QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Graham, WA

Yes. A magnitude 1.5 earthquake was recorded 40 km (25 mi) S of Graham, WA, at 7:35 am PDT on 26 October 2017 (14:35 UTC), 9.6 km deep.

This was on 26 October 2017. The latest near Graham: M 2.5 on 16 March 2026.

USGS: 13 km SSW of Alder, Washington

52 km (32 mi) SE of Lacey, WA · 103 km (64 mi) S of Seattle, WA

7:35 am PDT, Oct 26, 2017 · · 9.6 km deep · released about 5.9 lb of TNT

Every earthquake near Graham Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis County 13 kmPierce County 43 kmThurston County 45 kmCowlitz County 60 kmSkamania County 80 kmWahkiakum County 93 kmMason County 96 kmKing County 97 kmColumbia County 100 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
7:35 am PDT on 26 October 2017 ()
Where
40 km (25 mi) S of Graham, WA · earthquakes near Graham
Magnitude
M 1.5 (ml)
Depth
9.6 km below the surface
Felt
no reports yet
Nearest
Lewis County, 13 km S
Nearest mapped fault
Olympia structure, 22 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 569 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 4 km (2 mi) from the epicentre. In Graham, 40 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: Morton, Eatonville.

How big was it?

This earthquake released about 5.9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
  3. Around the size people start to feel M 3.0 160× the energy of this one
  4. This earthquake M 1.5 about 5.9 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 2 earthquakes of M5 or more within 50 km:

  1. 6.7 4 km WNW of Roy, Washington · 40 km NNW of this epicentre
  2. 5.2 23 km S of Morton, Washington · 39 km SSE 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 46.6918, -122.3547. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lewis County, WA 13 km (8 mi) S earthquakes near Lewis County
Pierce County, WA 43 km (27 mi) NNE earthquakes near Pierce County
Thurston County, WA 45 km (28 mi) NW earthquakes near Thurston County
Cowlitz County, WA 60 km (38 mi) SSW earthquakes near Cowlitz County
Skamania County, WA 80 km (50 mi) SSE earthquakes near Skamania County
Wahkiakum County, WA 93 km (58 mi) WSW earthquakes near Wahkiakum County

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

Aftershocks so far

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

  1. 1.8 2 km E of Kapowsin, Washington
  2. 1.5 6 km SE of Mossyrock, Washington
  3. 1.6 7 km SSE of Mossyrock, Washington
  4. 1.6 8 km SE of Mossyrock, Washington
  5. 1.6 15 km NE of Ashford, Washington
  6. 1.7 2 km W of Toledo, Washington
  7. 1.5 7 km SW of Morton, Washington
  8. 1.7 5 km ENE of Ashford, Washington
  9. 1.6 4 km SE of Ashford, Washington
  10. 1.8 3 km SW of Kapowsin, Washington
  11. 1.5 2 km ENE of Kapowsin, Washington
  12. 1.5 14 km SSE of Carbonado, Washington
  13. 1.6 19 km E of Morton, Washington
  14. 1.9 17 km ESE of Toledo, Washington
  15. 1.6 4 km N of Napavine, 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.