3.5

M3.5 Earthquake 9 km SE of Pole Ojea, Puerto Rico — June 25, 2021

2021-06-25 22:17:12 UTC (2021-06-25) · approx. 6:17 PM UTC-4 local

Felt by 19 people across nearby locations.

MagnitudeM3.5(md)
Time22:17 UTC≈ 6:17 PM UTC-4
Depth12.0 kmshallow crustal
Coordinates17.918°, -67.119°
Felt by19DYFI responses· max MMI 3.4
Status✓ Reviewed by USGS

On June 25, 2021 at 22:17 UTC, a magnitude 3.5 shallow crustal earthquake struck 9 km SE of Pole Ojea, Puerto Rico, at a depth of 12.0 km and coordinates 17.9176°, -67.1191°. The earthquake was reported felt by 19 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.4 (light). This earthquake was detected by 3 seismic stations with moderate location accuracy and was assigned a USGS significance rating of 193, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 3.5 releases seismic energy equivalent to roughly 2.3 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 147 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 17.92°, -67.12°

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 M3.5 earthquake near 9 km SE of Pole Ojea, 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 19 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 M3.5 earthquake near 9 km SE of Pole Ojea, Puerto Rico

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

Earthquake Details

Magnitude
3.5 md
Depth
12.0 km
shallow crustal
Location
17.9176°N
-67.1191°E
Felt Reports
19
DYFI responses
Intensity (MMI)
3.4
light
Community Intensity
4.8
CDI from reports

Technical Information

Event ID
pr2021176033
Event Type
earthquake
Status
✓ Reviewed
Significance
193
Stations Used
3
Azimuthal Gap
244.0°
Min Station Distance
0.089°
RMS Residual
0.24 sec
Last Updated
2021-09-09 22:04:57 UTC

Common Questions

How strong was the magnitude 3.5 earthquake near Pole Ojea, Puerto Rico?

The magnitude 3.5 earthquake that struck 9 km SE of Pole Ojea, Puerto Rico on June 25, 2021 at 22:17 UTC had a depth of 12.0 km. It was felt by 19 people with maximum shaking intensity of MMI 3.4 (light). For context, this was a minor earthquake typically detected only by instruments.

Where did the earthquake occur?

The earthquake epicenter was located at 17.9176°, -67.1191°, which is 9 km SE of Pole Ojea, Puerto Rico. View all earthquakes in Puerto Rico.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.5 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 3.5 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: pr2021176033). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, June 25, 2021). M3.5 Earthquake 9 km SE of Pole Ojea, Puerto Rico — June 25, 2021. Retrieved September 9, 2021 from https://www.earthquaketracker.org/earthquakes/event/pr2021176033/