QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Skagway, AK

USGS: 10 km ENE of Klukwan, Alaska

2:45 pm AKDT, Jul 28, 2018 · · 16 km deep · released about 15 lb of TNT

Every earthquake near Skagway Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Skagway Municipality 25 kmHaines Borough 41 kmHoonah-Angoon Census Area 118 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
2:45 pm AKDT on 28 July 2018 ()
Where
23 km (14 mi) W of Skagway, AK · earthquakes near Skagway
Magnitude
M 1.8 (ml)
Depth
16 km below the surface
Felt
no reports yet
Nearest
Skagway Municipality, 25 km ENE
Nearest mapped fault
Denali fault, 11 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 1144 days ago

A magnitude 1.8 earthquake was recorded 23 km (14 mi) W of Skagway, AK, at 2:45 pm AKDT on 28 July 2018 (22:45 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Haines.

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

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. 5.5 27 km WSW of Covenant Life, Alaska · 45 km WSW 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 59.4584, -135.7245. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Skagway Municipality, AK 25 km (15 mi) ENE earthquakes near Skagway Municipality
Haines Borough, AK 41 km (25 mi) SSE earthquakes near Haines Borough
Hoonah-Angoon Census Area, AK 118 km (73 mi) S earthquakes near Hoonah-Angoon Census Area

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

Aftershocks so far

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

  1. 1.6 10 km SSW of Lutak, Alaska
  2. 1.7 10 km SSW of Lutak, Alaska
  3. 1.8 21 km N of Mosquito Lake, Alaska
  4. 1.9 19 km N of Mosquito Lake, Alaska
  5. 1.7 10 km NNE of Mosquito Lake, Alaska
  6. 2.0 38 km WSW of Haines, Alaska
  7. 1.5 37 km WSW of Haines, Alaska
  8. 2.0 35 km WSW of Mud Bay, Alaska
  9. 1.5 35 km WSW of Haines, Alaska
  10. 1.6 12 km NE of Mosquito Lake, Alaska
  11. 1.5 39 km SSW of Klukwan, Alaska
  12. 1.5 12 km NE of Mosquito Lake, Alaska
  13. 1.5 13 km NNE of Mosquito Lake, Alaska
  14. 1.7 29 km SSW of Covenant Life, Alaska
  15. 2.2 9 km W of Haines, 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.