Earthquake · reviewed by a seismologist
M 2.8ml
189 km S of Adak, Alaska
Yes. A magnitude 2.8 earthquake was recorded 189 km S of Adak, Alaska at 05:01 UTC on 2025-06-27, 10 km deep.
- When
- Magnitude
- M 2.8 (ml)
- Depth
- 10 km below the surface
- Felt
- no reports yet
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 435 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 25 km (16 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
- Magna, Utah 2020 M 5.7 22,000× the energy of this one
- Around the size people start to feel M 3.0 2× the energy of this one
- This earthquake M 2.8 about 480 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 5.4 on 2019-09-09 — about 7,900 times the energy of this one.
Before 2016, the USGS record lists 14 earthquakes of M5 or more within 50 km; the five largest:
- 6.5 184 km SSW of Adak, Alaska · 43 km WNW of this epicentre
- 6.4 146 km S of Adak, Alaska · 44 km NNE of this epicentre
- 6.2 204 km S of Adak, Alaska · 22 km SE of this epicentre
- 6.1 198 km S of Adak, Alaska · 11 km SSE of this epicentre
- 6.1 189 km S of Adak, Alaska · 3 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 50.1829, -176.9891. Map © OpenStreetMap contributors.
Aftershocks so far
20 earthquakes have been recorded within 50 km since this one.
- 3.1 222 km S of Adak, Alaska
- 2.6 200 km S of Adak, Alaska
- 3.2 176 km S of Adak, Alaska
- 2.2 156 km S 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
- 2.7 143 km S of Adak, Alaska
- 2.9 191 km S of Adak, Alaska
- 2.6 171 km S of Adak, Alaska
- 2.7 220 km SSW of Adak, Alaska
- 2.7 172 km SSW of Adak, Alaska
- 2.4 185 km S of Adak, Alaska
- 2.4 169 km SSW of Adak, Alaska
- 2.5 182 km S 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.