Earthquakes on August 21, 2021
345
EARTHQUAKES on August 21, 2021
24-hour UTC period · USGS data
LARGEST: M5.2 — 153 km ENE of Hasaki, Japan
10 km deep · 2 people felt it
Elevated activitycompared to daily average (~250/day)
Magnitude Breakdown
M5.0+
1
M4.0–4.9
52
M3.0–3.9
17
M2.0–2.9
76
M1.0–1.9
199
Activity Summary
345
Total earthquakes
~250
Daily average
Elevated
Activity level
1
M5.0+ events
Geographic Breakdown
By US State
Significant Earthquakes (M4.5+)
5.2
153 km ENE of Hasaki, Japan
21:55 UTC · 10.0 km deep
Felt by 2
4.9
South Sandwich Islands region
15:53 UTC · 10.0 km deep
4.9
South Sandwich Islands region
14:54 UTC · 10.0 km deep
4.9
18 km SE of Bijie, China
02:20 UTC · 10.0 km deep
Felt by 2
4.9
South Sandwich Islands region
00:14 UTC · 74.0 km deep
4.9
South Sandwich Islands region
00:04 UTC · 38.9 km deep
4.8
51 km NNW of Ternate, Indonesia
15:37 UTC · 43.5 km deep
4.8
South Sandwich Islands region
11:04 UTC · 10.0 km deep
Earthquake Map — August 21, 2021
All Earthquakes — August 21, 2021
Showing 30 of 146 (filtered from 345)
(Filtered to M2.0+. Change the magnitude filter to see smaller events.)
| Time ↓ | Mag ↕ | Location ↕ | Depth ↕ | Felt ↕ | MMI | Alert | Status | Details |
|---|---|---|---|---|---|---|---|---|
2021-08-21 2021-08-21 23:58:33 UTC | 4.2mb | 287 km S of Nusa Dua, Indonesia -11.400°, 115.277° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 4.2 earthquake 287 km S of Nusa Dua, Indonesia with origin time 23:58 UTC on August 21, 2021. The event was offshore. See the M4.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 23:57:20 UTC | 2.3ml | 57 km S of Whites City, New Mexico 31.660°, -104.316° | 6.7 km | - | - | - | ✓ Reviewed | USGS → |
August 21, 2021 brought a magnitude 2.3 earthquake 57 km S of Whites City, New Mexico, logged at 23:57 UTC. It arrived roughly 3 hours after a larger magnitude 3.0 mainshock in the same 20 km area, placing it within the typical aftershock window. The event was offshore. See the M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 23:30:42 UTC | 2.8ml | 4 km NE of P?hala, Hawaii 19.229°, -155.440° | 38.5 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.8 earthquake 4 km NE of P?hala, Hawaii with origin time 23:30 UTC on August 21, 2021. It arrived roughly 19 hours after a larger magnitude 3.3 mainshock in the same 20 km area, placing it within the typical aftershock window. The event was offshore. See the M2.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 23:29:10 UTC | 2.3ml | 7 km ENE of P?hala, Hawaii 19.216°, -155.407° | 28.8 km | - | - | - | Auto | USGS → |
Reports of a magnitude 2.3 earthquake 7 km ENE of P?hala, Hawaii came in on August 21, 2021 at 23:29 UTC. This event falls inside the aftershock decay of a nearby magnitude 3.3 earthquake that occurred about 19 hours earlier. See the M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 23:28:53 UTC | 2.1md | 29km SE of Markleeville, CA 38.531°, -119.534° | 2.8 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2021, worldwide seismic activity registered a magnitude 2.1 earthquake 29km SE of Markleeville, CA at 23:28 UTC. It arrived roughly 1 hours after a larger magnitude 3.2 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 M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 23:15:55 UTC | 4.1mb | 226 km S of Sinabang, Indonesia 0.441°, 96.604° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2021 at 23:15 UTC, a magnitude 4.1 earthquake struck 226 km S of Sinabang, Indonesia. The event was offshore. See the M4.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 23:14:42 UTC | 2.2md | 29km SE of Markleeville, CA 38.528°, -119.534° | 2.4 km | 1 | - | - | ✓ Reviewed | USGS → |
On August 21, 2021, worldwide seismic activity registered a magnitude 2.2 earthquake 29km SE of Markleeville, CA at 23:14 UTC. This event falls inside the aftershock decay of a nearby magnitude 3.2 earthquake that occurred about 1 hours earlier. 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. | ||||||||
2021-08-21 2021-08-21 23:12:28 UTC | 2.7md | 11 km SSW of Guánica, Puerto Rico 17.879°, -66.960° | 12.0 km | - | - | - | ✓ Reviewed | USGS → |
August 21, 2021 brought a magnitude 2.7 earthquake 11 km SSW of Guánica, Puerto Rico, logged at 23:12 UTC. This event falls inside the aftershock decay of a nearby magnitude 2.8 earthquake that occurred about 14 hours earlier. See the M2.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 22:56:40 UTC | 3.2ml | 29km SE of Markleeville, CA 38.530°, -119.530° | 2.1 km | 6 | - | - | ✓ Reviewed | USGS → |
At 22:56 UTC on August 21, 2021, a magnitude 3.2 tremor occurred 29km SE of Markleeville, CA. In the 72 hours after this event, the USGS recorded 10 smaller earthquakes within 20 km, consistent with an ongoing aftershock sequence rooted here. See the M3.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 22:46:32 UTC | 2.5ml | 15 km S of Volcano, Hawaii 19.306°, -155.248° | 7.3 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2021 at 22:46 UTC, a magnitude 2.5 earthquake struck 15 km S of Volcano, Hawaii. The event was offshore. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 22:34:00 UTC | 4.4mb | 70 km WNW of Sinabang, Indonesia 2.635°, 95.763° | 25.0 km | - | - | - | ✓ Reviewed | USGS → |
At 22:34 UTC on August 21, 2021, a magnitude 4.4 tremor occurred 70 km WNW of Sinabang, Indonesia. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 22:23:11 UTC | 2.0ml | 55 km S of Whites City, New Mexico 31.680°, -104.413° | 6.2 km | - | - | - | ✓ Reviewed | USGS → |
At 22:23 UTC on August 21, 2021, a magnitude 2.0 tremor occurred 55 km S of Whites City, New Mexico. Coming 1 hours after a magnitude 3.0 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. The event was offshore. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 22:22:48 UTC | 2.0md | 4 km SSE of P?hala, Hawaii 19.167°, -155.463° | 34.7 km | - | - | - | Auto | USGS → |
Seismographs logged a magnitude 2.0 earthquake 4 km SSE of P?hala, Hawaii with origin time 22:22 UTC on August 21, 2021. It arrived roughly 18 hours after a larger magnitude 3.3 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. | ||||||||
2021-08-21 2021-08-21 22:07:50 UTC | 4.7mb | 25 km N of Arica, Chile -18.248°, -70.287° | 83.5 km | 2 | - | - | ✓ Reviewed | USGS → |
A magnitude 4.7 seismic event took place 25 km N of Arica, Chile on August 21, 2021 at 22:07 UTC. The event was offshore. See the M4.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 21:55:39 UTC | 5.2mww | 153 km ENE of Hasaki, Japan 36.039°, 142.491° | 10.0 km | 2 | - | - | ✓ Reviewed | USGS → |
On August 21, 2021 at 21:55 UTC, a magnitude 5.2 earthquake struck 153 km ENE of Hasaki, Japan. It is the largest earthquake currently listed for worldwide seismic activity on August 21, 2021. See the M5.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 21:45:53 UTC | 3.3ml | 49 km N of Atka, Alaska 52.641°, -174.114° | 247.2 km | - | - | - | ✓ Reviewed | USGS → |
August 21, 2021 brought a magnitude 3.3 earthquake 49 km N of Atka, Alaska, logged at 21:45 UTC. The event was offshore. See the M3.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 21:40:01 UTC | 3.0ml | 167 km SE of Atka, Alaska 51.145°, -172.472° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 3.0 seismic event took place 167 km SE of Atka, Alaska on August 21, 2021 at 21:40 UTC. The event was offshore. See the M3.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 21:33:10 UTC | 2.2ml | 7km N of Delta, B.C., MX 32.416°, -115.204° | 13.9 km | - | - | - | ✓ Reviewed | USGS → |
At 21:33 UTC on August 21, 2021, a magnitude 2.2 tremor occurred 7km N of Delta, B.C., MX. Coming 5 hours after a magnitude 2.4 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. The event was offshore. See the M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 21:20:55 UTC | 3.0ml | 55 km S of Whites City, New Mexico 31.678°, -104.407° | 6.8 km | - | - | - | ✓ Reviewed | USGS → |
August 21, 2021 brought a magnitude 3.0 earthquake 55 km S of Whites City, New Mexico, logged at 21:20 UTC. The event was offshore. See the M3.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 21:17:24 UTC | 2.0ml | 14 km N of Beluga, Alaska 61.272°, -151.035° | 72.4 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.0 earthquake 14 km N of Beluga, Alaska at 21:17 UTC on August 21, 2021. The event was offshore. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 20:49:30 UTC | 2.3md | 27km SSW of Smith Valley, NV 38.552°, -119.426° | 1.3 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 2.3 event was detected 27km SSW of Smith Valley, NV on August 21, 2021, with origin time 20:49 UTC. It arrived roughly 1 hours after a larger magnitude 3.1 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 M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 20:47:24 UTC | 2.2md | 28km SSW of Smith Valley, NV 38.544°, -119.429° | 0.8 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2021 at 20:47 UTC, a magnitude 2.2 earthquake struck 28km SSW of Smith Valley, NV. Coming 1 hours after a magnitude 3.1 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. 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. | ||||||||
2021-08-21 2021-08-21 20:41:37 UTC | 2.2md | 27km SSW of Smith Valley, NV 38.547°, -119.427° | -0.5 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.2 earthquake 27km SSW of Smith Valley, NV with origin time 20:41 UTC on August 21, 2021. This event falls inside the aftershock decay of a nearby magnitude 3.1 earthquake that occurred about 1 hours earlier. 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. | ||||||||
2021-08-21 2021-08-21 20:22:36 UTC | 2.1ml | 6 km E of P?hala, Hawaii 19.212°, -155.420° | 34.7 km | - | - | - | Auto | USGS → |
Reports of a magnitude 2.1 earthquake 6 km E of P?hala, Hawaii came in on August 21, 2021 at 20:22 UTC. It arrived roughly 16 hours after a larger magnitude 3.3 mainshock in the same 20 km area, placing it within the typical aftershock window. The event was offshore. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 20:22:01 UTC | 3.1ml | 27km SSW of Smith Valley, NV 38.553°, -119.429° | -1.5 km | 1 | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 3.1 earthquake 27km SSW of Smith Valley, NV came in on August 21, 2021 at 20:22 UTC. In the 72 hours after this event, the USGS recorded 17 smaller earthquakes within 20 km, consistent with an ongoing aftershock sequence rooted here. See the M3.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 20:16:03 UTC | 2.1md | 26km SSW of Smith Valley, NV 38.557°, -119.430° | -1.7 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.1 earthquake 26km SSW of Smith Valley, NV at 20:16 UTC on August 21, 2021. This event falls inside the aftershock decay of a nearby magnitude 2.6 earthquake that occurred about 1 hours earlier. 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. | ||||||||
2021-08-21 2021-08-21 20:12:31 UTC | 2.6md | 27km SSW of Smith Valley, NV 38.550°, -119.424° | 1.5 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.6 earthquake 27km SSW of Smith Valley, NV with origin time 20:12 UTC on August 21, 2021. In the 72 hours after this event, the USGS recorded 19 smaller earthquakes within 20 km, consistent with an ongoing aftershock sequence rooted here. See the M2.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 20:08:25 UTC | 2.5md | 3 km WSW of Guánica, Puerto Rico 17.959°, -66.934° | 14.0 km | - | - | - | ✓ Reviewed | USGS → |
August 21, 2021 brought a magnitude 2.5 earthquake 3 km WSW of Guánica, Puerto Rico, logged at 20:08 UTC. Coming 11 hours after a magnitude 2.8 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-21 2021-08-21 19:59:28 UTC | 2.4md | 27km SSW of Smith Valley, NV 38.546°, -119.422° | 2.3 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.4 earthquake 27km SSW of Smith Valley, NV at 19:59 UTC on August 21, 2021. Coming 1 hours after a magnitude 2.4 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. 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. | ||||||||
2021-08-21 2021-08-21 19:54:46 UTC | 3.1ml | 5km S of Ridgemark, CA 36.772°, -121.374° | 9.3 km | 17 | - | - | ✓ Reviewed | USGS → |
This magnitude 3.1 event was detected 5km S of Ridgemark, CA on August 21, 2021, with origin time 19:54 UTC. The event was offshore. See the M3.1 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 21, 2021. Data includes all events of magnitude 1.0 or greater. Past earthquake data is considered final after review by USGS seismologists.