M4.2 earthquake 12 km W of Maplewood, Washington, United States
A magnitude 4.2 earthquake struck 12 km W of Maplewood, Washington, United States at 14:05 local time (21:05 UTC) on 29 Sept 2026, at a depth of 28 km, according to USGS.
revised from M4.0 · 5935 reports to USGS “Did You Feel It?”
Data: USGS · updated 2026-09-29 22:11 UTC · reviewed
- Magnitude
- 4.2light
local magnitude (Richter) (ml)
revised from 4.0 - Depth
- 27.9 km
- Status
- Reviewed
- Origin time
- 2026-09-29 21:05:56 UTC
- Local: 29 Sept 2026, 14:05:56 (America/Los Angeles)
- Epicentre
- 47.400° N, 122.722° W
Advertisement
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 |
|---|---|---|
| MaplewoodWashington, United States · pop. 5,138 | 12 km | IIIWeak |
| Gig HarborWashington, United States · pop. 8,753 | 13 km | IIIWeak |
| BremertonWashington, United States · pop. 39,520 | 20 km | IIIWeak |
| University PlaceWashington, United States · pop. 32,842 | 22 km | IIIWeak |
| TacomaWashington, United States · pop. 222,906 | 27 km | IIIWeak |
| BurienWashington, United States · pop. 50,467 | 29 km | IIIWeak |
| SeattleWashington, United States · pop. 780,995 | 38 km | IIIWeak |
| VictoriaBritish Columbia, Canada · pop. 289,625 | 125 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. Likely felt out to about 43 km.
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 | 4.2 mlwas 4.2 | 27.9 km | 47.40° N, 122.72° W | – | Reviewed · 4 revisions |
Advertisement
How big was it?
Widely felt near the epicentre: rattling windows and objects. Significant damage is unlikely.
It released roughly the energy of 25 t 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 28 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M4.2 releases about 27× the energy of M3.2, and its waves are about 8.9× taller on a seismogram. Energy: 25 t of TNT vs 951 kg of TNT.
Each square is the energy of one M3.2. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
No later earthquakes have been recorded within 30 km so far. 3 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Advertisement
Event id ew1790715960. First recorded here 29 Sept 2026, 21:08:07 UTC. Solutions: USGS · UW (usgs:uw714111952). Cite as: SeismoAtlas, “M4.2 earthquake 12 km W of Maplewood, Washington, United States”, https://seismoatlas.com/earthquake/ew1790715960-m4-2-earthquake-12-km-w-of-maplewood-washington-united-states, data from USGS.
JSON: /api/v1/events/ew1790715960. SeismoAtlas is not an official warning service.