M2.1 earthquake 139 km N of Tanaina, Alaska, United States
A magnitude 2.1 earthquake struck 139 km N of Tanaina, Alaska, United States at 12:27 local time (20:27 UTC) on 31 Oct 2026, at a depth of 72 km, according to USGS.
Data: USGS · updated 2026-11-02 07:39 UTC · reviewed
- Magnitude
- 2.1micro
local magnitude (Richter) (ml) - Depth
- 72.1 km
- Status
- Reviewed
- Origin time
- 2026-10-31 20:27:36 UTC
- Local: 31 Oct 2026, 12:27:36 (America/Anchorage)
- Epicentre
- 62.877° N, 149.175° 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 |
|---|---|---|
| TanainaAlaska, United States · pop. 8,197 | 139 km | INot felt |
| LakesAlaska, United States · pop. 8,364 | 141 km | INot felt |
| AnchorageAlaska, United States · pop. 289,600 | 188 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, which has been reviewed by an analyst.
| Agency | Magnitude | Depth | Epicentre | Time offset | Status |
|---|---|---|---|---|---|
| USGS · AKheadlineAlaska Earthquake Center via U.S. Geological Survey | 2.1 ml | 72.1 km | 62.88° N, 149.18° W | – | Reviewed · 1 revision |
How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 21 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 72 km this was a intermediate-depth earthquake, which spreads shaking over a wider area but less intensely.
M2.1 releases about 32× the energy of M1.1, and its waves are about 10× taller on a seismogram. Energy: 21 kg of TNT vs 674 g of TNT.
Each square is the energy of one M1.1. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
5 later earthquakes within 30 km; the largest was M2.3 8 days ago. 5 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M2.1
5 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 2.68 | 1.9 | 15 |
| 71.25 | 2.1 | 76 |
| 81.97 | 2.3 | 81 |
| 106.39 | 2.1 | 75 |
| 148.82 | 1.6 | 73 |
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Reports on SeismoAtlas
No reports yet.
Event id aka2026vpfnze. First recorded here 31 Oct 2026, 20:30:20 UTC. Solutions: USGS · AK (usgs:aka2026vpfnze). Cite as: SeismoAtlas, “M2.1 earthquake 139 km N of Tanaina, Alaska, United States”, https://seismoatlas.com/earthquake/aka2026vpfnze-m2-1-earthquake-139-km-n-of-tanaina-alaska-united-states, data from USGS.
JSON: /api/v1/events/aka2026vpfnze. SeismoAtlas is not an official warning service.