3.5

M3.5 Earthquake 50 km W of Mentone, Texas — September 18, 2020

2020-09-18 21:48:27 UTC (2020-09-18) · approx. 2:48 PM UTC-7 local

MagnitudeM3.5(mwr)
Time21:48 UTC≈ 2:48 PM UTC-7
Depth5.0 kmshallow crustal
Coordinates31.706°, -104.133°
Felt by3DYFI responses· max MMI 4.2
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On September 18, 2020 at 21:48 UTC, a magnitude 3.5 shallow crustal earthquake struck 50 km W of Mentone, Texas, at a depth of 5.0 km and coordinates 31.7061°, -104.1334°. The earthquake was reported felt by 3 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.2 (moderate). The nearest populated place is Mentone (population 19).

Physical scale: An earthquake of magnitude 3.5 releases seismic energy equivalent to roughly 2.7 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 157 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 31.71°, -104.13°

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 M3.5 earthquake near 50 km W of Mentone, Texas

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 3 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 M3.5 earthquake near 50 km W of Mentone, Texas

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 3weak8,243
MMI 4light2

Earthquake Details

Magnitude
3.5 mwr
Depth
5.0 km
shallow crustal
Location
31.7061°N
-104.1334°E
Felt Reports
3
DYFI responses
Intensity (MMI)
4.2
moderate
Community Intensity
4.6
CDI from reports

Technical Information

Event ID
us7000bq0y
Event Type
earthquake
Status
✓ Reviewed
Significance
190
Azimuthal Gap
49.0°
Min Station Distance
0.091°
RMS Residual
0.44 sec
Last Updated
2020-11-28 21:31:52 UTC

Common Questions

How strong was the magnitude 3.5 earthquake near Mentone, Texas?

The magnitude 3.5 earthquake that struck 50 km W of Mentone, Texas on September 18, 2020 at 21:48 UTC had a depth of 5.0 km. It was felt by 3 people with maximum shaking intensity of MMI 4.2 (moderate). 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 3.5 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.5 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000bq0y). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, September 18, 2020). M3.5 Earthquake 50 km W of Mentone, Texas — September 18, 2020. Retrieved November 28, 2020 from https://www.earthquaketracker.org/earthquakes/event/us7000bq0y/