5.7

M5.7 Earthquake 156 km ESE of Akutan, Alaska — August 13, 2020

2020-08-13 06:40:00 UTC (2020-08-13) · approx. 7:40 PM UTC-11 local

MagnitudeM5.7(mww)
Time06:40 UTC≈ 7:40 PM UTC-11
Depth28.0 kmshallow crustal
Coordinates53.430°, -163.713°
Felt byNo felt reports
Status✓ Reviewed by USGS· Tsunami evaluation· green PAGER
green Alert— no significant casualties or damage expected
Tsunami Warning Issued

On August 13, 2020 at 06:40 UTC, a magnitude 5.7 shallow crustal earthquake struck 156 km ESE of Akutan, Alaska, at a depth of 28.0 km and coordinates 53.4301°, -163.7134°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Akutan (population 1,027).

Physical scale: An earthquake of magnitude 5.7 releases seismic energy equivalent to roughly 5 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 5.2 km — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Alaska, a region characterized by Pacific Plate subduction beneath the North American Plate, producing frequent megathrust and crustal earthquakes along the Aleutian arc. The nearest mapped fault system is the Aleutian megathrust. View all earthquakes in Alaska.

Learn more: Magnitude scale · Aftershock sequences

Nearest Populated Places

Akutanpop. 1,027
MMI 2.3 (weak)
Dutch Harborpop. 4,376
MMI 2.8 (weak)
Unalaskapop. 4,376
MMI 2.7 (weak)
Map showing earthquake epicenter at 53.43°, -163.71°

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 M5.7 earthquake near 156 km ESE of Akutan, Alaska

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

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 3weak5,089

Earthquake Details

Magnitude
5.7 mww
Depth
28.0 km
shallow crustal
Location
53.4301°N
-163.7134°E
Intensity (MMI)
3.4
light

Technical Information

Event ID
us6000bduv
Event Type
earthquake
Status
✓ Reviewed
Significance
500
Azimuthal Gap
119.0°
Min Station Distance
1.360°
RMS Residual
0.82 sec
Last Updated
2025-12-22 18:40:24 UTC

Common Questions

How strong was the magnitude 5.7 earthquake near Akutan, Alaska?

The magnitude 5.7 earthquake that struck 156 km ESE of Akutan, Alaska on August 13, 2020 at 06:40 UTC had a depth of 28.0 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at 53.4301°, -163.7134°, which is 156 km ESE of Akutan, Alaska. The nearest populated place is Akutan (population 1,027). View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.7 earthquakes can continue for days to weeks and gradually diminish over time.

Has Alaska had earthquakes this big before?

The largest recorded earthquake in Alaska was the M9.2 Great Alaska earthquake of March 27, 1964. Today's magnitude 5.7 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000bduv). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, August 13, 2020). M5.7 Earthquake 156 km ESE of Akutan, Alaska — August 13, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000bduv/