QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near South Hill, WA

Yes. A magnitude 1.8 earthquake was recorded 39 km (24 mi) SE of South Hill, WA, at 9:48 pm PDT on 13 September 2017 (04:48 UTC), 10 km deep.

This was on 13 September 2017. The latest near South Hill: M 2.5 on 24 October 2025.

USGS: 13 km NNE of Ashford, Washington

89 km (55 mi) SSE of Seattle, WA · 53 km (33 mi) SSE of Auburn, WA

9:48 pm PDT, Sep 13, 2017 · · 10 km deep · released about 14 lb of TNT

Every earthquake near South Hill Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Pierce County 26 kmLewis County 46 kmThurston County 68 kmKing County 70 kmCowlitz County 93 kmSkamania County 94 kmKittitas County 100 kmKitsap County 101 kmYakima County 102 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
9:48 pm PDT on 13 September 2017 ()
Where
39 km (24 mi) SE of South Hill, WA · earthquakes near South Hill
Magnitude
M 1.8 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Pierce County, 26 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3316 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 9 km (6 mi) from the epicentre. In South Hill, 39 km away, the estimate is intensity I (not felt). 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: Eatonville, Crocker.

How big was it?

This earthquake released about 14 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 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 46.8667, -121.9428. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Pierce County, WA 26 km (16 mi) NW earthquakes near Pierce County
Lewis County, WA 46 km (29 mi) SW earthquakes near Lewis County
Thurston County, WA 68 km (42 mi) W earthquakes near Thurston County
King County, WA 70 km (43 mi) N earthquakes near King County
Cowlitz County, WA 93 km (58 mi) SW earthquakes near Cowlitz County
Skamania County, WA 94 km (58 mi) S earthquakes near Skamania 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. 1.6 10 km W of Greenwater, Washington
  2. 1.6 11 km W of Greenwater, Washington
  3. 1.6 3 km ENE of Kapowsin, Washington
  4. 1.6 12 km W of Greenwater, Washington
  5. 2.0 13 km NNE of Ashford, Washington
  6. 1.6 1 km SE of Kapowsin, Washington
  7. 2.5 17 km NNE of Ashford, Washington
  8. 2.6 6 km SSW of Lake Morton-Berrydale, Washington
  9. 2.1 5 km SE of Lea Hill, Washington
  10. 1.7 9 km NNW of Morton, Washington
  11. 1.5 13 km ESE of Enumclaw, Washington
  12. 2.0 7 km S of Morton, Washington
  13. 1.7 1 km SE of Kapowsin, Washington
  14. 1.7 12 km W of Greenwater, Washington
  15. 1.6 12 km ESE of Enumclaw, 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.