Earthquakes on August 20, 2021
382
EARTHQUAKES on August 20, 2021
24-hour UTC period · USGS data
LARGEST: M5.3 — South Sandwich Islands region
38 km deep
Elevated activitycompared to daily average (~250/day)
Magnitude Breakdown
M5.0+
8
M4.0–4.9
49
M3.0–3.9
21
M2.0–2.9
86
M1.0–1.9
218
Activity Summary
382
Total earthquakes
~250
Daily average
Elevated
Activity level
8
M5.0+ events
Geographic Breakdown
By US State
Significant Earthquakes (M4.5+)
5.3
South Sandwich Islands region
15:56 UTC · 37.8 km deep
5.2
South Sandwich Islands region
15:07 UTC · 10.0 km deep
5.2
South Sandwich Islands region
03:21 UTC · 35.0 km deep
5.2
South Sandwich Islands region
03:13 UTC · 10.0 km deep
5.1
South Sandwich Islands region
03:41 UTC · 78.0 km deep
5.0
South Sandwich Islands region
22:25 UTC · 35.0 km deep
5.0
South Sandwich Islands region
18:59 UTC · 21.0 km deep
5.0
South Sandwich Islands region
01:09 UTC · 10.0 km deep
Earthquake Map — August 20, 2021
All Earthquakes — August 20, 2021
Showing 30 of 164 (filtered from 382)
(Filtered to M2.0+. Change the magnitude filter to see smaller events.)
| Time ↓ | Mag ↕ | Location ↕ | Depth ↕ | Felt ↕ | MMI | Alert | Status | Details |
|---|---|---|---|---|---|---|---|---|
2021-08-20 2021-08-20 23:59:58 UTC | 4.5mb | Kermadec Islands, New Zealand -29.828°, -178.577° | 214.6 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.5 earthquake was recorded near Kermadec Islands, New Zealand on August 20, 2021 at 23:59 UTC. See the M4.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:57:59 UTC | 2.9md | 15 km S of Fern Forest, Hawaii 19.323°, -155.114° | 10.9 km | - | - | - | ✓ Reviewed | USGS → |
August 20, 2021 brought a magnitude 2.9 earthquake 15 km S of Fern Forest, Hawaii, logged at 23:57 UTC. The event was offshore. See the M2.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:55:06 UTC | 4.4mb | 219 km SE of Sarangani, Philippines 3.806°, 126.632° | 53.1 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 4.4 earthquake 219 km SE of Sarangani, Philippines came in on August 20, 2021 at 23:55 UTC. The event was offshore. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:54:14 UTC | 2.2ml | 2 km SSW of Quinton, Oklahoma 35.106°, -95.382° | 6.1 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 2.2 event was detected 2 km SSW of Quinton, Oklahoma on August 20, 2021, with origin time 23:54 UTC. It arrived roughly 1 hours after a larger magnitude 2.6 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:48:31 UTC | 3.4ml | 156 km SSE of Chignik, Alaska 55.100°, -157.095° | 13.2 km | - | - | - | ✓ Reviewed | USGS → |
At 23:48 UTC on August 20, 2021, a magnitude 3.4 tremor occurred 156 km SSE of Chignik, Alaska. See the M3.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:41:31 UTC | 4.0mb | 210 km W of Severo-Kuril’sk, Russia 50.521°, 153.160° | 325.5 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.0 earthquake was recorded 210 km W of Severo-Kuril’sk, Russia on August 20, 2021 at 23:41 UTC. This deep-focus earthquake originated far below the brittle crust, deep inside the mantle. See the M4.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:35:06 UTC | 2.0ml | 89 km WNW of Karluk, Alaska 57.797°, -155.891° | 100.3 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2021, worldwide seismic activity registered a magnitude 2.0 earthquake 89 km WNW of Karluk, Alaska at 23:35 UTC. It arrived roughly 2 hours after a larger magnitude 2.3 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:33:56 UTC | 2.6ml | 1 km SSW of Quinton, Oklahoma 35.108°, -95.375° | 6.7 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.6 earthquake 1 km SSW of Quinton, Oklahoma at 23:33 UTC on August 20, 2021. See the M2.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:27:37 UTC | 2.2md | 29km SE of Markleeville, CA 38.528°, -119.531° | 2.4 km | - | - | - | ✓ Reviewed | USGS → |
August 20, 2021 brought a magnitude 2.2 earthquake 29km SE of Markleeville, CA, logged at 23:27 UTC. It arrived roughly 18 hours after a larger magnitude 2.6 mainshock in the same 20 km area, placing it within the typical aftershock window. This very shallow event was close enough to the surface that even modest magnitudes can produce significant local shaking. See the M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:26:20 UTC | 4.6mb | South Sandwich Islands region -60.321°, -27.946° | 17.6 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.6 earthquake in the South Sandwich Islands region at 23:26 UTC on August 20, 2021. See the M4.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:16:33 UTC | 4.0mb | 38 km SE of Champerico, Guatemala 14.046°, -91.664° | 75.5 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 4.0 earthquake 38 km SE of Champerico, Guatemala with origin time 23:16 UTC on August 20, 2021. The event was offshore. See the M4.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:16:10 UTC | 4.4mb | South Sandwich Islands region -57.940°, -23.901° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.4 seismic event took place in the South Sandwich Islands region on August 20, 2021 at 23:16 UTC. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 23:13:53 UTC | 2.5ml | 56 km SE of King Salmon, Alaska 58.316°, -156.014° | 155.3 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2021 at 23:13 UTC, a magnitude 2.5 earthquake struck 56 km SE of King Salmon, Alaska. The event was offshore. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 22:25:55 UTC | 5.0mb | South Sandwich Islands region -58.018°, -25.475° | 35.0 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 5.0 earthquake in the South Sandwich Islands region at 22:25 UTC on August 20, 2021. Coming 19 hours after a magnitude 5.2 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M5.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 22:25:26 UTC | 4.5mb | 138 km SSE of Isangel, Vanuatu -20.591°, 169.998° | 107.6 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 4.5 earthquake 138 km SSE of Isangel, Vanuatu with origin time 22:25 UTC on August 20, 2021. See the M4.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 22:21:53 UTC | 4.2mb | 287 km SSW of Maitum, Philippines 3.676°, 123.415° | 465.4 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 4.2 earthquake 287 km SSW of Maitum, Philippines with origin time 22:21 UTC on August 20, 2021. This deep-focus earthquake originated far below the brittle crust, deep inside the mantle. See the M4.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 22:20:30 UTC | 2.5ml | 12km W of Delta, B.C., MX 32.345°, -115.318° | 3.3 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 2.5 earthquake 12km W of Delta, B.C., MX came in on August 20, 2021 at 22:20 UTC. This very shallow event was close enough to the surface that even modest magnitudes can produce significant local shaking. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 22:17:44 UTC | 3.8mb | 272 km WSW of Adak, Alaska 51.177°, 179.594° | 26.3 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 3.8 seismic event took place 272 km WSW of Adak, Alaska on August 20, 2021 at 22:17 UTC. See the M3.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:55:33 UTC | 2.4ml | 66 km SE of Perryville, Alaska 55.471°, -158.420° | 14.4 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2021 at 21:55 UTC, a magnitude 2.4 earthquake struck 66 km SE of Perryville, Alaska. The event was offshore. See the M2.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:32:08 UTC | 2.9ml | 256 km WSW of Adak, Alaska 51.258°, 179.794° | 25.1 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2021 at 21:32 UTC, a magnitude 2.9 earthquake struck 256 km WSW of Adak, Alaska. See the M2.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:32:03 UTC | 4.6mb | South Sandwich Islands region -59.452°, -25.660° | 33.5 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 4.6 event was detected in the South Sandwich Islands region on August 20, 2021, with origin time 21:32 UTC. See the M4.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:25:47 UTC | 2.4ml | 154 km W of Elfin Cove, Alaska 58.078°, -138.953° | 24.8 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.4 earthquake was recorded 154 km W of Elfin Cove, Alaska on August 20, 2021 at 21:25 UTC. The event was offshore. See the M2.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:20:52 UTC | 4.6mb | Fiji region -19.169°, -177.426° | 417.4 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 4.6 earthquake in the Fiji region came in on August 20, 2021 at 21:20 UTC. This deep-focus earthquake originated far below the brittle crust, deep inside the mantle. See the M4.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:20:33 UTC | 2.1md | 12 km SSE of P?hala, Hawaii 19.111°, -155.418° | 36.3 km | - | - | - | Auto | USGS → |
At 21:20 UTC on August 20, 2021, a magnitude 2.1 tremor occurred 12 km SSE of P?hala, Hawaii. It arrived roughly 1 hours after a larger magnitude 3.3 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:17:27 UTC | 2.1ml | 5 km S of Princeton, Canada 49.406°, -120.509° | -0.4 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.1 earthquake 5 km S of Princeton, Canada with origin time 21:17 UTC on August 20, 2021. This very shallow event was close enough to the surface that even modest magnitudes can produce significant local shaking. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:12:18 UTC | 2.0ml | 3 km ESE of Quinton, Oklahoma 35.115°, -95.337° | 6.1 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.0 earthquake was recorded 3 km ESE of Quinton, Oklahoma on August 20, 2021 at 21:12 UTC. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:10:33 UTC | 4.4mb | South Sandwich Islands region -55.339°, -27.562° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
August 20, 2021 brought a magnitude 4.4 earthquake in the South Sandwich Islands region, logged at 21:10 UTC. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 21:07:39 UTC | 2.3ml | 81 km W of Karluk, Alaska 57.650°, -155.807° | 6.1 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.3 earthquake was recorded 81 km W of Karluk, Alaska on August 20, 2021 at 21:07 UTC. The event was offshore. See the M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 20:54:14 UTC | 4.4mb | 8 km ENE of Yachimata, Japan 35.684°, 140.401° | 48.0 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2021 at 20:54 UTC, a magnitude 4.4 earthquake struck 8 km ENE of Yachimata, Japan. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-20 2021-08-20 20:50:28 UTC | 2.4ml | 62 km E of Juneau, Alaska 58.359°, -133.361° | 0.0 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.4 earthquake 62 km E of Juneau, Alaska with origin time 20:50 UTC on August 20, 2021. This event falls inside the aftershock decay of a nearby magnitude 2.9 earthquake that occurred about 9 hours earlier. This very shallow event was close enough to the surface that even modest magnitudes can produce significant local shaking. See the M2.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
Legend:
Mag: Magnitude (magType = ml, mb, mw, etc.)
Felt: Number of DYFI felt reports
MMI: Modified Mercalli Intensity (I-X+)
Alert: PAGER alert level
Depth: Shallow (<70km), Intermediate, Deep (>300km)
Status: Auto = preliminary, Reviewed = verified by seismologist
Click any row to see additional technical details.
About This Page
This page shows all earthquakes recorded by the USGS Earthquake Hazards Program during the 24-hour UTC period on August 20, 2021. Data includes all events of magnitude 1.0 or greater. Past earthquake data is considered final after review by USGS seismologists.