Earthquake · reviewed by a seismologist
M 2.7ml
165 km SSW of Adak, Alaska
Yes. A magnitude 2.7 earthquake was recorded 165 km SSW of Adak, Alaska at 17:08 UTC on 2025-08-05, 38 km deep.
- When
- Magnitude
- M 2.7 (ml)
- Depth
- 38 km below the surface
- Felt
- no reports yet
- Nearest mapped fault
- Alaska-Aleutian subduction zone, 3 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 392 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 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 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
- Magna, Utah 2020 M 5.7 32,000× the energy of this one
- Around the size people start to feel M 3.0 2.8× the energy of this one
- This earthquake M 2.7 about 340 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 6.1 on 2024-12-09 — about 130,000 times the energy of this one.
Before 2016, the USGS record lists 19 earthquakes of M5 or more within 50 km; the five largest:
- 6.5 184 km SSW of Adak, Alaska · 23 km SW of this epicentre
- 6.4 146 km S of Adak, Alaska · 35 km ENE of this epicentre
- 6.1 198 km S of Adak, Alaska · 46 km SE of this epicentre
- 6.1 189 km S of Adak, Alaska · 33 km SSE of this epicentre
- 6.0 130 km SSW of Adak, Alaska · 45 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 50.4384, -177.2761. Map © OpenStreetMap contributors.
Aftershocks so far
17 earthquakes have been recorded within 50 km since this one.
- 2.6 200 km S of Adak, Alaska
- 2.4 120 km SSW of Adak, Alaska
- 3.2 176 km S of Adak, Alaska
- 3.5 215 km SSW of Adak, Alaska
- 3.6 165 km SSW of Adak, Alaska
- 2.8 153 km S of Adak, Alaska
- 2.7 156 km S of Adak, Alaska
- 2.8 149 km S of Adak, Alaska
- 2.9 191 km S of Adak, Alaska
- 2.6 171 km S of Adak, Alaska
- 4.0 118 km SSW of Adak, Alaska
- 2.4 129 km S of Adak, Alaska
- 3.2 121 km SSW of Adak, Alaska
- 2.9 175 km SSW of Adak, Alaska
- 2.7 172 km SSW of Adak, 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.