Earthquake · reviewed by a seismologist
M 3.1mb_lg
9 km ENE of Anoka, Nebraska
- When
- Magnitude
- M 3.1 (mb_lg)
- Depth
- 5.0 km below the surface
- Felt
- 24 reports · strongest reported intensity IV
- Nearest
- Boyd County, 12 km SSW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1748 days ago
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 24 people have reported feeling it to USGS.
How big was it?
This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 250,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
- Magna, Utah 2020 M 5.7 7,900× the energy of this one
- This earthquake M 3.1 about 1,300 lb of TNT
- Around the size people start to feel M 3.0 this one released 1.4× 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.
Where
Epicentre 42.9962, -98.7287. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Boyd County, NE | 12 km (7 mi) | NNE of here | earthquakes near Boyd County |
| Charles Mix County, SD | 26 km (16 mi) | SSW of here | earthquakes near Charles Mix County |
| Gregory County, SD | 44 km (27 mi) | ESE of here | earthquakes near Gregory County |
| Douglas County, SD | 53 km (33 mi) | SW of here | earthquakes near Douglas County |
| Holt County, NE | 60 km (37 mi) | N of here | earthquakes near Holt County |
| Bon Homme County, SD | 69 km (43 mi) | W of here | earthquakes near Bon Homme 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.
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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.