Earthquake · reviewed by a seismologist
M 1.8md
6km SSW of Fort Ross, CA
- When
- Magnitude
- M 1.8 (md)
- Depth
- 3.1 km below the surface
- Felt
- no reports yet
- Nearest
- Sonoma County, 31 km E
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2763 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 15 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.
- Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 730,000× the energy of this one
- Around the size people start to feel M 3.0 65× the energy of this one
- This earthquake M 1.8 about 15 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 38.4727, -123.2768. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Sonoma County, CA | 31 km (19 mi) | W of here | earthquakes near Sonoma County |
| Marin County, CA | 66 km (41 mi) | NW of here | earthquakes near Marin County |
| Napa County, CA | 83 km (51 mi) | W of here | earthquakes near Napa County |
| Lake County, CA | 84 km (52 mi) | SSW of here | earthquakes near Lake County |
| San Francisco County, CA | 86 km (53 mi) | NNW of here | earthquakes near San Francisco County |
| Mendocino County, CA | 108 km (67 mi) | S of here | earthquakes near Mendocino County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
1 earthquake has been recorded within 50 km since this one.
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.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.