QuakeIndex

ice quake · reviewed by a seismologist

M 3.4ml

Earthquake near Juneau, AK

No earthquake was likely felt in Juneau in the 24 hours to 3:34 am AKST (12:34 UTC). The last one was M 7.0, 367 km (228 mi) NW, at 11:41 am AKST on 6 December 2025, estimated intensity III (weak) in town; 1,058 felt reports to USGS. Every earthquake near Juneau

No: USGS classifies this as a ice quake, not an earthquake. A magnitude 3.4 ice quake was recorded 46 km (28 mi) north-northwest of Juneau, AK, at 9:27 am AKST on 30 December 2016 (18:27 UTC), less than 1 km deep.

USGS: 45 km NNW of Juneau, Alaska

9:27 am AKST, Dec 30, 2016 · · 0.3 km deep · released about 1.9 tons of TNT

10 km30 km60 km120 km N Juneau City and Borough 48 kmHaines Borough 66 kmHoonah-Angoon Census Area 71 kmSkagway Municipality 104 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
9:27 am AKST on 30 December 2016 ()
Where
46 km (28 mi) north-northwest of Juneau, AK · earthquakes near Juneau
Magnitude
M 3.4 (ml)
Depth
0.3 km below the surface
Felt
no reports yet
Measured shaking
intensity IV (ShakeMap)
Nearest
Juneau City and Borough, 48 km SE
Nearest mapped fault
Denali fault, 20 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 1197 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 58 km (36 mi) from the epicentre. In Juneau, 46 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.

USGS catalogues this as ice quake, not an earthquake.

How big was it?

This earthquake released about 1.9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 89,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,800× the energy of this one
  4. This earthquake M 3.4 about 1.9 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4× 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.0 23 km SSE of Mud Bay, Alaska · 42 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 58.6716, -134.7691. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Juneau City and Borough, AK 48 km (30 mi) SE earthquakes near Juneau City and Borough
Haines Borough, AK 66 km (41 mi) NW earthquakes near Haines Borough
Hoonah-Angoon Census Area, AK 71 km (44 mi) WSW earthquakes near Hoonah-Angoon Census Area
Skagway Municipality, AK 104 km (65 mi) NNW earthquakes near Skagway Municipality

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. 1.5 40 km ESE of Mud Bay, Alaska
  2. 1.5 56 km N of Juneau, Alaska
  3. 1.5 18 km SE of Excursion Inlet, Alaska
  4. 3.1 59 km N of Juneau, Alaska
  5. 3.1 60 km ESE of Mud Bay, Alaska
  6. 2.2 52 km N of Juneau, Alaska
  7. 3.4 53 km N of Juneau, Alaska
  8. 1.8 37 km ESE of Mud Bay, Alaska
  9. 2.1 15 km N of Juneau, Alaska
  10. 1.8 58 km N of Juneau, Alaska
  11. 1.8 61 km N of Juneau, Alaska
  12. 2.0 25 km SSE of Mud Bay, Alaska
  13. 1.8 Southeastern Alaska
  14. 2.3 27 km SSE of Mud Bay, Alaska
  15. 1.8 49 km NNW of Juneau, 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.