Alaska earthquakes

M3.4 earthquake 206 km ESE of Atka, Alaska

A magnitude 3.4 earthquake struck 206 km ESE of Atka, Alaska on Sun, Aug 16, 2020, 4:40 PM HADT (01:40 UTC), 21 km (13 mi) below the surface.

A larger quake followed: M3.8 183 km ESE of Atka, Alaska. This one was a foreshock.

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Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude
3.4 (ML, local (Richter)), minor
Magnitude from
USGS National Earthquake Information Center
Local time
UTC
2020-08-17 01:40:00 UTC
Depth
20.6 km (12.8 mi), shallow
Epicenter
51.434° N, 171.469° W
Region
Alaska
Tsunami flag
No
Status
Reviewed by a seismologist

Magnitude estimates

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.ScaleComputed byNotes
3.4ML, local (Richter)USGS National Earthquake Information CenterPreferred · Reviewed · ±0.105 · 12 stations
2.8ML, local (Richter)Alaska Earthquake CenterPreliminary

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty
About 10.3 km horizontally, 7.1 km in depth
Magnitude uncertainty
±0.10
Depth from
From location
Station coverage gap
342°, poorly surrounded by stations
Stations used
15

Nearby

Within 100 km, magnitude 1.5 and up: 17 in the 60 days after this one and 20 in the 30 days before it.

After

  1. 3.1132 km E of Atka, Alaska · 2240 days ago · 99 km deep · 96 km away
  2. 3.6196 km SW of Nikolski, Alaska · 2240 days ago · 23 km deep · 52 km away
  3. 3.4200 km SW of Nikolski, Alaska · 2240 days ago · 20 km deep · 45 km away
  4. 2.9135 km ESE of Atka, Alaska · 2239 days ago · 140 km deep · 72 km away
  5. 1.9129 km SE of Atka, Alaska · 2237 days ago · 21 km deep · 95 km away
  6. 2.8207 km SW of Nikolski, Alaska · 2237 days ago · 10 km deep · 49 km away
  7. 1.6116 km ESE of Atka, Alaska · 2236 days ago · 49 km deep · 92 km away
  8. 2.5147 km ESE of Atka, Alaska · 2236 days ago · 35 km deep · 62 km away
  9. 3.8183 km ESE of Atka, Alaska · 2227 days ago · 37 km deep · 48 km away
  10. 3.0209 km SW of Nikolski, Alaska · 2211 days ago · 36 km deep · 36 km away
  11. 2.9170 km SW of Nikolski, Alaska · 2211 days ago · 10 km deep · 79 km away
  12. 3.1200 km SE of Atka, Alaska · 2209 days ago · 10 km deep · 40 km away
  13. 3.0194 km ESE of Atka, Alaska · 2208 days ago · 36 km deep · 41 km away
  14. 2.9116 km ESE of Atka, Alaska · 2206 days ago · 35 km deep · 92 km away
  15. 3.0193 km WSW of Nikolski, Alaska · 2193 days ago · 35 km deep · 73 km away
  16. 2.7186 km E of Atka, Alaska · 2184 days ago · 35 km deep · 62 km away
  17. 3.0191 km E of Atka, Alaska · 2182 days ago · 37 km deep · 54 km away

Before

  1. 3.8224 km ESE of Atka, Alaska · 2240 days ago · 10 km deep · 22 km away
  2. 3.1232 km SW of Nikolski, Alaska · 2240 days ago · 10 km deep · 28 km away
  3. 2.9250 km ESE of Atka, Alaska · 2240 days ago · 10 km deep · 53 km away
  4. 5.8241 km ESE of Atka, Alaska · 2240 days ago · 18 km deep · 36 km away · felt by 1 · tsunami flag
  5. 3.9214 km SW of Nikolski, Alaska · 2241 days ago · 10 km deep · 31 km away
  6. 3.7212 km ESE of Atka, Alaska · 2241 days ago · 33 km deep · 30 km away
  7. 3.6201 km SW of Nikolski, Alaska · 2241 days ago · 33 km deep · 47 km away
  8. 3.8201 km E of Atka, Alaska · 2241 days ago · 35 km deep · 51 km away
  9. 3.3212 km ESE of Atka, Alaska · 2241 days ago · 26 km deep · 32 km away
  10. 4.3214 km ESE of Atka, Alaska · 2241 days ago · 10 km deep · 22 km away
  11. 3.3193 km ESE of Atka, Alaska · 2241 days ago · 25 km deep · 49 km away
  12. 2.9206 km ESE of Atka, Alaska · 2242 days ago · 10 km deep · 39 km away
  13. 3.0235 km ESE of Atka, Alaska · 2242 days ago · 10 km deep · 29 km away
  14. 1.8140 km ESE of Atka, Alaska · 2242 days ago · 56 km deep · 66 km away
  15. 2.6123 km ESE of Atka, Alaska · 2247 days ago · 35 km deep · 86 km away
  16. 2.8121 km SE of Atka, Alaska · 2262 days ago · 156 km deep · 93 km away
  17. 3.2210 km ESE of Atka, Alaska · 2267 days ago · 26 km deep · 35 km away
  18. 1.6108 km ESE of Atka, Alaska · 2268 days ago · 10 km deep · 99 km away
  19. 2.6140 km E of Atka, Alaska · 2269 days ago · 35 km deep · 80 km away
  20. 1.9119 km ESE of Atka, Alaska · 2270 days ago · 46 km deep · 87 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000bhns (also filed as ak020akefvpj). Read Mon, Oct 5, 2026, 4:12 AM UTC.