QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Webster, NH

USGS: 4 km SSE of Webster, New Hampshire

40 km (25 mi) NNW of Manchester, NH · 120 km (75 mi) NNW of Boston, MA

11:53 pm EST, Feb 26, 2017 · · 8.9 km deep · released about 21 lb of TNT

10 km30 km60 km120 km N Merrimack County 2 kmBelknap County 34 kmHillsborough County 43 kmSullivan County 43 kmStrafford County 54 kmRockingham County 60 kmCheshire County 60 kmGrafton County 71 kmCarroll County 76 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
11:53 pm EST on 26 February 2017 ()
Where
4 km (3 mi) SSE of Webster, NH · earthquakes near Webster
Magnitude
M 1.9 (ml)
Depth
8.9 km below the surface
Felt
21 reports · strongest reported intensity III
Nearest
Merrimack County, 2 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2758 days ago

A magnitude 1.9 earthquake was recorded 4 km (3 mi) SSE of Webster, NH, at 11:53 pm EST on 26 February 2017 (04:53 UTC). 21 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: Boscawen, Contoocook, Salisbury, Hopkinton, Canterbury, East Concord.

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.

  1. Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 500,000× the energy of this one
  3. Around the size people start to feel M 3.0 45× the energy of this one
  4. 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 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 43.2939, -71.7038. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Merrimack County, NH 2 km (1 mi) ENE earthquakes near Merrimack County
Belknap County, NH 34 km (21 mi) NE earthquakes near Belknap County
Hillsborough County, NH 43 km (26 mi) S earthquakes near Hillsborough County
Sullivan County, NH 43 km (26 mi) W earthquakes near Sullivan County
Strafford County, NH 54 km (34 mi) E earthquakes near Strafford County
Rockingham County, NH 60 km (37 mi) SE earthquakes near Rockingham County

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

Aftershocks so far

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

  1. 1.5 2 km S of Bedford, New Hampshire
  2. 2.1 2 km NNW of Milford, New Hampshire
  3. 1.9 2 km N of Webster, New Hampshire
  4. 1.9 4 km ESE of Northfield, New Hampshire
  5. 1.5 5 km SSE of Boscawen, New Hampshire
  6. 1.5 6 km SE of New Hampton, New Hampshire
  7. 2.0 5 km S of Alton, New Hampshire
  8. 1.6 2 km S of Henniker, New Hampshire
  9. 2.2 4 km NW of Gilford, New Hampshire
  10. 2.0 2 km WNW of Loudon, New Hampshire
  11. 2.7 5 km SW of Chichester, New Hampshire
  12. 2.2 1 km W of Andover, New Hampshire
  13. 2.1 4 km SE of Warner, New Hampshire
  14. 1.9 0 km SW of Bow Bog, New Hampshire
  15. 1.9 5 km SW of New Durham, 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.