Earthquake · reviewed by a seismologist
M 1.9md
Earthquake near Crockett, CA
No earthquake was likely felt in Crockett in the 24 hours to 2:45 am PST (10:45 UTC). The last one was M 1.8, 10 km (6 mi) NNE, at 11:09 am PST on 4 November 2026, estimated intensity II (weak) in town. Every earthquake near Crockett
This page: a magnitude 1.9 earthquake was recorded in Crockett, CA, at 8:51 am PDT on 30 June 2021 (15:51 UTC), 7.9 km deep. 2 people have reported feeling it to USGS.
USGS: 1km NNW of Crockett, CA
6 km (4 mi) SE of Vallejo, CA · 36 km (22 mi) NNE of San Francisco, CA
- When
- 8:51 am PDT on 30 June 2021 ()
- Where
- in Crockett, CA · earthquakes near Crockett
- Magnitude
- M 1.9 (md)
- Depth
- 7.9 km below the surface
- Felt
- 2 reports · strongest reported intensity II
- Nearest
- Contra Costa County, 28 km ESE
- Nearest mapped fault
- Green Valley fault, 12 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 1959 days ago
Earthquake alerts for Crockett, 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 13 km (8 mi) from the epicentre. 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: Crockett in town, intensity II · Benicia 5 km, intensity II · Vallejo 6 km, intensity II · Hercules 8 km, intensity II · Martinez 9 km, intensity II · Pinole 9 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 600,000× the energy of this one
- Magna, Utah 2020 M 5.7 420,000× the energy of this one
- Around the size people start to feel M 3.0 38× the energy of this one
- This earthquake M 1.9 about 25 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 4.5 on 2019-10-15 — about 5,800 times the energy of this one.
Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:
- 7.9 The 1906 San Francisco, California Earthquake · 45 km SW of this epicentre
- 6.0 The 2014 South Napa, California Earthquake · 19 km NNW of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 46 km ESE of this epicentre
- 5.4 South of Elmira, California · 39 km NE of this epicentre
- 5.3 The 1957 San Francisco, California Earthquake · 49 km SSW 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 38.0597, -122.2188. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Contra Costa County, CA | 28 km (17 mi) | ESE | earthquakes near Contra Costa County |
| Solano County, CA | 34 km (21 mi) | NE | earthquakes near Solano County |
| Marin County, CA | 46 km (29 mi) | W | earthquakes near Marin County |
| Napa County, CA | 51 km (31 mi) | N | earthquakes near Napa County |
| Alameda County, CA | 53 km (33 mi) | SSE | earthquakes near Alameda County |
| San Mateo County, CA | 73 km (45 mi) | S | earthquakes near San Mateo County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
47 earthquakes have been recorded within 50 km since this one.
- 1.8 5km SW of San Francisco Zoo, CA
- 1.5 3km N of San Leandro, CA
- 3.4 3km N of San Leandro, CA
- 3.0 3km N of San Leandro, CA
- 1.6 11km NE of Napa, CA
- 2.1 2km E of Hayward, CA
- 2.7 1km SSE of Vallejo, CA
- 1.8 1km WNW of Walnut Creek, CA
- 1.8 5km WNW of Dublin, CA
- 1.7 5km NW of Dublin, CA
- 1.6 5km NW of Dublin, CA
- 1.5 6km WNW of Dublin, CA
- 3.1 6km WNW of Dublin, CA
- 1.5 5km E of Vallejo, CA
- 1.8 6km W of Allendale, 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.