2.5

M2.5 Earthquake 16 km WSW of Lutak, AlaskaSeptember 28, 2021

2021-09-28 18:08:04 UTC (2021-09-28) · approx. 9:08 AM UTC-9 local

MagnitudeM2.5(ml)
Time18:08 UTC9:08 AM UTC-9
Depth19.9 kmshallow crustal
Coordinates59.261°, -135.804°
Felt by1DYFI response
StatusAutomatic (preliminary)

On September 28, 2021 at 18:08 UTC, a magnitude 2.5 shallow crustal earthquake struck 16 km WSW of Lutak, Alaska, at a depth of 19.9 km and coordinates 59.2605°, -135.8043°.

Physical scale: An earthquake of magnitude 2.5 releases seismic energy equivalent to roughly 84.8 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 32 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 59.26°, -135.80°

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 M2.5 earthquake near 16 km WSW of Lutak, Alaska

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

Earthquake Details

Magnitude
2.5 ml
Depth
19.9 km
shallow crustal
Location
59.2605°N
-135.8043°E
Felt Reports
1
DYFI responses
Community Intensity
2.2
CDI from reports

Technical Information

Event ID
ak021cghekt8
Event Type
earthquake
Status
Automatic
Significance
96
RMS Residual
1.16 sec
Last Updated
2021-12-04 14:27:47 UTC

Common Questions

How strong was the magnitude 2.5 earthquake near Lutak, Alaska?

The magnitude 2.5 earthquake that struck 16 km WSW of Lutak, Alaska on September 28, 2021 at 18:08 UTC had a depth of 19.9 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 2.5 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 2.5 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: ak021cghekt8). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, September 28, 2021). M2.5 Earthquake 16 km WSW of Lutak, AlaskaSeptember 28, 2021. Retrieved December 4, 2021 from https://www.earthquaketracker.org/earthquakes/event/ak021cghekt8/