QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Topaz Ranch Estates, NV

No earthquake was likely felt in Topaz Ranch Estates in the 24 hours to 6:03 pm PST (02:03 UTC). The last one was M 2.3, 8 km (5 mi) SW, at 6:36 pm PDT on 29 September 2026, estimated intensity II (weak) in town. Every earthquake near Topaz Ranch Estates

This page: a magnitude 1.8 earthquake was recorded 48 km (30 mi) south-southeast of Topaz Ranch Estates, NV, at 3:14 pm PDT on 15 October 2021 (22:14 UTC), 8.4 km deep.

USGS: 13km NW of Bridgeport, CA

3:14 pm PDT, Oct 15, 2021 · · 8.4 km deep · released about 15 lb of TNT

10 km30 km60 km120 km N Alpine County 51 kmMono County 61 kmTuolumne County 63 kmDouglas County 69 kmLyon County 79 kmMineral County 84 kmMariposa County 97 kmCarson City 99 kmCalaveras County 106 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
3:14 pm PDT on 15 October 2021 ()
Where
48 km (30 mi) south-southeast of Topaz Ranch Estates, NV · earthquakes near Topaz Ranch Estates
Magnitude
M 1.8 (md)
Depth
8.4 km below the surface
Felt
no reports yet
Nearest
Alpine County, 51 km NW
Nearest mapped fault
Robinson Creek 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 1850 days ago

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 10 km (6 mi) from the epicentre. In Topaz Ranch Estates, 48 km away, the estimate is intensity I (not felt). 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 15 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.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 2,100,000 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.8 3 km NE of Mono City, California · 35 km SE of this epicentre
  2. 5.2 23 km S of Walker, California · 13 km W of this epicentre
  3. 5.1 23 km E of Bridgeport, California · 34 km E of this epicentre
  4. 5.1 19 km W of Bridgeport, California · 14 km SW of this epicentre
  5. 5.0 Near Coleville, California · 32 km NNW 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 38.3215, -119.3510. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alpine County, CA 51 km (32 mi) NW earthquakes near Alpine County
Mono County, CA 61 km (38 mi) SE earthquakes near Mono County
Tuolumne County, CA 63 km (39 mi) WSW earthquakes near Tuolumne County
Douglas County, NV 69 km (43 mi) NNW earthquakes near Douglas County
Lyon County, NV 79 km (49 mi) N earthquakes near Lyon County
Mineral County, NV 84 km (52 mi) ENE earthquakes near Mineral County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

60 earthquakes have been recorded within 50 km since this one.

  1. 1.9 6km NW of Walker, CA
  2. 1.9 5km NW of Walker, CA
  3. 1.6 5km NW of Walker, CA
  4. 1.8 6km ESE of Walker, CA
  5. 1.5 6km NW of Walker, CA
  6. 2.2 6km NW of Walker, CA
  7. 1.6 5km NW of Walker, CA
  8. 1.9 12km SSE of Bodie, CA
  9. 1.7 12km SSE of Bodie, CA
  10. 1.6 4km W of Walker, CA
  11. 1.7 6km NNE of Walker, CA
  12. 1.7 5km SW of Walker, CA
  13. 2.0 7km SE of Markleeville, CA
  14. 1.7 5km NW of Walker, CA
  15. 2.8 4km W 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.