QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near King City, CA

No earthquake was likely felt in King City in the 24 hours to 11:57 am PST (19:57 UTC). The last one was M 2.5, 14 km (8 mi) E, at 4:39 pm PDT on 29 September 2026, estimated intensity II (weak) in town. Every earthquake near King City

This page: a magnitude 1.6 earthquake was recorded 48 km (30 mi) south-southwest of King City, CA, at 12:51 am PDT on 31 October 2021 (07:51 UTC), 13 km deep.

USGS: 24km NW of San Simeon, CA

12:51 am PDT, Oct 31, 2021 · · 13 km deep · released about 7.8 lb of TNT

10 km30 km60 km120 km N Monterey County 47 kmSan Benito County 92 kmSan Luis Obispo County 94 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
12:51 am PDT on 31 October 2021 ()
Where
48 km (30 mi) south-southwest of King City, CA · earthquakes near King City
Magnitude
M 1.6 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Monterey County, 47 km N
Nearest mapped fault
San Gregorio fault, 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 1829 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 King City, 48 km away, the estimate is intensity I (not felt). 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.

How big was it?

This earthquake released about 7.8 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 7.8 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 4.7 on 2021-10-25 — about 36,000 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 10 km NE of San Simeon, California · 26 km ESE of this epicentre
  2. 6.2 28km NW of Cambria, CA · 10 km S of this epicentre
  3. 5.7 Southwest of Cambria, California · 37 km SSE of this epicentre
  4. 5.2 26km NNW of Lake Nacimiento, CA · 37 km ENE of this epicentre
  5. 5.2 25 km NW of San Simeon, California · 2 km NNW 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 35.8150, -121.3457. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Monterey County, CA 47 km (29 mi) N earthquakes near Monterey County
San Benito County, CA 92 km (57 mi) NNE earthquakes near San Benito County
San Luis Obispo County, CA 94 km (58 mi) ESE earthquakes near San Luis Obispo County

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

Aftershocks so far

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

  1. 1.9 23km S of Lopez Point, CA
  2. 1.8 15km ENE of San Simeon, CA
  3. 3.0 24km SSE of Lopez Point, CA
  4. 2.2 24km NW of San Simeon, CA
  5. 1.5 7km NNE of San Simeon, CA
  6. 2.2 23km SSE of Lopez Point, CA
  7. 2.0 24km SSE of Lopez Point, CA
  8. 1.5 17km NNW of San Simeon, CA
  9. 1.6 8km NE of San Simeon, CA
  10. 2.2 8km NE of San Simeon, CA
  11. 2.1 8km NE of San Simeon, CA
  12. 2.5 8km NE of San Simeon, CA
  13. 1.9 26km W of San Simeon, CA
  14. 3.3 8km NE of San Simeon, CA
  15. 2.0 8km NNE of San Simeon, 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.