QuakeIndex

Earthquake · reviewed by a seismologist

M 4.8mwr

163 km W of Langlois, Oregon

Yes. A magnitude 4.8 earthquake was recorded 163 km W of Langlois, Oregon at 12:11 UTC on 2021-10-24, 10 km deep. 12 people have reported feeling it to USGS.

· 10 km deep · released about 240 tons of TNT

10 km30 km60 km120 km N
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
Magnitude
M 4.8 (mwr)
Depth
10 km below the surface
Felt
12 reports · strongest reported intensity III
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 326 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 170 km (106 mi) from the epicentre. 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 240 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.8 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 710× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 32× the energy of this one
  3. Magna, Utah 2020 M 5.7 22× the energy of this one
  4. This earthquake M 4.8 about 240 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 500× more

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

The largest earthquake within 50 km since 2016 was M 4.9 on 2016-01-23 — about 1.4 times the energy of this one.

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 43.1633, -126.4306. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.6 149 km WNW of Port Orford, Oregon
  2. 3.0 207 km W of Bandon, Oregon
  3. 3.2 197 km W of Bandon, Oregon
  4. 3.2 176 km W of Bandon, Oregon
  5. 3.7 201 km W of Langlois, Oregon
  6. 3.1 130 km W of Bandon, Oregon
  7. 3.2 153 km WNW of Langlois, Oregon
  8. 2.8 187 km WNW of Bandon, Oregon
  9. 3.6 160 km W of Langlois, Oregon
  10. 3.0 201 km W of Bandon, Oregon
  11. 2.8 159 km W of Port Orford, Oregon
  12. 2.8 189 km W of Bandon, Oregon
  13. 2.6 161 km W of Langlois, Oregon
  14. 2.6 173 km WNW of Port Orford, Oregon
  15. 2.8 196 km W of Bandon, 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.