QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near South Hill, WA

No earthquake was likely felt in South Hill in the 24 hours to 10:52 am PST (18:52 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 1.6 earthquake was recorded 50 km (31 mi) south-southeast of South Hill, WA, at 10:44 am PST on 29 November 2018 (18:44 UTC), 9.6 km deep.

USGS: 4 km SE of Ashford, Washington

10:44 am PST, Nov 29, 2018 · · 9.6 km deep · released about 8.4 lb of TNT

10 km30 km60 km120 km N Lewis County 34 kmPierce County 37 kmThurston County 68 kmSkamania County 79 kmCowlitz County 80 kmKing County 85 kmYakima County 100 kmKittitas County 109 kmKitsap County 112 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
10:44 am PST on 29 November 2018 ()
Where
50 km (31 mi) south-southeast of South Hill, WA · earthquakes near South Hill
Magnitude
M 1.6 (ml)
Depth
9.6 km below the surface
Felt
no reports yet
Nearest
Lewis County, 34 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2905 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 6 km (4 mi) from the epicentre. In South Hill, 50 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, Morton.

How big was it?

This earthquake released about 8.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 8.4 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 one earthquake of M5 or more within 50 km:

  1. 5.2 23 km S of Morton, Washington · 47 km SSW 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 46.7363, -121.9892. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lewis County, WA 34 km (21 mi) WSW earthquakes near Lewis County
Pierce County, WA 37 km (23 mi) NNW earthquakes near Pierce County
Thurston County, WA 68 km (42 mi) WNW earthquakes near Thurston County
Skamania County, WA 79 km (49 mi) S earthquakes near Skamania County
Cowlitz County, WA 80 km (50 mi) SW earthquakes near Cowlitz County
King County, WA 85 km (53 mi) N earthquakes near King County

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

Aftershocks so far

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

  1. 1.7 13 km W of Greenwater, Washington
  2. 1.8 8 km E of Ashford, Washington
  3. 1.6 6 km SSW of Morton, Washington
  4. 1.6 6 km ESE of Ashford, Washington
  5. 2.2 23 km S of Morton, Washington
  6. 1.8 17 km ESE of Packwood, Washington
  7. 1.9 1 km E of Kapowsin, Washington
  8. 2.6 8 km E of Ashford, Washington
  9. 1.6 17 km ESE of Packwood, Washington
  10. 1.6 Washington
  11. 2.0 7 km ESE of Ashford, Washington
  12. 2.0 0 km SE of Carbonado, Washington
  13. 1.6 2 km SW of Kapowsin, Washington
  14. 1.7 12 km W of Greenwater, Washington
  15. 1.6 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.