3.0

M3.0 Earthquake 25 km WSW of Karluk, Alaska — October 18, 2020

2020-10-18 23:46:10 UTC (2020-10-18) · approx. 1:46 PM UTC-10 local

MagnitudeM3.0(ml)
Time23:46 UTC≈ 1:46 PM UTC-10
Depth10.1 kmshallow crustal
Coordinates57.458°, -154.822°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 18, 2020 at 23:46 UTC, a magnitude 3.0 shallow crustal earthquake struck 25 km WSW of Karluk, Alaska, at a depth of 10.1 km and coordinates 57.4577°, -154.8221°.

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 57.46°, -154.82°

Earthquake Details

Magnitude
3.0 ml
Depth
10.1 km
shallow crustal
Location
57.4577°N
-154.8221°E

Technical Information

Event ID
ak020dfaw6qy
Event Type
earthquake
Status
✓ Reviewed
Significance
138
RMS Residual
0.79 sec
Last Updated
2020-12-29 23:07:36 UTC

Common Questions

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

The magnitude 3.0 earthquake that struck 25 km WSW of Karluk, Alaska on October 18, 2020 at 23:46 UTC had a depth of 10.1 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: ak020dfaw6qy). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, October 18, 2020). M3.0 Earthquake 25 km WSW of Karluk, Alaska — October 18, 2020. Retrieved December 29, 2020 from https://www.earthquaketracker.org/earthquakes/event/ak020dfaw6qy/