Earthquake · reviewed by a seismologist
M 2.1ml
99 km SSE of Adak, Alaska
Yes. A magnitude 2.1 earthquake was recorded 99 km SSE of Adak, Alaska at 05:41 UTC on 2024-09-25, 13 km deep.
- When
- Magnitude
- M 2.1 (ml)
- Depth
- 13 km below the surface
- Felt
- no reports yet
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 744 days ago
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 11 km (7 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 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
- Magna, Utah 2020 M 5.7 250,000× the energy of this one
- Around the size people start to feel M 3.0 22× the energy of this one
- This earthquake M 2.1 about 43 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 2017-04-04 — about 180,000 times the energy of this one.
Before 2016, the USGS record lists 86 earthquakes of M5 or more within 50 km; the five largest:
- 7.1 75 km S of Adak, Alaska · 37 km NW of this epicentre
- 7.0 101 km S of Adak, Alaska · 4 km SW of this epicentre
- 6.8 90 km SSW of Adak, Alaska · 49 km WNW of this epicentre
- 6.7 76 km SSE of Adak, Alaska · 28 km NNE of this epicentre
- 6.6 85 km SSW of Adak, Alaska · 47 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 51.0006, -176.3022. Map © OpenStreetMap contributors.
Aftershocks so far
58 earthquakes have been recorded within 50 km since this one.
- 3.0 102 km SSE of Adak, Alaska
- 3.2 93 km SSE of Adak, Alaska
- 3.4 117 km SSE of Adak, Alaska
- 3.4 106 km SSE of Adak, Alaska
- 3.3 103 km SSE of Adak, Alaska
- 3.6 101 km SSE of Adak, Alaska
- 3.1 109 km SSE of Adak, Alaska
- 3.8 104 km SSE of Adak, Alaska
- 4.5 98 km SSE of Adak, Alaska
- 3.1 94 km SSE of Adak, Alaska
- 4.0 104 km SSE of Adak, Alaska
- 3.2 103 km SSE of Adak, Alaska
- 2.7 98 km SSE of Adak, Alaska
- 3.0 109 km SSE of Adak, Alaska
- 1.9 78 km SSE 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.