QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Clarksville, Maryland

· 6.6 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Howard County 7 kmMontgomery County 21 kmDistrict of Columbia 32 kmBaltimore city 33 kmArlington County 37 kmFalls Church city 39 kmBaltimore County 41 kmCarroll County 41 kmAnne Arundel County 42 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
6.6 km below the surface
Felt
774 reports · strongest reported intensity IV
Nearest
Howard County, 7 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 985 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 774 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 39.1939, -76.9665. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Howard County, MD 7 km (5 mi) SSW of here earthquakes near Howard County
Montgomery County, MD 21 km (13 mi) ENE of here earthquakes near Montgomery County
District of Columbia, DC 32 km (20 mi) N of here earthquakes near District of Columbia
Baltimore city, MD 33 km (20 mi) WSW of here earthquakes near Baltimore city
Arlington County, VA 37 km (23 mi) NNE of here earthquakes near Arlington County
Falls Church city, VA 39 km (24 mi) NNE of here earthquakes near Falls Church city

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. 2.5 4 km E of Riverside, Maryland
  2. 1.8 1 km NE of Spencerville, Maryland
  3. 2.3 0 km WSW of Rockville, Maryland
  4. 2.0 4 km ESE of Sykesville, Maryland
  5. 1.7 0 km S of Woodlawn, Maryland

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.