QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7ml

Earthquake near Fort Irwin, CA

No earthquake was likely felt in Fort Irwin in the 24 hours to 7:20 am PST (15:20 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 2.7 earthquake was recorded 20 km (13 mi) southeast of Fort Irwin, CA, at 5:12 am PDT on 22 August 2017 (12:12 UTC), 9.7 km deep.

USGS: 20km SE of Fort Irwin, CA

5:12 am PDT, Aug 22, 2017 · · 9.7 km deep · released about 380 lb of TNT

Every earthquake near Fort Irwin Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Bernardino County 44 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
5:12 am PDT on 22 August 2017 ()
Where
20 km (13 mi) southeast of Fort Irwin, CA · earthquakes near Fort Irwin
Magnitude
M 2.7 (ml)
Depth
9.7 km below the surface
Felt
no reports yet
Nearest
San Bernardino County, 44 km SE
Nearest mapped fault
Manix fault, 17 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 3304 days ago

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 24 km (15 mi) from the epicentre. In Fort Irwin, 20 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.

Likely felt in: Fort Irwin 20 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 380 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 40,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 29,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.5× the energy of this one
  4. This earthquake M 2.7 about 380 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 The 1947 Manix, California Earthquake · 17 km S of this epicentre
  2. 5.3 20km ENE of Barstow, California · 33 km SW of this epicentre
  3. 5.1 46 km E of Barstow, California · 34 km S of this epicentre
  4. 5.1 25km W of Ludlow, CA · 48 km S of this epicentre
  5. 5.1 26km WNW of Ludlow, CA · 37 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 35.1382, -116.5205. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Bernardino County, CA 44 km (27 mi) SE earthquakes near San Bernardino County

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

Aftershocks so far

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

  1. 1.9 14km NW of Ludlow, CA
  2. 1.6 35km E of Barstow, CA
  3. 1.8 26km NW of Ludlow, CA
  4. 1.6 16km NNE of Barstow, CA
  5. 1.6 15km NW of Ludlow, CA
  6. 1.8 27km ENE of Barstow, CA
  7. 1.8 14km NW of Ludlow, CA
  8. 1.6 15km NW of Ludlow, CA
  9. 2.1 33km E of Barstow, CA
  10. 2.1 14km NW of Ludlow, CA
  11. 1.6 14km NW of Ludlow, CA
  12. 1.6 14km NW of Ludlow, CA
  13. 1.6 14km NW of Ludlow, CA
  14. 3.5 14km NW of Ludlow, CA
  15. 2.5 34km E of Barstow, 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.