QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Seward, AK

No earthquake was likely felt in Seward in the 24 hours to 8:39 am AKST (17:39 UTC). The last one was M 4.3, 83 km (52 mi) W, at 2:30 am AKST on 1 November 2026, estimated intensity II (weak) in town; 115 felt reports to USGS. Every earthquake near Seward

This page: a magnitude 1.5 earthquake was recorded 49 km (31 mi) east-southeast of Seward, AK, at 8:29 am AKDT on 20 April 2022 (16:29 UTC), 6.6 km deep.

USGS: 37 km WSW of Chenega, Alaska

8:29 am AKDT, Apr 20, 2022 · · 6.6 km deep · released about 5.4 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
8:29 am AKDT on 20 April 2022 ()
Where
49 km (31 mi) east-southeast of Seward, AK · earthquakes near Seward
Magnitude
M 1.5 (ml)
Depth
6.6 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1611 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 8 km (5 mi) from the epicentre. In Seward, 49 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 12 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 37 km SSE of Lowell Point, Alaska · 38 km WSW of this epicentre
  2. 6.1 25 km WSW of Chenega, Alaska · 13 km ENE of this epicentre
  3. 6.0 54 km SE of Lowell Point, Alaska · 30 km SSW of this epicentre
  4. 5.9 33 km SSE of Lowell Point, Alaska · 34 km WSW of this epicentre
  5. 5.8 29 km NW of Chenega, Alaska · 38 km NNE 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 59.9269, -148.6328. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.2 Kenai Peninsula, Alaska
  2. 2.0 20 km SSW of Chenega, Alaska
  3. 2.0 37 km WSW of Chenega, Alaska
  4. 2.0 Kenai Peninsula, Alaska
  5. 1.5 21 km SE of Lowell Point, Alaska
  6. 1.5 57 km SE of Lowell Point, Alaska
  7. 3.4 Kenai Peninsula, Alaska
  8. 1.5 55 km SE of Lowell Point, Alaska
  9. 1.5 27 km W of Chenega, Alaska
  10. 1.5 23 km WSW of Chenega, Alaska
  11. 1.9 17 km SE of Primrose, Alaska
  12. 1.7 18 km ESE of Lowell Point, Alaska
  13. 1.9 25 km SSW of Chenega, Alaska
  14. 1.6 Kenai Peninsula, Alaska
  15. 1.6 Kenai Peninsula, 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.