Earthquake · reviewed by a seismologist
M 1.7ml
Earthquake near Snoqualmie, WA
No earthquake was likely felt in Snoqualmie in the 24 hours to 4:33 pm PST (00:33 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 1.7 earthquake was recorded 7 km (4 mi) northeast of Snoqualmie, WA, at 12:35 am PST on 21 December 2021 (08:35 UTC), 9.3 km deep.
USGS: 6 km NE of Snoqualmie, Washington
43 km (27 mi) E of Seattle, WA · 20 km (12 mi) E of Sammamish, WA
- When
- 12:35 am PST on 21 December 2021 ()
- Where
- 7 km (4 mi) northeast of Snoqualmie, WA · earthquakes near Snoqualmie
- Magnitude
- M 1.7 (ml)
- Depth
- 9.3 km below the surface
- Felt
- no reports yet
- Nearest
- King County, 11 km SSW
- Nearest mapped fault
- Rattlesnake Mountain fault, 6 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 1787 days ago
Earthquake alerts for Snoqualmie, WA
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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, people at rest would likely notice it out to about 8 km (5 mi) from the epicentre. In Snoqualmie, 7 km away, the estimate is intensity II (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: Snoqualmie 7 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
- Around the size people start to feel M 3.0 89× the energy of this one
- This earthquake M 1.7 about 11 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 21,000 times the energy of this one.
Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:
- 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 22 km NNW of this epicentre
- 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 20 km NNW of this epicentre
- 5.0 4 km ENE of Machias, Washington · 50 km NNW of this epicentre
- 5.0 3 km WSW of Des Moines, Washington · 49 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 47.5768, -121.7748. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| King County, WA | 11 km (7 mi) | SSW | earthquakes near King County |
| Snohomish County, WA | 53 km (33 mi) | N | earthquakes near Snohomish County |
| Pierce County, WA | 65 km (40 mi) | SSW | earthquakes near Pierce County |
| Kitsap County, WA | 66 km (41 mi) | W | earthquakes near Kitsap County |
| Chelan County, WA | 92 km (57 mi) | ENE | earthquakes near Chelan County |
| Island County, WA | 93 km (58 mi) | NW | earthquakes near Island 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.
- 1.6 11 km ESE of Enumclaw, Washington
- 2.7 1 km NW of Maple Valley, Washington
- 1.8 1 km SSW of Three Lakes, Washington
- 1.7 6 km ESE of Tanner, Washington
- 1.8 1 km ESE of Union Hill-Novelty Hill, Washington
- 1.6 0 km NNE of Lake Marcel-Stillwater, Washington
- 1.6 Puget Sound region, Washington
- 1.6 0 km N of Lake Marcel-Stillwater, Washington
- 1.6 11 km W of Greenwater, Washington
- 2.3 3 km W of Hobart, Washington
- 2.8 2 km SW of Wilderness Rim, Washington
- 1.7 8 km ENE of Snoqualmie, Washington
- 1.7 Puget Sound region, Washington
- 1.6 2 km ESE of Wilderness Rim, Washington
- 1.5 12 km ESE of Riverbend, 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.