QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

12km SE of Point Arena, CA

· 3.9 km deep · released about 11 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 66 kmSonoma County 68 kmLake County 78 kmMarin County 115 kmNapa County 116 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
3.9 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 66 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1832 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 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× 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 38.8532, -123.5812. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 66 km (41 mi) S of here earthquakes near Mendocino County
Sonoma County, CA 68 km (42 mi) WNW of here earthquakes near Sonoma County
Lake County, CA 78 km (48 mi) WSW of here earthquakes near Lake County
Marin County, CA 115 km (71 mi) NW of here earthquakes near Marin County
Napa County, CA 116 km (72 mi) WNW of here earthquakes near Napa County
Colusa County, CA 122 km (76 mi) WSW of here earthquakes near Colusa County

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

Aftershocks so far

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

  1. 2.2 15km WSW of Lakeport, CA
  2. 1.8 32km WNW of Point Arena, CA
  3. 1.8 9km SE of Talmage, CA
  4. 1.7 16km WNW of Boonville, CA
  5. 1.6 21km WNW of Ukiah, CA
  6. 1.6 12km W of Ukiah, CA
  7. 2.0 21km WNW of Ukiah, CA
  8. 1.6 15km NNW of Cloverdale, CA
  9. 1.6 16km NNW of Cloverdale, CA
  10. 1.8 21km NNW of Boonville, CA
  11. 1.8 20km SSW of Willits, CA
  12. 1.8 20km SSW of Willits, CA
  13. 1.5 8km NE of Boonville, CA
  14. 1.9 14km S of Talmage, CA
  15. 1.8 18km SW of Willits, 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 2020-12-06 — 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.