M0.4 earthquake 15 km WNW of Bangor Trident Base, Washington, United States
A magnitude 0.4 earthquake struck 15 km WNW of Bangor Trident Base, Washington, United States at 05:09 local time (12:09 UTC) on 20 Oct 2026, at a depth of 21 km, according to USGS.
Data: USGS · updated 2026-10-20 18:28 UTC · reviewed
- Magnitude
- 0.4micro
duration magnitude (md) - Depth
- 21.3 km
- Status
- Reviewed
- Origin time
- 2026-10-20 12:09:45 UTC
- Local: 20 Oct 2026, 05:09:45 (America/Los Angeles)
- Epicentre
- 47.793° N, 122.884° 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 |
|---|---|---|
| Bangor Trident BaseWashington, United States · pop. 6,054 | 15 km | INot felt |
| PoulsboWashington, United States · pop. 10,041 | 18 km | INot felt |
| BremertonWashington, United States · pop. 39,520 | 31 km | INot felt |
| Bainbridge IslandWashington, United States · pop. 23,840 | 33 km | INot felt |
| EdmondsWashington, United States · pop. 41,375 | 38 km | INot felt |
| ShorelineWashington, United States · pop. 55,439 | 41 km | INot felt |
| SeattleWashington, United States · pop. 780,995 | 46 km | INot felt |
| VictoriaBritish Columbia, Canada · pop. 289,625 | 80 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 · UW, which has been reviewed by an analyst.
| Agency | Magnitude | Depth | Epicentre | Time offset | Status |
|---|---|---|---|---|---|
| USGS · UWheadlinePacific Northwest Seismic Network via U.S. Geological Survey | 0.4 md | 21.3 km | 47.79° N, 122.88° W | – | Reviewed |
How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 67 g 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 21 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M1.0 releases about 7.2× the energy of M0.4, and its waves are about 3.7× taller on a seismogram. Energy: 477 g of TNT vs 67 g of TNT.
Each square is the energy of one M0.4. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
14 later earthquakes within 30 km; the largest was M1.9 5 h 25 min ago. 6 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M0.4
14 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 30.99 | 1.3 | 0 |
| 70.24 | 1.5 | 40 |
| 71.25 | 0.4 | 22 |
| 136.95 | 1.1 | 5 |
| 223.53 | 1.3 | 0 |
| 322.41 | 0.4 | 20 |
| 326.33 | 1.1 | 20 |
| 382.02 | 0.9 | 21 |
| 404.50 | 0.9 | 23 |
| 443.39 | 1.3 | 18 |
| 482.77 | -0.3 | 11 |
| 483.61 | 0.5 | 22 |
| 560.25 | 1.8 | 8 |
| 583.61 | 1.9 | 0 |
- 1.911 km SW of Silverdale, Washington, United States11-13 19:46
- 1.816 km NNW of Poulsbo, Washington, United States11-12 20:24
- 1.530 km SSW of Sequim, Washington, United States10-23 10:24
- 1.320 km NNW of Poulsbo, Washington, United States10-29 19:41
- 1.38 km WSW of Tracyton, Washington, United States11-07 23:32
- 1.317 km NNW of Poulsbo, Washington, United States10-21 19:08
- 1.122 km NNW of Bangor Trident Base, Washington, United States11-03 02:29
- 1.113 km W of Bangor Trident Base, Washington, United States10-26 05:06
- 0.9Near Tracyton, Washington, United States11-06 08:39
- 0.912 km NW of Bangor Trident Base, Washington, United States11-05 10:10
- 0.511 km W of Port Orchard, Washington, United States11-09 15:46
- 0.413 km NW of Bangor Trident Base, Washington, United States10-23 11:25
- 0.411 km WNW of Bangor Trident Base, Washington, United States11-02 22:34
- -0.320 km W of Port Orchard, Washington, United States11-09 14:56
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Reports close 14 days after an earthquake.
Reports on SeismoAtlas
No reports yet.
Event id uw714122292. First recorded here 20 Oct 2026, 18:32:34 UTC. Solutions: USGS · UW (usgs:uw714122292). Cite as: SeismoAtlas, “M0.4 earthquake 15 km WNW of Bangor Trident Base, Washington, United States”, https://seismoatlas.com/earthquake/uw714122292-m0-4-earthquake-15-km-wnw-of-bangor-trident-base-washington-united-states, data from USGS.
JSON: /api/v1/events/uw714122292. SeismoAtlas is not an official warning service.