3.8

M3.8 Earthquake 2 km SE of Yauco, Puerto Rico — July 23, 2020

2020-07-23 21:10:43 UTC (2020-07-23) · approx. 5:10 PM UTC-4 local

Felt by 45 people across nearby locations.

MagnitudeM3.8(md)
Time21:10 UTC≈ 5:10 PM UTC-4
Depth12.0 kmshallow crustal
Coordinates18.018°, -66.832°
Felt by45DYFI responses
Status✓ Reviewed by USGS

On July 23, 2020 at 21:10 UTC, a magnitude 3.8 shallow crustal earthquake struck 2 km SE of Yauco, Puerto Rico, at a depth of 12.0 km and coordinates 18.0176°, -66.8325°. This earthquake was detected by 21 seismic stations with good location accuracy and was assigned a USGS significance rating of 236, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 3.8 releases seismic energy equivalent to roughly 6.4 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 233 m — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Puerto Rico, a region characterized by the Puerto Rico Trench oblique subduction zone and the Muertos Trough, with complex Caribbean–North American plate interactions. The nearest mapped fault system is the Puerto Rico Trench. View all earthquakes in Puerto Rico.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at 18.02°, -66.83°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 45 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 M3.8 earthquake near 2 km SE of Yauco, Puerto Rico

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

Earthquake Details

Magnitude
3.8 md
Depth
12.0 km
shallow crustal
Location
18.0176°N
-66.8325°E
Felt Reports
45
DYFI responses
Community Intensity
4.3
CDI from reports

Technical Information

Event ID
pr2020205004
Event Type
earthquake
Status
✓ Reviewed
Significance
236
Stations Used
21
Azimuthal Gap
133.0°
Min Station Distance
0.063°
RMS Residual
0.33 sec
Last Updated
2020-10-03 17:32:18 UTC

Common Questions

How strong was the magnitude 3.8 earthquake near Yauco, Puerto Rico?

The magnitude 3.8 earthquake that struck 2 km SE of Yauco, Puerto Rico on July 23, 2020 at 21:10 UTC had a depth of 12.0 km. For context, this was a minor earthquake typically detected only by instruments.

Where did the earthquake occur?

The earthquake epicenter was located at 18.0176°, -66.8325°, which is 2 km SE of Yauco, Puerto Rico. View all earthquakes in Puerto Rico.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.8 earthquakes can continue for several days and gradually diminish over time.

Has Puerto Rico had earthquakes this big before?

The largest recorded earthquake in Puerto Rico was the M7.3 offshore earthquake of October 11, 1918. Today's magnitude 3.8 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: pr2020205004). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, July 23, 2020). M3.8 Earthquake 2 km SE of Yauco, Puerto Rico — July 23, 2020. Retrieved October 3, 2020 from https://www.earthquaketracker.org/earthquakes/event/pr2020205004/