M 7.8 earthquake – 2020 Perryville, Alaska Earthquake
·
Local time: Jul 21, 2020 · 22:12 (UTC-8)
MajorShallow · 28 kmPAGER greenTsunami information issued
Reviewed by a seismologist
Loading the map…
- Magnitude
- 7.8moment magnitude (mww)
- Depth
- 28 kmShallow earthquake
- Epicenter
- 55.072, -158.596852 km from Anchorage
- Energy released
- 7.6 megatons of TNTabout 504 × Hiroshima
- Felt reports
- 195"Did You Feel It?" responses
- Shaking intensity
- 6.5max. instrumental (MMI)
- Aftershocks
- 500M2.5+ within 218 km, up to 60 days
- Significance
- 1,113USGS score, 0–1,000+
The strongest here since 1938
The last earthquake at least as strong within 300 km struck on Nov 10, 1938.
How strong was it?
Major earthquake. It released 7.6 megatons of TNT, 15,849 times the energy of a magnitude 5.0. Bars use the magnitude scale: every step is about 32 times more energy.
Aftershocks
500 earthquakes of M2.5+ within 218 km in the 60 days after.
- 6.1 101 km ESE of Sand Point, Alaska Jul 22, 2020
- 5.6 122 km ESE of Sand Point, Alaska Jul 22, 2020
- 4.5 126 km SSE of Perryville, Alaska Jul 22, 2020
- 2.8 72 km SSE of Sand Point, Alaska Jul 22, 2020
- 4.0 127 km SE of Sand Point, Alaska Jul 22, 2020
- 3.1 95 km SSW of Sand Point, Alaska Jul 22, 2020
- 4.2 113 km ESE of Sand Point, Alaska Jul 22, 2020
- 4.0 6 km SSE of Ivanof Bay, Alaska Jul 22, 2020
- 4.0 95 km SSE of Perryville, Alaska Jul 22, 2020
- 3.2 60 km S of Sand Point, Alaska Jul 22, 2020
The strongest earthquakes within 300 km
Since 1900.
- 8.2 1938 Semidi Islands, Alaska Earthquake Nov 10, 1938
- 8.2 2021 Chignik, Alaska Earthquake Jul 29, 2021
- 7.6 2020 Sand Point, Alaska Earthquake Oct 19, 2020
- 7.4 54 km SE of Sand Point, Alaska May 31, 1917
- 7.3 2025 Sand Point, Alaska Earthquake Jul 16, 2025
- 7.2 2023 Sand Point, Alaska Earthquake Jul 16, 2023
- 7.1 90 km SE of King Cove, Alaska May 14, 1948
- 7.0 71 km SE of King Cove, Alaska May 30, 1991
In the week before
Earthquakes within 218 km in the 7 days before this one: possible foreshocks.