Earthquakes on August 12, 2021
452
EARTHQUAKES on August 12, 2021
24-hour UTC period · USGS data
23 km deep
Elevated activitycompared to daily average (~250/day)
Magnitude Breakdown
M5.0+
65
M4.0–4.9
109
M3.0–3.9
13
M2.0–2.9
71
M1.0–1.9
194
Activity Summary
452
Total earthquakes
~250
Daily average
Elevated
Activity level
65
M5.0+ events
Geographic Breakdown
By US State
Top Countries (International)
Significant Earthquakes (M4.5+)
8.1
2021 South Sandwich Islands Earthquake
18:35 UTC · 22.8 km deep
7.5
South Sandwich Islands region
18:32 UTC · 47.2 km deep
Felt by 3
6.7
South Sandwich Islands region
18:36 UTC · 35.0 km deep
6.1
South Sandwich Islands region
18:41 UTC · 35.0 km deep
6.0
South Sandwich Islands region
19:43 UTC · 35.0 km deep
5.9
South Sandwich Islands region
19:44 UTC · 40.4 km deep
5.9
South Sandwich Islands region
19:07 UTC · 25.2 km deep
5.9
South Sandwich Islands region
18:49 UTC · 24.2 km deep
Earthquake Map — August 12, 2021
All Earthquakes — August 12, 2021
Showing 30 of 258 (filtered from 452)
(Filtered to M2.0+. Change the magnitude filter to see smaller events.)
| Time ↓ | Mag ↕ | Location ↕ | Depth ↕ | Felt ↕ | MMI | Alert | Status | Details |
|---|---|---|---|---|---|---|---|---|
2021-08-12 2021-08-12 23:58:35 UTC | 2.6md | 8 km ESE of Pole Ojea, Puerto Rico 17.934°, -67.117° | 9.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.6 earthquake was recorded 8 km ESE of Pole Ojea, Puerto Rico on August 12, 2021 at 23:58 UTC. 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 M2.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:58:06 UTC | 4.6mb | South Sandwich Islands region -58.760°, -25.153° | 32.9 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.6 earthquake in the South Sandwich Islands region at 23:58 UTC on August 12, 2021. Coming 1 hours after a magnitude 5.5 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M4.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:53:59 UTC | 4.9mb | South Sandwich Islands region -58.832°, -24.883° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.9 earthquake in the South Sandwich Islands region at 23:53 UTC on August 12, 2021. Coming 1 hours after a magnitude 5.5 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M4.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:50:11 UTC | 5.5mb | South Sandwich Islands region -58.374°, -24.323° | 10.0 km | - | III | green | ✓ Reviewed | USGS → |
This magnitude 5.5 event was detected in the South Sandwich Islands region on August 12, 2021, with origin time 23:50 UTC. The USGS PAGER system assigned a green alert level for this event, signalling no significant casualties or damage expected. See the M5.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:48:31 UTC | 4.8mb | South Sandwich Islands region -57.080°, -25.003° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
On August 12, 2021 at 23:48 UTC, a magnitude 4.8 earthquake struck in the South Sandwich Islands region. It arrived roughly 5 hours after a larger magnitude 5.9 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M4.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:45:28 UTC | 4.9mb | South Sandwich Islands region -58.747°, -25.138° | 35.0 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 4.9 event was detected in the South Sandwich Islands region on August 12, 2021, with origin time 23:45 UTC. It arrived roughly 1 hours after a larger magnitude 5.5 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M4.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:40:34 UTC | 4.4mb | South Sandwich Islands region -56.989°, -24.867° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 4.4 earthquake in the South Sandwich Islands region with origin time 23:40 UTC on August 12, 2021. Coming 5 hours after a magnitude 5.9 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:38:33 UTC | 4.7mb | South Sandwich Islands region -60.318°, -27.313° | 35.0 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.7 earthquake in the South Sandwich Islands region at 23:38 UTC on August 12, 2021. It arrived roughly 4 hours after a larger magnitude 5.4 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M4.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:35:05 UTC | 4.9mb | South Sandwich Islands region -58.813°, -25.055° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 4.9 earthquake in the South Sandwich Islands region came in on August 12, 2021 at 23:35 UTC. This event falls inside the aftershock decay of a nearby magnitude 5.5 earthquake that occurred about 1 hours earlier. See the M4.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:34:25 UTC | 4.9mb | South Sandwich Islands region -58.657°, -25.253° | 33.9 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.9 seismic event took place in the South Sandwich Islands region on August 12, 2021 at 23:34 UTC. Coming 3 hours after a magnitude 5.8 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M4.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:34:16 UTC | 2.2ml | 14 km SSE of Sunnyside, Utah 39.433°, -110.309° | -1.8 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 2.2 earthquake 14 km SSE of Sunnyside, Utah came in on August 12, 2021 at 23:34 UTC. 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. | ||||||||
2021-08-12 2021-08-12 23:33:55 UTC | 3.0md | 5 km ESE of Cataño, Puerto Rico 18.417°, -66.070° | 118.0 km | 3 | - | - | ✓ Reviewed | USGS → |
At 23:33 UTC on August 12, 2021, a magnitude 3.0 tremor occurred 5 km ESE of Cataño, Puerto Rico. See the M3.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:32:57 UTC | 5.0mb | South Sandwich Islands region -58.675°, -25.286° | 20.7 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 5.0 seismic event took place in the South Sandwich Islands region on August 12, 2021 at 23:32 UTC. It arrived roughly 3 hours after a larger magnitude 5.8 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M5.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:24:26 UTC | 5.5mb | South Sandwich Islands region -58.764°, -25.145° | 36.2 km | - | III | green | ✓ Reviewed | USGS → |
Reports of a magnitude 5.5 earthquake in the South Sandwich Islands region came in on August 12, 2021 at 23:24 UTC. In the 72 hours after this event, the USGS recorded 6 smaller earthquakes within 20 km, consistent with an ongoing aftershock sequence rooted here. The USGS PAGER system assigned a green alert level for this event, signalling no significant casualties or damage expected. See the M5.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:23:45 UTC | 5.2mb | South Sandwich Islands region -58.760°, -25.265° | 43.4 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 5.2 earthquake in the South Sandwich Islands region at 23:23 UTC on August 12, 2021. In the 72 hours after this event, the USGS recorded 5 smaller earthquakes within 20 km, consistent with an ongoing aftershock sequence rooted here. See the M5.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:20:03 UTC | 4.8mb | South Sandwich Islands region -58.791°, -25.214° | 35.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.8 earthquake was recorded in the South Sandwich Islands region on August 12, 2021 at 23:20 UTC. This event falls inside the aftershock decay of a nearby magnitude 5.1 earthquake that occurred about 2 hours earlier. See the M4.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:18:42 UTC | 5.2mb | western Indian-Antarctic Ridge -50.295°, 114.039° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 5.2 event was detected near western Indian-Antarctic Ridge on August 12, 2021, with origin time 23:18 UTC. See the M5.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:17:17 UTC | 3.3md | 7 km SW of La Parguera, Puerto Rico 17.930°, -67.094° | 10.0 km | 1 | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 3.3 earthquake 7 km SW of La Parguera, Puerto Rico came in on August 12, 2021 at 23:17 UTC. 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. The event was offshore. See the M3.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:17:03 UTC | 4.5mb | South Sandwich Islands region -60.565°, -26.325° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.5 seismic event took place in the South Sandwich Islands region on August 12, 2021 at 23:17 UTC. It arrived roughly 1 hours after a larger magnitude 5.2 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M4.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:14:50 UTC | 4.7mb | South Sandwich Islands region -58.740°, -25.160° | 15.0 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 4.7 event was detected in the South Sandwich Islands region on August 12, 2021, with origin time 23:14 UTC. This event falls inside the aftershock decay of a nearby magnitude 5.2 earthquake that occurred about 3 hours earlier. See the M4.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:14:23 UTC | 4.7mb | South Sandwich Islands region -58.054°, -25.759° | 25.5 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 4.7 earthquake in the South Sandwich Islands region came in on August 12, 2021 at 23:14 UTC. See the M4.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:14:08 UTC | 4.9mb | South Sandwich Islands region -58.243°, -25.419° | 35.0 km | - | - | - | ✓ Reviewed | USGS → |
August 12, 2021 brought a magnitude 4.9 earthquake in the South Sandwich Islands region, logged at 23:14 UTC. It arrived roughly 5 hours after a larger magnitude 8.1 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M4.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:08:12 UTC | 5.1mb | South Sandwich Islands region -59.881°, -26.239° | 35.0 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 5.1 earthquake in the South Sandwich Islands region at 23:08 UTC on August 12, 2021. Coming 5 hours after a magnitude 6.7 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M5.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:07:41 UTC | 4.8mb | South Sandwich Islands region -58.708°, -25.312° | 35.0 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 4.8 earthquake in the South Sandwich Islands region with origin time 23:07 UTC on August 12, 2021. Coming 3 hours after a magnitude 5.8 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M4.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:02:05 UTC | 4.6mb | South Sandwich Islands region -58.918°, -25.101° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 4.6 event was detected in the South Sandwich Islands region on August 12, 2021, with origin time 23:02 UTC. It arrived roughly 1 hours after a larger magnitude 4.8 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M4.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 23:01:01 UTC | 4.9mb | South Sandwich Islands region -57.986°, -25.151° | 35.0 km | - | - | - | ✓ Reviewed | USGS → |
On August 12, 2021 at 23:01 UTC, a magnitude 4.9 earthquake struck in the South Sandwich Islands region. This event falls inside the aftershock decay of a nearby magnitude 5.6 earthquake that occurred about 1 hours earlier. See the M4.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 22:59:49 UTC | 4.7mb | South Sandwich Islands region -58.106°, -24.898° | 23.3 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.7 seismic event took place in the South Sandwich Islands region on August 12, 2021 at 22:59 UTC. See the M4.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 22:54:48 UTC | 4.5mb | South Sandwich Islands region -58.275°, -24.437° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
August 12, 2021 brought a magnitude 4.5 earthquake in the South Sandwich Islands region, logged at 22:54 UTC. See the M4.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 22:53:44 UTC | 4.8mb | 17 km S of Yonakuni, Japan 24.313°, 122.983° | 45.1 km | - | - | - | ✓ Reviewed | USGS → |
On August 12, 2021, worldwide seismic activity registered a magnitude 4.8 earthquake 17 km S of Yonakuni, Japan at 22:53 UTC. The event was offshore. See the M4.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-08-12 2021-08-12 22:51:48 UTC | 4.7mb | South Sandwich Islands region -55.583°, -26.136° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
August 12, 2021 brought a magnitude 4.7 earthquake in the South Sandwich Islands region, logged at 22:51 UTC. See the M4.7 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 12, 2021. Data includes all events of magnitude 1.0 or greater. Past earthquake data is considered final after review by USGS seismologists.