M 4.1 - 3 km NNE of Little Creek, Delaware

  • 2017-11-30 21:47:31 (UTC)
  • 39.198°N 75.433°W
  • 9.9 km depth

Regional Seismicity Background

This is the largest quake within a 150 km radius of this hypocenter at least since 1994 (M4.6 near Reading, PA) and it may be the largest earthquake in Delaware since an event on Oct 09, 1871 along the Delaware River near Wilmington. The 1871 quake has no magnitude estimate, but caused some damage at Wilmington and New Castle, Delaware and at Oxford, Pennsylvania.

Since 1973 there have been several more quakes north of today’s hypocenter on the New Jersey side of the Delaware Bay and Delaware River. The largest of these was an M 3.8 quake on Feb 28, 1973 across the river from Wilmington. That earthquake was felt widely in Delaware, New Jersey and Pennsylvania. Other events in this area include a M3.2 near Pennsville, NJ on Oct 23, 1990 (Oct 22 local time) and an M2.8 near on July 1, 2009 slightly closer to Pennsville, NJ.

Although today's event is farther down Delaware Bay, since colonial times people in the New York - Philadelphia - Wilmington urban corridor have felt small earthquakes and suffered damage from infrequent larger ones. New York City was damaged in 1737 and 1884. Moderately damaging earthquakes strike somewhere in the urban corridor roughly twice a century, and smaller earthquakes are felt roughly every 2-3 years.

For More Information