QuakeIndex

Earthquake · reviewed by a seismologist

M 4.7mwr

Earthquake near Sand Point, AK

No earthquake was likely felt in Sand Point in the 24 hours to 12:35 pm AKST (21:35 UTC). The last one was M 4.2, 99 km (61 mi) SE, at 10:44 pm AKDT on 22 October 2026, estimated intensity II (weak) in town. Every earthquake near Sand Point

This page: a magnitude 4.7 earthquake was recorded 42 km (26 mi) south-southeast of Sand Point, AK, at 10:11 am AKST on 23 December 2017 (19:11 UTC), 44 km deep. 1 person has reported feeling it to USGS.

USGS: 41 km SSE of Sand Point, Alaska

10:11 am AKST, Dec 23, 2017 · · 44 km deep · released about 170 tons of TNT

10 km30 km60 km120 km N Aleutians East Borough 109 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
10:11 am AKST on 23 December 2017 ()
Where
42 km (26 mi) south-southeast of Sand Point, AK · earthquakes near Sand Point
Magnitude
M 4.7 (mwr)
Depth
44 km below the surface
Felt
1 report · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
Nearest
Aleutians East Borough, 109 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1191 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 153 km (95 mi) from the epicentre. In Sand Point, 42 km away, the estimate is intensity III (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.

Likely felt in: Sand Point 42 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 170 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 1,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 45× the energy of this one
  3. Magna, Utah 2020 M 5.7 32× the energy of this one
  4. This earthquake M 4.7 about 170 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 350× 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

The largest earthquake within 50 km (31 mi) since our catalogue begins in 2016. The previous largest was M 4.1 on 2016-12-01.

Before 2016, the USGS record lists 35 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.4 54 km SE of Sand Point, Alaska · 31 km E of this epicentre
  2. 6.9 17 km S of Sand Point, Alaska · 24 km NNW of this epicentre
  3. 6.6 72 km SE of Sand Point, Alaska · 49 km E of this epicentre
  4. 6.3 68 km SE of Sand Point, Alaska · 46 km E of this epicentre
  5. 6.2 35 km S of Sand Point, Alaska · 11 km WNW 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 54.9689, -160.3611. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aleutians East Borough, AK 109 km (67 mi) WNW earthquakes near Aleutians East Borough

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

Aftershocks so far

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

  1. 2.8 59 km SSE of Sand Point, Alaska
  2. 1.9 48 km SE of Sand Point, Alaska
  3. 1.9 74 km SSE of Sand Point, Alaska
  4. 1.9 48 km SSE of Sand Point, Alaska
  5. 2.1 88 km S of Sand Point, Alaska
  6. 2.1 70 km SSW of Sand Point, Alaska
  7. 2.0 21 km S of Sand Point, Alaska
  8. 2.1 49 km SE of Sand Point, Alaska
  9. 2.0 65 km S of Sand Point, Alaska
  10. 1.7 75 km SSE of Sand Point, Alaska
  11. 2.1 38 km ESE of Sand Point, Alaska
  12. 1.9 71 km SSE of Sand Point, Alaska
  13. 3.2 84 km S of Sand Point, Alaska
  14. 1.9 59 km S of Sand Point, Alaska
  15. 2.8 58 km SSE of Sand Point, 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.