Earthquake · reviewed by a seismologist
M 1.8ml
Earthquake near Snoqualmie, WA
No earthquake was likely felt in Snoqualmie in the 24 hours to 4:36 am PST (12:36 UTC). The last one was M 2.6, 12 km (8 mi) S, at 6:09 pm PDT on 14 October 2026, estimated intensity II (weak) in town; 46 felt reports to USGS. Every earthquake near Snoqualmie
This page: a magnitude 1.8 earthquake was recorded in Snoqualmie, WA, at 6:32 am PDT on 13 September 2021 (13:32 UTC), 19 km deep.
USGS: 1 km SW of Snoqualmie, Washington
40 km (25 mi) ESE of Seattle, WA · 17 km (11 mi) ESE of Sammamish, WA
- When
- 6:32 am PDT on 13 September 2021 ()
- Where
- in Snoqualmie, WA · earthquakes near Snoqualmie
- Magnitude
- M 1.8 (ml)
- Depth
- 19 km below the surface
- Felt
- no reports yet
- Nearest
- King County, 3 km S
- Nearest mapped fault
- Rattlesnake Mountain fault, under 1 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 614 days ago
Earthquake alerts for Snoqualmie, WA
Get a notification in this browser when USGS records an earthquake near Snoqualmie, 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 minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth it was probably too small to be felt, even directly above it. 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.
Earthquakes near other towns within 30 km: North Bend, Fall City, Tanner, Riverbend, Wilderness Rim, Mirrormont.
How big was it?
This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 730,000× the energy of this one
- Around the size people start to feel M 3.0 65× the energy of this one
- This earthquake M 1.8 about 15 lb of TNT
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
The largest earthquake within 50 km since 2016 was M 4.6 on 2019-07-12 — about 15,000 times the energy of this one.
Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:
- 6.7 1 km ENE of Dash Point, Washington · 48 km WSW of this epicentre
- 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 27 km N of this epicentre
- 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 26 km N of this epicentre
- 5.0 3 km WSW of Des Moines, Washington · 42 km WSW 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 47.5183, -121.8405. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| King County, WA | 3 km (2 mi) | S | earthquakes near King County |
| Pierce County, WA | 57 km (35 mi) | SSW | earthquakes near Pierce County |
| Snohomish County, WA | 60 km (37 mi) | N | earthquakes near Snohomish County |
| Kitsap County, WA | 62 km (39 mi) | WNW | earthquakes near Kitsap County |
| Island County, WA | 94 km (59 mi) | NW | earthquakes near Island County |
| Kittitas County, WA | 98 km (61 mi) | ESE | earthquakes near Kittitas County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
55 earthquakes have been recorded within 50 km since this one.
- 1.7 1 km WNW of Bonney Lake, Washington
- 2.7 4 km E of Lake Marcel-Stillwater, Washington
- 1.8 8 km SSW of Sultan, Washington
- 2.3 3 km WNW of Duvall, Washington
- 1.6 6 km ENE of Mirrormont, Washington
- 1.6 6 km W of Wilderness Rim, Washington
- 1.5 0 km SSE of Wilderness Rim, Washington
- 2.1 5 km SW of Black Diamond, Washington
- 1.5 5 km SW of Des Moines, Washington
- 1.8 5 km SW of Des Moines, Washington
- 1.6 6 km SW of Sultan, Washington
- 1.6 Washington
- 1.6 Puget Sound region, Washington
- 1.5 Washington
- 1.8 2 km SSE of Lake Forest Park, Washington
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.