QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near La Cañada Flintridge, CA

No earthquake was likely felt in La Cañada Flintridge in the 24 hours to 4:45 am PST (12:45 UTC). The last one was M 3.8, 57 km (35 mi) WNW, at 8:00 pm PDT on 29 September 2026, estimated intensity II (weak) in town; 199 felt reports to USGS. Every earthquake near La Cañada Flintridge

This page: a magnitude 1.7 earthquake was recorded in La Cañada Flintridge, CA, at 5:24 pm PDT on 24 October 2017 (00:24 UTC), 7.2 km deep.

USGS: 2km NE of La Canada Flintridge, CA

6 km (4 mi) NNW of Pasadena, CA · 30 km (19 mi) NE of Los Angeles, CA

5:24 pm PDT, Oct 24, 2017 · · 7.2 km deep · released about 11 lb of TNT

Every earthquake near La Cañada Flintridge Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 8 kmOrange County 70 kmVentura County 90 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
5:24 pm PDT on 24 October 2017 ()
Where
in La Cañada Flintridge, CA · earthquakes near La Cañada Flintridge
Magnitude
M 1.7 (ml)
Depth
7.2 km below the surface
Felt
no reports yet
Nearest
Los Angeles County, 8 km W
Nearest mapped fault
Sierra Madre 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 3304 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 10 km (6 mi) from the epicentre. 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: Altadena 5 km, intensity II · Pasadena 7 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 11 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 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 24 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 Northridge, California, earthquake · 33 km W of this epicentre
  2. 6.6 1971 San Fernando Earthquake, California · 29 km NW of this epicentre
  3. 5.9 The 1987 Whittier Narrows, California Earthquake · 19 km SSE of this epicentre
  4. 5.9 1km ENE of Granada Hills, California · 30 km WNW of this epicentre
  5. 5.8 10km SSW of Agua Dulce, CA · 29 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 34.2105, -118.1742. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Los Angeles County, CA 8 km (5 mi) W earthquakes near Los Angeles County
Orange County, CA 70 km (43 mi) SSE earthquakes near Orange County
Ventura County, CA 90 km (56 mi) W earthquakes near Ventura County

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

Aftershocks so far

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

  1. 1.7 4km SW of Paramount, CA
  2. 1.5 6km NNE of Granada Hills, CA
  3. 2.5 3km N of Carson, CA
  4. 1.5 2km WSW of East Los Angeles, CA
  5. 1.8 6km NW of Signal Hill, CA
  6. 2.3 5km NNW of Pearblossum, CA
  7. 1.6 7km SSW of Littlerock, CA
  8. 1.7 3km WSW of Culver City, CA
  9. 1.6 3km NW of Inglewood, CA
  10. 1.6 2km WNW of Inglewood, CA
  11. 1.8 1km E of South Whittier, CA
  12. 1.5 3km WSW of Manhattan Beach, CA
  13. 1.9 4km SW of Sunland, CA
  14. 2.5 3km N of Huntington Park, CA
  15. 1.6 1km E of Yorba Linda, 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.