QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2md

21km NNE of Rockport, CA

· 5.0 km deep · released about 52 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 60 kmHumboldt County 89 kmTrinity County 97 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 2.2 (md)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 60 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2236 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 52 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 290,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 200,000× the energy of this one
  3. Around the size people start to feel M 3.0 18× the energy of this one
  4. This earthquake M 2.2 about 52 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 39.9178, -123.7448. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 60 km (37 mi) NNW of here earthquakes near Mendocino County
Humboldt County, CA 89 km (55 mi) S of here earthquakes near Humboldt County
Trinity County, CA 97 km (60 mi) SSW of here earthquakes near Trinity County
Glenn County, CA 120 km (75 mi) WNW of here earthquakes near Glenn County
Lake County, CA 124 km (77 mi) NW of here earthquakes near Lake County

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

Aftershocks so far

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

  1. 1.7 8km WSW of Covelo, CA
  2. 1.9 12km SE of Laytonville, CA
  3. 1.9 20km NNE of Redway, CA
  4. 2.1 11km WSW of Cape Vizcaino, CA
  5. 1.6 20km NNE of Rockport, CA
  6. 1.7 26km NE of Redway, CA
  7. 1.5 8km SSE of Laytonville, CA
  8. 1.6 8km SSE of Laytonville, CA
  9. 1.7 13km N of Laytonville, CA
  10. 2.3 9km SSE of Laytonville, CA
  11. 2.0 3km SE of Redway, CA
  12. 1.8 21km NNE of Rockport, CA
  13. 2.1 28km ENE of Redway, CA
  14. 1.8 20km NNE of Rockport, CA
  15. 1.9 8km SSE of Laytonville, 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 1,400 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.