3.0

M3.0 Earthquake 18 km S of Adak, Alaska — August 11, 2020

2020-08-11 21:44:27 UTC (2020-08-11) · approx. 9:44 AM UTC-12 local

MagnitudeM3.0(ml)
Time21:44 UTC≈ 9:44 AM UTC-12
Depth69.1 kmshallow crustal
Coordinates51.707°, -176.619°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 11, 2020 at 21:44 UTC, a magnitude 3.0 shallow crustal earthquake struck 18 km S of Adak, Alaska, at a depth of 69.1 km and coordinates 51.7073°, -176.6188°.

Physical scale: An earthquake of magnitude 3.0 releases seismic energy equivalent to roughly 477 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 71 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 51.71°, -176.62°

Earthquake Details

Magnitude
3.0 ml
Depth
69.1 km
shallow crustal
Location
51.7073°N
-176.6188°E

Technical Information

Event ID
us7000bhjy
Event Type
earthquake
Status
✓ Reviewed
Significance
138
Azimuthal Gap
193.0°
Min Station Distance
0.180°
RMS Residual
0.47 sec
Last Updated
2020-10-21 22:04:19 UTC

Common Questions

How strong was the magnitude 3.0 earthquake near Adak, Alaska?

The magnitude 3.0 earthquake that struck 18 km S of Adak, Alaska on August 11, 2020 at 21:44 UTC had a depth of 69.1 km. 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 3.0 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.0 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000bhjy). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, August 11, 2020). M3.0 Earthquake 18 km S of Adak, Alaska — August 11, 2020. Retrieved October 21, 2020 from https://www.earthquaketracker.org/earthquakes/event/us7000bhjy/