QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

11 km S of Shelton, Washington

· -0.5 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mason County 26 kmThurston County 30 kmGrays Harbor County 53 kmKitsap County 68 kmPierce County 74 kmPacific County 80 kmLewis County 82 kmJefferson County 83 kmWahkiakum County 94 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
Magnitude
M 1.8 (ml)
Depth
-0.5 km below the surface
Felt
no reports yet
Nearest
Mason County, 26 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2335 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

USGS catalogues this as explosion, not an earthquake.

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 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× 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.

Where

Epicentre 47.1152, -123.1220. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mason County, WA 26 km (16 mi) S of here earthquakes near Mason County
Thurston County, WA 30 km (19 mi) NW of here earthquakes near Thurston County
Grays Harbor County, WA 53 km (33 mi) E of here earthquakes near Grays Harbor County
Kitsap County, WA 68 km (42 mi) SSW of here earthquakes near Kitsap County
Pierce County, WA 74 km (46 mi) W of here earthquakes near Pierce County
Pacific County, WA 80 km (50 mi) NE of here earthquakes near Pacific County

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

Aftershocks so far

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

  1. 1.6 8 km WSW of Home, Washington
  2. 2.3 5 km WNW of Wauna, Washington
  3. 1.5 3 km W of Hoodsport, Washington
  4. 1.6 11 km S of Shelton, Washington
  5. 1.5 5 km N of Belfair, Washington
  6. 1.9 2 km NE of Tanglewilde-Thompson Place, Washington
  7. 2.0 13 km WSW of Longbranch, Washington
  8. 1.6 11 km S of Shelton, Washington
  9. 1.6 21 km SE of Neilton, Washington
  10. 1.5 2 km WNW of Gig Harbor, Washington
  11. 1.5 7 km ENE of Allyn, Washington
  12. 1.9 4 km NE of Home, Washington
  13. 2.1 0 km S of Skokomish, Washington
  14. 2.0 3 km WSW of Home, Washington
  15. 1.8 4 km N of Belfair, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.1 on 2017-02-23 — it released about 2,700 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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