Earthquake · reviewed by a seismologist
M 1.9ml
Earthquake near Sanbornton, NH
USGS: 4 km WNW of Sanbornton, New Hampshire
59 km (37 mi) NNW of Manchester, NH · 138 km (86 mi) NNW of Boston, MA
- When
- 8:59 pm EST on 21 November 2018 ()
- Where
- 4 km (3 mi) WNW of Sanbornton, NH · earthquakes near Sanbornton
- Magnitude
- M 1.9 (ml)
- Depth
- 5.0 km below the surface
- Felt
- 3 reports · strongest reported intensity II
- Nearest
- Belknap County, 17 km E
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 613 days ago
A magnitude 1.9 earthquake was recorded 4 km (3 mi) WNW of Sanbornton, NH, at 8:59 pm EST on 21 November 2018 (01:59 UTC). 3 people have reported feeling it to USGS. This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Hill, Franklin, Tilton-Northfield, Tilton, Northfield, Bristol.
How big was it?
This earthquake released about 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
- Magna, Utah 2020 M 5.7 500,000× the energy of this one
- Around the size people start to feel M 3.0 45× the energy of this one
- This earthquake M 1.9 about 21 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 one earthquake of M5 or more within 50 km:
- 5.3 8 km W of Tamworth, New Hampshire · 46 km NNE 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 43.5000, -71.6305. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Belknap County, NH | 17 km (10 mi) | E | earthquakes near Belknap County |
| Merrimack County, NH | 23 km (14 mi) | S | earthquakes near Merrimack County |
| Sullivan County, NH | 50 km (31 mi) | WSW | earthquakes near Sullivan County |
| Grafton County, NH | 50 km (31 mi) | NNW | earthquakes near Grafton County |
| Strafford County, NH | 53 km (33 mi) | ESE | earthquakes near Strafford County |
| Carroll County, NH | 53 km (33 mi) | NE | earthquakes near Carroll County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
30 earthquakes have been recorded within 50 km since this one.
- 1.6 2 km SW of Center Sandwich, New Hampshire
- 1.9 2 km N of Webster, New Hampshire
- 1.9 4 km ESE of Northfield, New Hampshire
- 1.5 5 km SSE of Boscawen, New Hampshire
- 1.5 6 km SE of New Hampton, New Hampshire
- 2.0 5 km S of Alton, New Hampshire
- 1.6 2 km S of Henniker, New Hampshire
- 2.2 4 km NW of Gilford, New Hampshire
- 2.0 2 km WNW of Loudon, New Hampshire
- 2.7 5 km SW of Chichester, New Hampshire
- 2.2 1 km W of Andover, New Hampshire
- 1.8 3 km SW of Center Sandwich, New Hampshire
- 2.9 4 km SW of Center Sandwich, New Hampshire
- 2.1 4 km SE of Warner, New Hampshire
- 1.9 0 km SW of Bow Bog, New Hampshire
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.