Investigating the Tewksbury Earthquake: An Analysis of Seismic Impacts and Reports
On April 5, 2024, a magnitude 4.8 earthquake near Tewksbury, New Jersey, surprised millions with strong shaking perceptions, particularly in New York City, 65 kilometers away. Researchers investigated why extensive damage was minimal at the epicenter but reports of shaking were widespread. Their studies indicated that the earthquake’s rupture direction affected how seismic energy was distributed, with findings suggesting a combination of thrust and strike-slip mechanisms at play in this unusual event.
On April 5, 2024, a magnitude 4.8 earthquake originated near Tewksbury, New Jersey, startling millions across the eastern United States with reports of strong ground shaking, especially from individuals living up to 65 kilometers away in New York City. This event is notable as the largest instrumentally recorded earthquake in New Jersey since 1900. Research conducted by YoungHee Kim from Seoul National University and colleagues sought to uncover the reasons behind the anomalous shaking reports, especially given that damage around the epicenter was minimal. Following their field visit to the earthquake’s epicenter eight hours post-event, Kim and her colleagues discovered an unexpected lack of property damage; local police reports indicated minimal disruption. In contrast, substantial shaking was reported from New York City, with more than 180,000 submissions logged in the U.S. Geological Survey’s “Did You Feel It?” app. The earthquake was felt by an estimated 42 million people from Virginia to Maine, yet the intensity varied significantly, with reports of weak shaking southwest of the epicenter and light to moderate shaking northeast. To understand the shaking patterns, the researchers analyzed the earthquake’s rupture direction and found it propagated towards the east-northeast down a fault plane that dips eastward. This trajectory likely redirected the seismic vibrations away from the epicenter towards densely populated regions. The earthquake mechanism was unusual for the northeastern United States, as it exhibited attributes associated with both thrust and strike-slip faults—typical in less active areas like New Jersey. Aftershocks confirmed the presence of a hidden fault plane in the vicinity, based on several minor tremors detected. Furthermore, while minor damages such as drywall cracks and shelf items falling were documented, the well-known Ramapo fault system did not show activity during this event. Importantly, seismologists emphasize that this earthquake may redefine collated data regarding stress and strain accommodation in eastern U.S. seismic zones. New instruments deployed to the area will assist in studying post-event seismic responses and enhancing understanding of local earthquake hazards. This research not only illustrates the complexities behind earthquake intensity reports but also underscores the necessity for ongoing monitoring to better predict seismic activity in the region.
The article discusses the significant earthquake that struck New Jersey on April 5, 2024, and the subsequent analysis performed by researchers regarding the unusual shaking reports from distant locations. It provides insight into geological mechanisms affecting seismic activity and highlights the challenges in understanding earthquake impacts in populated areas, particularly in regions that are not typically prone to significant seismic events. The study aims to address discrepancies between observed damage and felt intensity reports, which were unusually high in nearby metropolitan areas despite minimal local damage.
The investigation into the April 2024 Tewksbury earthquake provides crucial insights into the mechanisms of seismic activity in the northeastern United States. The peculiar pattern of shaking reported miles from the epicenter suggests that the direction of the earthquake’s rupture played a vital role in how the event was felt across a broad area. As researchers continue to analyze the aftermath and the geological characteristics of the region, this may lead to a better understanding of earthquake dynamics and potential hazards in an area previously thought to be less seismically active.
Original Source: phys.org
