South Middlesex Times

A Rutgers University–New Brunswick-led team of geologists has initiated a comprehensive effort to analyze and record the seismicity near the epicenter of the April 5 earthquake in Tewksbury Township, New Jersey. The project aims to provide the clearest measurements yet of the subterranean geological conditions in portions of the Ramapo Fault Zone, a 20-mile-wide area adjacent to and west of the Ramapo Fault. This fault zone is where most New Jersey earthquakes have occurred.

James Bourke, a postdoctoral associate in the Department of Earth and Planetary Sciences at Rutgers, stated that creating this "highly detailed map of seismicity" will help scientists better understand associated hazards and more accurately predict future earthquakes.

The project employs 110 advanced seismometers—sensors that capture the severity, distribution, and frequency of shaking and ground noises—installed primarily in Hunterdon County but also in Middlesex, Morris, and Somerset counties. These devices will gather data for periods ranging from one month to several years. In a subsequent phase, up to 500 additional devices are planned for installation along the broader Ramapo Fault region.

Bourke explained that these seismometers are buried two feet below ground and powered by boat batteries connected to above-ground solar cells and computers that record ground motion. "We’ll be studying the earthquake and its aftershocks," said Bourke. "But we can also align the instrument array to ask other science questions at the same time."

Kenneth Miller, a distinguished professor in Rutgers' Department of Earth and Planetary Sciences, described how nearly 200 aftershocks have followed the initial earthquake. "The rock in that area is acting a bit like Jell-O," he said. "After the first big shock, it shook a lot. And now it will shake just a little bit for a long time."

Lauren Neitzke Adamo, an associate professor at Rutgers, noted that finding recently active faults east of the Rocky Mountains is challenging because East Coast earthquakes rarely break the surface compared to those on the West Coast. "On the East Coast, if there is any evidence of an earthquake, it’s likely to have been eroded away," she said.

The installed seismometers will not only collect data about aftershocks but also capture images of underground rock formations using techniques similar to sonar. This information will be sent to the U.S. Geological Survey’s National Earthquake Information Center in Colorado for analysis.

Bourke mentioned that preliminary results are being prepared for submission to a peer-reviewed journal with more in-depth analysis expected over the next year or so.

Permission for device installation was obtained from property managers including those at Hunterdon County's Raritan Headwaters Association and Tewksbury Land Trust. The equipment used is on loan from a research consortium supported by both the National Science Foundation and U.S. Geological Survey.

"We’re really excited to be doing this work," Bourke concluded. "This is an adventure, for sure."