Earthquake · reviewed by a seismologist
M 2.8ml
Earthquake near Fall City, WA
No earthquake was likely felt in Fall City in the 24 hours to 7:51 pm PST (03:51 UTC). The last one was M 4.2, 65 km (41 mi) WSW, at 2:05 pm PDT on 29 September 2026, estimated intensity II (weak) in town; 9,329 felt reports to USGS. Every earthquake near Fall City
This page: a magnitude 2.8 earthquake was recorded 9 km (5 mi) east-northeast of Fall City, WA, at 4:51 am PDT on 8 August 2023 (11:51 UTC), 16 km deep. 94 people have reported feeling it to USGS.
USGS: 8 km ENE of Fall City, Washington
42 km (26 mi) E of Seattle, WA · 19 km (12 mi) E of Sammamish, WA
- When
- 4:51 am PDT on 8 August 2023 ()
- Where
- 9 km (5 mi) east-northeast of Fall City, WA · earthquakes near Fall City
- Magnitude
- M 2.8 (ml)
- Depth
- 16 km below the surface
- Felt
- 94 reports · strongest reported intensity III
- Nearest
- King County, 13 km SSW
- Nearest mapped fault
- Rattlesnake Mountain fault, 8 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 967 days ago
Earthquake alerts for Fall City, WA
Get a notification in this browser when USGS records an earthquake near Fall City, 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 24 km (15 mi) from the epicentre. In Fall City, 9 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: Fall City 9 km, intensity II · Snoqualmie 9 km, intensity II · City of Sammamish 19 km, intensity II · Issaquah 20 km, intensity II · Sammamish 22 km, intensity II · West Lake Sammamish 24 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 550 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 28,000× the energy of this one
- Magna, Utah 2020 M 5.7 19,000× the energy of this one
- Around the size people start to feel M 3.0 1.7× the energy of this one
- This earthquake M 2.8 about 550 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 410 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 · 19 km NNW of this epicentre
- 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 17 km N of this epicentre
- 5.0 4 km ENE of Machias, Washington · 47 km NNW of this epicentre
- 5.0 3 km WSW of Des Moines, Washington · 50 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 47.6038, -121.7875. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| King County, WA | 13 km (8 mi) | SSW | earthquakes near King County |
| Snohomish County, WA | 50 km (31 mi) | N | earthquakes near Snohomish County |
| Kitsap County, WA | 65 km (40 mi) | W | earthquakes near Kitsap County |
| Pierce County, WA | 67 km (42 mi) | SSW | earthquakes near Pierce County |
| Island County, WA | 90 km (56 mi) | NW | earthquakes near Island County |
| Chelan County, WA | 92 km (57 mi) | ENE | earthquakes near Chelan County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
56 earthquakes have been recorded within 50 km since this one.
- 1.6 10 km NNE of Snoqualmie, Washington
- 2.5 10 km NE of Snoqualmie, Washington
- 2.0 0 km WSW of Lynnwood, Washington
- 1.7 3 km N of Woods Creek, Washington
- 1.9 11 km NE of Snoqualmie, Washington
- 1.5 5 km WSW of Black Diamond, Washington
- 1.9 3 km SSE of Woods Creek, Washington
- 1.6 4 km N of Woods Creek, Washington
- 2.2 3 km SW of Redmond, Washington
- 2.7 2 km E of Redmond, Washington
- 2.0 6 km NE of Snoqualmie, Washington
- 1.5 7 km NNE of Lake Marcel-Stillwater, Washington
- 2.3 1 km S of Fall City, Washington
- 1.6 2 km S of Sultan, Washington
- 1.8 2 km NW of Duvall, 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.