QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9mwr

Earthquake near Broken Bow, NE

No earthquake was likely felt in Broken Bow in the 24 hours to 12:17 am CST (06:17 UTC). The last one was M 5.0, 622 km (387 mi) S, at 5:21 am CDT on 23 July 2026, estimated intensity II (weak) in town; 499 felt reports to USGS. Every earthquake near Broken Bow

This page: a magnitude 3.9 earthquake was recorded 41 km (26 mi) west of Broken Bow, NE, at 3:42 am CDT on 1 July 2018 (08:42 UTC), 5.0 km deep. 41 people have reported feeling it to USGS.

USGS: 8 km SE of Arnold, Nebraska

3:42 am CDT, Jul 1, 2018 · · 5.0 km deep · released about 11 tons of TNT

Every earthquake near Broken Bow Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Logan County 33 kmCuster County 34 kmDawson County 61 kmLincoln County 62 kmThomas County 64 kmBlaine County 65 kmLoup County 79 kmMcPherson County 89 kmFrontier County 95 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
3:42 am CDT on 1 July 2018 ()
Where
41 km (26 mi) west of Broken Bow, NE · earthquakes near Broken Bow
Magnitude
M 3.9 (mwr)
Depth
5.0 km below the surface
Felt
41 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Nearest
Logan County, 33 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2974 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 431 km (268 mi) from the epicentre. In Broken Bow, 41 km away, the estimate is intensity III (weak). 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.

Likely felt in: Broken Bow 41 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× more

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 4.1 on 2018-06-30 — about 2 times the energy of this one.

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 41.3603, -100.1290. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Logan County, NE 33 km (21 mi) NW earthquakes near Logan County
Custer County, NE 34 km (21 mi) E earthquakes near Custer County
Dawson County, NE 61 km (38 mi) SSE earthquakes near Dawson County
Lincoln County, NE 62 km (39 mi) WSW earthquakes near Lincoln County
Thomas County, NE 64 km (40 mi) NNW earthquakes near Thomas County
Blaine County, NE 65 km (40 mi) N earthquakes near Blaine County

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

Aftershocks so far

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

  1. 3.0 10 km S of Arnold, Nebraska
  2. 2.1 5 km S of Arnold, Nebraska
  3. 2.6 8 km SE of Arnold, Nebraska
  4. 2.5 13 km WNW of Callaway, Nebraska
  5. 2.6 7 km WSW of Arnold, Nebraska
  6. 2.6 6 km SE of Arnold, Nebraska
  7. 2.7 4 km E of Arnold, Nebraska
  8. 3.6 7 km SE of Arnold, Nebraska
  9. 2.0 4 km SE of Arnold, Nebraska
  10. 2.8 11 km SE of Arnold, Nebraska
  11. 2.4 7 km S of Arnold, Nebraska
  12. 2.4 8 km SSE of Arnold, Nebraska
  13. 3.6 5 km ESE of Arnold, Nebraska
  14. 2.7 8 km SE of Arnold, Nebraska
  15. 3.8 2 km SE of Arnold, Nebraska

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.