M3.2 Earthquake 2 km SSE of Detroit Beach, Michigan — August 21, 2020
2020-08-21 22:55:09 UTC (2020-08-21) · approx. 4:55 PM UTC-6 local
Felt by 2,157 people across a wide area.
On August 21, 2020 at 22:55 UTC, a magnitude 3.2 shallow crustal earthquake struck 2 km SSE of Detroit Beach, Michigan, at a depth of 9.2 km and coordinates 41.9125°, -83.3179°. The earthquake was reported felt by 2,157 peopleacross a wide area, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.9 (light).
Physical scale: An earthquake of magnitude 3.2 releases seismic energy equivalent to roughly 951 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 97 m — a useful intuition for the size of the slip patch on the fault.
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 2,157 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
-83.3179°E
Technical Information
Common Questions
How strong was the magnitude 3.2 earthquake near Detroit Beach, Michigan?
The magnitude 3.2 earthquake that struck 2 km SSE of Detroit Beach, Michigan on August 21, 2020 at 22:55 UTC had a depth of 9.2 km. It was felt by 2,157 people with maximum shaking intensity of MMI 3.9 (light). For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 41.9125°, -83.3179°, which is 2 km SSE of Detroit Beach, Michigan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.2 earthquakes can continue for several days and gradually diminish over time.
Authoritative source: USGS event page (event ID: us6000bis9). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, August 21, 2020). M3.2 Earthquake 2 km SSE of Detroit Beach, Michigan — August 21, 2020. Retrieved January 25, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000bis9/