3.0

M3.0 Earthquake 88 km WSW of Nikolski, Alaska — July 4, 2021

2021-07-04 23:08:03 UTC (2021-07-04) · approx. 12:08 PM UTC-11 local

MagnitudeM3.0(ml)
Time23:08 UTC≈ 12:08 PM UTC-11
Depth144.3 kmintermediate depth
Coordinates52.711°, -170.111°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 4, 2021 at 23:08 UTC, a magnitude 3.0 intermediate depth earthquake struck 88 km WSW of Nikolski, Alaska, at a depth of 144.3 km and coordinates 52.7108°, -170.1114°.

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 52.71°, -170.11°

Earthquake Details

Magnitude
3.0 ml
Depth
144.3 km
intermediate depth
Location
52.7108°N
-170.1114°E

Technical Information

Event ID
us6000f76x
Event Type
earthquake
Status
✓ Reviewed
Significance
138
Azimuthal Gap
190.0°
Min Station Distance
0.173°
RMS Residual
0.40 sec
Last Updated
2021-09-10 20:07:18 UTC

Common Questions

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

The magnitude 3.0 earthquake that struck 88 km WSW of Nikolski, Alaska on July 4, 2021 at 23:08 UTC had a depth of 144.3 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: us6000f76x). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, July 4, 2021). M3.0 Earthquake 88 km WSW of Nikolski, Alaska — July 4, 2021. Retrieved September 10, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f76x/