QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Porterville, CA

No earthquake was likely felt in Porterville in the 24 hours to 2:05 pm PST (22:05 UTC). The last one was M 1.6, 9 km (6 mi) SE, at 3:02 pm PDT on 22 September 2026, estimated intensity II (weak) in town. Every earthquake near Porterville

This page: a magnitude 1.8 earthquake was recorded 8 km (5 mi) north-northeast of Porterville, CA, at 10:01 am PDT on 29 June 2018 (17:01 UTC), 7.5 km deep.

USGS: 8km NNE of Porterville, CA

9 km (5 mi) NE of Porterville, CA · 104 km (64 mi) SE of Fresno, CA

10:01 am PDT, Jun 29, 2018 · · 7.5 km deep · released about 16 lb of TNT

10 km30 km60 km120 km N Tulare County 21 kmKings County 76 kmKern County 89 kmFresno 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
10:01 am PDT on 29 June 2018 ()
Where
8 km (5 mi) north-northeast of Porterville, CA · earthquakes near Porterville
Magnitude
M 1.8 (ml)
Depth
7.5 km below the surface
Felt
no reports yet
Nearest
Tulare County, 21 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3031 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 Porterville, 8 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: East Porterville, Strathmore, Lindsay, Poplar-Cotton Center, Terra Bella, Woodville.

How big was it?

This earthquake released about 16 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 970,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 680,000× the energy of this one
  3. Around the size people start to feel M 3.0 61× the energy of this one
  4. This earthquake M 1.8 about 16 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 one earthquake of M5 or more within 50 km:

  1. 5.0 5 km S of Springville, California · 14 km ESE 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 36.1247, -118.9740. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Tulare County, CA 21 km (13 mi) NE earthquakes near Tulare County
Kings County, CA 76 km (47 mi) W earthquakes near Kings County
Kern County, CA 89 km (55 mi) SSE earthquakes near Kern County
Fresno County, CA 93 km (58 mi) NW earthquakes near Fresno County

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

Aftershocks so far

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

  1. 1.7 8 km NNE of Porterville, CA
  2. 1.6 15 km ESE of Porterville, CA
  3. 1.8 13 km E of Porterville, CA
  4. 1.6 29 km NW of Kernville, CA
  5. 2.5 29 km ENE of Porterville, CA
  6. 2.0 4 km SE of Delano, CA
  7. 1.7 10 km ESE of Three Rivers, CA
  8. 1.7 7 km NNE of Porterville, CA
  9. 1.9 7 km N of Delano, CA
  10. 1.9 34 km ENE of Porterville, CA
  11. 1.7 45 km WSW of Olancha, CA
  12. 1.8 7 km NNW of Delano, CA
  13. 2.4 28 km ENE of Porterville, CA
  14. 1.6 17 km E of Delano, CA
  15. 2.5 34 km SE of Three Rivers, 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.