Earthquake · reviewed by a seismologist
M 4.2mb
285 km SW of Yakutat, Alaska
Yes. A magnitude 4.2 earthquake was recorded 285 km SW of Yakutat, Alaska at 10:05 UTC on 2026-04-09, 10 km deep.
- When
- Magnitude
- M 4.2 (mb)
- Depth
- 10 km below the surface
- Felt
- no reports yet
- Nearest mapped fault
- Gulf of Alaska shear zone, 4 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 142 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 112 km (70 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 30 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 5,600× the energy of this one
- Mineral, Virginia 2011 M 5.8 250× the energy of this one
- Magna, Utah 2020 M 5.7 180× the energy of this one
- This earthquake M 4.2 about 30 tons of TNT
- Around the size people start to feel M 3.0 this one released 63× 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 (31 mi) since our catalogue begins in 2016. No other earthquake of M4 or more has been recorded this close in that time.
Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 283 km SW of Yakutat, Alaska · 8 km NW of this epicentre
- 6.3 266 km SW of Yakutat, Alaska · 29 km N of this epicentre
- 6.2 290 km SW of Yakutat, Alaska · 5 km SSW of this epicentre
- 5.8 243 km SW of Yakutat, Alaska · 47 km N of this epicentre
- 5.8 296 km SW of Yakutat, Alaska · 18 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 57.5361, -142.7634. Map © OpenStreetMap contributors.
Aftershocks so far
4 earthquakes have been recorded within 50 km since this one.
- 3.1 286 km SW of Yakutat, Alaska
- 2.4 Gulf of Alaska
- 2.8 287 km SW of Yakutat, Alaska
- 2.8 269 km SW of Yakutat, 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.