Columbia Team Ties New Jersey's 4.8 Quake to Newly Mapped Mountainville Fault
Updated
Updated · ScienceAlert · Aug 13
Columbia Team Ties New Jersey's 4.8 Quake to Newly Mapped Mountainville Fault
3 articles · Updated · ScienceAlert · Aug 13
Summary
A Columbia University study says the April 2024 magnitude 4.8 Tewksbury earthquake was caused by the previously unmapped Mountainville Fault, not the nearly 300-km Ramapo Fault.
Aftershock locations, 3D seismic-wave data, LiDAR topography and field mapping traced the fault zone about 3.5 km west of the epicenter and showed it could slip under current stress conditions.
Researchers classify Mountainville as an immature fault in old crystalline bedrock, and say a shallow local stress change—such as shifting water pressure or rock removal—may have helped trigger the quake.
The team argues the Ramapo Fault's poor orientation for slip may instead concentrate stress in nearby crust, making smaller hidden faults more likely to fail.
That finding points to a broader hazard on the densely populated U.S. East Coast, where similar little-known faults may be more important earthquake sources than previously recognized.