3.9

M3.9 Earthquake 2 km SW of Indios, Puerto RicoJuly 8, 2026

2026-07-08 20:07:31 UTC (3 hours ago) · approx. 4:07 PM UTC-4 local

MagnitudeM3.9(ml)
Time20:07 UTC4:07 PM UTC-4
Depth15.0 kmshallow crustal
Coordinates17.978°, -66.835°
Felt by9DYFI responses· max MMI 4.0
Status✓ Reviewed by USGS

On July 8, 2026 at 20:07 UTC, a magnitude 3.9 shallow crustal earthquake struck 2 km SW of Indios, Puerto Rico, at a depth of 15.0 km and coordinates 17.9778°, -66.8351°. The earthquake was reported felt by 9 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.0 (light).

Physical scale: An earthquake of magnitude 3.9 releases seismic energy equivalent to roughly 11 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 296 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 17.98°, -66.84°

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 M3.9 earthquake near 2 km SW of Indios, 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 9 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 M3.9 earthquake near 2 km SW of Indios, Puerto Rico

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

Earthquake Details

Magnitude
3.9 ml
Depth
15.0 km
shallow crustal
Location
17.9778°N
-66.8351°E
Felt Reports
9
DYFI responses
Intensity (MMI)
4.0
light
Community Intensity
3.4
CDI from reports

Technical Information

Event ID
pr2026189001
Event Type
earthquake
Status
✓ Reviewed
Significance
237
Stations Used
24
Azimuthal Gap
160.0°
Min Station Distance
0.044°
RMS Residual
0.21 sec
Last Updated
2026-07-08 22:23:23 UTC

Common Questions

How strong was the magnitude 3.9 earthquake near Indios, Puerto Rico?

The magnitude 3.9 earthquake that struck 2 km SW of Indios, Puerto Rico on July 8, 2026 at 20:07 UTC had a depth of 15.0 km. It was felt by 9 people with maximum shaking intensity of MMI 4.0 (light). 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 3.9 earthquakes can continue for several days and gradually diminish over time.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: pr2026189001). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, July 8, 2026). M3.9 Earthquake 2 km SW of Indios, Puerto RicoJuly 8, 2026. Retrieved July 8, 2026 from https://www.earthquaketracker.org/earthquakes/event/pr2026189001/