RESULTS FROM 30 YEARS OF REGIONAL SEISMIC NETWORK MONITORING IN NEW ENGLAND

In the mid-1970s under the directorship of Rev. James W. Skehan, S.J., Weston Observatory established a regional seismic network in New England to study the modern earthquake activity. In the past thirty years, this network has captured important data concerning the earthquakes in the region, leading to new interpretations of the modern seismotectonics. Most of this region's earthquakes take place in southern Connecticut, Rhode Island, eastern Massachusetts, southern and central New Hampshire, and across a broad belt along coastal Maine that stretches inland about 100 km. Some offshore earthquakes are also observed. Earthquake depths are almost invariably less than 10 km throughout the region, and the earthquakes have predominantly thrust focal mechanisms that strongly favor NE-SW to E-W maximum compression. The rate of seismicity is quite steady and is about 90 times less than that in California. Localized seismicity clusters may be late aftershock activity of strong earthquakes that took place many centuries ago. While no active faults in the region have yet been confirmed, the general patterns of the regional seismicity suggest that the earthquakes are utilizing preexisting zones of weakness to release modern plate tectonic stresses.