3.2

M3.2 Earthquake in the Puerto Rico region — July 28, 2020

2020-07-28 22:14:26 UTC (2020-07-28) · approx. 6:14 PM UTC-4 local

MagnitudeM3.2(md)
Time22:14 UTC≈ 6:14 PM UTC-4
Depth12.0 kmshallow crustal
Coordinates17.989°, -66.785°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 28, 2020 at 22:14 UTC, a magnitude 3.2 shallow crustal earthquake struck in the Puerto Rico region, at a depth of 12.0 km and coordinates 17.9893°, -66.7846°.

Physical scale: An earthquake of magnitude 3.2 releases seismic energy equivalent to roughly 829 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 91 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 17.99°, -66.78°

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 M3.2 earthquake near Puerto Rico region

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

Earthquake Details

Magnitude
3.2 md
Depth
12.0 km
shallow crustal
Location
17.9893°N
-66.7846°E
Intensity (MMI)
2.6
weak

Technical Information

Event ID
pr20202100015
Event Type
earthquake
Status
✓ Reviewed
Significance
154
Stations Used
23
Azimuthal Gap
167.0°
Min Station Distance
0.096°
RMS Residual
0.14 sec
Last Updated
2020-10-03 17:32:29 UTC

Common Questions

How strong was the magnitude 3.2 earthquake in the Puerto Rico region?

The magnitude 3.2 earthquake that struck in the Puerto Rico region on July 28, 2020 at 22:14 UTC had a depth of 12.0 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 3.2 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.2 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: pr20202100015). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, July 28, 2020). M3.2 Earthquake in the Puerto Rico region — July 28, 2020. Retrieved October 3, 2020 from https://www.earthquaketracker.org/earthquakes/event/pr20202100015/