Earthquake · reviewed by a seismologist
M 2.8ml
Earthquake near Hydesville, CA
No earthquake was likely felt in Hydesville in the 24 hours to 2:28 am PST (10:28 UTC). The last one was M 5.0, 127 km (79 mi) W, at 8:56 pm PST on 4 November 2026, estimated intensity II (weak) in town; 145 felt reports to USGS. Every earthquake near Hydesville
This page: a magnitude 2.8 earthquake was recorded 5 km (3 mi) northeast of Hydesville, CA, at 12:56 pm PST on 8 December 2017 (20:56 UTC), 28 km deep. 44 people have reported feeling it to USGS.
USGS: 5km NE of Hydesville, CA
- When
- 12:56 pm PST on 8 December 2017 ()
- Where
- 5 km (3 mi) northeast of Hydesville, CA · earthquakes near Hydesville
- Magnitude
- M 2.8 (ml)
- Depth
- 28 km below the surface
- Felt
- 44 reports · strongest reported intensity IV
- Nearest
- Humboldt County, 18 km NE
- Nearest mapped fault
- Little Salmon fault, under 1 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3255 days ago
Earthquake alerts for Hydesville, CA
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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 8 km (5 mi) from the epicentre. In Hydesville, 5 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.
Earthquakes near other towns within 30 km: Rio Dell, Fortuna, Ferndale, Pine Hills, Humboldt Hill, Cutten.
How big was it?
This earthquake released about 550 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.
- Mineral, Virginia 2011 M 5.8 28,000× the energy of this one
- Magna, Utah 2020 M 5.7 19,000× the energy of this one
- Around the size people start to feel M 3.0 1.7× the energy of this one
- This earthquake M 2.8 about 550 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 4.8 on 2016-07-21 — about 900 times the energy of this one.
Before 2016, the USGS record lists 33 earthquakes of M5 or more within 50 km; the five largest:
- 7.2 The 1992 Petrolia, California Earthquake · 30 km SSW of this epicentre
- 6.6 32 km SW of Ferndale, California · 48 km WSW of this epicentre
- 6.5 The 1932 Eureka, California Earthquake · 26 km NW of this epicentre
- 6.5 30 km WSW of Ferndale, California · 46 km WSW of this epicentre
- 6.4 The 1954 Eureka-Arcata, California Earthquake · 33 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 40.5722, -124.0507. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Humboldt County, CA | 18 km (11 mi) | NE | earthquakes near Humboldt County |
| Trinity County, CA | 79 km (49 mi) | E | earthquakes near Trinity County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
51 earthquakes have been recorded within 50 km since this one.
- 2.4 20km WNW of Petrolia, CA
- 2.4 11km WSW of Rio Dell, CA
- 2.5 17km ESE of Hydesville, CA
- 1.8 12km SSE of Rio Dell, CA
- 2.5 20km WNW of Petrolia, CA
- 1.9 11km S of Rio Dell, CA
- 2.3 25km WNW of Petrolia, CA
- 1.7 19km NW of Petrolia, CA
- 2.9 18km NW of Petrolia, CA
- 2.2 10km S of Ferndale, CA
- 2.5 18km WNW of Petrolia, CA
- 4.7 22km WNW of Petrolia, CA
- 4.4 17km W of Humboldt Hill, CA
- 2.5 17km WSW of Petrolia, CA
- 2.5 30km W of Bayview, 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
- 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.