QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Forks, WA

USGS: 32 km SW of Forks, Washington

4:08 pm PDT, Sep 11, 2023 · · -0.3 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Clallam County 73 kmJefferson County 91 kmGrays Harbor County 101 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
4:08 pm PDT on 11 September 2023 ()
Where
32 km (20 mi) SW of Forks, WA · earthquakes near Forks
Magnitude
M 1.8 (ml)
Depth
-0.3 km below the surface
Felt
no reports yet
Nearest
Clallam County, 73 km ENE
Nearest mapped fault
Cascadia fold and fault belt, 8 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 1116 days ago

A magnitude 1.8 earthquake was recorded 32 km (20 mi) SW of Forks, WA, at 4:08 pm PDT on 11 September 2023 (23:08 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 13 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 since 1900 lists no earthquake of M5 or more within 50 km.

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 47.7830, -124.7385. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Clallam County, WA 73 km (45 mi) ENE earthquakes near Clallam County
Jefferson County, WA 91 km (56 mi) E earthquakes near Jefferson County
Grays Harbor County, WA 101 km (63 mi) SE earthquakes near Grays Harbor County
Mason County, WA 127 km (79 mi) ESE earthquakes near Mason County

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

Aftershocks so far

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

  1. 1.6 16 km NNW of Queets, Washington
  2. 1.5 19 km NNW of Forks, Washington
  3. 2.1 26 km W of Forks, Washington
  4. 1.7 12 km S of Forks, Washington
  5. 1.5 6 km E of Queets, Washington
  6. 1.6 11 km E of Forks, Washington
  7. 1.6 20 km N of Queets, Washington
  8. 1.6 4 km WSW of Forks, Washington
  9. 1.9 21 km NNW of Forks, Washington
  10. 1.8 21 km NNW of Forks, Washington
  11. 1.8 7 km SE of Queets, Washington
  12. 1.6 4 km WSW of Forks, Washington
  13. 1.8 18 km NNW of Forks, Washington
  14. 1.6 2 km WSW of Forks, Washington
  15. 2.5 8 km ESE of Forks, 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.