Earthquake · reviewed by a seismologist
M 2.4md
5km SE of Portola Valley, CA
- When
- Magnitude
- M 2.4 (md)
- Depth
- 10 km below the surface
- Felt
- 12 reports · strongest reported intensity III
- Nearest
- San Mateo County, 16 km WNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1868 days ago
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 12 people have reported feeling it to USGS.
How big was it?
This earthquake released about 110 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
- Magna, Utah 2020 M 5.7 95,000× the energy of this one
- Around the size people start to feel M 3.0 8.5× the energy of this one
- This earthquake M 2.4 about 110 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 37.3510, -122.2030. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| San Mateo County, CA | 16 km (10 mi) | ESE of here | earthquakes near San Mateo County |
| Santa Cruz County, CA | 41 km (26 mi) | NNW of here | earthquakes near Santa Cruz County |
| Alameda County, CA | 42 km (26 mi) | SW of here | earthquakes near Alameda County |
| Santa Clara County, CA | 48 km (30 mi) | WNW of here | earthquakes near Santa Clara County |
| Contra Costa County, CA | 67 km (42 mi) | SSW of here | earthquakes near Contra Costa County |
| San Francisco County, CA | 84 km (52 mi) | ESE of here | earthquakes near San Francisco County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
53 earthquakes have been recorded within 50 km since this one.
- 2.0 5km E of Fremont, CA
- 1.6 6km N of San Leandro, CA
- 1.5 2km SW of San Francisco Zoo, CA
- 2.6 8km ENE of Alum Rock, CA
- 1.6 4km ENE of Burlingame, CA
- 1.6 10km NE of Milpitas, CA
- 1.6 9km SE of Sunol, CA
- 2.8 16km SSE of Livermore, CA
- 1.6 3km W of Fruitdale, CA
- 1.5 11km WSW of Saratoga, CA
- 1.6 11km WSW of Saratoga, CA
- 1.7 11km WSW of Saratoga, CA
- 2.5 16km SSW of Bonny Doon, CA
- 1.6 12km W of Saratoga, CA
- 1.6 4km SSW of San Francisco Zoo, 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 4.1 on 2017-10-10 — it released about 370 times the energy of this one.
From the QuakeIndex catalogue, built from the USGS FDSN event service.
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.