M1.5 earthquake 13 km W of Port Orchard, Washington, United States
A magnitude 1.5 earthquake struck 13 km W of Port Orchard, Washington, United States at 16:58 local time (23:58 UTC) on 27 Oct 2026, at a depth of 18 km, according to USGS.
Data: USGS · updated 2026-10-28 19:58 UTC · reviewed
- Magnitude
- 1.5micro
local magnitude (Richter) (ml) - Depth
- 18.1 km
- Status
- Reviewed
- Origin time
- 2026-10-27 23:58:21 UTC
- Local: 27 Oct 2026, 16:58:21 (America/Los Angeles)
- Epicentre
- 47.519° N, 122.805° 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 |
|---|---|---|
| Port OrchardWashington, United States · pop. 13,607 | 13 km | INot felt |
| East Port OrchardWashington, United States · pop. 5,919 | 14 km | INot felt |
| BremertonWashington, United States · pop. 39,520 | 14 km | INot felt |
| Bainbridge IslandWashington, United States · pop. 23,840 | 25 km | INot felt |
| BurienWashington, United States · pop. 50,467 | 35 km | INot felt |
| University PlaceWashington, United States · pop. 32,842 | 36 km | INot felt |
| SeattleWashington, United States · pop. 780,995 | 37 km | INot felt |
| VictoriaBritish Columbia, Canada · pop. 289,625 | 110 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 | 1.5 ml | 18.1 km | 47.52° N, 122.80° W | – | Reviewed |
How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 3 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 18 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M1.5 releases about 5.6× the energy of M1.0, and its waves are about 3.2× taller on a seismogram. Energy: 3 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
8 later earthquakes within 30 km; the largest was M2.2 1 day ago. 2 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M1.5
8 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 142.60 | 0.4 | 20 |
| 202.21 | 0.9 | 21 |
| 224.69 | 0.9 | 23 |
| 263.58 | 1.3 | 18 |
| 302.96 | -0.3 | 11 |
| 303.80 | 0.5 | 22 |
| 362.93 | 2.2 | 28 |
| 403.80 | 1.9 | 0 |
- 2.25 km N of Vashon, Washington, United States11-12 02:54
- 1.911 km SW of Silverdale, Washington, United States11-13 19:46
- 1.38 km WSW of Tracyton, Washington, United States11-07 23:32
- 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
- 0.411 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 uw714130621. First recorded here 28 Oct 2026, 19:59:36 UTC. Solutions: USGS · UW (usgs:uw714130621). Cite as: SeismoAtlas, “M1.5 earthquake 13 km W of Port Orchard, Washington, United States”, https://seismoatlas.com/earthquake/uw714130621-m1-5-earthquake-13-km-w-of-port-orchard-washington-united-states, data from USGS.
JSON: /api/v1/events/uw714130621. SeismoAtlas is not an official warning service.