QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

8 km SE of South Portland, Maine

· 6.7 km deep · released about 43 lb of TNT

10 km30 km60 km120 km N Cumberland County 28 kmYork County 44 kmSagadahoc County 46 kmAndroscoggin County 65 kmLincoln County 70 kmStrafford County 77 kmCarroll County 88 kmKennebec County 98 kmRockingham County 100 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 2.1 (ml)
Depth
6.7 km below the surface
Felt
135 reports · strongest reported intensity IV
Nearest
Cumberland County, 28 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1698 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 135 people have reported feeling it to USGS.

How big was it?

This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 43.5824, -70.1738. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Cumberland County, ME 28 km (17 mi) SSE of here earthquakes near Cumberland County
York County, ME 44 km (27 mi) ENE of here earthquakes near York County
Sagadahoc County, ME 46 km (28 mi) SW of here earthquakes near Sagadahoc County
Androscoggin County, ME 65 km (40 mi) S of here earthquakes near Androscoggin County
Lincoln County, ME 70 km (44 mi) SW of here earthquakes near Lincoln County
Strafford County, NH 77 km (48 mi) ENE of here earthquakes near Strafford County

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

Aftershocks so far

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

  1. 1.8 2 km SW of Gray, Maine
  2. 1.9 8 km ENE of Lake Arrowhead, Maine
  3. 1.9 3 km WSW of Dayton, Maine
  4. 2.4 42 km SE of Old Orchard Beach, Maine
  5. 2.6 38 km SE of Old Orchard Beach, Maine

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.