QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

1 km S of Boxborough, Massachusetts

· 5.3 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Middlesex County 11 kmWorcester County 38 kmNorfolk County 44 kmSuffolk County 45 kmHillsborough County 51 kmEssex County 58 kmRockingham County 67 kmProvidence County 67 kmCheshire County 77 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
Magnitude
M 1.8 (ml)
Depth
5.3 km below the surface
Felt
30 reports · strongest reported intensity III
Nearest
Middlesex County, 11 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1376 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 30 people have reported feeling it to USGS.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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.

Where

Epicentre 42.4754, -71.5301. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Middlesex County, MA 11 km (7 mi) W of here earthquakes near Middlesex County
Worcester County, MA 38 km (24 mi) ENE of here earthquakes near Worcester County
Norfolk County, MA 44 km (28 mi) NW of here earthquakes near Norfolk County
Suffolk County, MA 45 km (28 mi) WNW of here earthquakes near Suffolk County
Hillsborough County, NH 51 km (32 mi) SSE of here earthquakes near Hillsborough County
Essex County, MA 58 km (36 mi) WSW of here earthquakes near Essex County

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

Aftershocks so far

6 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. 1.5 3 km SSW of Westminster, Massachusetts
  4. 1.8 4 km ENE of Hubbardston, Massachusetts
  5. 2.1 3 km SSW of Westminster, Massachusetts
  6. 1.7 3 km SW of Townsend, Massachusetts

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.