Earthquake · reviewed by a seismologist
M 1.9md
8km NNE of Bridgeport, CA
Yes. A magnitude 1.9 earthquake was recorded 8km NNE of Bridgeport, CA, at 1:32 am PST on 16 December 2021 (09:32 UTC), 9.0 km deep.
- When
- Magnitude
- M 1.9 (md)
- Depth
- 9.0 km below the surface
- Felt
- no reports yet
- Nearest
- Mono County, 52 km SSE
- Nearest mapped fault
- Smith Valley fault, 10 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 1792 days ago
Earthquake alerts for Smith Valley, NV
Get a notification in this browser when USGS records an earthquake near Smith Valley, NV. 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 11 km (7 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 20 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 760,000× the energy of this one
- Magna, Utah 2020 M 5.7 540,000× the energy of this one
- Around the size people start to feel M 3.0 48× the energy of this one
- This earthquake M 1.9 about 20 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 6.0 on 2021-07-08 — about 1,500,000 times the energy of this one.
Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:
- 5.8 3 km NE of Mono City, California · 29 km SSE of this epicentre
- 5.2 23 km S of Walker, California · 27 km W of this epicentre
- 5.2 21 km S of Hawthorne, Nevada · 45 km E of this epicentre
- 5.2 31 km ENE of Mono City, California · 37 km ESE of this epicentre
- 5.1 23 km E of Bridgeport, California · 20 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 38.3160, -119.1893. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Mono County, CA | 52 km (32 mi) | SSE | earthquakes near Mono County |
| Alpine County, CA | 63 km (39 mi) | WNW | earthquakes near Alpine County |
| Mineral County, NV | 71 km (44 mi) | ENE | earthquakes near Mineral County |
| Douglas County, NV | 75 km (47 mi) | NNW | earthquakes near Douglas County |
| Tuolumne County, CA | 75 km (47 mi) | WSW | earthquakes near Tuolumne County |
| Lyon County, NV | 79 km (49 mi) | N | earthquakes near Lyon 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.
- 2.2 6km WNW of Walker, CA
- 2.3 29km ESE of Bodie, CA
- 2.2 5km WNW of Walker, CA
- 1.6 27km ESE of Bodie, CA
- 1.8 5km SW of Walker, CA
- 2.2 6km WNW of Walker, CA
- 1.5 17 km ENE of Coleville, California
- 1.5 5 km SW of Walker, California
- 2.3 8km E of Walker, CA
- 2.2 5km WNW of Walker, CA
- 2.2 29km ESE of Bodie, CA
- 1.5 8 km ENE of Walker, California
- 1.8 27km ESE of Bodie, CA
- 2.3 7km WNW of Walker, CA
- 1.7 7km WNW of Walker, 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.