QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

21 km NE of Big Bend, CA

· 4.8 km deep · released about 10 lb of TNT

10 km30 km60 km120 km N Shasta County 51 kmSiskiyou County 81 kmModoc County 98 kmLassen County 107 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
Magnitude
M 1.7 (md)
Depth
4.8 km below the surface
Felt
no reports yet
Nearest
Shasta County, 51 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3 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 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.

  1. Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 95× the energy of this one
  4. 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.

Where

Epicentre 41.1610, -121.7487. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Shasta County, CA 51 km (32 mi) NNE of here earthquakes near Shasta County
Siskiyou County, CA 81 km (50 mi) SE of here earthquakes near Siskiyou County
Modoc County, CA 98 km (61 mi) WSW of here earthquakes near Modoc County
Lassen County, CA 107 km (66 mi) WNW of here earthquakes near Lassen County
Tehama County, CA 122 km (76 mi) NNE of here earthquakes near Tehama County
Trinity County, CA 128 km (80 mi) ENE of here earthquakes near Trinity 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.

  1. 2.0 13 km SSW of Tennant, 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 5.0 on 2023-09-08 — it released about 92,000 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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