QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Ojai, CA

No earthquake was likely felt in Ojai in the 24 hours to 7:43 am PST (15:43 UTC). The last one was M 1.5, 7 km (5 mi) S, at 2:56 am PST on 6 November 2026, estimated intensity II (weak) in town. Every earthquake near Ojai

This page: a magnitude 1.7 earthquake was recorded 9 km (5 mi) east of Ojai, CA, at 11:51 pm PDT on 28 August 2021 (06:51 UTC), 13 km deep.

USGS: 8km E of Ojai, CA

82 km (51 mi) NW of Los Angeles, CA · 21 km (13 mi) NNE of San Buenaventura (Ventura), CA

11:51 pm PDT, Aug 28, 2021 · · 13 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Ventura County 9 kmSanta Barbara County 82 kmLos Angeles County 86 kmKern County 108 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
11:51 pm PDT on 28 August 2021 ()
Where
9 km (5 mi) east of Ojai, CA · earthquakes near Ojai
Magnitude
M 1.7 (ml)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Ventura County, 9 km S
Nearest mapped fault
Mission Ridge fault system, 3 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 1899 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 Ojai, 9 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: Meiners Oaks, Mira Monte, Santa Paula, Oak View, Saticoy, Fillmore.

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 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 900,000× the energy of this one
  3. Around the size people start to feel M 3.0 80× 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 4,000 times the energy of this one.

Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.6 7km NNE of Simi Valley, California · 43 km ESE of this epicentre
  2. 5.5 Southwest of Tejon Pass, California · 32 km NNE of this epicentre
  3. 5.5 10 km NE of Toro Canyon, California · 33 km WNW of this epicentre
  4. 5.5 The 1941 Santa Barbara, California Earthquake · 40 km WSW of this epicentre
  5. 5.2 9 km SW of Channel Islands Beach, California · 40 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 34.4392, -119.1507. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Ventura County, CA 9 km (6 mi) S earthquakes near Ventura County
Santa Barbara County, CA 82 km (51 mi) W earthquakes near Santa Barbara County
Los Angeles County, CA 86 km (53 mi) ESE earthquakes near Los Angeles County
Kern County, CA 108 km (67 mi) NNE earthquakes near Kern County
San Luis Obispo County, CA 159 km (99 mi) NW earthquakes near San Luis Obispo 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. 1.5 10km NW of Santa Paula, CA
  2. 1.9 10km NW of Santa Paula, CA
  3. 2.6 10km NW of Santa Paula, CA
  4. 1.7 10km NNW of Santa Paula, CA
  5. 1.6 10km NW of Santa Paula, CA
  6. 3.9 10km NW of Santa Paula, CA
  7. 2.3 10km NW of Santa Paula, CA
  8. 2.0 10km NW of Santa Paula, CA
  9. 2.1 8km SW of Camarillo, CA
  10. 1.6 9km SE of Piru, CA
  11. 1.7 20km SSE of Port Hueneme, CA
  12. 2.4 19km SSE of Port Hueneme, CA
  13. 1.9 18km SSE of Port Hueneme, CA
  14. 2.3 8km SE of Piru, CA
  15. 1.6 6km W of Ojai, 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.