QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9ml

Earthquake near Unalaska, AK

No earthquake was likely felt in Unalaska in the 24 hours to 6:07 pm AKST (03:07 UTC). The last one was M 4.4, 117 km (72 mi) ESE, at 3:00 pm AKST on 11 November 2026, estimated intensity II (weak) in town. Every earthquake near Unalaska

This page: a magnitude 2.9 earthquake was recorded 48 km (30 mi) southeast of Unalaska, AK, at 7:39 pm AKST on 4 January 2019 (04:39 UTC), 35 km deep.

USGS: 47 km SE of Unalaska, Alaska

7:39 pm AKST, Jan 4, 2019 · · 35 km deep · released about 680 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
7:39 pm AKST on 4 January 2019 ()
Where
48 km (30 mi) southeast of Unalaska, AK · earthquakes near Unalaska
Magnitude
M 2.9 (ml)
Depth
35 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2807 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 it was probably too small to be felt, even directly above it. In Unalaska, 48 km away, the estimate is intensity II (weak). 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 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.4× the energy of this one
  4. This earthquake M 2.9 about 680 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

The largest earthquake within 50 km since 2016 was M 4.8 on 2016-09-18 — about 710 times the energy of this one.

Before 2016, the USGS record lists 34 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.1 39 km S of Akutan, Alaska · 22 km NNE of this epicentre
  2. 6.2 57 km SE of Unalaska, Alaska · 10 km SSE of this epicentre
  3. 6.2 36 km ESE of Unalaska, Alaska · 13 km NNW of this epicentre
  4. 6.2 53 km S of Akutan, Alaska · 22 km ENE of this epicentre
  5. 6.1 90 km SE of Unalaska, Alaska · 46 km SSE 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 53.6144, -165.9560. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 1.6 53 km ESE of Unalaska, Alaska
  2. 2.8 13 km SSE of Unalaska, Alaska
  3. 2.6 40 km S of Akutan, Alaska
  4. 1.6 74 km SSE of Akutan, Alaska
  5. 2.7 64 km SE of Unalaska, Alaska
  6. 1.6 37 km SSE of Akutan, Alaska
  7. 3.0 46 km S of Akutan, Alaska
  8. 1.6 64 km SSE of Akutan, Alaska
  9. 1.8 71 km SE of Unalaska, Alaska
  10. 2.6 19 km ENE of Dutch Harbor, Alaska
  11. 2.5 53 km SE of Unalaska, Alaska
  12. 2.0 55 km SE of Unalaska, Alaska
  13. 2.0 76 km SE of Unalaska, Alaska
  14. 2.1 47 km SSE of Akutan, Alaska
  15. 3.0 67 km SE of Unalaska, 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.