QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Highland, CA

No earthquake was likely felt in Highland in the 24 hours to 9:55 pm PST (05:55 UTC). The last one was M 2.1, 11 km (7 mi) SSW, at 10:40 am PDT on 31 October 2026, estimated intensity II (weak) in town. Every earthquake near Highland

This page: a magnitude 1.6 earthquake was recorded 5 km (3 mi) northwest of Highland, CA, at 4:10 am PDT on 28 July 2017 (11:10 UTC), 3.3 km deep.

USGS: 5km NW of Highland, CA

5 km (3 mi) ENE of San Bernardino, CA

4:10 am PDT, Jul 28, 2017 · · 3.3 km deep · released about 7.8 lb of TNT

10 km30 km60 km120 km N Orange County 73 kmLos Angeles County 93 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
4:10 am PDT on 28 July 2017 ()
Where
5 km (3 mi) northwest of Highland, CA · earthquakes near Highland
Magnitude
M 1.6 (ml)
Depth
3.3 km below the surface
Felt
no reports yet
Nearest
Orange County, 73 km SW
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 3303 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 11 km (7 mi) from the epicentre. In Highland, 5 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: Highland 5 km, intensity II · San Bernardino 7 km, intensity II · Muscoy 9 km, intensity II · Lake Arrowhead 11 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 7.8 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 7.8 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 2016-01-06 — about 15,000 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 The 1992 Big Bear, California Earthquake · 39 km E of this epicentre
  2. 6.2 3 km SE of San Bernardino, California · 8 km S of this epicentre
  3. 5.6 7km ENE of Running Springs, CA · 21 km ENE of this epicentre
  4. 5.5 The 1990 Upland, California Earthquake · 41 km W of this epicentre
  5. 5.5 11km SSE of Big Bear Lake, California · 36 km E 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 34.1642, -117.2467. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 73 km (45 mi) SW earthquakes near Orange County
Los Angeles County, CA 93 km (58 mi) W earthquakes near Los Angeles County
San Bernardino County, CA 124 km (77 mi) NE earthquakes near San Bernardino County
Riverside County, CA 125 km (77 mi) ESE earthquakes near Riverside County

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

Aftershocks so far

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

  1. 1.6 1km NNW of Loma Linda, CA
  2. 2.4 2km SE of Redlands, CA
  3. 1.5 2km SSE of Redlands, CA
  4. 1.5 2km SE of Redlands, CA
  5. 1.6 2km SE of Redlands, CA
  6. 1.9 2km SE of Redlands, CA
  7. 1.6 3km SE of Redlands, CA
  8. 1.6 2km SSE of Redlands, CA
  9. 1.7 2km SE of Redlands, CA
  10. 1.5 3km SW of Big Bear City, CA
  11. 1.5 5km S of Redlands, CA
  12. 1.6 6km N of Fontana, CA
  13. 2.6 8km NNW of Big Bear City, CA
  14. 1.7 11km NE of Running Springs, CA
  15. 2.6 9km E 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.