QuakeIndex

quarry blast · reviewed by a seismologist

M 1.9ml

Earthquake near Calipatria, CA

No earthquake was likely felt in Calipatria in the 24 hours to 4:09 am PST (12:09 UTC). The last one was M 4.9, 83 km (52 mi) SSE, at 10:27 am PST on 3 November 2026, estimated intensity III (weak) in town; 321 felt reports to USGS. Every earthquake near Calipatria

No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.9 quarry blast was recorded 48 km (30 mi) east of Calipatria, CA, at 3:26 pm PDT on 24 August 2017 (22:26 UTC), less than 1 km deep.

USGS: 47km NE of Holtville, CA

77 km (48 mi) NW of Yuma, AZ

3:26 pm PDT, Aug 24, 2017 · · -0.1 km deep · released about 21 lb of TNT

10 km30 km60 km120 km N Imperial County 34 kmYuma County 107 kmLa Paz County 114 kmRiverside County 118 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
3:26 pm PDT on 24 August 2017 ()
Where
48 km (30 mi) east of Calipatria, CA · earthquakes near Calipatria
Magnitude
M 1.9 (ml)
Depth
-0.1 km below the surface
Felt
no reports yet
Nearest
Imperial County, 34 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3367 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 15 km (9 mi) from the epicentre. In Calipatria, 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.

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 21 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.

  1. Mineral, Virginia 2011 M 5.8 730,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 520,000× the energy of this one
  3. Around the size people start to feel M 3.0 46× the energy of this one
  4. This earthquake M 1.9 about 21 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. 6.9 The 1940 Imperial Valley, California Earthquake · 44 km SW of this epicentre
  2. 5.5 Near Holtville, California · 42 km SW of this epicentre
  3. 5.3 8km E of Holtville, CA · 41 km SW of this epicentre
  4. 5.3 7km ESE of Calipatria, CA · 42 km W of this epicentre
  5. 5.3 6km ESE of Brawley, CA · 46 km WSW 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 33.0790, -114.9968. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Imperial County, CA 34 km (21 mi) W earthquakes near Imperial County
Yuma County, AZ 107 km (66 mi) ESE earthquakes near Yuma County
La Paz County, AZ 114 km (71 mi) NE earthquakes near La Paz County
Riverside County, CA 118 km (73 mi) NW earthquakes near Riverside County

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

Aftershocks so far

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

  1. 1.6 45km NE of Holtville, CA
  2. 1.8 8km SSE of Brawley, CA
  3. 1.7 8km SSE of Brawley, CA
  4. 1.7 8km SSE of Brawley, CA
  5. 1.9 8km SSE of Brawley, CA
  6. 1.9 9km SSE of Brawley, CA
  7. 1.7 8km SSE of Brawley, CA
  8. 1.8 46km NE of Holtville, CA
  9. 1.5 47km NE of Holtville, CA
  10. 1.5 46km NE of Holtville, 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.