QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

11km WSW of Cape Vizcaino, CA

· 2.8 km deep · released about 38 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 51 kmHumboldt County 114 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 2.1 (md)
Depth
2.8 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 51 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2148 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 38 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 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.

Where

Epicentre 39.6805, -123.9495. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 51 km (32 mi) WNW of here earthquakes near Mendocino County
Humboldt County, CA 114 km (71 mi) S of here earthquakes near Humboldt County
Lake County, CA 121 km (75 mi) WNW of here earthquakes near Lake County
Trinity County, CA 129 km (80 mi) SSW of here earthquakes near Trinity 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. 1.9 7km NW of Laytonville, CA
  2. 1.8 0km SW of Laytonville, CA
  3. 1.5 13km N of Brooktrails, CA
  4. 1.8 19km NNW of Laytonville, CA
  5. 1.6 7km NNW of Laytonville, CA
  6. 2.1 13km ESE of Redway, CA
  7. 1.7 10km SSE of Laytonville, CA
  8. 1.9 12km NNW of Laytonville, CA
  9. 1.7 18km NNW of Laytonville, CA
  10. 1.6 6km W of Laytonville, CA
  11. 1.9 10km SSE of Redway, CA
  12. 1.9 4km ESE of Redway, CA
  13. 2.4 12km N of Laytonville, CA
  14. 1.7 10km SSE of Laytonville, CA
  15. 1.6 9km SSE of Redway, 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 4.3 on 2017-12-14 — it released about 1,900 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.