Earthquake · automatic estimate, may change
M 1.5ml
49 km NE of Whittier, Alaska
Yes. A magnitude 1.5 earthquake was recorded 49 km NE of Whittier, Alaska, 100 km (62 mi) E of Anchorage, AK, at 4:03 am AKDT on 21 June 2021 (12:03 UTC), 20 km deep. The magnitude and location are an automatic first estimate and may change.
100 km (62 mi) E of Anchorage, AK
- When
- Magnitude
- M 1.5 (ml)
- Depth
- 20 km below the surface
- Felt
- no reports yet
- Nearest
- Anchorage Municipality, 66 km W
- Status
- Automatic — a machine’s first estimate, which may change
USGS · last changed by USGS · we first saw it 1949 days ago
Earthquake alerts for Girdwood, AK
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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.
How big was it?
This earthquake released about 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 19 earthquakes of M5 or more within 50 km; the five largest:
- 9.2 The 1964 Prince William Sound, Alaska Earthquake · 44 km ESE of this epicentre
- 6.8 31 km SSW of Glacier View, Alaska · 50 km NNE of this epicentre
- 6.6 57 km ENE of Whittier, Alaska · 18 km ESE of this epicentre
- 6.6 37 km WNW of Tatitlek, Alaska · 42 km E of this epicentre
- 6.4 22 km ENE of Whittier, Alaska · 30 km SSW 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 61.1001, -148.0566. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Anchorage Municipality, AK | 66 km (41 mi) | W | earthquakes near Anchorage Municipality |
| Chugach Census Area, AK | 121 km (75 mi) | ESE | earthquakes near Chugach Census Area |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
55 earthquakes have been recorded within 50 km since this one.
- 1.6 48 km ESE of Knik River, Alaska
- 2.6 50 km WSW of Tatitlek, Alaska
- 1.5 34 km SSE of Chickaloon, Alaska
- 1.6 41 km S of Glacier View, Alaska
- 1.5 60 km S of Glacier View, Alaska
- 1.5 62 km S of Glacier View, Alaska
- 1.5 55 km WSW of Tatitlek, Alaska
- 1.5 43 km S of Glacier View, Alaska
- 1.5 43 km NNE of Whittier, Alaska
- 1.6 30 km SE of Knik River, Alaska
- 1.5 45 km S of Glacier View, Alaska
- 1.7 35 km NNE of Whittier, Alaska
- 1.8 36 km NNE of Whittier, Alaska
- 1.5 59 km S of Glacier View, Alaska
- 1.6 52 km ESE of Knik River, 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.