Earthquake · reviewed by a seismologist
M 1.7md
Earthquake near Concord, CA
No earthquake was likely felt in Concord in the 24 hours to 4:11 pm PST (00:11 UTC). The last one was M 2.1, 5 km (3 mi) SW, at 4:05 am PST on 8 November 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Concord
This page: a magnitude 1.7 earthquake was recorded 11 km (7 mi) south-southeast of Concord, CA, at 1:42 am PDT on 6 June 2017 (08:42 UTC), 9.9 km deep.
USGS: 3 km SE of North Gate, California
6 km (4 mi) ESE of Walnut Creek, CA · 41 km (26 mi) ENE of San Francisco, CA
- When
- 1:42 am PDT on 6 June 2017 ()
- Where
- 11 km (7 mi) south-southeast of Concord, CA · earthquakes near Concord
- Magnitude
- M 1.7 (md)
- Depth
- 9.9 km below the surface
- Felt
- no reports yet
- Nearest
- Contra Costa County, 4 km NNE
- Nearest mapped fault
- Greenville fault, 7 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 3446 days ago
Earthquake alerts for Concord, CA
Get a notification in this browser when USGS records an earthquake near Concord, 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, people at rest would likely notice it out to about 8 km (5 mi) from the epicentre. In Concord, 11 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.
Likely felt in: Alamo 7 km, intensity II · Danville 8 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,300,000× the energy of this one
- Magna, Utah 2020 M 5.7 900,000× the energy of this one
- Around the size people start to feel M 3.0 80× the energy of this one
- This earthquake M 1.7 about 12 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:
- 6.0 The 2014 South Napa, California Earthquake · 47 km NW of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 19 km ESE of this epicentre
- 5.4 South of Elmira, California · 46 km N of this epicentre
- 5.4 9 km NE of Livermore, California · 28 km ESE of this epicentre
- 5.1 11 km E of Blackhawk, California · 19 km ESE 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 37.8883, -121.9713. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Contra Costa County, CA | 4 km (2 mi) | NNE | earthquakes near Contra Costa County |
| Alameda County, CA | 27 km (17 mi) | S | earthquakes near Alameda County |
| Solano County, CA | 42 km (26 mi) | N | earthquakes near Solano County |
| San Joaquin County, CA | 62 km (38 mi) | E | earthquakes near San Joaquin County |
| San Mateo County, CA | 63 km (39 mi) | SW | earthquakes near San Mateo County |
| Marin County, CA | 70 km (44 mi) | WNW | earthquakes near Marin County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
53 earthquakes have been recorded within 50 km since this one.
- 1.5 2 km ESE of Berkeley, California
- 1.6 1 km NNW of Crockett, California
- 2.7 1 km SE of Pacheco, California
- 1.8 4 km SE of Livermore, California
- 2.0 1 km W of Kensington, California
- 1.7 3 km NNE of Danville, California
- 2.0 2 km ESE of Blackhawk, California
- 1.9 10 km NE of Milpitas, California
- 2.1 1 km ESE of Diablo, California
- 2.0 2 km SW of Alamo, California
- 2.1 4 km E of Union City, California
- 1.8 2 km NNE of North Gate, California
- 1.6 0 km ENE of North Gate, California
- 2.5 1 km N of Pleasant Hill, California
- 1.8 1 km NNW of Pleasant Hill, California
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.