QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Morton, WA

No earthquake was likely felt in Morton in the 24 hours to 10:01 am PST (18:01 UTC). The last one was M 4.2, 100 km (62 mi) NNW, at 2:05 pm PDT on 29 September 2026, estimated intensity II (weak) in town; 9,329 felt reports to USGS. Every earthquake near Morton

This page: a magnitude 1.7 earthquake was recorded 37 km (23 mi) southeast of Morton, WA, at 3:15 am PST on 9 December 2018 (11:15 UTC), 11 km deep.

USGS: 30 km SSW of Packwood, Washington

3:15 am PST, Dec 9, 2018 · · 11 km deep · released about 9.6 lb of TNT

Every earthquake near Morton Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Skamania County 39 kmLewis County 45 kmCowlitz County 65 kmPierce County 78 kmClark County 82 kmYakima County 88 kmThurston County 96 kmHood River County 97 kmMultnomah 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
3:15 am PST on 9 December 2018 ()
Where
37 km (23 mi) southeast of Morton, WA · earthquakes near Morton
Magnitude
M 1.7 (ml)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Skamania County, 39 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2893 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 Morton, 37 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.

How big was it?

This earthquake released about 9.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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 17 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.7 38 km NNE of Amboy, Washington · 30 km SW of this epicentre
  2. 5.2 37 km NNE of Amboy, Washington · 31 km SW of this epicentre
  3. 5.2 23 km S of Morton, Washington · 28 km W of this epicentre
  4. 5.1 28 km ENE of Amboy, Washington · 43 km SSW of this epicentre
  5. 5.1 Washington · 28 km SW 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 46.3740, -121.8777. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Skamania County, WA 39 km (24 mi) S earthquakes near Skamania County
Lewis County, WA 45 km (28 mi) WNW earthquakes near Lewis County
Cowlitz County, WA 65 km (40 mi) WSW earthquakes near Cowlitz County
Pierce County, WA 78 km (49 mi) NNW earthquakes near Pierce County
Clark County, WA 82 km (51 mi) SW earthquakes near Clark County
Yakima County, WA 88 km (54 mi) E earthquakes near Yakima County

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

Aftershocks so far

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

  1. 1.6 31 km S of Morton, Washington
  2. 2.0 37 km NNE of Amboy, Washington
  3. 2.4 9 km SE of Mossyrock, Washington
  4. 1.6 37 km NNE of Amboy, Washington
  5. 2.0 5 km WNW of Packwood, Washington
  6. 1.7 22 km S of Morton, Washington
  7. 1.7 7 km ESE of Ashford, Washington
  8. 1.6 7 km ESE of Ashford, Washington
  9. 1.8 20 km SSW of Morton, Washington
  10. 2.9 4 km W of Ashford, Washington
  11. 1.6 18 km SSE of Mossyrock, Washington
  12. 1.6 5 km ESE of Mossyrock, Washington
  13. 1.5 18 km E of Packwood, Washington
  14. 1.9 23 km NE of Amboy, Washington
  15. 2.2 37 km SSE of Morton, 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.