Earthquake · reviewed by a seismologist
M 1.7md
Earthquake near Ashland, CA
Yes. A magnitude 1.7 earthquake was recorded in Ashland, CA, at 4:04 pm PDT on 15 August 2016 (23:04 UTC), 5.5 km deep.
This was on 15 August 2016. The latest near Ashland: M 2.5 on 19 September 2026.
USGS: 1 km NNW of Ashland, California
11 km (7 mi) SE of Oakland, CA · in San Leandro, CA
- When
- 4:04 pm PDT on 15 August 2016 ()
- Where
- in Ashland, CA · earthquakes near Ashland
- Magnitude
- M 1.7 (md)
- Depth
- 5.5 km below the surface
- Felt
- no reports yet
- Nearest
- Alameda County, 19 km ESE
- Nearest mapped fault
- Hayward fault, under 1 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3532 days ago
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 11 km (7 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Likely felt in: Ashland in town, intensity II · Castro Valley 3 km, intensity II · San Leandro 4 km, intensity II · Cherryland 4 km, intensity II · San Lorenzo 4 km, intensity II · Hayward 6 km, intensity II · Fairview 7 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 10 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.
- Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
- Around the size people start to feel M 3.0 95× the energy of this one
- This earthquake M 1.7 about 10 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.
For this area
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:
- 7.9 The 1906 San Francisco, California Earthquake · 38 km W of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 34 km ENE of this epicentre
- 5.7 15 km NE of East Foothills, California · 46 km SE of this epicentre
- 5.5 6 km NNE of East Foothills, California · 43 km SE of this epicentre
- 5.4 9 km NE of Livermore, California · 37 km E of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 37.7105, -122.1188. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Alameda County, CA | 19 km (12 mi) | ESE | earthquakes near Alameda County |
| Contra Costa County, CA | 27 km (17 mi) | NNE | earthquakes near Contra Costa County |
| San Mateo County, CA | 40 km (25 mi) | SW | earthquakes near San Mateo County |
| Solano County, CA | 64 km (40 mi) | NNE | earthquakes near Solano County |
| Santa Clara County, CA | 66 km (41 mi) | SE | earthquakes near Santa Clara County |
| Marin County, CA | 67 km (42 mi) | NW | earthquakes near Marin County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
52 earthquakes have been recorded within 50 km since this one.
- 1.6 2 km S of Loyola, California
- 1.5 2 km N of Piedmont, California
- 2.1 6 km S of Sunol, California
- 2.2 7 km E of Blackhawk, California
- 1.8 10 km NW of Broadmoor, California
- 1.6 1 km ESE of Pacheco, California
- 1.5 5 km E of Alameda, California
- 1.5 5 km ENE of Chinatown, California
- 1.9 2 km ENE of Diablo, California
- 1.7 2 km S of Loyola, California
- 1.6 2 km SSW of Loyola, California
- 2.4 8 km NNE of East Foothills, California
- 1.6 5 km ESE of Piedmont, California
- 2.4 6 km WNW of Broadmoor, California
- 1.6 1 km NW of Ashland, California
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.