Earthquake · reviewed by a seismologist
M 3.3ml
Earthquake near Middletown, CA
No earthquake was likely felt in Middletown in the 24 hours to 2:55 am PST (10:55 UTC). The last one was M 1.6, 9 km (6 mi) WNW, at 5:12 am PST on 10 November 2026, estimated intensity II (weak) in town. Every earthquake near Middletown
This page: a magnitude 3.3 earthquake was recorded 12 km (7 mi) southeast of Middletown, CA, at 12:01 am PDT on 10 September 2024 (07:01 UTC), 6.9 km deep. 180 people have reported feeling it to USGS.
USGS: 12 km SE of Middletown, CA
32 km (20 mi) NNE of Santa Rosa, CA · 102 km (63 mi) N of San Francisco, CA
- When
- 12:01 am PDT on 10 September 2024 ()
- Where
- 12 km (7 mi) southeast of Middletown, CA · earthquakes near Middletown
- Magnitude
- M 3.3 (ml)
- Depth
- 6.9 km below the surface
- Felt
- 180 reports · strongest reported intensity IV
- Nearest
- Napa County, 26 km SE
- Nearest mapped fault
- Hunting Creek-Berryessa fault system, 8 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 721 days ago
Earthquake alerts for Middletown, 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 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 49 km (30 mi) from the epicentre. In Middletown, 12 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: Angwin 14 km, intensity III · Calistoga 14 km, intensity III · Cobb 24 km, intensity II · Kenwood 31 km, intensity II · Windsor 31 km, intensity II · Clearlake 32 km, intensity II · Healdsburg 33 km, intensity II · Santa Rosa 33 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 1.2 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 140,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 6,500× the energy of this one
- Magna, Utah 2020 M 5.7 4,600× the energy of this one
- This earthquake M 3.3 about 1.2 tons of TNT
- Around the size people start to feel M 3.0 this one released 2.5× 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 5.0 on 2016-12-14 — about 420 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 · 49 km SSW of this epicentre
- 5.3 Northern California · 50 km SW 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 38.6897, -122.5047. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Napa County, CA | 26 km (16 mi) | SE | earthquakes near Napa County |
| Sonoma County, CA | 41 km (25 mi) | WSW | earthquakes near Sonoma County |
| Lake County, CA | 51 km (32 mi) | NNW | earthquakes near Lake County |
| Yolo County, CA | 52 km (32 mi) | E | earthquakes near Yolo County |
| Colusa County, CA | 59 km (37 mi) | NNE | earthquakes near Colusa County |
| Solano County, CA | 68 km (42 mi) | SE | earthquakes near Solano County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 1.6 5 km NW of The Geysers, CA
- 1.5 5 km NW of The Geysers, CA
- 2.1 5 km NW of The Geysers, CA
- 2.2 5 km WNW of The Geysers, CA
- 1.7 7 km NNW of The Geysers, CA
- 1.7 13 km NW of Calistoga, CA
- 1.5 7 km NNW of The Geysers, CA
- 1.7 7 km NNW of The Geysers, CA
- 2.1 7 km NNW of The Geysers, CA
- 1.8 7 km NNW of The Geysers, CA
- 1.6 4 km WSW of Anderson Springs, CA
- 2.9 8 km NNW of The Geysers, CA
- 1.9 4 km ENE of Saint Helena, CA
- 2.5 3 km ENE of Saint Helena, CA
- 2.2 3 km ENE of Saint Helena, 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.