M3.1 Earthquake 75 km NNW of San Antonio, Puerto Rico — December 29, 2020
2020-12-29 20:28:55 UTC (2020-12-29) · approx. 4:28 PM UTC-4 local
On December 29, 2020 at 20:28 UTC, a magnitude 3.1 shallow crustal earthquake struck 75 km NNW of San Antonio, Puerto Rico, at a depth of 22.0 km and coordinates 19.1556°, -67.2621°.
Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 747 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 87 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-67.2621°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.1 earthquake near San Antonio, Puerto Rico?
The magnitude 3.1 earthquake that struck 75 km NNW of San Antonio, Puerto Rico on December 29, 2020 at 20:28 UTC had a depth of 22.0 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.
Actions
Understanding This Data
Magnitude 3.1 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: pr2020364012). 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 75 km NNW of San Antonio, Puerto Rico — December 29, 2020. Retrieved December 29, 2020 from https://www.earthquaketracker.org/earthquakes/event/pr2020364012/