QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Mount Vernon, WA

No earthquake was likely felt in Mount Vernon in the 24 hours to 5:33 am PST (13:33 UTC). The last one was M 2.6, 2 km (1 mi) ENE, at 9:17 pm PDT on 11 September 2026, estimated intensity II (weak) in town; 10 felt reports to USGS. Every earthquake near Mount Vernon

This page: a magnitude 1.7 earthquake was recorded in Mount Vernon, WA, at 3:45 pm PST on 5 December 2021 (23:45 UTC), 7.4 km deep. 1 person has reported feeling it to USGS.

USGS: 1 km SE of Mount Vernon, Washington

88 km (55 mi) N of Seattle, WA · 39 km (24 mi) NNW of Marysville, WA

3:45 pm PST, Dec 5, 2021 · · 7.4 km deep · released about 10 lb of TNT

Every earthquake near Mount Vernon Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Skagit County 38 kmIsland County 38 kmSnohomish County 57 kmSan Juan County 59 kmWhatcom County 59 kmKitsap County 89 kmKing County 109 kmJefferson County 112 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
3:45 pm PST on 5 December 2021 ()
Where
in Mount Vernon, WA · earthquakes near Mount Vernon
Magnitude
M 1.7 (ml)
Depth
7.4 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Skagit County, 38 km ENE
Nearest mapped fault
Utsalady Point 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 1803 days ago

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 10 km (6 mi) from the epicentre. 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: Mount Vernon in town, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 10 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 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 92× the energy of this one
  4. This earthquake M 1.7 about 10 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

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:

  1. 6.0 San Juan Islands, Washington · 48 km NW of this epicentre
  2. 5.0 6 km W of Conway, Washington · 12 km SW of this epicentre
  3. 5.0 4 km ENE of Deming, Washington · 49 km NNE 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 48.4130, -122.3190. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Skagit County, WA 38 km (24 mi) ENE earthquakes near Skagit County
Island County, WA 38 km (24 mi) SW earthquakes near Island County
Snohomish County, WA 57 km (36 mi) SE earthquakes near Snohomish County
San Juan County, WA 59 km (37 mi) W earthquakes near San Juan County
Whatcom County, WA 59 km (37 mi) NE earthquakes near Whatcom County
Kitsap County, WA 89 km (56 mi) SSW earthquakes near Kitsap County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

58 earthquakes have been recorded within 50 km since this one.

  1. 1.6 9 km NNE of Sedro-Woolley, Washington
  2. 3.1 6 km N of Camano, Washington
  3. 1.5 2 km E of Granite Falls, Washington
  4. 1.8 4 km NNW of Bryant, Washington
  5. 1.5 Washington
  6. 1.7 4 km E of Granite Falls, Washington
  7. 1.9 1 km ENE of Granite Falls, Washington
  8. 2.0 13 km W of Ault Field, Washington
  9. 1.6 14 km NNE of Hamilton, Washington
  10. 1.8 2 km SW of Deming, Washington
  11. 1.9 4 km ENE of La Conner, Washington
  12. 1.7 1 km ENE of Granite Falls, Washington
  13. 1.7 1 km E of Granite Falls, Washington
  14. 1.6 2 km E of Granite Falls, Washington
  15. 1.8 2 km E of Granite Falls, 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.