Friday at 5:59 p.m. The rest were comparatively smaller, with magnitudes between 1.5 and 2.6, and much less perceptible to New Jersey residents.
The weakest measurable quakes since Friday morning came at 7:31 p.m. Sunday, when a 1.3-magnitude event was recorded near Califon. That was followed by a 1.4-magnitude near Whitehouse Station at 1:21 a.m. Monday and a 1.5-magnitude near Gladstone at 2:13 a.m.
Outlook for future quakes
Although it is impossible to predict when or where any quakes will take place, the USGS relies on the recorded aftershocks to determine the likelihood of another event occurring. As of Sunday afternoon, the Friday evening aftershock was the only one measuring at least a 3.
Based on the data, the USGS estimates there is a 24% chance of an aftershock of 3 or above through 5 p.m. on Sunday, April 14. However, that number drops to 3% for an event of 4 or above, like the Friday morning earthquake, during the same time frame.
It is also possible, yet highly unlikely, that Friday's rumble was a foreshock, an earthquake that precedes a larger seismic event.
The USGS puts the chances of a New Jersey earthquake measuring 4.8 or higher in the next week at 1 in 200, or 0.5%. The odds go down to 0.3% for a quake 5 or above, 0.03% for 6 or above and 0.003% for 7 or above.
This article originally appeared on NorthJersey.com: New Jersey earthquake after shocks could last a week
