Scientists Trace 2024 New Jersey Earthquake to Previously Unmapped Mountainville Fault Zone
A magnitude 4.8 earthquake that occurred in New Jersey in April 2024, felt by an estimated 42 million people from Virginia to Maine, has been traced to a previously unmapped fault zone in the New Jersey Highlands. Researchers, initially considering the Ramapo Fault, discovered the earthquake's epicenter was too far from it and its seismic pattern did not match. The study, published in JGR Solid Earth, identified the source as an unmapped fault zone approximately two miles west of the epicenter, which has been named the Mountainville Fault. This event marks New Jersey's largest recorded earthquake since 1900, despite causing no major damage. Lead author Folarin Kolawole, a structural geologist at Columbia University's Lamont-Doherty Earth Observatory, explained that aftershock data, field mapping, friction lab work, stress analysis, and LiDAR imaging were used to pinpoint the source. The aftershocks aligned with an unmapped geologic feature, and fractures in nearby bedrock matched the seismometer records.