QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Ault Field, WA

No earthquake was likely felt in Ault Field in the 24 hours to 1:15 pm PST (21:15 UTC). The last one was M 4.2, 104 km (65 mi) S, at 2:05 pm PDT on 29 September 2026, estimated intensity II (weak) in town; 9,329 felt reports to USGS. Every earthquake near Ault Field

This page: a magnitude 1.7 earthquake was recorded 14 km (8 mi) west of Ault Field, WA, at 6:25 pm PST on 5 November 2018 (02:25 UTC), 24 km deep. 1 person has reported feeling it to USGS.

USGS: 13 km W of Ault Field, Washington

90 km (56 mi) NNW of Seattle, WA · 52 km (32 mi) SSW of Bellingham, WA

6:25 pm PST, Nov 5, 2018 · · 24 km deep · released about 12 lb of TNT

Every earthquake near Ault Field Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Juan County 25 kmIsland County 26 kmSkagit County 78 kmJefferson County 79 kmClallam County 81 kmKitsap County 82 kmSnohomish County 88 kmWhatcom County 92 kmMason County 115 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
6:25 pm PST on 5 November 2018 ()
Where
14 km (8 mi) west of Ault Field, WA · earthquakes near Ault Field
Magnitude
M 1.7 (ml)
Depth
24 km below the surface
Felt
1 report · strongest reported intensity IV
Nearest
San Juan County, 25 km NW
Nearest mapped fault
Utsalady Point 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 2929 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 Ault Field, 14 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: Oak Harbor, Coupeville, Friday Harbor, Anacortes, Port Townsend.

How big was it?

This earthquake released about 12 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 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 900,000× the energy of this one
  3. Around the size people start to feel M 3.0 80× the energy of this one
  4. This earthquake M 1.7 about 12 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 2 earthquakes of M5 or more within 50 km:

  1. 6.0 San Juan Islands, Washington · 38 km N of this epicentre
  2. 5.0 6 km W of Conway, Washington · 31 km E 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 48.3598, -122.8553. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Juan County, WA 25 km (15 mi) NW earthquakes near San Juan County
Island County, WA 26 km (16 mi) SSE earthquakes near Island County
Skagit County, WA 78 km (49 mi) ENE earthquakes near Skagit County
Jefferson County, WA 79 km (49 mi) SW earthquakes near Jefferson County
Clallam County, WA 81 km (51 mi) WSW earthquakes near Clallam County
Kitsap County, WA 82 km (51 mi) S earthquakes near Kitsap County

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

Aftershocks so far

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

  1. 1.9 16 km E of North Saanich, Canada
  2. 1.8 4 km NW of Orcas, Washington
  3. 2.2 8 km SW of Warm Beach, Washington
  4. 1.8 17 km WNW of Coupeville, Washington
  5. 1.7 10 km SE of Friday Harbor, Washington
  6. 2.2 15 km SSE of Friday Harbor, Washington
  7. 2.2 12 km WNW of Ault Field, Washington
  8. 2.3 12 km NW of Ault Field, Washington
  9. 2.2 12 km WNW of Ault Field, Washington
  10. 1.7 12 km NW of Ault Field, Washington
  11. 1.7 5 km ENE of Anacortes, Washington
  12. 1.8 9 km NNW of Freeland, Washington
  13. 1.8 10 km NE of Port Angeles East, Washington
  14. 1.8 4 km NE of Anacortes, Washington
  15. 2.3 4 km N of Port Townsend, 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.