3.1

M3.1 Earthquake 8 km SE of Maria Antonia, Puerto Rico — December 29, 2020

2020-12-29 22:14:15 UTC (2020-12-29) · approx. 6:14 PM UTC-4 local

MagnitudeM3.1(md)
Time22:14 UTC≈ 6:14 PM UTC-4
Depth12.0 kmshallow crustal
Coordinates17.918°, -66.844°
Felt by4DYFI responses
Status✓ Reviewed by USGS

On December 29, 2020 at 22:14 UTC, a magnitude 3.1 shallow crustal earthquake struck 8 km SE of Maria Antonia, Puerto Rico, at a depth of 12.0 km and coordinates 17.9180°, -66.8435°.

Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 674 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 83 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 17.92°, -66.84°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 4 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M3.1 earthquake near 8 km SE of Maria Antonia, Puerto Rico

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
3.1 md
Depth
12.0 km
shallow crustal
Location
17.9180°N
-66.8435°E
Felt Reports
4
DYFI responses
Community Intensity
2.2
CDI from reports

Technical Information

Event ID
pr2020364017
Event Type
earthquake
Status
✓ Reviewed
Significance
149
Stations Used
24
Azimuthal Gap
200.0°
Min Station Distance
0.067°
RMS Residual
0.17 sec
Last Updated
2021-03-06 23:20:27 UTC

Common Questions

How strong was the magnitude 3.1 earthquake near Maria Antonia, Puerto Rico?

The magnitude 3.1 earthquake that struck 8 km SE of Maria Antonia, Puerto Rico on December 29, 2020 at 22:14 UTC had a depth of 12.0 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: pr2020364017). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, December 29, 2020). M3.1 Earthquake 8 km SE of Maria Antonia, Puerto Rico — December 29, 2020. Retrieved March 6, 2021 from https://www.earthquaketracker.org/earthquakes/event/pr2020364017/