QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

29 km NNE of Spencer, Idaho

Yes. A magnitude 1.6 earthquake was recorded 29 km NNE of Spencer, Idaho, at 4:42 pm MDT on 30 August 2019 (22:42 UTC), 2.7 km deep.

· 2.7 km deep · released about 6.6 lb of TNT

10 km30 km60 km120 km N Clark County 43 kmFremont County 62 kmMadison County 80 kmBeaverhead County 89 kmJefferson County 93 kmMadison County 96 kmTeton County 115 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
Idaho today
every earthquake in Idaho in the last 24 hours
Magnitude
M 1.6 (ml)
Depth
2.7 km below the surface
Felt
no reports yet
Nearest
Clark County, 43 km SW
Nearest mapped fault
Centennial 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 2630 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 10 km (6 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 6.6 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 2,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
  3. Around the size people start to feel M 3.0 140× the energy of this one
  4. This earthquake M 1.6 about 6.6 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

The largest earthquake within 50 km since 2016 was M 4.6 on 2019-04-09 — about 36,000 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 5.2 32 km WNW of Hebgen Lake Estates, Montana · 48 km NE of this epicentre
  2. 5.0 31 km W of Hebgen Lake Estates, Montana · 43 km ENE of this epicentre
  3. 5.0 39 km W of Hebgen Lake Estates, Montana · 31 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 44.6077, -112.0413. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Clark County, ID 43 km (27 mi) SW earthquakes near Clark County
Fremont County, ID 62 km (38 mi) SE earthquakes near Fremont County
Madison County, MT 80 km (50 mi) N earthquakes near Madison County
Beaverhead County, MT 89 km (55 mi) NW earthquakes near Beaverhead County
Jefferson County, ID 93 km (58 mi) SSW earthquakes near Jefferson County
Madison County, ID 96 km (60 mi) SSE earthquakes near Madison County

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

Aftershocks so far

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

  1. 1.9 6 km E of Lima, Montana
  2. 1.6 26 km W of Hebgen Lake Estates, Montana
  3. 1.8 43 km NE of Spencer, Idaho
  4. 1.6 36 km N of Spencer, Idaho
  5. 2.3 31 km SSE of Virginia City, Montana
  6. 2.2 42 km W of Hebgen Lake Estates, Montana
  7. 1.7 43 km NE of Spencer, Idaho
  8. 2.2 42 km NNE of Spencer, Idaho
  9. 1.8 43 km NE of Spencer, Idaho
  10. 1.9 43 km NE of Spencer, Idaho
  11. 1.7 47 km SSE of Virginia City, Montana
  12. 1.5 47 km SSE of Virginia City, Montana
  13. 1.9 29 km NNE of Spencer, Idaho
  14. 2.3 33 km SSE of Virginia City, Montana
  15. 2.4 Idaho-Montana border region

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.