QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6md

Earthquake near Eureka, CA

No earthquake was likely felt in Eureka in the 24 hours to 2:38 am PST (10:38 UTC). The last one was M 5.0, 128 km (79 mi) WSW, at 8:56 pm PST on 4 November 2026, estimated intensity II (weak) in town; 145 felt reports to USGS. Every earthquake near Eureka

This page: a magnitude 2.6 earthquake was recorded 42 km (26 mi) west-southwest of Eureka, CA, at 5:59 pm PDT on 30 May 2018 (00:59 UTC), 22 km deep.

USGS: 35km WNW of Ferndale, CA

5:59 pm PDT, May 30, 2018 · · 22 km deep · released about 280 lb of TNT

10 km30 km60 km120 km N Humboldt County 61 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
5:59 pm PDT on 30 May 2018 ()
Where
42 km (26 mi) west-southwest of Eureka, CA · earthquakes near Eureka
Magnitude
M 2.6 (md)
Depth
22 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 61 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3086 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 10 km (6 mi) from the epicentre. In Eureka, 42 km away, the estimate is intensity II (weak). 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 280 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 53,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 38,000× the energy of this one
  3. Around the size people start to feel M 3.0 3.3× the energy of this one
  4. This earthquake M 2.6 about 280 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 5.1 on 2017-07-29 — about 4,400 times the energy of this one.

Before 2016, the USGS record lists 36 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.6 32 km SW of Ferndale, California · 35 km SSE of this epicentre
  2. 6.5 The 1932 Eureka, California Earthquake · 30 km E of this epicentre
  3. 6.5 30 km WSW of Ferndale, California · 30 km SSE of this epicentre
  4. 6.5 The 2010 Eureka, California Earthquake · 6 km SW of this epicentre
  5. 6.4 Northwest of Eureka, California · 36 km NNE 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 40.6948, -124.6440. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Humboldt County, CA 61 km (38 mi) E earthquakes near Humboldt County
Del Norte County, CA 130 km (81 mi) NNE earthquakes near Del Norte 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. 2.5 28km WNW of Petrolia, CA
  2. 2.3 14km WSW of Petrolia, CA
  3. 3.0 25km W of Petrolia, CA
  4. 2.6 64km WNW of Ferndale, CA
  5. 2.2 22km WSW of Petrolia, CA
  6. 2.7 42km WNW of Petrolia, CA
  7. 3.4 55km WNW of Ferndale, CA
  8. 2.6 19km W of Petrolia, CA
  9. 2.6 39km WNW of Petrolia, CA
  10. 2.5 65km WNW of Bayview, CA
  11. 2.0 6km WSW of Rio Dell, CA
  12. 2.2 26km W of Petrolia, CA
  13. 1.9 10km W of Petrolia, CA
  14. 2.7 23km W of Petrolia, CA
  15. 1.9 2km SW of Arcata, 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.