QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Rancho Cucamonga, CA

No earthquake was likely felt in Rancho Cucamonga in the 24 hours to 6:54 am PST (14:54 UTC). The last one was M 2.0, 10 km (6 mi) E, at 2:35 am PDT on 23 October 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Rancho Cucamonga

This page: a magnitude 1.5 earthquake was recorded 23 km (14 mi) north-northeast of Rancho Cucamonga, CA, at 9:33 pm PST on 16 November 2020 (05:33 UTC), 11 km deep.

USGS: 6km NNW of Lytle Creek, CA

87 km (54 mi) ENE of Los Angeles, CA · 20 km (13 mi) N of Rancho Cucamonga, CA

9:33 pm PST, Nov 16, 2020 · · 11 km deep · released about 5.7 lb of TNT

Every earthquake near Rancho Cucamonga Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 68 kmOrange County 74 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
9:33 pm PST on 16 November 2020 ()
Where
23 km (14 mi) north-northeast of Rancho Cucamonga, CA · earthquakes near Rancho Cucamonga
Magnitude
M 1.5 (ml)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Los Angeles County, 68 km W
Nearest mapped fault
San Andreas fault, under 1 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 2186 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Rancho Cucamonga, 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.

Earthquakes near other towns within 30 km: Wrightwood, Phelan, Oak Hills, Piñon Hills, San Antonio Heights, Crestline.

How big was it?

This earthquake released about 5.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.7 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 4.4 on 2018-08-29 — about 19,000 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. 6.2 3 km SE of San Bernardino, California · 35 km SE of this epicentre
  2. 5.8 The 1991 Sierra Madre, California Earthquake · 42 km W of this epicentre
  3. 5.6 7km ENE of Running Springs, CA · 46 km E of this epicentre
  4. 5.5 The 1990 Upland, California Earthquake · 24 km SW of this epicentre
  5. 5.4 5km S of Chino Hills, CA · 45 km SSW 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 34.3095, -117.5347. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Los Angeles County, CA 68 km (42 mi) W earthquakes near Los Angeles County
Orange County, CA 74 km (46 mi) SSW earthquakes near Orange County
Kern County, CA 159 km (99 mi) NW earthquakes near Kern 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. 1.6 6km NE of Moreno Valley, CA
  2. 1.5 7km ENE of Running Springs, CA
  3. 2.2 14km NNE of Glendora, CA
  4. 1.7 5km WSW of Lytle Creek, CA
  5. 1.8 4km SE of Loma Linda, CA
  6. 1.6 5km E of Lake Arrowhead, CA
  7. 1.8 3km NNW of Loma Linda, CA
  8. 2.0 4km ESE of Mentone, CA
  9. 1.6 6km SSE of Loma Linda, CA
  10. 1.9 5km SSW of Redlands, CA
  11. 2.4 5km SSW of Redlands, CA
  12. 2.1 5km W of Devore, CA
  13. 2.0 8km E of Yorba Linda, CA
  14. 2.2 6km NE of Running Springs, CA
  15. 1.6 6km NE of Running Springs, 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.