Earthquake · reviewed by a seismologist
M 1.5ml
73 km E of Cantwell, Alaska
Yes. A magnitude 1.5 earthquake was recorded 73 km E of Cantwell, Alaska, at 11:58 pm AKST on 1 December 2021 (08:58 UTC), 12 km deep.
- When
- Magnitude
- M 1.5 (ml)
- Depth
- 12 km below the surface
- Felt
- no reports yet
- Nearest mapped fault
- Denali fault, under 1 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1773 days ago
Earthquake alerts for Healy, AK
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth it was probably too small to be felt, even directly above it. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
How big was it?
This earthquake released about 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 lb of TNT
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:
- 7.9 2002 Denali Fault, Alaska Earthquake · 2 km ESE of this epicentre
- 6.6 53 km ENE of Cantwell, Alaska · 20 km W of this epicentre
- 5.1 77 km E of Cantwell, Alaska · 4 km E of this epicentre
- 5.1 78 km ESE of McKinley Park, Alaska · 5 km E of this epicentre
- 5.1 36 km ENE of Cantwell, Alaska · 37 km W of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 63.5203, -147.5013. Map © OpenStreetMap contributors.
Aftershocks so far
60 earthquakes have been recorded within 50 km since this one.
- 1.6 80 km ESE of Denali Park, Alaska
- 1.7 60 km E of Cantwell, Alaska
- 1.5 81 km ESE of Denali Park, Alaska
- 1.5 59 km ESE of Denali Park, Alaska
- 1.5 71 km ESE of Denali Park, Alaska
- 1.6 64 km ESE of Denali Park, Alaska
- 2.3 64 km E of Cantwell, Alaska
- 1.7 Central Alaska
- 1.5 76 km E of Cantwell, Alaska
- 1.7 84 km ESE of Denali Park, Alaska
- 1.6 81 km E of Cantwell, Alaska
- 2.7 48 km ESE of Denali Park, Alaska
- 1.9 73 km E of Cantwell, Alaska
- 1.8 78 km ESE of Denali Park, Alaska
- 1.9 Central Alaska
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.