Earthquake · reviewed by a seismologist
M 2.6ml
117 km SSE of Chignik, Alaska
Yes. A magnitude 2.6 earthquake was recorded 117 km SSE of Chignik, Alaska at 23:42 UTC on 2023-06-20, less than 1 km deep.
- When
- Magnitude
- M 2.6 (ml)
- Depth
- 0.1 km below the surface
- Felt
- no reports yet
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1175 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 23 km (14 mi) from the epicentre. 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 240 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 63,000× the energy of this one
- Magna, Utah 2020 M 5.7 45,000× the energy of this one
- Around the size people start to feel M 3.0 4× the energy of this one
- This earthquake M 2.6 about 240 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 8.2 on 2021-07-29 — about 250,000,000 times the energy of this one.
Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:
- 8.2 1938 Semidi Islands, Alaska Earthquake · 49 km WSW of this epicentre
- 6.9 105 km ESE of Perryville, Alaska · 16 km WNW of this epicentre
- 6.7 121 km SE of Chignik, Alaska · 22 km ENE of this epicentre
- 6.0 98 km ESE of Perryville, Alaska · 23 km WNW of this epicentre
- 5.2 116 km SE of Perryville, Alaska · 34 km SW 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 55.3743, -157.4895. Map © OpenStreetMap contributors.
Aftershocks so far
53 earthquakes have been recorded within 50 km since this one.
- 2.2 110 km SE of Chignik, Alaska
- 2.4 143 km SE of Perryville, Alaska
- 3.7 86 km SE of Chignik, Alaska
- 2.0 113 km SE of Perryville, Alaska
- 1.5 92 km SSE of Chignik, Alaska
- 1.8 89 km ESE of Perryville, Alaska
- 2.8 107 km SE of Perryville, Alaska
- 2.4 93 km SE of Chignik, Alaska
- 2.6 149 km SE of Perryville, Alaska
- 2.0 158 km SE of Perryville, Alaska
- 4.7 143 km SE of Perryville, Alaska
- 3.5 141 km SE of Perryville, Alaska
- 2.9 129 km SE of Chignik, Alaska
- 2.1 123 km SE of Perryville, Alaska
- 2.5 115 km SE of Perryville, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.