3.8

M3.8 Earthquake 7 km ESE of La Parguera, Puerto Rico — October 15, 2020

2020-10-15 18:06:34 UTC (2020-10-15) · approx. 2:06 PM UTC-4 local

Felt by 27 people across nearby locations.

MagnitudeM3.8(md)
Time18:06 UTC≈ 2:06 PM UTC-4
Depth10.0 kmshallow crustal
Coordinates17.940°, -66.984°
Felt by27DYFI responses· max MMI 3.8
Status✓ Reviewed by USGS

On October 15, 2020 at 18:06 UTC, a magnitude 3.8 shallow crustal earthquake struck 7 km ESE of La Parguera, Puerto Rico, at a depth of 10.0 km and coordinates 17.9400°, -66.9838°. The earthquake was reported felt by 27 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.8 (light). This earthquake was detected by 27 seismic stations with moderate location accuracy and was assigned a USGS significance rating of 237, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 3.8 releases seismic energy equivalent to roughly 8.1 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 260 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 17.94°, -66.98°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M3.8 earthquake near 7 km ESE of La Parguera, Puerto Rico

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 27 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 7 km ESE of La Parguera, 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
10.0 km
shallow crustal
Location
17.9400°N
-66.9838°E
Felt Reports
27
DYFI responses
Intensity (MMI)
3.8
light
Community Intensity
4.5
CDI from reports

Technical Information

Event ID
pr2020289007
Event Type
earthquake
Status
✓ Reviewed
Significance
237
Stations Used
27
Azimuthal Gap
216.0°
Min Station Distance
0.067°
RMS Residual
0.12 sec
Last Updated
2020-12-29 23:07:24 UTC

Common Questions

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

The magnitude 3.8 earthquake that struck 7 km ESE of La Parguera, Puerto Rico on October 15, 2020 at 18:06 UTC had a depth of 10.0 km. It was felt by 27 people with maximum shaking intensity of MMI 3.8 (light). For context, this was a minor earthquake typically detected only by instruments.

Where did the earthquake occur?

The earthquake epicenter was located at 17.9400°, -66.9838°, which is 7 km ESE of La Parguera, 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: pr2020289007). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, October 15, 2020). M3.8 Earthquake 7 km ESE of La Parguera, Puerto Rico — October 15, 2020. Retrieved December 29, 2020 from https://www.earthquaketracker.org/earthquakes/event/pr2020289007/