On April 5, 2024, a magnitude 4.8 earthquake in Tewksbury, New Jersey, elicited widespread reports of shaking, particularly in New York City. Researchers investigated the earthquake’s rupture direction and found that its propagation toward the east-northeast likely contributed to the notable shaking reports despite minimal damage near the epicenter. These findings offer valuable insights into seismic activity in the region and highlight the need for continued monitoring and study of earthquake sources in Eastern North America.
The recent magnitude 4.8 earthquake in Tewksbury, New Jersey, has sparked significant interest among researchers due to its unexpected impact. While the earthquake was the largest instrumentally recorded in New Jersey since 1900, it raised questions concerning the intensity of shaking experienced by residents far from its epicenter. A study published in The Seismic Record by YoungHee Kim from Seoul National University and colleagues reexamines the earthquake’s rupture dynamics, particularly how the rupture’s direction might elucidate the pronounced reports of strong shaking in New York City, located approximately 40 miles away from the epicenter, where minimal damage was noted. Upon visiting the region shortly after the event, Kim and co-author Won-Young Kim expressed surprise at the lack of significant property damage in the vicinity of the epicenter, contrary to expectations for a magnitude of this caliber. They noted a contrasting response from residents farther away, who reported significant shaking from the earthquake. The event garnered over 180,000 felt reports, the largest for a single earthquake recorded by the U.S. Geological Survey’s “Did You Feel It?” app, with impacts felt by an estimated 42 million people between Virginia and Maine. Investigating the earthquake’s directivity, the authors utilized seismic wave data known as Lg waves to model the rupture propagation, revealing that it moved toward the east-northeast down an east-dipping fault plane. This pattern likely funneled the shaking away from the epicenter, accounting for the widespread felt reports in the northeast region. Unlike typical northeastern U.S. earthquakes, which primarily occur along established faults, this event exhibited characteristics of both thrust and strike-slip faulting along a previously unidentified fault plane trending north-northeast. Although some minor damages were reported, including structural damage to a local historical site, a comprehensive assessment of potential new fault lines remains ongoing. Such findings may provide insights into earthquake origins and stress distribution in Eastern North America as researchers continue to monitor the region using newly deployed seismometers. Their findings hold promise for enhancing our understanding of seismic hazards in this area.
The Tewksbury earthquake of April 5, 2024, represents a significant geological occurrence in New Jersey, as it is the most substantial seismic event recorded in the state since 1900. Its unusual characteristics, particularly the discrepancies in perceived shaking intensity among people in different locations, have necessitated a deeper investigation into the mechanics of seismic waves and fault interactions in the northeastern United States. The importance of understanding seismic activity in this relatively stable region underscores concerns regarding infrastructure resilience and emergency preparedness for future geological events.
In summary, the Tewksbury earthquake has prompted renewed focus on the complexity of seismic activity in the northeastern United States. The distinct patterns of shaking experienced by residents far from the epicenter illuminate the need for further research into earthquake mechanics and fault systems in the area. As seismic monitoring continues, these insights will contribute to a greater understanding of potential risks and aid in developing mitigation strategies for future seismic events.
Original Source: phys.org
