QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Kenai, AK

No earthquake was likely felt in Kenai in the 24 hours to 5:14 am AKST (14:14 UTC). The last one was M 4.3, 43 km (27 mi) SSE, at 2:30 am AKST on 1 November 2026, estimated intensity II (weak) in town; 115 felt reports to USGS. Every earthquake near Kenai

This page: a magnitude 1.7 earthquake was recorded in Kenai, AK, at 8:58 pm AKDT on 21 September 2018 (04:58 UTC), 68 km deep.

USGS: 1 km NNE of Kenai, Alaska

8:58 pm AKDT, Sep 21, 2018 · · 68 km deep · released about 11 lb of TNT

Every earthquake near Kenai Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kenai Peninsula Borough 63 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
8:58 pm AKDT on 21 September 2018 ()
Where
in Kenai, AK · earthquakes near Kenai
Magnitude
M 1.7 (ml)
Depth
68 km below the surface
Felt
no reports yet
Nearest
Kenai Peninsula Borough, 63 km WSW
Nearest mapped fault
Middle Ground Shoal anticline (Cook Inlet folds), 18 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 1185 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.

Earthquakes near other towns within 30 km: Ridgeway, Soldotna, Nikiski, Kalifornsky, Cohoe, Sterling.

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 5.3 on 2017-05-07 — about 250,000 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 24 km ENE of Sterling, Alaska · 47 km ENE of this epicentre
  2. 6.7 6 km WNW of Nikiski, Alaska · 18 km NNW of this epicentre
  3. 6.4 19 km SSE of Tyonek, Alaska · 38 km NNE of this epicentre
  4. 6.0 31 km S of Funny River, Alaska · 50 km SE of this epicentre
  5. 5.7 19 km NNW of Nikiski, Alaska · 33 km NNW 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 60.5688, -151.2395. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kenai Peninsula Borough, AK 63 km (39 mi) WSW earthquakes near Kenai Peninsula Borough
Anchorage Municipality, AK 125 km (78 mi) ENE earthquakes near Anchorage Municipality

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

Aftershocks so far

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

  1. 1.6 9 km SW of Tyonek, Alaska
  2. 1.6 7 km SE of Soldotna, Alaska
  3. 2.2 13 km SE of Tyonek, Alaska
  4. 1.6 7 km WSW of Point Possession, Alaska
  5. 1.6 21 km ESE of Kasilof, Alaska
  6. 1.6 20 km W of Cohoe, Alaska
  7. 1.5 4 km ESE of Salamatof, Alaska
  8. 1.5 19 km SE of Kasilof, Alaska
  9. 1.6 16 km SSE of Soldotna, Alaska
  10. 2.1 23 km W of Salamatof, Alaska
  11. 1.5 8 km WNW of Point Possession, Alaska
  12. 1.8 21 km WSW of Point Possession, Alaska
  13. 1.8 10 km S of Tyonek, Alaska
  14. 1.8 5 km N of Clam Gulch, Alaska
  15. 1.9 2 km N of Kenai, 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.