QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Akutan, AK

No earthquake was likely felt in Akutan in the 24 hours to 1:30 pm AKST (22:30 UTC). The last one was M 4.4, 84 km (52 mi) SE, at 3:00 pm AKST on 11 November 2026, estimated intensity II (weak) in town. Every earthquake near Akutan

This page: a magnitude 1.8 earthquake was recorded 46 km (29 mi) south of Akutan, AK, at 3:36 am AKST on 18 February 2017 (12:36 UTC), 59 km deep.

USGS: 46 km S of Akutan, Alaska

3:36 am AKST, Feb 18, 2017 · · 59 km deep · released about 15 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
3:36 am AKST on 18 February 2017 ()
Where
46 km (29 mi) south of Akutan, AK · earthquakes near Akutan
Magnitude
M 1.8 (ml)
Depth
59 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1197 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In Akutan, 46 km away, the estimate is intensity I (not felt). 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 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 32,000 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 · 7 km N of this epicentre
  2. 6.4 50 km SE of Akutan, Alaska · 39 km ENE of this epicentre
  3. 6.2 57 km SE of Unalaska, Alaska · 22 km SSW of this epicentre
  4. 6.2 36 km ESE of Unalaska, Alaska · 18 km W of this epicentre
  5. 6.2 53 km S of Akutan, Alaska · 11 km ESE 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 53.7168, -165.7814. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.4 14 km W of Akutan, Alaska
  2. 1.8 75 km SSE of Akutan, Alaska
  3. 1.7 87 km SE of Unalaska, Alaska
  4. 2.3 75 km SSE of Akutan, Alaska
  5. 2.1 75 km SSE of Akutan, Alaska
  6. 2.0 45 km SE of Akutan, Alaska
  7. 1.6 68 km SE of Unalaska, Alaska
  8. 1.5 50 km SSE of Unalaska, Alaska
  9. 1.8 58 km SSE of Unalaska, Alaska
  10. 1.7 15 km E of Unalaska, Alaska
  11. 2.3 70 km SE of Unalaska, Alaska
  12. 1.9 59 km SE of Unalaska, Alaska
  13. 1.6 41 km S of Akutan, Alaska
  14. 2.2 29 km SSW of Akutan, Alaska
  15. 1.8 35 km SSW of Akutan, 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.