QuakeIndex

Earthquake · automatic estimate, may change

M 1.8md

Earthquake near Fortuna, CA

Yes. A magnitude 1.8 earthquake was recorded 39 km (24 mi) south of Fortuna, CA, at 7:12 pm PDT on 21 October 2026 (02:12 UTC), 13 km deep. No felt reports to USGS yet. The magnitude and location are an automatic first estimate and may change.

USGS: 13 km SE of Petrolia, CA

7:12 pm PDT, Oct 21, 2026 · · 13 km deep · released about 17 lb of TNT

10 km30 km60 km120 km N Humboldt County 55 kmTrinity County 100 kmMendocino County 110 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
7:12 pm PDT on 21 October 2026 ()
Where
39 km (24 mi) south of Fortuna, CA · earthquakes near Fortuna
Magnitude
M 1.8 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 55 km NNE
Nearest mapped fault
San Andreas fault, 11 km from its surface trace — near is not the same as on
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 15 hours 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 6 km (4 mi) from the epicentre. In Fortuna, 39 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: Rio Dell.

How big was it?

This earthquake released about 17 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 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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

The largest earthquake within 50 km since 2016 was M 6.4 on 2022-12-20 — about 6,900,000 times the energy of this one.

Before 2016, the USGS record lists 30 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.2 The 1992 Petrolia, California Earthquake · 11 km NNW of this epicentre
  2. 6.6 32 km SW of Ferndale, California · 36 km WNW of this epicentre
  3. 6.5 30 km WSW of Ferndale, California · 39 km WNW of this epicentre
  4. 6.0 Near Rio Dell, California · 28 km N of this epicentre
  5. 6.0 53 km SW of Ferndale, California · 46 km W of this epicentre

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 40.2457, -124.1715. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Humboldt County, CA 55 km (34 mi) NNE earthquakes near Humboldt County
Trinity County, CA 100 km (62 mi) ENE earthquakes near Trinity County
Mendocino County, CA 110 km (68 mi) SE earthquakes near Mendocino County

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

Aftershocks so far

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

  1. 1.7 16 km SE of Petrolia, CA
  2. 1.5 15 km SE of Petrolia, CA
  3. 2.1 30 km WSW of Petrolia, CA
  4. 1.5 14 km SE of Petrolia, CA
  5. 1.1 14 km SE 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.