QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

16 km ENE of Rockport, CA

· -0.4 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 47 kmHumboldt County 101 kmTrinity County 103 kmGlenn County 111 kmLake County 112 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 1.8 (md)
Depth
-0.4 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 47 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 606 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 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 39.8208, -123.6638. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 47 km (29 mi) NNW of here earthquakes near Mendocino County
Humboldt County, CA 101 km (63 mi) SSE of here earthquakes near Humboldt County
Trinity County, CA 103 km (64 mi) SSW of here earthquakes near Trinity County
Glenn County, CA 111 km (69 mi) WNW of here earthquakes near Glenn County
Lake County, CA 112 km (69 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

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

  1. 1.8 10 km NNE of Brooktrails, CA
  2. 1.7 6 km N of Laytonville, CA
  3. 1.7 12 km W of Brooktrails, CA
  4. 1.5 3 km WNW of Redway, CA
  5. 2.2 4 km N of Laytonville, CA
  6. 1.7 11 km SSE of Redway, CA
  7. 1.6 15 km SSE of Laytonville, CA
  8. 1.9 15 km SSE of Laytonville, CA
  9. 1.9 13 km NNE of Brooktrails, CA
  10. 1.7 15 km SSE of Laytonville, CA
  11. 1.6 10 km ESE of Rockport, CA
  12. 1.9 5 km E of Covelo, CA
  13. 1.9 5 km E of Covelo, CA
  14. 1.6 5 km NNE of Laytonville, CA
  15. 2.4 19 km NNW 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 2024-06-22 — it released about 6,900 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.