Aftershock Potential Looms After 3.8 Magnitude Quake Near York Harbor Sparks Inquiry

In the wake of the 3.8 magnitude earthquake that struck near York Harbor on Monday, experts are weighing in on the potential for aftershocks. While this seismic event was not classified as a large earthquake, it has left residents and scientists alike pondering the implications of the tremor and whether it might be followed by additional quakes. John Ebel, a senior research scientist at Weston Observatory, emphasizes that aftershocks are indeed a possibility following the initial quake. He explains that the magnitude of the earthquake correlates with the duration during which aftershocks might occur. In this instance, with a magnitude of 3.8, Ebel estimates a window of about two weeks during which aftershocks could manifest. “For a magnitude 4.0, it’s like two weeks; for a magnitude 7.0, it’s a few years,” he noted, drawing from his extensive experience analyzing seismic activity, particularly in regions like California. Aftershocks are defined as smaller earthquakes that occur in the vicinity of the epicenter or along the fault line where the primary rupture took place. These occurrences are part of the natural readjustment process following the initial seismic event, according to the United States Geological Survey (USGS). However, the likelihood of substantial aftershocks diminishes as time passes after the initial quake. The USGS has provided an "aftershock forecast," estimating that there is only a 9 percent chance of an aftershock reaching a magnitude of 3 or higher that would be perceptible to the general public. As Ebel points out, while aftershocks are common, they typically fall below the threshold that people can feel, which is around 2.5 to 2.8 on the Richter scale. Sophie Coulson, an assistant professor of Earth Science at the University of New Hampshire, reiterates that any aftershocks from this most recent quake would likely be weaker than the original tremor and may go unnoticed. "Certainly, aftershocks could be happening over the next couple days, but these would likely be much smaller events that we wouldn't even necessarily feel," she stated. Geology professor Tasha Dunn from Colby College further adds that the Northeast experiences numerous minor earthquakes regularly, making it challenging to distinguish aftershocks from the typical seismic noise in the region. During Monday's tremor, Coulson’s students reported slight movements in classroom projectors and pictures on the walls, with the majority feeling the quake's effects. Ebel also mentioned that the relatively low seismic activity in New England allows researchers to monitor aftershocks with greater accuracy compared to more quake-prone areas. He speculates that the epicenter of the York Harbor quake may have been located offshore, in an area that has exhibited seismic activity since the 1970s. Ebel points to the Norumbega Fault Zone as a likely contributor to the recent quake, although he suggests that the activity may stem from even older, less-studied faults in the region. In conclusion, while experts believe aftershocks from the recent earthquake are possible, they are likely to be minor and may go unnoticed. The event serves as a reminder of the complex geological forces at work in New England, a region where seismic activity, though infrequent, still has the potential to surprise its residents. As scientists continue to study and monitor the aftermath, the mysteries of ancient faults and their potential activity will remain a subject of interest and investigation.