QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5mw

4km SSE of Parkfield, CA

· 8.4 km deep · released about 2.7 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Luis Obispo County 53 kmKings County 59 kmMonterey County 91 kmSan Benito County 103 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
Magnitude
M 3.5 (mw)
Depth
8.4 km below the surface
Felt
79 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
Nearest
San Luis Obispo County, 53 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2658 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 79 people have reported feeling it to USGS.

How big was it?

This earthquake released about 2.7 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 63,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 2,800× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,000× the energy of this one
  4. This earthquake M 3.5 about 2.7 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 5.6× more

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.

Where

Epicentre 35.8610, -120.4127. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Luis Obispo County, CA 53 km (33 mi) N of here earthquakes near San Luis Obispo County
Kings County, CA 59 km (36 mi) WSW of here earthquakes near Kings County
Monterey County, CA 91 km (57 mi) ESE of here earthquakes near Monterey County
San Benito County, CA 103 km (64 mi) SE of here earthquakes near San Benito County
Fresno County, CA 121 km (75 mi) SW of here earthquakes near Fresno County

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

Aftershocks so far

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

  1. 1.8 16km SSE of New Idria, CA
  2. 2.5 16km NW of Parkfield, CA
  3. 1.5 10km NNW of Cholame, CA
  4. 1.7 9km ENE of Coalinga, CA
  5. 2.4 14km NE of Coalinga, CA
  6. 1.7 5km NW of Parkfield, CA
  7. 1.7 5km NW of Parkfield, CA
  8. 2.4 11km NW of Parkfield, CA
  9. 2.0 10km WSW of Huron, CA
  10. 2.0 5km NW of Parkfield, CA
  11. 1.6 24km ENE of San Ardo, CA
  12. 1.8 11km ENE of Coalinga, CA
  13. 1.6 16km NW of Coalinga, CA
  14. 1.9 2km N of Cholame, CA
  15. 1.9 2km NNE of Cholame, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.0 on 2018-11-27 — it released about 5.6 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.