Weston Observatory seismographs on 4-12-2012, have recorded several earthquakes located ~260 miles offshore of Boston MA.
Information regarding the largest event is found here:
http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0009131.php
Be sure to visit the New England Seismic Network website (aki.bc.edu) to check if any more earthquakes occur.
Below is a screenshot of the WES seismic station. The large peaks are those offshore earthquakes.
