QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

31 km E of Tennant, CA

Yes. A magnitude 1.8 earthquake was recorded 31 km E of Tennant, CA, at 10:33 am PDT on 15 July 2026 (17:33 UTC), 1.4 km deep.

· 1.4 km deep · released about 17 lb of TNT

10 km30 km60 km120 km N Modoc County 69 kmSiskiyou County 82 kmShasta County 103 kmKlamath County 120 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 1.8 (md)
Depth
1.4 km below the surface
Felt
no reports yet
Nearest
Modoc County, 69 km E
Nearest mapped fault
Mayfield fault, 20 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 108 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 14 km (9 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 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 640,000× the energy of this one
  3. Around the size people start to feel M 3.0 57× the energy of this one
  4. This earthquake M 1.8 about 17 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 since 1900 lists no earthquake of M5 or more within 50 km.

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 41.6102, -121.5462. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Modoc County, CA 69 km (43 mi) E earthquakes near Modoc County
Siskiyou County, CA 82 km (51 mi) W earthquakes near Siskiyou County
Shasta County, CA 103 km (64 mi) SSW earthquakes near Shasta County
Klamath County, OR 120 km (74 mi) N earthquakes near Klamath County
Lassen County, CA 126 km (78 mi) SE earthquakes near Lassen County
Jackson County, OR 129 km (80 mi) NW earthquakes near Jackson County

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

Aftershocks so far

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

  1. 2.0 13 km SSW of Tennant, CA
  2. 2.1 5 km SSW of Merrill, Oregon
  3. 1.6 25 km NW of McArthur, 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.