3.1

M3.1 Earthquake 20 km ESE of Kasilof, Alaska — August 25, 2020

2020-08-25 23:41:09 UTC (2020-08-25) · approx. 1:41 PM UTC-10 local

MagnitudeM3.1(ml)
Time23:41 UTC≈ 1:41 PM UTC-10
Depth65.8 kmshallow crustal
Coordinates60.289°, -150.920°
Felt by1DYFI response· max MMI 2.5
Status✓ Reviewed by USGS

On August 25, 2020 at 23:41 UTC, a magnitude 3.1 shallow crustal earthquake struck 20 km ESE of Kasilof, Alaska, at a depth of 65.8 km and coordinates 60.2892°, -150.9198°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.5 (weak).

Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 674 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 83 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 60.29°, -150.92°

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 M3.1 earthquake near 20 km ESE of Kasilof, Alaska

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 1 citizen response 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 M3.1 earthquake near 20 km ESE of Kasilof, Alaska

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

Earthquake Details

Magnitude
3.1 ml
Depth
65.8 km
shallow crustal
Location
60.2892°N
-150.9198°E
Felt Reports
1
DYFI responses
Intensity (MMI)
2.5
weak
Community Intensity
2.0
CDI from reports

Technical Information

Event ID
ak020axzudh7
Event Type
earthquake
Status
✓ Reviewed
Significance
148
RMS Residual
1.03 sec
Last Updated
2020-10-31 19:06:29 UTC

Common Questions

How strong was the magnitude 3.1 earthquake near Kasilof, Alaska?

The magnitude 3.1 earthquake that struck 20 km ESE of Kasilof, Alaska on August 25, 2020 at 23:41 UTC had a depth of 65.8 km. It was felt by 1 person with maximum shaking intensity of MMI 2.5 (weak). 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 3.1 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.1 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: ak020axzudh7). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, August 25, 2020). M3.1 Earthquake 20 km ESE of Kasilof, Alaska — August 25, 2020. Retrieved October 31, 2020 from https://www.earthquaketracker.org/earthquakes/event/ak020axzudh7/