Earthquake · reviewed by a seismologist
M 4.1mwr
66 km W of Cantwell, Alaska
Yes. A magnitude 4.1 earthquake was recorded 66 km W of Cantwell, Alaska, at 6:01 pm AKDT on 29 March 2025 (02:01 UTC), 13 km deep. 27 people have reported feeling it to USGS.
- When
- Magnitude
- M 4.1 (mwr)
- Depth
- 13 km below the surface
- Felt
- 27 reports · strongest reported intensity IV
- Measured shaking
- intensity IV (ShakeMap)
- Nearest
- Denali Borough, 32 km NNE
- Nearest mapped fault
- Denali fault, 14 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 524 days ago
This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.
At this magnitude and depth, people at rest would likely notice it out to about 104 km (65 mi) from the epicentre. 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 21 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.1 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 7,900× the energy of this one
- Mineral, Virginia 2011 M 5.8 350× the energy of this one
- Magna, Utah 2020 M 5.7 250× the energy of this one
- This earthquake M 4.1 about 21 tons of TNT
- Around the size people start to feel M 3.0 this one released 45× more
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
The largest earthquake within 50 km since 2016 was M 5.0 on 2018-07-01 — about 22 times the energy of this one.
Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:
- 7.2 Mount McKinley (Denali) area, Alaska · 11 km SW of this epicentre
- 6.4 Mount McKinley (Denali) area, Alaska · 11 km WNW of this epicentre
- 5.8 52 km WSW of Ferry, Alaska · 48 km N of this epicentre
- 5.7 66 km ESE of Denali National Park, Alaska · 28 km SW of this epicentre
- 5.5 53 km ESE of Denali National Park, Alaska · 21 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 63.4165, -150.2754. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Denali Borough, AK | 32 km (20 mi) | NNE | earthquakes near Denali Borough |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
57 earthquakes have been recorded within 50 km since this one.
- 1.6 64 km ESE of Denali National Park, Alaska
- 1.9 62 km NNE of Petersville, Alaska
- 1.7 69 km N of Petersville, Alaska
- 1.6 59 km WNW of Cantwell, Alaska
- 1.6 62 km N of Petersville, Alaska
- 1.6 44 km WSW of Denali Park, Alaska
- 1.7 62 km N of Petersville, Alaska
- 2.6 52 km E of Denali National Park, Alaska
- 1.9 58 km NNE of Petersville, Alaska
- 1.6 57 km W of Cantwell, Alaska
- 1.6 65 km ESE of Denali National Park, Alaska
- 1.6 65 km NNE of Petersville, Alaska
- 2.0 68 km ESE of Denali National Park, Alaska
- 1.9 73 km WSW of Cantwell, Alaska
- 1.9 63 km SE of Denali National Park, 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.