QuakeIndex

explosion · reviewed by a seismologist

M 1.7ml

Earthquake near Altamont, OR

USGS: 7 km W of Merrill, Oregon

2:52 pm PST, Feb 7, 2018 · · -1.6 km deep · released about 9.6 lb of TNT

10 km30 km60 km120 km N Klamath County 73 kmSiskiyou County 85 kmJackson County 92 kmModoc County 94 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
2:52 pm PST on 7 February 2018 ()
Where
20 km (12 mi) SSE of Altamont, OR · earthquakes near Altamont
Magnitude
M 1.7 (ml)
Depth
-1.6 km below the surface
Felt
no reports yet
Nearest
Klamath County, 73 km N
Nearest mapped fault
Klamath graben fault system, 2 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 3158 days ago

A magnitude 1.7 earthquake was recorded 20 km (12 mi) SSE of Altamont, OR, at 2:52 pm PST on 7 February 2018 (22:52 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Klamath Falls.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 9.6 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 1,600,000× 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 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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 3 earthquakes of M5 or more within 50 km:

  1. 6.0 27 km WNW of Klamath Falls, Oregon · 47 km NW of this epicentre
  2. 5.9 22 km WNW of Klamath Falls, Oregon · 42 km NW of this epicentre
  3. 5.1 20 km WNW of Klamath Falls, Oregon · 39 km NW 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 42.0300, -121.6895. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Klamath County, OR 73 km (45 mi) N earthquakes near Klamath County
Siskiyou County, CA 85 km (53 mi) SW earthquakes near Siskiyou County
Jackson County, OR 92 km (57 mi) WNW earthquakes near Jackson County
Modoc County, CA 94 km (58 mi) ESE earthquakes near Modoc County
Lake County, OR 136 km (85 mi) NE earthquakes near Lake County

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

Aftershocks so far

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

  1. 1.6 11 km NNW of Klamath Falls, Oregon
  2. 2.2 5 km W of Merrill, Oregon
  3. 1.6 23 km WSW of Klamath Falls, Oregon
  4. 1.6 25 km WNW of Klamath Falls, Oregon
  5. 1.8 16 km ESE of Dorris, California
  6. 2.5 6 km NW of Macdoel, CA
  7. 1.7 10 km NNW of Klamath Falls, Oregon
  8. 1.7 26 km WNW of Klamath Falls, Oregon
  9. 1.6 10 km WSW of Klamath Falls, Oregon
  10. 1.6 7 km WSW of Klamath Falls, Oregon
  11. 2.4 4 km E of Bonanza, Oregon
  12. 1.8 20 km NW of Macdoel, CA
  13. 1.9 6 km WSW of Klamath Falls, Oregon
  14. 2.1 5 km WSW of Klamath Falls, Oregon
  15. 1.6 9 km NNW of Klamath Falls, Oregon

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.