QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

10 km ENE of Rockport, CA

· 4.3 km deep · released about 11 lb of TNT

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10 km30 km60 km120 km N Mendocino County 44 kmHumboldt County 106 kmTrinity County 110 kmLake County 111 kmGlenn County 113 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 1.7 (md)
Depth
4.3 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 44 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 34 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 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 930,000× the energy of this one
  3. Around the size people start to feel M 3.0 83× the energy of this one
  4. This earthquake M 1.7 about 11 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 39.7710, -123.7055. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 44 km (27 mi) NNW of here earthquakes near Mendocino County
Humboldt County, CA 106 km (66 mi) S of here earthquakes near Humboldt County
Trinity County, CA 110 km (68 mi) SSW of here earthquakes near Trinity County
Lake County, CA 111 km (69 mi) NW of here earthquakes near Lake County
Glenn County, CA 113 km (70 mi) W of here earthquakes near Glenn County

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

Aftershocks so far

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

  1. 1.4 13 km SSE of Redway, CA
  2. 1.8 3 km SE of Redway, CA
  3. 1.9 9 km ENE of Brooktrails, CA
  4. 2.2 15 km NNE of Fort Bragg, CA
  5. 1.6 4 km ESE of Redway, CA
  6. 2.0 5 km NE of Willits, CA
  7. 2.0 17 km WNW of Cape Vizcaino, CA
  8. 1.7 20 km WNW of Cape Vizcaino, CA
  9. 1.6 2 km ENE of Redway, CA
  10. 1.8 1 km N of Redway, CA
  11. 1.8 7 km E of Covelo, CA
  12. 1.9 16 km W of Cape Vizcaino, CA
  13. 1.7 15 km W of Cape Vizcaino, CA
  14. 1.9 10 km ENE of Rockport, 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 4.4 on 2026-07-11 — it released about 11,000 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.