QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2ml

120 km S of Sand Point, Alaska

Yes. A magnitude 3.2 earthquake was recorded 120 km S of Sand Point, Alaska, at 7:04 pm AKDT on 5 August 2020 (03:04 UTC), 35 km deep.

· 35 km deep · released about 1,900 lb of TNT

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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 3.2 (ml)
Depth
35 km below the surface
Felt
no reports yet
Nearest
Aleutians East Borough, 148 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2214 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 31 km (19 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 1,900 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 180,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 5,600× the energy of this one
  4. This earthquake M 3.2 about 1,900 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 2× more

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

The largest earthquake within 50 km since 2016 was M 5.8 on 2018-07-19 — about 7,900 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 101 km SSW of Sand Point, Alaska · 48 km WNW of this epicentre
  2. 5.9 131 km S of Sand Point, Alaska · 11 km SSE of this epicentre
  3. 5.7 100 km SSW of Sand Point, Alaska · 46 km NW of this epicentre
  4. 5.6 84 km S of Sand Point, Alaska · 42 km NNW of this epicentre
  5. 5.6 98 km SSW of Sand Point, Alaska · 47 km NW 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 54.2521, -160.4563. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aleutians East Borough, AK 148 km (92 mi) NW earthquakes near Aleutians East Borough

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

Aftershocks so far

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

  1. 2.4 106 km SSE of Sand Point, Alaska
  2. 2.8 115 km SSW of Sand Point, Alaska
  3. 1.7 113 km S of Sand Point, Alaska
  4. 1.6 94 km SSW of Sand Point, Alaska
  5. 1.9 75 km S of Sand Point, Alaska
  6. 1.8 76 km SSE of Sand Point, Alaska
  7. 3.0 106 km SSW of Sand Point, Alaska
  8. 2.0 114 km SSW of Sand Point, Alaska
  9. 2.1 120 km SSW of Sand Point, Alaska
  10. 1.7 104 km S of Sand Point, Alaska
  11. 1.6 80 km SSW of Sand Point, Alaska
  12. 2.0 102 km S of Sand Point, Alaska
  13. 1.5 86 km S of Sand Point, Alaska
  14. 1.8 94 km SSW of Sand Point, Alaska
  15. 2.0 95 km SSW of Sand Point, 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.