84 km SSW of Nikolski, Alaska
A magnitude 6.3 earthquake struck near 84 km SSW of Nikolski, Alaska on September 3, 2026 at 11:17 AM UTC. The event occurred at a depth of 35.0 km, releasing energy equivalent to 2.8 atomic bombs. This is classified as a Strong earthquake on the Richter magnitude scale. The hypocenter depth is categorized as Shallow (< 70 km). Shaking from this event may have been felt within an estimated radius of 247 km from the epicenter.
Magnitude Scale
Depth Gauge
Intensity
('III', 'Felt indoors; hanging objects swing.')
Impact Assessment
2 people reported feeling this earthquake through the USGS "Did You Feel It?" system.
USGS PAGER alert level: Green. This estimates the overall impact based on population exposure and shaking intensity.
This is a highly significant seismic event based on magnitude, felt reports, and estimated impact.
This earthquake has been reviewed and confirmed by USGS seismologists.
Nearby Earthquakes
| Mag | Place | Time |
|---|---|---|
| 4.0 | 188 km SW of Nikolski, Alaska | 2 days, 6 hours ago |
| 3.9 | 187 km SW of Nikolski, Alaska | 2 days, 6 hours ago |
| 4.0 | 187 km SW of Nikolski, Alaska | 2 days, 6 hours ago |
| 6.5 | 165 km W of Nikolski, Alaska | 2 days, 7 hours ago |
| 3.6 | 89 km SSW of Nikolski, Alaska | 1 week, 3 days ago |
Frequently Asked Questions
Yes. A magnitude 6.3 (Strong) earthquake was recorded near 84 km SSW of Nikolski, Alaska on September 03, 2026 at a depth of 35.0 km (shallow (< 70 km)).
The earthquake had a magnitude of 6.3, classified as "Strong" on the magnitude scale. It released energy equivalent to approximately 2.8 atomic bombs.
The earthquake occurred at a depth of 35.0 km, which is considered shallow (< 70 km). Shallow earthquakes typically cause stronger shaking near the epicenter.
A tsunami alert was associated with this magnitude 6.3 earthquake. Tsunamis can be generated when large, shallow earthquakes occur under or near the ocean floor with significant vertical displacement.
Earthquake depth (also called focal depth or hypocentral depth) is the vertical distance from the Earth's surface to where the earthquake rupture begins. Shallow earthquakes (0-70 km) tend to cause more surface damage, intermediate (70-300 km) are felt over wider areas, and deep earthquakes (300-700 km) rarely cause significant damage at the surface.
The Modified Mercalli Intensity (MMI) scale measures the effects of an earthquake at a specific location, ranging from I (not felt) to XII (total destruction). Unlike magnitude, which measures energy released at the source, MMI describes how strongly shaking is felt and what damage occurs at a given place.
The felt radius is the maximum distance from an earthquake's epicenter at which ground shaking can be perceived by people. It depends primarily on magnitude, depth, and local geology. A shallow M6.0 earthquake might be felt 300-500 km away, while a deep M6.0 might be felt over a wider but less intense area.
Earthquake energy is often expressed in TNT equivalents for intuitive comparison. A M5.0 earthquake releases energy equivalent to about 32,000 tons of TNT (a small nuclear weapon), while a M9.0 releases 32 billion tons of TNT — roughly 1,000 times more than the largest nuclear weapon ever detonated.
Tsunami generation requires three conditions: the earthquake must be large (typically M7.0+), shallow (under 100 km depth), and occur beneath or near the ocean floor with significant vertical displacement. Strike-slip faults rarely generate tsunamis because they move horizontally rather than vertically.