QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

8km E of Point Arena, CA

· 7.6 km deep · released about 25 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 61 kmSonoma County 72 kmLake County 78 kmNapa County 119 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 1.9 (md)
Depth
7.6 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 61 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1338 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 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 620,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 440,000× the energy of this one
  3. Around the size people start to feel M 3.0 39× the energy of this one
  4. This earthquake M 1.9 about 25 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 38.8995, -123.6058. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 61 km (38 mi) SSW of here earthquakes near Mendocino County
Sonoma County, CA 72 km (45 mi) NW of here earthquakes near Sonoma County
Lake County, CA 78 km (48 mi) WSW of here earthquakes near Lake County
Napa County, CA 119 km (74 mi) WNW of here earthquakes near Napa County
Marin County, CA 120 km (75 mi) NW of here earthquakes near Marin 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

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

  1. 1.6 15 km ENE of Point Arena, CA
  2. 1.8 23 km E of Navarro Head, CA
  3. 2.0 14 km W of Lakeport, CA
  4. 2.0 15km NE of Point Arena, CA
  5. 2.2 15km NE of Point Arena, CA
  6. 1.5 4km SSE of Point Arena, CA
  7. 1.5 16km SE of Boonville, CA
  8. 1.9 5km NE of Ukiah, CA
  9. 1.7 16km WSW of Redwood Valley, CA
  10. 1.7 21km E of Navarro Head, CA
  11. 2.1 21km E of Navarro Head, CA
  12. 4.3 8km SE of Talmage, CA
  13. 1.7 23km SSW of Willits, CA
  14. 1.8 23km SSW of Willits, CA
  15. 1.7 17km NNW of Cloverdale, 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 4,700 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.