QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Simi Valley, CA

No earthquake was likely felt in Simi Valley in the 24 hours to 1:48 am PST (09:48 UTC). The last one was M 2.3, 17 km (10 mi) E, at 9:45 am PST on 7 November 2026, estimated intensity II (weak) in town; 26 felt reports to USGS. Every earthquake near Simi Valley

This page: a magnitude 1.7 earthquake was recorded 6 km (4 mi) northeast of Simi Valley, CA, at 3:22 pm PDT on 11 April 2017 (22:22 UTC), 20 km deep.

USGS: 4km N of Simi Valley, CA

in Simi Valley, CA · 44 km (27 mi) NW of Los Angeles, CA

3:22 pm PDT, Apr 11, 2017 · · 20 km deep · released about 12 lb of TNT

Every earthquake near Simi Valley Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Ventura County 37 kmLos Angeles County 46 kmOrange County 113 kmKern County 115 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
3:22 pm PDT on 11 April 2017 ()
Where
6 km (4 mi) northeast of Simi Valley, CA · earthquakes near Simi Valley
Magnitude
M 1.7 (ml)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Ventura County, 37 km W
Nearest mapped fault
Sierra Madre fault, 4 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 3467 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 Simi Valley, 6 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: Piru, Moorpark, Oak Park, Val Verde, Stevenson Ranch, Thousand Oaks.

How big was it?

This earthquake released about 12 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 4.1 on 2016-03-12 — about 3,800 times the energy of this one.

Before 2016, the USGS record lists 20 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 Northridge, California, earthquake · 21 km ESE of this epicentre
  2. 6.6 1971 San Fernando Earthquake, California · 36 km ENE of this epicentre
  3. 5.9 1km ENE of Granada Hills, California · 23 km E of this epicentre
  4. 5.8 10km SSW of Agua Dulce, CA · 36 km ENE of this epicentre
  5. 5.8 10km SSW of Agua Dulce, CA · 36 km ENE 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, -118.7390. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Ventura County, CA 37 km (23 mi) W earthquakes near Ventura County
Los Angeles County, CA 46 km (28 mi) ESE earthquakes near Los Angeles County
Orange County, CA 113 km (70 mi) SE earthquakes near Orange County
Kern County, CA 115 km (72 mi) N earthquakes near Kern County
Santa Barbara County, CA 122 km (76 mi) WNW earthquakes near Santa Barbara County

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

Aftershocks so far

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

  1. 1.5 7km N of Ventura, CA
  2. 1.9 3km SE of Chatsworth, CA
  3. 1.5 8km E of Ojai, CA
  4. 1.6 15km NNE of Ojai, CA
  5. 1.9 5km NW of Westwood, CA
  6. 3.6 5km NW of Westwood, CA
  7. 2.0 17km SSE of Malibu, CA
  8. 2.1 2km N of Ojai, CA
  9. 1.5 6km SSE of Malibu, CA
  10. 1.8 17km SSE of Malibu, CA
  11. 1.6 4km S of Hollywood, CA
  12. 1.7 3km NW of Castaic, CA
  13. 3.4 3km NW of Castaic, CA
  14. 1.5 2km N of Ojai, CA
  15. 1.8 0km WNW of View Park-Windsor Hills, 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.