Earthquake · reviewed by a seismologist
M 3.2ml
Earthquake near Sudden Valley, WA
No earthquake was likely felt in Sudden Valley in the 24 hours to 5:04 pm PST (01:04 UTC). The last one was M 3.8, 52 km (32 mi) SSW, at 11:35 pm PDT on 1 July 2026, estimated intensity II (weak) in town; 2,030 felt reports to USGS. Every earthquake near Sudden Valley
This page: a magnitude 3.2 earthquake was recorded 5 km (3 mi) east-northeast of Sudden Valley, WA, at 11:50 pm PDT on 6 September 2016 (06:50 UTC), 18 km deep. 220 people have reported feeling it to USGS.
USGS: 4 km ENE of Sudden Valley, Washington
13 km (8 mi) E of Bellingham, WA · 125 km (78 mi) N of Seattle, WA
- When
- 11:50 pm PDT on 6 September 2016 ()
- Where
- 5 km (3 mi) east-northeast of Sudden Valley, WA · earthquakes near Sudden Valley
- Magnitude
- M 3.2 (ml)
- Depth
- 18 km below the surface
- Felt
- 220 reports · strongest reported intensity IV
- Measured shaking
- intensity III (ShakeMap)
- Nearest
- Whatcom County, 35 km ENE
- Nearest mapped fault
- Birch Bay fault, 21 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3632 days ago
Earthquake alerts for Sudden Valley, WA
Get a notification in this browser when USGS records an earthquake near Sudden Valley, WA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 41 km (25 mi) from the epicentre. In Sudden Valley, 5 km away, the estimate is intensity III (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Likely felt in: Bellingham 15 km, intensity II · Sedro-Woolley 27 km, intensity II · Anacortes 35 km, intensity II · Mount Vernon 36 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 1,700 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 200,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 9,100× the energy of this one
- Magna, Utah 2020 M 5.7 6,500× the energy of this one
- This earthquake M 3.2 about 1,700 lb of TNT
- Around the size people start to feel M 3.0 this one released 1.7× more
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:
- 6.0 San Juan Islands, Washington · 38 km W of this epicentre
- 5.0 6 km W of Conway, Washington · 47 km SSW of this epicentre
- 5.0 4 km ENE of Deming, Washington · 15 km NE of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 48.7447, -122.2888. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Whatcom County, WA | 35 km (22 mi) | ENE | earthquakes near Whatcom County |
| Skagit County, WA | 45 km (28 mi) | SE | earthquakes near Skagit County |
| San Juan County, WA | 65 km (41 mi) | WSW | earthquakes near San Juan County |
| Island County, WA | 71 km (44 mi) | SSW | earthquakes near Island County |
| Snohomish County, WA | 86 km (53 mi) | SSE | earthquakes near Snohomish County |
| Clallam County, WA | 138 km (85 mi) | WSW | earthquakes near Clallam County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
48 earthquakes have been recorded within 50 km since this one.
- 2.3 5 km NNE of Alger, Washington
- 1.6 3 km NNW of Hamilton, Washington
- 2.0 2 km S of Marietta, Washington
- 1.8 13 km S of Birch Bay, Washington
- 2.1 6 km SSE of Acme, Washington
- 1.6 4 km SW of Geneva, Washington
- 1.7 5 km E of Ferndale, Washington
- 1.6 7 km SSW of Geneva, Washington
- 1.7 6 km SSE of Acme, Washington
- 1.5 1 km ENE of Bay View, Washington
- 1.7 6 km ESE of Nooksack, Washington
- 1.6 8 km NW of Concrete, Washington
- 2.3 6 km W of Lake Cavanaugh, Washington
- 1.7 3 km NNW of Alger, Washington
- 1.8 3 km ENE of Concrete, WA
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.