QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7ml

Earthquake near South Hill, WA

No earthquake was likely felt in South Hill in the 24 hours to 7:10 am PST (15:10 UTC). The last one was M 4.2, 45 km (28 mi) NW, at 2:05 pm PDT on 29 September 2026, estimated intensity III (weak) in town; 9,329 felt reports to USGS. Every earthquake near South Hill

This page: a magnitude 2.7 earthquake was recorded 42 km (26 mi) southeast of South Hill, WA, at 4:44 pm PDT on 22 August 2023 (23:44 UTC), 7.8 km deep. 8 people have reported feeling it to USGS.

USGS: 16 km NE of Ashford, Washington

90 km (56 mi) SSE of Seattle, WA · 54 km (34 mi) SSE of Auburn, WA

4:44 pm PDT, Aug 22, 2023 · · 7.8 km deep · released about 390 lb of TNT

10 km30 km60 km120 km N Pierce County 28 kmLewis County 49 kmKing County 69 kmThurston County 72 kmSkamania County 94 kmCowlitz County 96 kmKittitas County 96 kmYakima County 99 kmKitsap County 103 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
4:44 pm PDT on 22 August 2023 ()
Where
42 km (26 mi) southeast of South Hill, WA · earthquakes near South Hill
Magnitude
M 2.7 (ml)
Depth
7.8 km below the surface
Felt
8 reports · strongest reported intensity IV
Nearest
Pierce County, 28 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 554 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 24 km (15 mi) from the epicentre. In South Hill, 42 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: Crocker, Eatonville.

How big was it?

This earthquake released about 390 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 39,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 28,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.5× the energy of this one
  4. This earthquake M 2.7 about 390 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 46.8693, -121.8907. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Pierce County, WA 28 km (18 mi) NW earthquakes near Pierce County
Lewis County, WA 49 km (31 mi) SW earthquakes near Lewis County
King County, WA 69 km (43 mi) N earthquakes near King County
Thurston County, WA 72 km (45 mi) W earthquakes near Thurston County
Skamania County, WA 94 km (58 mi) S earthquakes near Skamania County
Cowlitz County, WA 96 km (60 mi) SW earthquakes near Cowlitz County

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

Aftershocks so far

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

  1. 1.7 2 km SE of Kapowsin, Washington
  2. 1.6 12 km ESE of Enumclaw, Washington
  3. 2.2 13 km NNE of Ashford, Washington
  4. 1.5 1 km SSE of Kapowsin, Washington
  5. 1.9 5 km E of Enumclaw, Washington
  6. 1.6 1 km WNW of Kapowsin, Washington
  7. 1.6 24 km NNE of Packwood, Washington
  8. 1.5 5 km WSW of Black Diamond, Washington
  9. 1.5 2 km ESE of Buckley, Washington
  10. 1.7 0 km WSW of Kapowsin, Washington
  11. 1.7 12 km E of Wilkeson, Washington
  12. 1.6 1 km SE of Kapowsin, Washington
  13. 1.5 15 km NNE of Ashford, Washington
  14. 1.5 19 km SSE of Carbonado, Washington
  15. 1.8 17 km SE of Carbonado, 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.