QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

Earthquake near Eugene, OR

No earthquake was likely felt in Eugene in the 24 hours to 9:20 pm PST (05:20 UTC). The last one was M 1.8, 7 km (4 mi) ESE, at 10:54 am PDT on 25 August 2026, estimated intensity II (weak) in town. Every earthquake near Eugene

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.8 explosion was recorded 43 km (26 mi) east-northeast of Eugene, OR, at 3:48 pm PST on 29 December 2020 (23:48 UTC), less than 1 km deep.

USGS: 25 km SE of Holley, Oregon

45 km (28 mi) ENE of Eugene, OR · 35 km (21 mi) ENE of Springfield, OR

3:48 pm PST, Dec 29, 2020 · · -0.8 km deep · released about 15 lb of TNT

10 km30 km60 km120 km N Linn County 35 kmLane County 37 kmBenton County 76 kmMarion County 80 kmPolk County 103 kmDouglas County 109 kmDeschutes County 112 kmClackamas County 114 kmLincoln County 117 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
3:48 pm PST on 29 December 2020 ()
Where
43 km (26 mi) east-northeast of Eugene, OR · earthquakes near Eugene
Magnitude
M 1.8 (ml)
Depth
-0.8 km below the surface
Felt
no reports yet
Nearest
Linn County, 35 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2143 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 14 km (9 mi) from the epicentre. In Eugene, 43 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: Sweet Home.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 44.1778, -122.5835. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Linn County, OR 35 km (22 mi) N earthquakes near Linn County
Lane County, OR 37 km (23 mi) SW earthquakes near Lane County
Benton County, OR 76 km (47 mi) WNW earthquakes near Benton County
Marion County, OR 80 km (50 mi) N earthquakes near Marion County
Polk County, OR 103 km (64 mi) NW earthquakes near Polk County
Douglas County, OR 109 km (68 mi) SSW earthquakes near Douglas County

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

Aftershocks so far

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

  1. 1.6 9 km SSE of Crawfordsville, Oregon
  2. 1.5 4 km SSE of Cascadia, Oregon
  3. 1.5 1 km NNE of Cascadia, Oregon
  4. 2.0 4 km N of Sweet Home, Oregon
  5. 1.8 5 km N of Waterloo, Oregon
  6. 1.6 4 km NW of Brownsville, Oregon
  7. 1.5 3 km S of Brownsville, Oregon
  8. 1.6 22 km N of Unity, Oregon
  9. 1.9 5 km ENE of Lebanon, Oregon
  10. 2.2 3 km NNW of Sweet Home, Oregon
  11. 1.6 2 km SSE of Sodaville, Oregon
  12. 1.7 29 km SE of Cascadia, Oregon
  13. 1.7 9 km SSW of Holley, Oregon
  14. 1.8 6 km ENE of Lebanon, Oregon
  15. 1.8 12 km SSW of Holley, Oregon

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.