4.9

M4.9 Earthquake 5 km SE of La Parguera, Puerto Rico — July 3, 2020

2020-07-03 13:54:50 UTC (2020-07-03) · approx. 9:54 AM UTC-4 local

Felt by 142 people across surrounding communities. Maximum shaking intensity MMI 5.8 (strong).

MagnitudeM4.9(mwp)
Time13:54 UTC≈ 9:54 AM UTC-4
Depth6.0 kmshallow crustal
Coordinates17.944°, -67.004°
Felt by142DYFI responses· max MMI 5.8
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On July 3, 2020 at 13:54 UTC, a magnitude 4.9 shallow crustal earthquake struck 5 km SE of La Parguera, Puerto Rico, at a depth of 6.0 km and coordinates 17.9443°, -67.0035°. The earthquake was reported felt by 142 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 5.8 (strong). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 22 seismic stations with moderate location accuracy and was assigned a USGS significance rating of 453, placing it among routine seismic activity. The nearest populated place is La Parguera (population 1,141).

Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 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

Nearest Populated Places

La Parguerapop. 1,141
MMI 5.2 (strong)
Fuigpop. 1,204
MMI 5.1 (strong)
Guanicapop. 9,224
MMI 4.9 (moderate)
Boqueronpop. 2,017
MMI 4.7 (moderate)
Maria Antoniapop. 1,479
MMI 4.6 (moderate)
Palmarejopop. 1,169
MMI 4.5 (moderate)

What the Shaking Felt Like

At MMI 5.8 (strong), people in the most strongly affected areas would have experienced: Moderate shaking that everyone in the area would feel. Sleeping people are awakened. Dishes and windows may break. Unstable objects may be knocked over.

Map showing earthquake epicenter at 17.94°, -67.00°

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 M4.9 earthquake near 5 km SE of La Parguera, 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 142 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 M4.9 earthquake near 5 km SE of La Parguera, Puerto Rico

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

Population exposure (USGS PAGER)

Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.

Shaking intensity (MMI)DescriptionPopulation exposed
MMI 3weak2,649,023
MMI 4light436,187
MMI 5moderate40,125
MMI 6strong949

Earthquake Details

Magnitude
4.9 mwp
Depth
6.0 km
shallow crustal
Location
17.9443°N
-67.0035°E
Felt Reports
142
DYFI responses
Intensity (MMI)
5.8
strong
Community Intensity
5.9
CDI from reports

Technical Information

Event ID
pr2020185007
Event Type
earthquake
Status
✓ Reviewed
Significance
453
Stations Used
22
Azimuthal Gap
224.0°
Min Station Distance
0.048°
RMS Residual
0.39 sec
Last Updated
2021-07-22 13:11:16 UTC

Common Questions

How strong was the magnitude 4.9 earthquake near La Parguera, Puerto Rico?

The magnitude 4.9 earthquake that struck 5 km SE of La Parguera, Puerto Rico on July 3, 2020 at 13:54 UTC had a depth of 6.0 km. It was felt by 142 people with maximum shaking intensity of MMI 5.8 (strong). For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 17.9443°, -67.0035°, which is 5 km SE of La Parguera, Puerto Rico. The nearest populated place is La Parguera (population 1,141). View all earthquakes in Puerto Rico.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 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 4.9 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: pr2020185007). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, July 3, 2020). M4.9 Earthquake 5 km SE of La Parguera, Puerto Rico — July 3, 2020. Retrieved July 22, 2021 from https://www.earthquaketracker.org/earthquakes/event/pr2020185007/