M1.5 Earthquake near Nikiski, Alaska — 21 August 2026
A micro earthquake of magnitude 1.5 was recorded near Nikiski, Alaska on , with an epicentre 21 km north-northeast of Nikiski, at a focal depth of 73.7 km.
Time (UTC): 2026-08-21 00:51:46
Time (your timezone): —
Magnitude: 1.5 (micro)
Focal depth: 73.7 km (intermediate)
Epicentre: 60.8680, -151.1400
Location: 21 km NNE of Nikiski, Alaska
USGS link to NOAA tsunami information: Not linked
Review status: Reviewed
Source: USGS event page
How strong was this earthquake?
Micro earthquakes are almost never felt at the surface and are recorded only by seismographs.
A magnitude 1.5 earthquake radiates roughly 2.7 kg of TNT equivalent in seismic energy.
The USGS assigns this earthquake a significance score of 35, which is below the USGS threshold of more than 600 for its significant-earthquake list. The ranking combines magnitude with available Did You Feel It responses and PAGER alert level; it is not a direct measurement of damage.
Where was the epicentre?
The epicentre was located at 60.8680, -151.1400 — 21 km north-northeast of Nikiski. The closest other recorded event was a magnitude 2.2 earthquake 16 km east-northeast of here on 20 August 2026.
Why the 74 km depth matters
At 74 km this was an intermediate-depth earthquake. Energy from events at this depth spreads out before it reaches the surface, which usually means weaker shaking near the epicentre than a shallow quake of the same magnitude, but shaking felt across a wider area.
This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, events this small are usually detected by instruments rather than people. Its intermediate depth normally reduces peak shaking near the epicentre compared with a shallow event of the same magnitude.
What does the tsunami information flag mean?
The USGS record does not carry a link to NOAA tsunami information. That field is not an all-clear and does not state whether a tsunami occurred. In this case, a damaging tsunami would be less likely because at M1.5 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; it occurred inland rather than beneath the sea floor. For an active coastal alert, use tsunami.gov or your local warning authority.
How earthquakes generate tsunamis, and what the alert levels mean →
Aftershocks and local seismic history
1 further earthquakes have been recorded within about 150 km of the epicentre in the 6 hours since this event, the largest of them magnitude 1.3.
41 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.0 event near Susitna on 27 November 2025. This M1.5 event released about 5.6 million times less energy than that event.
How long aftershock sequences last, and how large they get →
Where this event sits in the record
This earthquake is part of the August 2026 worldwide record. Browse the full monthly archive to compare periods.
Nearest recorded earthquakes to this epicentre
- M2.2 earthquake near Point Possession, Alaska — (16 km ENE)
- M1.4 earthquake near Nikiski, Alaska — (35 km W)
- M1.3 earthquake near Tyonek, Alaska — (48 km WNW)
- M1.4 earthquake near Tyonek, Alaska — (52 km WNW)
- M1.8 earthquake near Tyonek, Alaska — (53 km NW)
- M3.0 earthquake near Point Possession, Alaska — (54 km ESE)
- M1.6 earthquake near Kalifornsky, Alaska — (61 km SW)
- M1.7 earthquake near Cohoe, Alaska — (62 km SSW)
- M2.2 earthquake near Cohoe, Alaska — (62 km SW)
- M1.9 earthquake near Cooper Landing, Alaska — (68 km SE)
Other magnitude 1 earthquakes worldwide
- M1.8 earthquake near Nanwalek, Alaska —
- M1.3 earthquake near Susitna North, Alaska —
- M1.3 earthquake near Cobb, CA —
- M1.6 earthquake near Chenega, Alaska —
- M1.8 earthquake near Nanwalek, Alaska —
- M1.5 earthquake near Carlsbad —
- M1.7 earthquake near Volcano, Hawaii —
- M1.7 earthquake near Cloverdale, CA —
Questions about this earthquake
How strong is a magnitude 1.5 earthquake?
Micro earthquakes are almost never felt at the surface and are recorded only by seismographs. A magnitude 1.5 earthquake radiates roughly 2.7 kg of TNT equivalent in seismic energy.
How deep was the earthquake near Nikiski?
At 74 km this was an intermediate-depth earthquake. Energy from events at this depth spreads out before it reaches the surface, which usually means weaker shaking near the epicentre than a shallow quake of the same magnitude, but shaking felt across a wider area.
Was the M1.5 earthquake near Nikiski felt?
This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, events this small are usually detected by instruments rather than people. Its intermediate depth normally reduces peak shaking near the epicentre compared with a shallow event of the same magnitude.
What does the USGS tsunami field mean for this event?
The USGS record does not carry a link to NOAA tsunami information. That field is not an all-clear and does not state whether a tsunami occurred. In this case, a damaging tsunami would be less likely because at M1.5 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; it occurred inland rather than beneath the sea floor. For an active coastal alert, use tsunami.gov or your local warning authority.
Have there been aftershocks?
1 further earthquakes have been recorded within about 150 km of the epicentre in the 6 hours since this event, the largest of them magnitude 1.3.
How often do earthquakes happen near Nikiski?
41 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.0 event near Susitna on 27 November 2025. This M1.5 event released about 5.6 million times less energy than that event.