Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Mendota, CA
No earthquake was likely felt in Mendota in the 24 hours to 10:08 am PST (18:08 UTC). The last one was M 3.9, 74 km (46 mi) WSW, at 3:19 am PDT on 11 August 2026, estimated intensity II (weak) in town; 34 felt reports to USGS. Every earthquake near Mendota
This page: a magnitude 1.8 earthquake was recorded 33 km (20 mi) southwest of Mendota, CA, at 1:32 am PDT on 23 August 2021 (08:32 UTC), 10 km deep.
USGS: 17km N of New Idria, CA
- When
- 1:32 am PDT on 23 August 2021 ()
- Where
- 33 km (20 mi) southwest of Mendota, CA · earthquakes near Mendota
- Magnitude
- M 1.8 (md)
- Depth
- 10 km below the surface
- Felt
- no reports yet
- Nearest
- San Benito County, 38 km W
- Nearest mapped fault
- Great Valley thrust fault system, 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 1907 days ago
Earthquake alerts for Mendota, CA
Get a notification in this browser when USGS records an earthquake near Mendota, 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 Mendota, 33 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.
How big was it?
This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
- Magna, Utah 2020 M 5.7 840,000× the energy of this one
- Around the size people start to feel M 3.0 75× the energy of this one
- This earthquake M 1.8 about 13 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 4.3 on 2021-01-02 — about 7,200 times the energy of this one.
Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 The 1983 Coalinga, California Earthquake · 49 km SE of this epicentre
- 6.1 Northwest of Huron, California · 9 km SE of this epicentre
- 5.8 29 km NE of San Lucas, California · 31 km SSW of this epicentre
- 5.4 22 km SSW of Three Rocks, California · 31 km SSE of this epicentre
- 5.4 11 km NNW of Coalinga, California · 43 km SSE 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 36.5658, -120.6663. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Benito County, CA | 38 km (23 mi) | W | earthquakes near San Benito County |
| Monterey County, CA | 68 km (43 mi) | WSW | earthquakes near Monterey County |
| Merced County, CA | 70 km (44 mi) | N | earthquakes near Merced County |
| Fresno County, CA | 93 km (58 mi) | ENE | earthquakes near Fresno County |
| Kings County, CA | 94 km (58 mi) | SE | earthquakes near Kings County |
| Madera County, CA | 108 km (67 mi) | NE | earthquakes near Madera County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
54 earthquakes have been recorded within 50 km since this one.
- 2.3 11km SE of Pinnacles, CA
- 1.9 6km ENE of Pinnacles, CA
- 2.3 2km N of Pinnacles, CA
- 2.3 8km ESE of Pinnacles, CA
- 2.0 7km NW of Pinnacles, CA
- 2.1 7km NNW of Pinnacles, CA
- 2.2 7km NNW of Pinnacles, CA
- 1.6 7km WNW of Pinnacles, CA
- 2.1 6km NNW of Pinnacles, CA
- 2.1 5km NE of New Idria, CA
- 2.0 11km SE of Pinnacles, CA
- 2.2 7km N of Pinnacles, CA
- 2.2 6km NNW of Pinnacles, CA
- 2.1 24km NE of King City, CA
- 1.8 22km NNE of San Ardo, 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.