QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

113km W of Trinidad, CA

Yes. A magnitude 2.7 earthquake was recorded 113km W of Trinidad, CA, at 6:26 pm PDT on 29 April 2023 (01:26 UTC), 10 km deep.

· 10 km deep · released about 390 lb of TNT

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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 2.7 (md)
Depth
10 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1216 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 24 km (15 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.

How big was it?

This earthquake released about 390 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 39,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 28,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.5× the energy of this one
  4. This earthquake M 2.7 about 390 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

The largest earthquake within 50 km since 2016 was M 5.1 on 2017-07-29 — about 3,200 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 6.3 67 km W of Trinidad, California · 45 km E of this epicentre
  2. 5.8 near the coast of Northern California · 48 km ESE of this epicentre
  3. 5.6 71 km WNW of Samoa, California · 41 km E of this epicentre
  4. 5.3 71 km W of Trinidad, California · 42 km ENE 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 41.0303, -125.4835. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.1 80 km WNW of Ferndale, CA
  2. 2.8 67 km WNW of Bayview, CA
  3. 2.8 103 km WNW of Ferndale, CA
  4. 2.8 94 km W of Trinidad, CA
  5. 2.8 112 km W of Ferndale, CA
  6. 2.6 81 km WNW of Trinidad, CA
  7. 2.9 108 km WNW of Ferndale, CA
  8. 2.7 65 km WNW of Ferndale, CA
  9. 4.3 90 km W of Ferndale, CA
  10. 2.8 74 km WNW of Bayview, CA
  11. 3.3 83 km W of Trinidad, CA
  12. 4.5 74 km WNW of Ferndale, CA
  13. 3.6 146 km WNW of Trinidad, CA
  14. 2.9 106 km WNW of Trinidad, CA
  15. 2.9 90 km WNW of Bayview, 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.

On USGS

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