QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Maple Valley, WA

No earthquake was likely felt in Maple Valley in the 24 hours to 1:23 am PST (09:23 UTC). The last one was M 4.2, 51 km (32 mi) W, at 2:05 pm PDT on 29 September 2026, estimated intensity II (weak) in town; 9,329 felt reports to USGS. Every earthquake near Maple Valley

This page: a magnitude 1.8 earthquake was recorded 3 km (2 mi) east-northeast of Maple Valley, WA, at 7:22 pm PDT on 4 April 2020 (02:22 UTC), 20 km deep.

USGS: 2 km ENE of Maple Valley, Washington

35 km (22 mi) SE of Seattle, WA · 15 km (9 mi) E of Kent, WA

7:22 pm PDT, Apr 4, 2020 · · 20 km deep · released about 15 lb of TNT

10 km30 km60 km120 km N King County 17 kmPierce County 41 kmKitsap County 54 kmSnohomish County 75 kmThurston County 81 kmMason County 87 kmLewis County 96 kmIsland County 97 kmKittitas County 106 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
7:22 pm PDT on 4 April 2020 ()
Where
3 km (2 mi) east-northeast of Maple Valley, WA · earthquakes near Maple Valley
Magnitude
M 1.8 (ml)
Depth
20 km below the surface
Felt
no reports yet
Nearest
King County, 17 km NE
Nearest mapped fault
Seattle fault, 7 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 2413 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 Maple Valley, 3 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: Hobart, Ravensdale, Mirrormont, Maple Heights-Lake Desire, Covington, Lake Morton-Berrydale.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 4 earthquakes of M5 or more within 50 km:

  1. 6.7 1 km ENE of Dash Point, Washington · 31 km WSW of this epicentre
  2. 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 41 km NNE of this epicentre
  3. 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 41 km NNE of this epicentre
  4. 5.0 3 km WSW of Des Moines, Washington · 26 km W 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 47.4053, -122.0142. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
King County, WA 17 km (10 mi) NE earthquakes near King County
Pierce County, WA 41 km (25 mi) SSW earthquakes near Pierce County
Kitsap County, WA 54 km (34 mi) WNW earthquakes near Kitsap County
Snohomish County, WA 75 km (46 mi) NNE earthquakes near Snohomish County
Thurston County, WA 81 km (50 mi) SW earthquakes near Thurston County
Mason County, WA 87 km (54 mi) W earthquakes near Mason County

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

Aftershocks so far

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

  1. 2.2 3 km S of Duvall, Washington
  2. 1.7 2 km NE of Mirrormont, Washington
  3. 1.6 7 km NE of Tanner, Washington
  4. 1.7 3 km ENE of Enetai, Washington
  5. 1.5 2 km NNW of Manchester, Washington
  6. 1.8 2 km SW of Ravensdale, Washington
  7. 2.3 2 km SSW of Ravensdale, Washington
  8. 3.2 2 km S of Ravensdale, Washington
  9. 1.8 12 km W of Greenwater, Washington
  10. 3.0 6 km ENE of Carnation, Washington
  11. 2.2 3 km ENE of Lake Marcel-Stillwater, Washington
  12. 1.6 3 km ENE of Echo Lake, Washington
  13. 2.9 4 km S of Monroe, Washington
  14. 2.0 2 km N of North Bend, Washington
  15. 2.0 2 km NE of Black Diamond, 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.