M1.8 earthquake 86 km WNW of Anchorage, Alaska, United States
A magnitude 1.8 earthquake struck 86 km WNW of Anchorage, Alaska, United States at 08:39 local time (16:39 UTC) on 28 Sept 2026, at a depth of 11 km, according to USGS.
revised from M1.9
Data: USGS · updated 2026-09-30 05:57 UTC · reviewed
- Magnitude
- 1.8micro
local magnitude (Richter) (ml)
revised from 1.9 - Depth
- 11.2 km
- Status
- Reviewed
- Origin time
- 2026-09-28 16:39:02 UTC
- Local: 28 Sept 2026, 08:39:02 (America/Anchorage)
- Epicentre
- 61.599° N, 151.315° W
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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 | 86 km | INot felt |
| Meadow LakesAlaska, United States · pop. 7,570 | 91 km | INot felt |
| Eagle RiverAlaska, United States · pop. 24,793 | 98 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 | 1.8 mlwas 1.9 | 11.2 km | 61.60° N, 151.31° W | – | Reviewed · 1 revision |
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How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 8 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 11 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M1.8 releases about 16× the energy of M1.0, and its waves are about 6.3× taller on a seismogram. Energy: 8 kg of TNT vs 477 g of TNT.
Each square is the energy of one M1.0. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
11 later earthquakes within 30 km; the largest was M2.4 1 day ago. 8 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M1.8
11 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 17.98 | 0.6 | 15 |
| 39.49 | 0.7 | 10 |
| 119.27 | 1.8 | 77 |
| 150.64 | 2.1 | 5 |
| 180.72 | 2.4 | 81 |
| 181.37 | 1.6 | 88 |
| 189.12 | 1.9 | 90 |
| 193.53 | 1.8 | 86 |
| 196.06 | 1.6 | 64 |
| 197.26 | 2.3 | 61 |
| 220.69 | 1.2 | 18 |
- 2.498 km WNW of Anchorage, Alaska, United States10-06 05:22
- 2.360 km WNW of Anchorage, Alaska, United States10-06 21:54
- 2.171 km WNW of Anchorage, Alaska, United States10-04 23:17
- 1.9112 km W of Meadow Lakes, Alaska, United States10-06 13:46
- 1.898 km WNW of Meadow Lakes, Alaska, United States10-03 15:55
- 1.8101 km WNW of Anchorage, Alaska, United States10-06 18:11
- 1.6112 km WNW of Anchorage, Alaska, United States10-06 06:01
- 1.659 km WNW of Anchorage, Alaska, United States10-06 20:42
- 1.2107 km WNW of Meadow Lakes, Alaska, United States10-07 21:20
- 0.785 km WNW of Anchorage, Alaska, United States09-30 08:08
- 0.684 km WNW of Anchorage, Alaska, United States09-29 10:37
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.
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Event id aka2026tfzfrs. First recorded here 28 Sept 2026, 17:32:05 UTC. Solutions: USGS · AK (usgs:aka2026tfzfrs). Cite as: SeismoAtlas, “M1.8 earthquake 86 km WNW of Anchorage, Alaska, United States”, https://seismoatlas.com/earthquake/aka2026tfzfrs-m1-8-earthquake-86-km-wnw-of-anchorage-alaska-united-states, data from USGS.
JSON: /api/v1/events/aka2026tfzfrs. SeismoAtlas is not an official warning service.