Magnitude 4.1 Earthquake near Dover, Delaware

Release Date:

The USGS has up-to-date details on the November 30, 2017 event.

A magnitude 4.1 earthquake struck near Dover Delaware on November 30, 2017 at 4:48 pm Eastern Standard Time.

This is the largest earthquake to occur within about a 90 mile radius since 1994 when a M4.6 event was recorded near Reading, Pennsylvania, and it might be the largest in Delaware since an earthquake of unknown magnitude near Wilmington on October 9, 1871. The 1871 earthquake caused some damage at Wilmington and New Castle, Delaware and at Oxford, Pennsylvania.

Map showing that the November 30, 2017 earthquake near Dover was felt from central Virginia to Massachusetts
The November 30, 2017 earthquake in Delaware was felt in major cities along  the U.S. East Coast. (USGS Public domain.)

Yesterday’s earthquake was felt along the U.S. East Coast from Massachusetts to central Virginia, including New York City, Philadelphia, and Washington D.C. The USGS has so far received more than 16,000 reports on its “Did You Feel It?” website.

Since 1973, several other earthquakes were recorded north of the Dover event on the New Jersey side of the Delaware Bay and Delaware River. The largest of these was an M 3.8 on February 28, 1973 across the river fromWilmington. That earthquake was felt widely in Delaware, New Jersey and Pennsylvania.

People in the New York – Philadelphia – Wilmington urban corridor have, since colonial times, felt small earthquakes and suffered damage from infrequent larger ones. New York City was damaged in 1737 and 1884. Moderately damaging earthquakes strike in the urban corridor roughly twice a century and smaller earthquakes are felt about every 2-3 years.

Regional map showing earthquake epicenter near Dover, Delaware
Regional map showing the November 30, 2017 earthquake epicenter near Dover, Delaware. (USGS Public Domain)

Field crews from Carnegie Institute, the University of Maryland, Columbia University and Lehigh University and USGS are deploying seismometers in Delaware and New Jersey to record aftershocks.

Visit the USGS event page for more information. For estimates of casualties and damage, visit the USGS Prompt Assessment of Global Earthquakes for Response (PAGER) website.

If you felt this earthquake, report your experience on the “USGS Did You Feel It?” website for this event.

The USGS operates a 24/7 National Earthquake Information Center in Colorado that can be reached for more information at 303-273-8500.

Learn more about the USGS Earthquake Hazards Program.

 

US map shows that earthquakes East of the Rockies are felt over larger areas than those in the West
"Did You Feel It?" map of the U.S. lower 48 states shows that earthquakes East of the Rocky Mountains are felt over larger areas than those in the West. (Robert Williams and Eric Jones, USGS)(Public domain.)