QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near Dallas, OR

USGS: 4 km WNW of Dallas, Oregon

88 km (54 mi) SW of Portland, OR · 28 km (17 mi) W of Salem, OR

3:53 pm PST, Dec 6, 2017 · · -0.2 km deep · released about 7.6 lb of TNT

10 km30 km60 km120 km N Polk County 4 kmYamhill County 35 kmBenton County 49 kmLincoln County 54 kmMarion County 63 kmTillamook County 65 kmWashington County 72 kmLinn County 83 kmClackamas County 96 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
3:53 pm PST on 6 December 2017 ()
Where
5 km (3 mi) WNW of Dallas, OR · earthquakes near Dallas
Magnitude
M 1.6 (ml)
Depth
-0.2 km below the surface
Felt
no reports yet
Nearest
Polk County, 4 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3221 days ago

A magnitude 1.6 earthquake was recorded 5 km (3 mi) WNW of Dallas, OR, at 3:53 pm PST on 6 December 2017 (23:53 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Monmouth, Independence, Willamina, Sheridan, Grand Ronde, Amity.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 7.6 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 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 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 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 44.9348, -123.3730. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Polk County, OR 4 km (3 mi) SSW earthquakes near Polk County
Yamhill County, OR 35 km (22 mi) N earthquakes near Yamhill County
Benton County, OR 49 km (31 mi) S earthquakes near Benton County
Lincoln County, OR 54 km (33 mi) SW earthquakes near Lincoln County
Marion County, OR 63 km (39 mi) E earthquakes near Marion County
Tillamook County, OR 65 km (41 mi) NNW earthquakes near Tillamook County

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

Aftershocks so far

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

  1. 1.6 11 km NNW of Sheridan, Oregon
  2. 2.2 1 km SW of Carlton, Oregon
  3. 2.0 6 km NE of Amity, Oregon
  4. 1.6 4 km WNW of Adair Village, Oregon
  5. 1.9 5 km W of Dallas, Oregon
  6. 1.9 4 km ENE of Lafayette, Oregon
  7. 1.5 5 km NNW of Adair Village, Oregon
  8. 1.6 7 km NNW of Philomath, Oregon
  9. 2.0 4 km ESE of Rose Lodge, Oregon
  10. 2.4 4 km SE of Rose Lodge, Oregon
  11. 3.5 6 km NNW of Fort Hill Census Designated Place, Oregon
  12. 1.6 4 km ESE of Rose Lodge, Oregon
  13. 1.6 7 km NW of Philomath, Oregon
  14. 3.2 3 km ESE of Rose Lodge, Oregon
  15. 1.9 3 km WSW of Dundee, 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.