QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Ladera, CA

No earthquake was likely felt in Ladera in the 24 hours to 9:27 pm PST (05:27 UTC). The last one was M 2.0, 15 km (9 mi) SE, at 9:23 am PST on 10 November 2026, estimated intensity II (weak) in town; 4 felt reports to USGS. Every earthquake near Ladera

This page: a magnitude 1.6 earthquake was recorded in Ladera, CA, at 7:53 pm PDT on 9 August 2017 (02:53 UTC), 3.6 km deep.

USGS: 1 km N of Ladera, California

5 km (3 mi) WNW of Palo Alto, CA · 36 km (23 mi) WNW of San Jose, CA

7:53 pm PDT, Aug 9, 2017 · · 3.6 km deep · released about 8.4 lb of TNT

10 km30 km60 km120 km N San Mateo County 15 kmAlameda County 36 kmSanta Cruz County 47 kmSanta Clara County 50 kmContra Costa County 61 kmSan Francisco County 81 kmMarin County 86 kmSolano County 98 kmSan Joaquin County 100 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
7:53 pm PDT on 9 August 2017 ()
Where
in Ladera, CA · earthquakes near Ladera
Magnitude
M 1.6 (md)
Depth
3.6 km below the surface
Felt
no reports yet
Nearest
San Mateo County, 15 km W
Nearest mapped fault
Monte Vista-Shannon fault, 3 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 3373 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: Menlo Park 5 km, intensity II · Palo Alto 6 km, intensity II · Los Altos 8 km, intensity II · East Palo Alto 8 km, intensity II · Redwood City 9 km, intensity II · Mountain View 11 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 8.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 8.4 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 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.9 The 1906 San Francisco, California Earthquake · 49 km NW of this epicentre
  2. 6.2 Near San Jose, California · 37 km ESE of this epicentre
  3. 6.2 The 1984 Morgan Hill, California Earthquake · 47 km ESE of this epicentre
  4. 6.1 Near San Jose, California · 42 km ESE of this epicentre
  5. 5.8 7 km NNW of Boulder Creek, California · 25 km S 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 37.4113, -122.1983. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Mateo County, CA 15 km (10 mi) W earthquakes near San Mateo County
Alameda County, CA 36 km (23 mi) NE earthquakes near Alameda County
Santa Cruz County, CA 47 km (29 mi) SSE earthquakes near Santa Cruz County
Santa Clara County, CA 50 km (31 mi) ESE earthquakes near Santa Clara County
Contra Costa County, CA 61 km (38 mi) NNE earthquakes near Contra Costa County
San Francisco County, CA 81 km (51 mi) WNW earthquakes near San Francisco County

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

Aftershocks so far

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

  1. 1.6 12 km ESE of East Foothills, California
  2. 1.6 6 km NNW of Day Valley, California
  3. 2.5 19 km WNW of Davenport, California
  4. 2.3 2 km SSE of Dublin, California
  5. 2.6 15 km SSE of Livermore, California
  6. 1.6 0 km S of Los Altos Hills, California
  7. 2.9 15 km SSE of Livermore, California
  8. 2.3 15 km SSE of Livermore, California
  9. 1.7 11 km SSE of Livermore, California
  10. 1.9 6 km ENE of East Foothills, California
  11. 1.6 2 km W of Danville, California
  12. 1.5 2 km NNE of Millbrae, California
  13. 1.6 8 km WNW of Broadmoor, California
  14. 2.2 15 km E of Seven Trees, California
  15. 1.7 7 km E of East Foothills, 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.