M4.8 Earthquake 13 km SE of Esperanza, Puerto Rico — October 8, 2021
2021-10-08 18:28:23 UTC (2021-10-08) · approx. 2:28 PM UTC-4 local
Felt by 241 people across surrounding communities.
On October 8, 2021 at 18:28 UTC, a magnitude 4.8 shallow crustal earthquake struck 13 km SE of Esperanza, Puerto Rico, at a depth of 11.0 km and coordinates 18.0105°, -65.3871°. This earthquake was detected by 34 seismic stations with moderate location accuracy and was assigned a USGS significance rating of 463, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.8 releases seismic energy equivalent to roughly 239 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.2 km — 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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 241 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-65.3871°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.8 earthquake near Esperanza, Puerto Rico?
The magnitude 4.8 earthquake that struck 13 km SE of Esperanza, Puerto Rico on October 8, 2021 at 18:28 UTC had a depth of 11.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 18.0105°, -65.3871°, which is 13 km SE of Esperanza, Puerto Rico. View all earthquakes in Puerto Rico.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 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 4.8 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: pr2021281003). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 8, 2021). M4.8 Earthquake 13 km SE of Esperanza, Puerto Rico — October 8, 2021. Retrieved December 18, 2021 from https://www.earthquaketracker.org/earthquakes/event/pr2021281003/