QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

69 km W of Happy Valley, Alaska

Yes. A magnitude 1.7 earthquake was recorded 69 km W of Happy Valley, Alaska, at 7:52 pm AKDT on 12 August 2019 (03:52 UTC), 101 km deep.

· 101 km deep · released about 11 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kenai Peninsula Borough 51 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
Magnitude
M 1.7 (ml)
Depth
101 km below the surface
Felt
no reports yet
Nearest
Kenai Peninsula Borough, 51 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2621 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. 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 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 5.6 on 2018-11-21 — about 710,000 times the energy of this one.

Before 2016, the USGS record lists 27 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 75 km WNW of Ninilchik, Alaska · 28 km N of this epicentre
  2. 6.4 52 km ENE of Pedro Bay, Alaska · 20 km SW of this epicentre
  3. 6.2 70 km E of Port Alsworth, Alaska · 14 km NNW of this epicentre
  4. 6.1 73 km WNW of Ninilchik, Alaska · 39 km NNE of this epicentre
  5. 6.0 53 km W of Anchor Point, Alaska · 27 km SSE 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 60.0346, -152.9579. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kenai Peninsula Borough, AK 51 km (32 mi) NE earthquakes near Kenai Peninsula Borough

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. 1.9 55 km W of Anchor Point, Alaska
  2. 2.1 47 km W of Anchor Point, Alaska
  3. 1.7 59 km W of Anchor Point, Alaska
  4. 2.0 38 km WSW of Anchor Point, Alaska
  5. 1.5 62 km ENE of Pedro Bay, Alaska
  6. 2.6 57 km NW of Ninilchik, Alaska
  7. 1.7 72 km E of Port Alsworth, Alaska
  8. 1.6 52 km E of Pedro Bay, Alaska
  9. 2.3 49 km E of Pedro Bay, Alaska
  10. 1.5 65 km E of Port Alsworth, Alaska
  11. 1.5 48 km WNW of Ninilchik, Alaska
  12. 1.6 69 km ENE of Pedro Bay, Alaska
  13. 1.8 58 km E of Port Alsworth, Alaska
  14. 1.5 48 km E of Pedro Bay, Alaska
  15. 1.9 48 km NE of Pedro Bay, 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.