QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0ml

20 km S of Chenega, Alaska

Yes. A magnitude 2.0 earthquake was recorded 20 km S of Chenega, Alaska at 08:58 UTC on 2020-11-18, 11 km deep. 1 person has reported feeling it to USGS.

· 11 km deep · released about 30 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Chugach Census Area 118 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 2.0 (ml)
Depth
11 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Chugach Census Area, 118 km NE
Nearest mapped fault
Patton Bay fault, 14 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2170 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 11 km (7 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 30 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 350,000× the energy of this one
  3. Around the size people start to feel M 3.0 32× the energy of this one
  4. This earthquake M 2.0 about 30 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 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 25 km WSW of Chenega, Alaska · 30 km WNW of this epicentre
  2. 5.8 29 km NW of Chenega, Alaska · 48 km NNW of this epicentre
  3. 5.7 Southern Alaska · 23 km NE of this epicentre
  4. 5.7 23 km SSE of Chenega, Alaska · 3 km SE of this epicentre
  5. 5.7 43 km WSW of Chenega, Alaska · 41 km W 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 59.8816, -147.9545. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Chugach Census Area, AK 118 km (73 mi) NE earthquakes near Chugach Census Area

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

Aftershocks so far

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

  1. 1.9 14 km ESE of Chenega, Alaska
  2. 1.5 6 km E of Chenega, Alaska
  3. 1.8 9 km E of Chenega, Alaska
  4. 1.6 6 km ESE of Chenega, Alaska
  5. 1.5 30 km NNE of Chenega, Alaska
  6. 1.7 3 km E of Chenega, Alaska
  7. 2.2 26 km W of Chenega, Alaska
  8. 3.4 21 km WNW of Chenega, Alaska
  9. 2.2 4 km ESE of Chenega, Alaska
  10. 2.0 27 km S of Chenega, Alaska
  11. 2.0 26 km WSW of Chenega, Alaska
  12. 1.8 25 km SSW of Chenega, Alaska
  13. 1.9 15 km WSW of Chenega, Alaska
  14. 1.5 19 km S of Chenega, Alaska
  15. 1.5 15 km E of Chenega, Alaska

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.