Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Blue Lake, CA
No earthquake was likely felt in Blue Lake in the 24 hours to 9:50 am PST (17:50 UTC). The last one was M 5.0, 145 km (90 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 Blue Lake
This page: a magnitude 1.8 earthquake was recorded 15 km (9 mi) southeast of Blue Lake, CA, at 12:59 pm PDT on 6 July 2018 (19:59 UTC), 25 km deep.
USGS: 15km SE of Blue Lake, CA
- When
- 12:59 pm PDT on 6 July 2018 ()
- Where
- 15 km (9 mi) southeast of Blue Lake, CA · earthquakes near Blue Lake
- Magnitude
- M 1.8 (md)
- Depth
- 25 km below the surface
- Felt
- no reports yet
- Nearest
- Humboldt County, 11 km SSW
- Nearest mapped fault
- Mad River fault, 2 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 3051 days ago
Earthquake alerts for Blue Lake, CA
Get a notification in this browser when USGS records an earthquake near Blue Lake, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth it was probably too small to be felt, even directly above it. In Blue Lake, 15 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: Bayside, Arcata, Myrtletown, Cutten, Pine Hills, Eureka.
How big was it?
This earthquake released about 14 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.
- Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
- Magna, Utah 2020 M 5.7 760,000× the energy of this one
- Around the size people start to feel M 3.0 68× the energy of this one
- This earthquake M 1.8 about 14 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 35,000 times the energy of this one.
Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:
- 7.2 The 1980 Eureka, California Earthquake · 49 km NW of this epicentre
- 6.5 The 1932 Eureka, California Earthquake · 36 km W of this epicentre
- 6.4 The 1954 Eureka-Arcata, California Earthquake · 7 km NNW of this epicentre
- 6.0 Near Rio Dell, California · 43 km SW of this epicentre
- 5.8 Near Eureka, California · 12 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 40.7890, -123.8630. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Humboldt County, CA | 11 km (7 mi) | SSW | earthquakes near Humboldt County |
| Trinity County, CA | 65 km (40 mi) | ESE | earthquakes near Trinity County |
| Del Norte County, CA | 107 km (67 mi) | N | earthquakes near Del Norte County |
| Siskiyou County, CA | 142 km (88 mi) | NE | earthquakes near Siskiyou County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
39 earthquakes have been recorded within 50 km since this one.
- 1.9 20km SE of Rio Dell, CA
- 2.0 38km E of Hydesville, CA
- 1.9 29km NNE of Redway, CA
- 2.5 20km SE of Rio Dell, CA
- 3.3 14km ESE of Willow Creek, CA
- 2.3 20km ENE of Willow Creek, CA
- 2.0 14km WNW of Hayfork, CA
- 2.4 6km WSW of Ferndale, CA
- 1.9 23km NNW of Hayfork, CA
- 3.4 6km NE of Willow Creek, CA
- 1.9 13km WSW of Rio Dell, CA
- 1.6 29km NNW of Hayfork, CA
- 2.5 30km N of Redway, CA
- 2.1 22km SSW of Willow Creek, CA
- 1.9 28km W of Hayfork, 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.