QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Fort Irwin, CA

No earthquake was likely felt in Fort Irwin in the 24 hours to 4:02 am PST (12:02 UTC). The last one was M 4.3, 103 km (64 mi) W, at 9:40 am PDT on 13 July 2026, estimated intensity II (weak) in town; 1,090 felt reports to USGS. Every earthquake near Fort Irwin

This page: a magnitude 2.1 earthquake was recorded 48 km (30 mi) west of Fort Irwin, CA, at 7:29 am PDT on 20 August 2019 (14:29 UTC), 1.9 km deep.

USGS: 39km E of Johannesburg, CA

7:29 am PDT, Aug 20, 2019 · · 1.9 km deep · released about 41 lb of TNT

Every earthquake near Fort Irwin Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Bernardino County 107 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
7:29 am PDT on 20 August 2019 ()
Where
48 km (30 mi) west of Fort Irwin, CA · earthquakes near Fort Irwin
Magnitude
M 2.1 (ml)
Depth
1.9 km below the surface
Felt
no reports yet
Nearest
San Bernardino County, 107 km ESE
Nearest mapped fault
Blackwater fault, 6 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 752 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 17 km (11 mi) from the epicentre. In Fort Irwin, 48 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 41 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 370,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 260,000× the energy of this one
  3. Around the size people start to feel M 3.0 23× the energy of this one
  4. This earthquake M 2.1 about 41 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 4.9 on 2019-07-12 — about 16,000 times the energy of this one.

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 35.3245, -117.2045. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Bernardino County, CA 107 km (66 mi) ESE earthquakes near San Bernardino County

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

Aftershocks so far

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

  1. 2.3 8km E of Ridgecrest, CA
  2. 3.0 13km ENE of Ridgecrest, CA
  3. 1.9 14km SW of Searles Valley, CA
  4. 2.4 8km E of Ridgecrest, CA
  5. 2.2 11km SSW of Searles Valley, CA
  6. 1.5 10km ENE of Ridgecrest, CA
  7. 1.6 14km SSW of Searles Valley, CA
  8. 1.9 15km S of Searles Valley, CA
  9. 1.8 26km NE of Johannesburg, CA
  10. 1.6 15km SSW of Searles Valley, CA
  11. 2.2 13km SSW of Searles Valley, CA
  12. 1.7 24km ESE of Ridgecrest, CA
  13. 3.0 12km SW of Searles Valley, CA
  14. 1.8 14km SW of Searles Valley, CA
  15. 1.6 14km SSW of Searles Valley, 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.