4.2

M4.2 Earthquake 3 km S of Lima, MontanaJuly 14, 2023

2023-07-14 22:26:08 UTC (2023-07-14) · approx. 2:26 PM UTC-8 local

MagnitudeM4.2(mwr)
Time22:26 UTC2:26 PM UTC-8
Depth11.6 kmshallow crustal
Coordinates44.610°, -112.597°
Felt by9DYFI responses· max MMI 4.2
Status✓ Reviewed by USGS· green PAGER
green Alertno significant casualties or damage expected

On July 14, 2023 at 22:26 UTC, a magnitude 4.2 shallow crustal earthquake struck 3 km S of Lima, Montana, at a depth of 11.6 km and coordinates 44.6097°, -112.5975°. The earthquake was reported felt by 9 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.2 (moderate). The nearest populated place is Dubois (population 677).

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 44.61°, -112.60°

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 M4.2 earthquake near 3 km S of Lima, Montana

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 M4.2 earthquake near 3 km S of Lima, Montana

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 3weak913
MMI 4light198

Earthquake Details

Magnitude
4.2 mwr
Depth
11.6 km
shallow crustal
Location
44.6097°N
-112.5975°E
Felt Reports
9
DYFI responses
Intensity (MMI)
4.2
moderate
Community Intensity
4.6
CDI from reports

Technical Information

Event ID
us7000kfv7
Event Type
earthquake
Status
✓ Reviewed
Significance
276
Stations Used
67
Azimuthal Gap
26.0°
Min Station Distance
0.034°
RMS Residual
0.59 sec
Last Updated
2023-09-16 19:16:16 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near Lima, Montana?

The magnitude 4.2 earthquake that struck 3 km S of Lima, Montana on July 14, 2023 at 22:26 UTC had a depth of 11.6 km. It was felt by 9 people with maximum shaking intensity of MMI 4.2 (moderate). For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.2 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000kfv7). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, July 14, 2023). M4.2 Earthquake 3 km S of Lima, MontanaJuly 14, 2023. Retrieved September 16, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000kfv7/