QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Longview, WA

No earthquake was likely felt in Longview in the 24 hours to 5:15 am PST (13:15 UTC). The last one was M 3.0, 29 km (18 mi) SSE, at 7:25 am PDT on 22 October 2026, estimated intensity II (weak) in town; 113 felt reports to USGS. Every earthquake near Longview

This page: a magnitude 1.8 earthquake was recorded 48 km (30 mi) east-northeast of Longview, WA, at 3:21 am PDT on 12 March 2020 (10:21 UTC), 14 km deep.

USGS: 23 km SSE of Mossyrock, Washington

90 km (56 mi) NNE of Portland, OR

3:21 am PDT, Mar 12, 2020 · · 14 km deep · released about 13 lb of TNT

Every earthquake near Longview Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cowlitz County 27 kmLewis County 28 kmSkamania County 47 kmClark County 62 kmColumbia County 69 kmThurston County 76 kmWahkiakum County 80 kmPierce County 82 kmMultnomah County 87 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
3:21 am PDT on 12 March 2020 ()
Where
48 km (30 mi) east-northeast of Longview, WA · earthquakes near Longview
Magnitude
M 1.8 (ml)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Cowlitz County, 27 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2437 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Longview, 48 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.

How big was it?

This earthquake released about 13 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 16 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.7 38 km NNE of Amboy, Washington · 20 km SE of this epicentre
  2. 5.2 37 km NNE of Amboy, Washington · 20 km SE of this epicentre
  3. 5.2 23 km S of Morton, Washington · 12 km ENE of this epicentre
  4. 5.1 28 km ENE of Amboy, Washington · 39 km SSE of this epicentre
  5. 5.1 Washington · 20 km SE 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 46.3275, -122.3830. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cowlitz County, WA 27 km (17 mi) WSW earthquakes near Cowlitz County
Lewis County, WA 28 km (17 mi) N earthquakes near Lewis County
Skamania County, WA 47 km (29 mi) SE earthquakes near Skamania County
Clark County, WA 62 km (39 mi) S earthquakes near Clark County
Columbia County, OR 69 km (43 mi) SW earthquakes near Columbia County
Thurston County, WA 76 km (47 mi) NNW earthquakes near Thurston County

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

Aftershocks so far

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

  1. 1.8 20 km SSW of Morton, Washington
  2. 1.7 16 km NNE of Amboy, Washington
  3. 1.7 26 km N of Amboy, Washington
  4. 1.6 18 km SSE of Mossyrock, Washington
  5. 1.8 19 km WSW of Alder, Washington
  6. 1.8 1 km ENE of Prescott, Oregon
  7. 1.6 5 km ESE of Mossyrock, Washington
  8. 1.7 21 km E of Castle Rock, Washington
  9. 1.6 10 km SSE of Toledo, Washington
  10. 1.6 21 km E of Castle Rock, Washington
  11. 2.1 9 km NNE of Mossyrock, Washington
  12. 1.7 21 km E of Castle Rock, Washington
  13. 2.1 29 km E of Castle Rock, Washington
  14. 1.6 21 km E of Castle Rock, Washington
  15. 1.9 10 km SSE of Toledo, 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.