M2.8 earthquake 105 km WNW of Anchorage, Alaska, United States
A magnitude 2.8 earthquake struck 105 km WNW of Anchorage, Alaska, United States at 13:17 local time (21:17 UTC) on 21 Sept 2026, at a depth of 101 km, according to USGS. The solution is preliminary and may be revised.
1 reports to USGS “Did You Feel It?”
Data: USGS · updated 2026-09-22 01:45 UTC · automatic solution
- Magnitude
- 2.8micro
local magnitude (Richter) (ml) - Depth
- 100.5 km
- Status
- Automatic
- Origin time
- 2026-09-21 21:17:48 UTC
- Local: 21 Sept 2026, 13:17:48 (America/Anchorage)
- Epicentre
- 61.651° N, 151.659° W
Circles show this event and others within 30 km from 7 days before to 30 days after. Lines: plate boundaries and GEM active faults. Open on the live map
Nearby places
| Place | Distance | Est. shaking |
|---|---|---|
| AnchorageAlaska, United States · pop. 289,600 | 105 km | INot felt |
| Meadow LakesAlaska, United States · pop. 7,570 | 109 km | INot felt |
| Eagle RiverAlaska, United States · pop. 24,793 | 117 km | INot felt |
Shaking is an estimate from the intensity prediction equation of Allen, Wald & Worden (2012), not an observation. Local ground and buildings can change it by a level or more.
Every agency's solution
Agencies locate earthquakes with their own stations and methods, so their numbers differ. We match reports of the same event by time, distance and magnitude and show them side by side. The headline uses USGS · AK.
| Agency | Magnitude | Depth | Epicentre | Time offset | Status |
|---|---|---|---|---|---|
| USGS · AKheadlineAlaska Earthquake Center via U.S. Geological Survey | 2.8 ml | 100.5 km | 61.65° N, 151.66° W | – | Automatic |
How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 239 kg of TNT. Magnitude is logarithmic: each whole step means about 32 times more energy and 10 times larger waves on a seismogram. Depth matters too: at 101 km this was a intermediate-depth earthquake, which spreads shaking over a wider area but less intensely.
M2.8 releases about 32× the energy of M1.8, and its waves are about 10× taller on a seismogram. Energy: 239 kg of TNT vs 8 kg of TNT.
Each square is the energy of one M1.8. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
3 later earthquakes within 30 km; the largest was M1.9 4 h 34 min ago. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M2.8
3 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 64.95 | 0.5 | 17 |
| 154.74 | 1.2 | 19 |
| 163.35 | 1.9 | 5 |
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Event id aka2026stkjjp. First recorded here 28 Sept 2026, 17:32:10 UTC. Solutions: USGS · AK (usgs:aka2026stkjjp). Cite as: SeismoAtlas, “M2.8 earthquake 105 km WNW of Anchorage, Alaska, United States”, https://seismoatlas.com/earthquake/aka2026stkjjp-m2-8-earthquake-105-km-wnw-of-anchorage-alaska-united-states, data from USGS.
JSON: /api/v1/events/aka2026stkjjp. SeismoAtlas is not an official warning service.