M4.2 Earthquake 6 km WNW of Wauna, Washington — September 29, 2026
2026-09-29 21:05:56 UTC (1 hour ago) · approx. 1:05 PM UTC-8 local
Felt by 6,052 people across a wide area.
On September 29, 2026 at 21:05 UTC, a magnitude 4.2 shallow crustal earthquake struck 6 km WNW of Wauna, Washington, at a depth of 27.9 km and coordinates 47.4003°, -122.7220°. The earthquake was reported felt by 6,052 peopleacross a wide area, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.5 (light). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 180 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 645, making it a moderate-impact event. The nearest populated place is Stansberry Lake (population 2,062).
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 25 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 440 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Washington, a region characterized by the Cascadia Subduction Zone, where the Juan de Fuca Plate subducts beneath North America and is capable of producing M9+ megathrust earthquakes. The nearest mapped fault system is the Cascadia Subduction Zone. View all earthquakes in Washington.
Learn more: Cascadia Subduction Zone · Magnitude scale · Aftershock sequences
Nearest Populated Places
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 6,052 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 2,287,090 |
Earthquake Details
-122.7220°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.2 earthquake near Wauna, Washington?
The magnitude 4.2 earthquake that struck 6 km WNW of Wauna, Washington on September 29, 2026 at 21:05 UTC had a depth of 27.9 km. It was felt by 6,052 people with maximum shaking intensity of MMI 3.5 (light). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 47.4003°, -122.7220°, which is 6 km WNW of Wauna, Washington. The nearest populated place is Stansberry Lake (population 2,062). View all earthquakes in Washington.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.
Has Washington had earthquakes this big before?
The largest recorded earthquake in Washington was the M7.4 offshore earthquake of April 13, 1949. Today's magnitude 4.2 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: uw714111952). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, September 29, 2026). M4.2 Earthquake 6 km WNW of Wauna, Washington — September 29, 2026. Retrieved September 29, 2026 from https://www.earthquaketracker.org/earthquakes/event/uw714111952/