Earthquake · reviewed by a seismologist
M 1.5ml
Earthquake near Modesto, CA
USGS: 9 km W of Chinese Camp, California
48 km (30 mi) ENE of Modesto, CA · 129 km (80 mi) ENE of San Jose, CA
- When
- 12:25 pm PDT on 6 April 2018 ()
- Where
- 48 km (30 mi) ENE of Modesto, CA · earthquakes near Modesto
- Magnitude
- M 1.5 (ml)
- Depth
- 0.0 km below the surface
- Felt
- no reports yet
- Nearest
- Calaveras County, 36 km N
- Nearest mapped fault
- Foothills fault system, under 1 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 3101 days ago
A magnitude 1.5 earthquake was recorded 48 km (30 mi) ENE of Modesto, CA, at 12:25 pm PDT on 6 April 2018 (19:25 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Jamestown, Copperopolis, Sonora, East Sonora, Angels Camp, Columbia.
How big was it?
This earthquake released about 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 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 since 1900 lists no earthquake of M5 or more within 50 km.
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 37.8707, -120.5389. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Calaveras County, CA | 36 km (22 mi) | N | earthquakes near Calaveras County |
| Tuolumne County, CA | 53 km (33 mi) | ENE | earthquakes near Tuolumne County |
| Stanislaus County, CA | 53 km (33 mi) | SW | earthquakes near Stanislaus County |
| Mariposa County, CA | 64 km (40 mi) | ESE | earthquakes near Mariposa County |
| Amador County, CA | 64 km (40 mi) | N | earthquakes near Amador County |
| San Joaquin County, CA | 65 km (40 mi) | W | earthquakes near San Joaquin County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
15 earthquakes have been recorded within 50 km since this one.
- 2.2 9 km NW of Chinese Camp, CA
- 1.9 18km E of Groveland-Big Oak Flat, CA
- 2.3 6km S of Vallecito, CA
- 2.1 11km E of Groveland-Big Oak Flat, CA
- 1.8 7km WNW of Chinese Camp, CA
- 1.5 16km ESE of Groveland-Big Oak Flat, CA
- 2.5 18km SE of Groveland-Big Oak Flat, CA
- 1.9 3km WNW of Chinese Camp, CA
- 2.3 14km S of Groveland-Big Oak Flat, CA
- 1.7 4 km SSE of Vallecito, California
- 1.5 Northern California
- 1.7 3 km ESE of Murphys, California
- 1.5 4 km WNW of Tuttletown, California
- 1.5 4 km ESE of Vallecito, California
- 1.6 2 km ESE of Vallecito, 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.