QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

136km W of Petrolia, CA

Yes. A magnitude 3.1 earthquake was recorded 136km W of Petrolia, CA, at 7:46 pm PST on 28 November 2022 (03:46 UTC), 10 km deep. 3 people have reported feeling it to USGS.

· 10 km deep · released about 1,300 lb of TNT

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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 3.1 (ml)
Depth
10 km below the surface
Felt
3 reports · strongest reported intensity II
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1376 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 39 km (24 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 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 270,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 12,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 8,500× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.3× 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 6.6 on 2016-12-08 — about 190,000 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 40.4835, -125.8787. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.6 111 km WSW of Ferndale, California
  2. 2.6 108 km W of Petrolia, CA
  3. 4.0 165 km WSW of Ferndale, California
  4. 3.2 114 km WSW of Ferndale, California
  5. 2.7 120 km WSW of Ferndale, California
  6. 2.9 129 km WNW of Petrolia, CA
  7. 4.2 135 km WNW of Petrolia, CA
  8. 4.4 145 km WNW of Petrolia, CA
  9. 2.7 169 km W of Ferndale, California
  10. 2.9 123 km WNW of Petrolia, CA
  11. 2.9 93 km WNW of Petrolia, CA
  12. 3.9 127 km WNW of Petrolia, CA
  13. 4.2 118 km WNW of Petrolia, CA
  14. 4.3 170 km W of Ferndale, California
  15. 3.7 108 km WNW of Petrolia, CA

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.