M3.9 Earthquake 13 km NNE of Tetonia, Idaho — December 8, 2023
2023-12-08 23:21:52 UTC (2023-12-08) · approx. 4:21 PM UTC-7 local
Felt by 117 people across surrounding communities. Maximum shaking intensity MMI 4.2 (moderate).
On December 8, 2023 at 23:21 UTC, a magnitude 3.9 shallow crustal earthquake struck 13 km NNE of Tetonia, Idaho, at a depth of 10.0 km and coordinates 43.9200°, -111.0723°. The earthquake was reported felt by 117 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.2 (moderate). This earthquake was detected by 26 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 288, placing it among routine seismic activity.
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.
The epicenter is located in Idaho, a region characterized by the track of the Yellowstone hotspot and the Centennial Tectonic Belt, producing both volcanic and tectonic seismicity. View all earthquakes in Idaho.
Learn more: Magnitude scale · Aftershock sequences
What the Shaking Felt Like
At MMI 4.2 (moderate), people in the most strongly affected areas would have experienced: Mild shaking, similar to a passing truck. Hanging objects swing. Glasses and dishes may rattle. Not commonly felt outdoors.
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.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 117 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-111.0723°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.9 earthquake near Tetonia, Idaho?
The magnitude 3.9 earthquake that struck 13 km NNE of Tetonia, Idaho on December 8, 2023 at 23:21 UTC had a depth of 10.0 km. It was felt by 117 people with maximum shaking intensity of MMI 4.2 (moderate). For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 43.9200°, -111.0723°, which is 13 km NNE of Tetonia, Idaho. View all earthquakes in Idaho.
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.
Has Idaho had earthquakes this big before?
The largest recorded earthquake in Idaho was the M7.3 Borah Peak earthquake of October 28, 1983. Today's magnitude 3.9 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us7000lhmj). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, December 8, 2023). M3.9 Earthquake 13 km NNE of Tetonia, Idaho — December 8, 2023. Retrieved February 10, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000lhmj/