3.1

M3.1 Earthquake in the Puerto Rico regionDecember 11, 2021

2021-12-11 22:27:58 UTC (2021-12-11) · approx. 6:27 PM UTC-4 local

MagnitudeM3.1(md)
Time22:27 UTC6:27 PM UTC-4
Depth13.0 kmshallow crustal
Coordinates18.765°, -66.680°
Felt byNo felt reports
Status✓ Reviewed by USGS

On December 11, 2021 at 22:27 UTC, a magnitude 3.1 shallow crustal earthquake struck in the Puerto Rico region, at a depth of 13.0 km and coordinates 18.7650°, -66.6803°.

Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 629 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 80 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 18.77°, -66.68°

Earthquake Details

Magnitude
3.1 md
Depth
13.0 km
shallow crustal
Location
18.7650°N
-66.6803°E

Technical Information

Event ID
pr2021345010
Event Type
earthquake
Status
✓ Reviewed
Significance
146
Stations Used
19
Azimuthal Gap
246.0°
Min Station Distance
0.325°
RMS Residual
0.26 sec
Last Updated
2022-02-24 21:00:02 UTC

Common Questions

How strong was the magnitude 3.1 earthquake in the Puerto Rico region?

The magnitude 3.1 earthquake that struck in the Puerto Rico region on December 11, 2021 at 22:27 UTC had a depth of 13.0 km. For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.1 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.1 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: pr2021345010). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, December 11, 2021). M3.1 Earthquake in the Puerto Rico regionDecember 11, 2021. Retrieved February 24, 2022 from https://www.earthquaketracker.org/earthquakes/event/pr2021345010/