Earthquake near Pine Hills, CA

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 78 km (48 mi) from the epicentre. In Pine Hills, 16 km away, the estimate is intensity III (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.

Likely felt in: Bayside 18 km, intensity III · Humboldt Hill 19 km, intensity III · Fortuna 20 km, intensity III · Eureka 21 km, intensity III · Rio Dell 25 km, intensity III · Ferndale 29 km, intensity III · McKinleyville 30 km, intensity III · Willow Creek 39 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 7.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 24,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 1,100× the energy of this one
3. Magna, Utah 2020 M 5.7 760× the energy of this one
4. This earthquake M 3.8 about 7.1 tons of TNT
5. Around the size people start to feel M 3.0 this one released 15× 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 4.8 on 2016-07-21 — about 35 times the energy of this one.

Before 2016, the USGS record lists 18 earthquakes of M5 or more within 50 km; the five largest:

1. 7.2 The 1992 Petrolia, California Earthquake · 46 km SSW of this epicentre Apr 25, 1992
2. 6.5 The 1932 Eureka, California Earthquake · 28 km W of this epicentre Jun 6, 1932
3. 6.4 The 1954 Eureka-Arcata, California Earthquake · 18 km NNE of this epicentre Dec 21, 1954
4. 6.0 Near Rio Dell, California · 29 km SW of this epicentre Oct 29, 1909
5. 5.8 Near Eureka, California · 12 km NNW of this epicentre Aug 18, 1908

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, -123.9637. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 1.8 16km ESE of Willow Creek, CA 20:11 UTC
2. 1.5 8km NNW of Petrolia, CA 04:48 UTC
3. 2.1 9km S of Ferndale, CA 16:58 UTC
4. 2.0 35km W of Hayfork, CA 07:27 UTC
5. 1.6 9km W of Rio Dell, CA 13:35 UTC
6. 1.6 4km NNE of Petrolia, CA 02:39 UTC
7. 2.4 6km WNW of Ferndale, CA 03:03 UTC
8. 2.4 16km NW of Petrolia, CA 02:14 UTC
9. 1.7 5km N of Ferndale, CA 12:58 UTC
10. 2.4 4km NNW of Petrolia, CA 00:10 UTC
11. 1.7 12km SW of Rio Dell, CA 09:36 UTC
12. 2.3 6km ENE of Hydesville, CA 10:12 UTC
13. 2.3 15km W of McKinleyville, CA 02:31 UTC
14. 2.2 6km W of Rio Dell, CA 12:10 UTC
15. 1.8 17km ESE of Pine Hills, CA 19:26 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:11 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

• The official USGS event page — the source of record for every value above
• Did you feel it? Report it to USGS — reports go to USGS, not to us
• ShakeMap for this event, when USGS has produced one

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