QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

45km W of Petrolia, CA

· 13 km deep · released about 510 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 83 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
Magnitude
M 2.8 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 83 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2748 days ago

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

How big was it?

This earthquake released about 510 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 30,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 21,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.9× the energy of this one
  4. This earthquake M 2.8 about 510 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.

Where

Epicentre 40.3787, -124.8080. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Humboldt County, CA 83 km (52 mi) WSW of here earthquakes near Humboldt County
Mendocino County, CA 157 km (98 mi) NW of here earthquakes near Mendocino County

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

Aftershocks so far

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

  1. 2.0 12km WSW of Petrolia, CA
  2. 2.8 6km SW of Petrolia, CA
  3. 2.3 14km WSW of Petrolia, CA
  4. 1.5 22km NW of Petrolia, CA
  5. 2.6 13km WSW of Petrolia, CA
  6. 2.3 12km W of Petrolia, CA
  7. 2.6 37km WNW of Petrolia, CA
  8. 1.7 23km WNW of Petrolia, CA
  9. 2.0 12km NW of Petrolia, CA
  10. 1.7 17km W of Petrolia, CA
  11. 1.7 16km WNW of Petrolia, CA
  12. 1.7 16km W of Petrolia, CA
  13. 1.8 12km SW of Ferndale, CA
  14. 2.5 84km W of Petrolia, CA
  15. 3.9 49km W 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.7 on 2018-03-23 — it released about 580 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.