QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Twentynine Palms, CA

No earthquake was likely felt in Twentynine Palms in the 24 hours to 1:36 pm PST (21:36 UTC). The last one was M 3.2, 30 km (19 mi) SW, at 9:51 am PDT on 1 August 2026, estimated intensity II (weak) in town; 46 felt reports to USGS. Every earthquake near Twentynine Palms

This page: a magnitude 1.7 earthquake was recorded 23 km (14 mi) south-southeast of Twentynine Palms, CA, at 2:42 pm PDT on 4 August 2020 (21:42 UTC), 1.7 km deep.

USGS: 24km SSE of Twentynine Palms, CA

32 km (20 mi) NE of Indio, CA · 129 km (80 mi) E of Riverside, CA

2:42 pm PDT, Aug 4, 2020 · · 1.7 km deep · released about 9.3 lb of TNT

Every earthquake near Twentynine Palms Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Riverside County 23 kmSan Bernardino County 104 kmImperial County 116 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
2:42 pm PDT on 4 August 2020 ()
Where
23 km (14 mi) south-southeast of Twentynine Palms, CA · earthquakes near Twentynine Palms
Magnitude
M 1.7 (ml)
Depth
1.7 km below the surface
Felt
no reports yet
Nearest
Riverside County, 23 km S
Nearest mapped fault
Pinto Mountain fault (includes Morongo Valley fault), 19 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 2291 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 12 km (7 mi) from the epicentre. In Twentynine Palms, 23 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 9.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 100× the energy of this one
  4. This earthquake M 1.7 about 9.3 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 4.2 on 2019-07-22 — about 6,500 times the energy of this one.

Before 2016, the USGS record lists 18 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 The 1992 Joshua Tree, California Earthquake · 30 km W of this epicentre
  2. 6.0 The 1948 Desert Hot Springs, California Earthquake · 32 km W of this epicentre
  3. 5.8 3km NE of Yucca Valley, California · 44 km WNW of this epicentre
  4. 5.7 38km ESE of Twentynine Palms, CA · 28 km ENE of this epicentre
  5. 5.7 2km SSW of Joshua Tree, California · 37 km NW 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 33.9352, -115.9898. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Riverside County, CA 23 km (14 mi) S earthquakes near Riverside County
San Bernardino County, CA 104 km (65 mi) N earthquakes near San Bernardino County
Imperial County, CA 116 km (72 mi) SSE earthquakes near Imperial County
San Diego County, CA 125 km (78 mi) SW earthquakes near San Diego County

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

Aftershocks so far

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

  1. 1.9 23km ENE of Thermal, CA
  2. 2.2 24km ENE of Thermal, CA
  3. 2.3 23km ENE of Thermal, CA
  4. 2.4 23km ENE of Thermal, CA
  5. 1.9 23km ENE of Thermal, CA
  6. 2.0 23km ENE of Thermal, CA
  7. 1.7 12km E of Desert Hot Springs, CA
  8. 2.2 12km N of Indio, CA
  9. 1.6 16km NE of Thousand Palms, CA
  10. 1.9 28km NE of Indio, CA
  11. 1.8 7km E of Desert Hot Springs, CA
  12. 1.5 12km ENE of Thousand Palms, CA
  13. 1.7 13km NE of Indio, CA
  14. 1.6 13km NE of Indio, CA
  15. 1.8 15km S of Joshua Tree, 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.