Morris County, New Jersey logged seven shallow earthquakes inside a 17-hour window on July 21. All registered between M0.7 and M2.0. The strongest hit at 21:00 EDT, clocking M2.0 just southeast of Randolph. Depths held steady around 5 km. No injuries. No damage. But residents heard it. Felt it. Called it in. The Morris County Office of Emergency Management confirmed multiple 911 reports of loud booms and light shaking. One caller described it as “something huge fell on my house.” Another said the couch jumped.
The Ramapo Fault is the likely culprit. It runs beneath the region, stretching over 185 miles between the Appalachian Mountains and the Piedmont. It’s not a high-frequency zone, but it’s known for intraplate seismicity. The USGS flagged the swarm as unrelated to the M4.8 quake that hit New Jersey in April 2024. That one followed a typical aftershock pattern. This swarm didn’t.
The first tremor struck at 05:40 EDT. The last came at 23:25 EDT. All seven were shallow. All clustered near Randolph and Mendham. The final quake measured M1.1. Emergency services stayed on alert but reported no structural impact. The Watchers confirmed the sequence and noted the swarm’s unusual pacing. EarthquakeTrack shows Randolph has logged 19 quakes in the past year, but none in this tight of a cluster.
The Ramapo Fault has history. It’s been quiet. But it’s not dormant. And shallow quakes carry sound. That’s why residents heard the boom. It wasn’t thunder. It wasn’t construction. It was the ground.
https://watchers.news/2025/07/23/new-jersey-earthquake-swarm-july-2025/
https://earthquaketrack.com/us-nj-randolph/recent
https://www.aol.com/news/six-earthquakes-rattle-same-jersey-214632907.html