Earthquake · automatic estimate, may change
M 1.7md
Earthquake near Concord, CA
No earthquake was likely felt in Concord in the 24 hours to 9:16 pm PST (05:16 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 4 km (2 mi) southwest of Concord, CA, at 11:45 am PST on 15 December 2024 (19:45 UTC), 8.0 km deep. 1 person has reported feeling it to USGS. The magnitude and location are an automatic first estimate and may change.
USGS: 1 km of Pleasant Hill, CA
6 km (4 mi) WSW of Concord, CA · 37 km (23 mi) ENE of San Francisco, CA
- When
- 11:45 am PST on 15 December 2024 ()
- Where
- 4 km (2 mi) southwest of Concord, CA · earthquakes near Concord
- Magnitude
- M 1.7 (md)
- Depth
- 8.0 km below the surface
- Felt
- 1 report · strongest reported intensity III
- Nearest
- Contra Costa County, 11 km ESE
- Nearest mapped fault
- Concord fault, 3 km from its surface trace — near is not the same as on
- Status
- Automatic — a machine’s first estimate, which may change
USGS · last changed by USGS · we first saw it 696 days ago
Earthquake alerts for Concord, 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 9 km (6 mi) from the epicentre. In Concord, 4 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: Pleasant Hill in town, intensity II · Pacheco 3 km, intensity II · Concord 4 km, intensity II · Walnut Creek 6 km, intensity II · Martinez 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 9.6 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 1,600,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
- Around the size people start to feel M 3.0 99× the energy of this one
- This earthquake M 1.7 about 9.6 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 4.5 on 2019-10-15 — about 15,000 times the energy of this one.
Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:
- 7.9 The 1906 San Francisco, California Earthquake · 49 km WSW of this epicentre
- 6.0 The 2014 South Napa, California Earthquake · 36 km NW of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 29 km ESE of this epicentre
- 5.4 South of Elmira, California · 41 km NNE of this epicentre
- 5.4 9 km NE of Livermore, California · 39 km SE 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 37.9580, -122.0637. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Contra Costa County, CA | 11 km (7 mi) | ESE | earthquakes near Contra Costa County |
| Solano County, CA | 36 km (22 mi) | NNE | earthquakes near Solano County |
| Alameda County, CA | 37 km (23 mi) | SSE | earthquakes near Alameda County |
| Marin County, CA | 61 km (38 mi) | W | earthquakes near Marin County |
| Napa County, CA | 65 km (41 mi) | NNW | earthquakes near Napa County |
| San Mateo County, CA | 66 km (41 mi) | SSW | earthquakes near San Mateo County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
49 earthquakes have been recorded within 50 km since this one.
- 1.6 6 km SW of Clayton, CA
- 1.8 2 km E of Hayward, CA
- 2.2 7 km NE of Alamo, CA
- 2.5 5 km W of Pleasant Hill, CA
- 2.4 3 km NW of Bayview-Montalvin, CA
- 2.1 2 km E of Hayward, CA
- 3.6 2 km E of Hayward, CA
- 2.0 3 km E of Hayward, CA
- 3.1 2 km E of Hayward, CA
- 3.3 2 km E of Hayward, CA
- 2.6 2 km E of Hayward, CA
- 2.3 2 km E of Hayward, CA
- 1.5 5 km E of Vallejo, CA
- 1.5 3 km SW of Clayton, CA
- 1.5 2 km NE of San Leandro, 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.