Earthquake · automatic estimate, may change
M 1.9ml
Earthquake near Nikiski, AK
No earthquake was likely felt in Nikiski in the 24 hours to 5:15 am AKST (14:15 UTC). The last one was M 4.3, 58 km (36 mi) SSE, at 2:30 am AKST on 1 November 2026, estimated intensity II (weak) in town; 115 felt reports to USGS. Every earthquake near Nikiski
This page: a magnitude 1.9 earthquake was recorded 40 km (25 mi) northeast of Nikiski, AK, at 5:51 am AKDT on 19 May 2021 (13:51 UTC), 3.3 km deep. The magnitude and location are an automatic first estimate and may change.
USGS: 8 km NW of Point Possession, Alaska
57 km (35 mi) WSW of Anchorage, AK
- When
- 5:51 am AKDT on 19 May 2021 ()
- Where
- 40 km (25 mi) northeast of Nikiski, AK · earthquakes near Nikiski
- Magnitude
- M 1.9 (ml)
- Depth
- 3.3 km below the surface
- Felt
- no reports yet
- Nearest
- Anchorage Municipality, 86 km ENE
- Status
- Automatic — a machine’s first estimate, which may change
USGS · last changed by USGS · we first saw it 1990 days ago
Earthquake alerts for Nikiski, AK
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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 14 km (9 mi) from the epicentre. In Nikiski, 40 km away, the estimate is intensity II (weak). 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 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
- Magna, Utah 2020 M 5.7 500,000× the energy of this one
- Around the size people start to feel M 3.0 45× the energy of this one
- This earthquake M 1.9 about 21 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 4.5 on 2018-10-15 — about 7,900 times the energy of this one.
Before 2016, the USGS record lists 19 earthquakes of M5 or more within 50 km; the five largest:
- 6.8 Southern Alaska · 21 km NW of this epicentre
- 6.8 4 km NE of Beluga, Alaska · 25 km NNW of this epicentre
- 6.8 24 km ENE of Sterling, Alaska · 42 km SSE of this epicentre
- 6.7 6 km WNW of Nikiski, Alaska · 42 km SW of this epicentre
- 6.4 19 km SSE of Tyonek, Alaska · 15 km WSW 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 60.9693, -150.8218. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Anchorage Municipality, AK | 86 km (53 mi) | ENE | earthquakes near Anchorage Municipality |
| Kenai Peninsula Borough, AK | 106 km (66 mi) | SW | earthquakes near Kenai Peninsula Borough |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
56 earthquakes have been recorded within 50 km since this one.
- 1.5 21 km NNE of Nikiski, Alaska
- 1.6 11 km SSW of Tyonek, Alaska
- 1.5 19 km NE of Point Possession, Alaska
- 1.6 14 km NNE of Ridgeway, Alaska
- 1.8 12 km W of Point Possession, Alaska
- 2.5 21 km SSE of Point Possession, Alaska
- 1.5 24 km SSW of Susitna, Alaska
- 1.8 2 km ESE of Beluga, Alaska
- 1.5 30 km ENE of Beluga, Alaska
- 1.5 8 km NNW of Ridgeway, Alaska
- 2.8 28 km WSW of Susitna, Alaska
- 1.6 26 km NE of Beluga, Alaska
- 1.5 14 km SSW of Tyonek, Alaska
- 1.6 13 km SW of Point Possession, Alaska
- 1.8 14 km SE of Point Possession, 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.