Earthquake · reviewed by a seismologist
M 3.5ml
27 km NNW of Benton, California
Yes. A magnitude 3.5 earthquake was recorded 27 km NNW of Benton, California, at 7:23 am PDT on 29 July 2021 (14:23 UTC), 10 km deep. 4 people have reported feeling it to USGS.
- When
- Magnitude
- M 3.5 (ml)
- Depth
- 10 km below the surface
- Felt
- 4 reports · strongest reported intensity II
- Measured shaking
- intensity III (ShakeMap)
- Nearest
- Mono County, 27 km WSW
- Nearest mapped fault
- Huntoon Valley fault system, 2 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 1867 days ago
Earthquake alerts for Mammoth Lakes, CA
Get a notification in this browser when USGS records an earthquake near Mammoth Lakes, 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 small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 63 km (39 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.
How big was it?
This earthquake released about 2.7 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 63,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 2,800× the energy of this one
- Magna, Utah 2020 M 5.7 2,000× the energy of this one
- This earthquake M 3.5 about 2.7 tons of TNT
- Around the size people start to feel M 3.0 this one released 5.6× more
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 5.6 on 2016-12-28 — about 1,400 times the energy of this one.
Before 2016, the USGS record lists 29 earthquakes of M5 or more within 50 km; the five largest:
- 6.3 The 1934 Excelsior Mountains, Nevada Earthquake · 35 km NE of this epicentre
- 6.0 7 km ENE of Mammoth Lakes, California · 47 km SSW of this epicentre
- 5.9 8 km NNE of Mammoth Lakes, California · 45 km SW of this epicentre
- 5.8 3 km NE of Mono City, California · 44 km W of this epicentre
- 5.6 Excelsior Mountains, Nevada (Foreshock) · 35 km NNE 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 38.0392, -118.6142. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Mono County, CA | 27 km (17 mi) | WSW | earthquakes near Mono County |
| Mineral County, NV | 56 km (35 mi) | NNE | earthquakes near Mineral County |
| Esmeralda County, NV | 91 km (56 mi) | ESE | earthquakes near Esmeralda County |
| Tuolumne County, CA | 118 km (74 mi) | W | earthquakes near Tuolumne County |
| Lyon County, NV | 121 km (75 mi) | NNW | earthquakes near Lyon County |
| Alpine County, CA | 122 km (76 mi) | WNW | earthquakes near Alpine County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
56 earthquakes have been recorded within 50 km since this one.
- 1.5 13km SSE of Bodie, CA
- 1.6 13km SSE of Bodie, CA
- 1.8 13km SSE of Bodie, CA
- 2.3 9 km SW of Mina, Nevada
- 1.5 13km SSE of Bodie, CA
- 1.7 41km NNE of Toms Place, CA
- 2.5 13km SSE of Bodie, CA
- 1.8 24 km S of Mina, Nevada
- 1.8 32 km ENE of Mono City, California
- 1.5 26 km S of Hawthorne, Nevada
- 1.8 13km SSE of Bodie, CA
- 1.6 39km NNE of Toms Place, CA
- 2.2 39km NNE of Toms Place, CA
- 2.4 39km NNE of Toms Place, CA
- 1.7 29km SE of Bodie, 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.