Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Healdsburg, CA
No earthquake was likely felt in Healdsburg in the 24 hours to 10:33 am PST (18:33 UTC). The last one was M 2.6, 22 km (14 mi) NNE, at 4:44 pm PST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Healdsburg
This page: a magnitude 1.6 earthquake was recorded 9 km (5 mi) north-northwest of Healdsburg, CA, at 11:01 pm PST on 25 November 2018 (07:01 UTC), 8.4 km deep.
USGS: 9km NNW of Healdsburg, CA
31 km (20 mi) NNW of Santa Rosa, CA · 109 km (68 mi) NNW of San Francisco, CA
- When
- 11:01 pm PST on 25 November 2018 ()
- Where
- 9 km (5 mi) north-northwest of Healdsburg, CA · earthquakes near Healdsburg
- Magnitude
- M 1.6 (md)
- Depth
- 8.4 km below the surface
- Felt
- no reports yet
- Nearest
- Sonoma County, 18 km S
- Nearest mapped fault
- Alexander-Redwood Hill fault, 4 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 2907 days ago
Earthquake alerts for Healdsburg, CA
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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, people at rest would likely notice it out to about 7 km (4 mi) from the epicentre. In Healdsburg, 9 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: Cloverdale, Windsor, Cobb, Guerneville, Larkfield-Wikiup, Forestville.
How big was it?
This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
- Around the size people start to feel M 3.0 130× the energy of this one
- This earthquake M 1.6 about 7.6 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 5.0 on 2016-12-14 — about 130,000 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 5.3 3 km E of Bloomfield, California · 42 km S of this epicentre
- 5.3 Northern California · 41 km S 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 38.6862, -122.8962. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Sonoma County, CA | 18 km (11 mi) | S | earthquakes near Sonoma County |
| Lake County, CA | 49 km (30 mi) | NNE | earthquakes near Lake County |
| Napa County, CA | 53 km (33 mi) | ESE | earthquakes near Napa County |
| Marin County, CA | 72 km (45 mi) | S | earthquakes near Marin County |
| Colusa County, CA | 79 km (49 mi) | NE | earthquakes near Colusa County |
| Yolo County, CA | 86 km (54 mi) | E | earthquakes near Yolo County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
60 earthquakes have been recorded within 50 km since this one.
- 2.0 5km WNW of Cobb, CA
- 2.3 7km WNW of The Geysers, CA
- 1.8 5km SSW of Anderson Springs, CA
- 1.7 4km WNW of The Geysers, CA
- 1.9 5km SSE of The Geysers, CA
- 1.7 9km WNW of Cobb, CA
- 1.5 5km SSW of Anderson Springs, CA
- 2.2 5km SSW of Anderson Springs, CA
- 1.6 5km SSW of Anderson Springs, CA
- 1.8 3km S of Anderson Springs, CA
- 3.1 5km SSW of Anderson Springs, CA
- 2.0 5km NW of The Geysers, CA
- 2.4 4km WSW of Glen Ellen, CA
- 1.6 5km SW of Anderson Springs, CA
- 1.6 6km W of Cobb, 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.