Earthquakes on September 21, 2021
314
EARTHQUAKES on September 21, 2021
24-hour UTC period · USGS data
LARGEST: M6.4 — 73 km W of Talcahuano, Chile
19 km deep · 83 people felt it
Elevated activitycompared to daily average (~250/day)
Magnitude Breakdown
M5.0+
5
M4.0–4.9
35
M3.0–3.9
17
M2.0–2.9
60
M1.0–1.9
197
Activity Summary
314
Total earthquakes
~250
Daily average
Elevated
Activity level
5
M5.0+ events
Geographic Breakdown
By US State
Top Countries (International)
Significant Earthquakes (M4.5+)
6.4
73 km W of Talcahuano, Chile
13:14 UTC · 18.8 km deep
Felt by 83
5.9
39 km S of Mount Buller, Australia
23:15 UTC · 12.0 km deep
Felt by 5,846
5.4
Easter Island region
10:14 UTC · 10.0 km deep
Felt by 1
5.2
Izu Islands, Japan region
10:19 UTC · 10.0 km deep
Felt by 1
5.0
Indian Ocean Triple Junction
18:24 UTC · 10.0 km deep
4.9
0 km NE of Cabacao, Philippines
16:43 UTC · 80.7 km deep
Felt by 10
4.9
southeast Indian Ridge
03:29 UTC · 10.0 km deep
4.9
76 km NNW of Ambon, Indonesia
01:20 UTC · 44.1 km deep
Earthquake Map — September 21, 2021
All Earthquakes — September 21, 2021
Showing 30 of 117 (filtered from 314)
(Filtered to M2.0+. Change the magnitude filter to see smaller events.)
| Time ↓ | Mag ↕ | Location ↕ | Depth ↕ | Felt ↕ | MMI | Alert | Status | Details |
|---|---|---|---|---|---|---|---|---|
2021-09-21 2021-09-21 23:59:47 UTC | 2.1ml | 36 km ENE of Pedro Bay, Alaska 59.927°, -153.508° | 139.9 km | - | - | - | ✓ Reviewed | USGS → |
At 23:59 UTC on September 21, 2021, a magnitude 2.1 tremor occurred 36 km ENE of Pedro Bay, Alaska. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 23:54:34 UTC | 4.4mb | South Sandwich Islands region -58.798°, -23.474° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.4 earthquake was recorded in the South Sandwich Islands region on September 21, 2021 at 23:54 UTC. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 23:33:38 UTC | 4.1mb | 35 km SSW of Mount Buller, Australia -37.435°, 146.253° | 10.0 km | 70 | - | - | ✓ Reviewed | USGS → |
At 23:33 UTC on September 21, 2021, a magnitude 4.1 tremor occurred 35 km SSW of Mount Buller, Australia. This event falls inside the aftershock decay of a nearby magnitude 5.9 earthquake that occurred about 1 hours earlier. See the M4.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 23:15:53 UTC | 5.9mww | 39 km S of Mount Buller, Australia -37.492°, 146.353° | 12.0 km | 5,846 | VII | yellow | ✓ Reviewed | USGS → |
A magnitude 5.9 earthquake was recorded 39 km S of Mount Buller, Australia on September 21, 2021 at 23:15 UTC. The USGS PAGER system assigned a yellow alert level for this event, signalling local impact possible. The event was offshore. See the M5.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 23:00:01 UTC | 2.3ml | 10km NNW of Anza, CA 33.636°, -116.711° | 13.0 km | - | - | - | ✓ Reviewed | USGS → |
On September 21, 2021 at 23:00 UTC, a magnitude 2.3 earthquake struck 10km NNW of Anza, CA. It arrived roughly 1 hours after a larger magnitude 3.4 mainshock in the same 20 km area, placing it within the typical aftershock window. See the M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 22:59:54 UTC | 2.8ml | 11 km E of P?hala, Hawaii 19.222°, -155.369° | 33.2 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.8 earthquake 11 km E of P?hala, Hawaii at 22:59 UTC on September 21, 2021. Coming 11 hours after a magnitude 3.3 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. The event was offshore. See the M2.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 22:57:32 UTC | 3.3ml | 10km NNW of Anza, CA 33.635°, -116.711° | 13.4 km | 143 | III | - | ✓ Reviewed | USGS → |
September 21, 2021 brought a magnitude 3.3 earthquake 10km NNW of Anza, CA, logged at 22:57 UTC. This event falls inside the aftershock decay of a nearby magnitude 3.4 earthquake that occurred about 1 hours earlier. See the M3.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 22:55:49 UTC | 2.2ml | 7 km NW of Stanley, Idaho 44.262°, -115.010° | 10.7 km | - | - | - | ✓ Reviewed | USGS → |
At 22:55 UTC on September 21, 2021, a magnitude 2.2 tremor occurred 7 km NW of Stanley, Idaho. The event was offshore. See the M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 22:53:13 UTC | 2.8md | 11 km S of Emajagua, Puerto Rico 17.895°, -65.894° | 8.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.8 earthquake was recorded 11 km S of Emajagua, Puerto Rico on September 21, 2021 at 22:53 UTC. The event was offshore. See the M2.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 22:48:00 UTC | 2.1ml | 9km NNW of Anza, CA 33.632°, -116.706° | 12.8 km | 2 | - | - | ✓ Reviewed | USGS → |
A magnitude 2.1 seismic event took place 9km NNW of Anza, CA on September 21, 2021 at 22:48 UTC. It arrived roughly 1 hours after a larger magnitude 3.4 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. | ||||||||
2021-09-21 2021-09-21 22:41:30 UTC | 3.4mw | 10km NNW of Anza, CA 33.635°, -116.715° | 13.2 km | 296 | III | - | ✓ Reviewed | USGS → |
This magnitude 3.4 event was detected 10km NNW of Anza, CA on September 21, 2021, with origin time 22:41 UTC. In the 72 hours after this event, the USGS recorded 37 smaller earthquakes within 20 km, consistent with an ongoing aftershock sequence rooted here. See the M3.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 22:12:08 UTC | 3.1ml | 24 km NNW of Cordova, Alaska 60.748°, -145.909° | 10.3 km | 1 | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 3.1 earthquake 24 km NNW of Cordova, Alaska at 22:12 UTC on September 21, 2021. See the M3.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 22:12:07 UTC | 2.2ml | 9 km E of P?hala, Hawaii 19.216°, -155.394° | 31.1 km | - | - | - | Auto | USGS → |
On September 21, 2021, worldwide seismic activity registered a magnitude 2.2 earthquake 9 km E of P?hala, Hawaii at 22:12 UTC. It arrived roughly 10 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 M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 22:12:03 UTC | 2.2ml | 49 km NNW of Yakutat, Alaska 59.931°, -140.169° | 2.9 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.2 earthquake 49 km NNW of Yakutat, Alaska at 22:12 UTC on September 21, 2021. Coming 1 hours after a magnitude 3.2 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. | ||||||||
2021-09-21 2021-09-21 22:08:18 UTC | 2.4md | 31km SE of Markleeville, CA 38.526°, -119.502° | 6.9 km | 1 | - | - | ✓ Reviewed | USGS → |
A magnitude 2.4 seismic event took place 31km SE of Markleeville, CA on September 21, 2021 at 22:08 UTC. It arrived roughly 19 hours after a larger magnitude 2.8 mainshock in the same 20 km area, placing it within the typical aftershock window. The event was offshore. See the M2.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 21:35:38 UTC | 2.1ml | 2 km SE of P?hala, Hawaii 19.191°, -155.460° | 35.5 km | - | - | - | Auto | USGS → |
On September 21, 2021, worldwide seismic activity registered a magnitude 2.1 earthquake 2 km SE of P?hala, Hawaii at 21:35 UTC. This event falls inside the aftershock decay of a nearby magnitude 3.3 earthquake that occurred about 9 hours earlier. The event was offshore. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 21:33:53 UTC | 4.1mb | 237 km ESE of Pondaguitan, Philippines 5.324°, 128.058° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.1 earthquake 237 km ESE of Pondaguitan, Philippines at 21:33 UTC on September 21, 2021. See the M4.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 21:13:58 UTC | 2.0ml | 52 km NNW of Yakutat, Alaska 59.968°, -140.132° | 4.4 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.0 earthquake was recorded 52 km NNW of Yakutat, Alaska on September 21, 2021 at 21:13 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 M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 21:12:11 UTC | 2.1ml | 55 km NNW of Yakutat, Alaska 59.996°, -140.139° | 7.9 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.1 earthquake 55 km NNW of Yakutat, Alaska at 21:12 UTC on September 21, 2021. 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. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 21:10:24 UTC | 4.7mb | 118 km W of Lata, Solomon Islands -10.784°, 164.714° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
On September 21, 2021 at 21:10 UTC, a magnitude 4.7 earthquake struck 118 km W of Lata, Solomon Islands. The event was offshore. See the M4.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 21:00:16 UTC | 3.2ml | 55 km NNW of Yakutat, Alaska 59.990°, -140.165° | 9.2 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 3.2 earthquake was recorded 55 km NNW of Yakutat, Alaska on September 21, 2021 at 21:00 UTC. In the 72 hours after this event, the USGS recorded 4 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. | ||||||||
2021-09-21 2021-09-21 20:37:09 UTC | 2.2ml | 47 km NW of Ninilchik, Alaska 60.384°, -152.195° | 79.8 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 2.2 event was detected 47 km NW of Ninilchik, Alaska on September 21, 2021, with origin time 20:37 UTC. The event was offshore. See the M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 19:58:22 UTC | 2.4ml | 15 km NE of Leon, Oklahoma 33.959°, -97.296° | 11.7 km | - | - | - | ✓ Reviewed | USGS → |
On September 21, 2021 at 19:58 UTC, a magnitude 2.4 earthquake struck 15 km NE of Leon, Oklahoma. The event was offshore. See the M2.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 19:50:33 UTC | 2.1ml | 7km N of Westmorland, CA 33.102°, -115.619° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
September 21, 2021 brought a magnitude 2.1 earthquake 7km N of Westmorland, CA, logged at 19:50 UTC. The event was offshore. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 19:37:32 UTC | 2.2ml | 17 km NNE of Hermleigh, Texas 32.768°, -100.659° | 8.9 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 2.2 earthquake 17 km NNE of Hermleigh, Texas came in on September 21, 2021 at 19:37 UTC. See the M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 19:33:52 UTC | 4.5mb | 52 km WSW of Shikotan, Russia 43.559°, 146.167° | 74.7 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 4.5 event was detected 52 km WSW of Shikotan, Russia on September 21, 2021, with origin time 19:33 UTC. See the M4.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 19:27:14 UTC | 2.2ml | 11 km E of P?hala, Hawaii 19.212°, -155.369° | 32.1 km | - | - | - | Auto | USGS → |
A magnitude 2.2 seismic event took place 11 km E of P?hala, Hawaii on September 21, 2021 at 19:27 UTC. Coming 7 hours after a magnitude 3.3 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. | ||||||||
2021-09-21 2021-09-21 19:12:01 UTC | 2.2ml | 19 km ESE of Dyer, Nevada 37.599°, -117.867° | 0.3 km | - | - | - | ✓ Reviewed | USGS → |
September 21, 2021 brought a magnitude 2.2 earthquake 19 km ESE of Dyer, Nevada, logged at 19:12 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. | ||||||||
2021-09-21 2021-09-21 19:03:42 UTC | 2.0ml | 9km S of Lamont, CA 35.180°, -118.924° | 4.8 km | - | - | - | ✓ Reviewed | USGS → |
On September 21, 2021 at 19:03 UTC, a magnitude 2.0 earthquake struck 9km S of Lamont, CA. This very shallow event was close enough to the surface that even modest magnitudes can produce significant local shaking. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2021-09-21 2021-09-21 18:48:39 UTC | 4.0mb | 257 km WSW of Adak, Alaska 51.466°, 179.706° | 106.2 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 4.0 earthquake 257 km WSW of Adak, Alaska came in on September 21, 2021 at 18:48 UTC. See the M4.0 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 September 21, 2021. Data includes all events of magnitude 1.0 or greater. Past earthquake data is considered final after review by USGS seismologists.