QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Fall City, WA

No earthquake was likely felt in Fall City in the 24 hours to 2:53 am PST (10:53 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 1.7 earthquake was recorded 5 km (3 mi) southwest of Fall City, WA, at 12:02 am PST on 19 December 2021 (08:02 UTC), 17 km deep.

USGS: 5 km SW of Fall City, Washington

10 km (6 mi) SE of Sammamish, WA · 33 km (20 mi) ESE of Seattle, WA

12:02 am PST, Dec 19, 2021 · · 17 km deep · released about 9.3 lb of TNT

Every earthquake near Fall City Felt it? Tell USGS Check my area
10 km30 km60 km120 km N King County 9 kmKitsap County 55 kmPierce County 56 kmSnohomish County 59 kmIsland County 89 kmThurston County 95 kmMason County 95 kmChelan County 105 kmKittitas County 105 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
12:02 am PST on 19 December 2021 ()
Where
5 km (3 mi) southwest of Fall City, WA · earthquakes near Fall City
Magnitude
M 1.7 (ml)
Depth
17 km below the surface
Felt
no reports yet
Nearest
King County, 9 km ESE
Nearest mapped fault
Rattlesnake Mountain fault, 2 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

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. In Fall City, 5 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.

Earthquakes near other towns within 30 km: Klahanie, Issaquah, Snoqualmie, Mirrormont, City of Sammamish, Ames Lake.

How big was it?

This earthquake released about 9.3 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.

  1. Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 100× the energy of this one
  4. This earthquake M 1.7 about 9.3 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 24,000 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 6.7 1 km ENE of Dash Point, Washington · 43 km WSW of this epicentre
  2. 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 26 km N of this epicentre
  3. 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 25 km NNE of this epicentre
  4. 5.0 3 km WSW of Des Moines, Washington · 36 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 47.5333, -121.9332. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
King County, WA 9 km (5 mi) ESE earthquakes near King County
Kitsap County, WA 55 km (34 mi) WNW earthquakes near Kitsap County
Pierce County, WA 56 km (35 mi) SSW earthquakes near Pierce County
Snohomish County, WA 59 km (37 mi) NNE earthquakes near Snohomish County
Island County, WA 89 km (55 mi) NW earthquakes near Island County
Thurston County, WA 95 km (59 mi) SW earthquakes near Thurston 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. 2.4 0 km NW of Des Moines, Washington
  2. 1.7 2 km SSW of Burien, Washington
  3. 1.6 4 km ENE of Lake Marcel-Stillwater, Washington
  4. 1.5 3 km WSW of North Bend, Washington
  5. 1.9 1 km WNW of Bonney Lake, Washington
  6. 1.5 3 km ENE of Lake Marcel-Stillwater, Washington
  7. 1.6 0 km SW of Esperance, Washington
  8. 1.5 Puget Sound region, Washington
  9. 2.2 7 km WSW of Seattle, Washington
  10. 1.9 3 km NNE of White Center, Washington
  11. 1.6 11 km NE of North Bend, Washington
  12. 1.6 0 km WSW of Esperance, Washington
  13. 1.7 5 km S of Black Diamond, Washington
  14. 1.7 1 km WNW of Bonney Lake, Washington
  15. 2.7 4 km E of Lake Marcel-Stillwater, 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.