Earthquakes on October 21, 2023
266
EARTHQUAKES on October 21, 2023
24-hour UTC period · USGS data
10 km deep · 70 people felt it
Normal activitycompared to daily average (~250/day)
Magnitude Breakdown
M5.0+
2
M4.0–4.9
40
M3.0–3.9
13
M2.0–2.9
48
M1.0–1.9
163
Activity Summary
266
Total earthquakes
~250
Daily average
Normal
Activity level
2
M5.0+ events
Geographic Breakdown
By US State
Top Countries (International)
Significant Earthquakes (M4.5+)
5.2
14 km NNE of San Isidro, Costa Rica
10:45 UTC · 10.0 km deep
Felt by 70
5.1
121 km WSW of Puerto Madero, Mexico
17:10 UTC · 9.8 km deep
4.9
27 km ENE of Sur, Oman
06:00 UTC · 10.0 km deep
Felt by 8
4.8
16 km WNW of Apollo Bay, Australia
15:11 UTC · 10.0 km deep
Felt by 282
4.7
Izu Islands, Japan region
15:40 UTC · 18.2 km deep
4.7
62 km NW of Dompu, Indonesia
12:04 UTC · 10.0 km deep
4.7
113 km NE of Tobelo, Indonesia
05:32 UTC · 232.3 km deep
4.7
35 km ENE of La Paz, Philippines
05:32 UTC · 64.9 km deep
Earthquake Map — October 21, 2023
All Earthquakes — October 21, 2023
Showing 30 of 103 (filtered from 266)
(Filtered to M2.0+. Change the magnitude filter to see smaller events.)
| Time ↓ | Mag ↕ | Location ↕ | Depth ↕ | Felt ↕ | MMI | Alert | Status | Details |
|---|---|---|---|---|---|---|---|---|
2023-10-21 2023-10-21 23:39:00 UTC | 4.5mb | 22 km NW of Zaragoza, Colombia 7.617°, -75.025° | 59.0 km | - | - | - | ✓ Reviewed | USGS → |
At 23:39 UTC on October 21, 2023, a magnitude 4.5 tremor occurred 22 km NW of Zaragoza, Colombia. The event was offshore. See the M4.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 22:54:06 UTC | 3.2ml | Rat Islands, Aleutian Islands, Alaska 51.000°, 179.142° | 26.1 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 3.2 seismic event took place near Rat Islands, Aleutian Islands, Alaska on October 21, 2023 at 22:54 UTC. See the M3.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 22:37:35 UTC | 3.8md | 72 km NNW of San Antonio, Puerto Rico 19.125°, -67.292° | 87.0 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 3.8 earthquake 72 km NNW of San Antonio, Puerto Rico with origin time 22:37 UTC on October 21, 2023. See the M3.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 22:12:54 UTC | 2.1ml | 2 km WSW of Pāhala, Hawaii 19.191°, -155.502° | 35.1 km | - | - | - | Auto | USGS → |
Reports of a magnitude 2.1 earthquake 2 km WSW of Pāhala, Hawaii came in on October 21, 2023 at 22:12 UTC. This event falls inside the aftershock decay of a nearby magnitude 2.1 earthquake that occurred about 17 hours earlier. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 21:19:16 UTC | 4.0mb | Izu Islands, Japan region 30.987°, 138.398° | 390.4 km | - | - | - | ✓ Reviewed | USGS → |
On October 21, 2023 at 21:19 UTC, a magnitude 4.0 earthquake struck in the Izu Islands, Japan region. This is the deepest earthquake in the current dataset — a deep-focus event. See the M4.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 20:01:07 UTC | 4.2mb | 44 km WSW of Arauco, Argentina -28.741°, -67.208° | 135.3 km | - | - | - | ✓ Reviewed | USGS → |
On October 21, 2023 at 20:01 UTC, a magnitude 4.2 earthquake struck 44 km WSW of Arauco, Argentina. See the M4.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 19:56:26 UTC | 2.2ml(texnet) | 37 km W of Mentone, Texas 31.724°, -103.990° | 6.1 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.2 earthquake was recorded 37 km W of Mentone, Texas on October 21, 2023 at 19:56 UTC. It arrived roughly 1 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 M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 19:51:33 UTC | 3.0ml(texnet) | western Texas 31.721°, -103.996° | 6.7 km | - | - | - | ✓ Reviewed | USGS → |
On October 21, 2023, worldwide seismic activity registered a magnitude 3.0 earthquake near western Texas at 19:51 UTC. See the M3.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 19:50:20 UTC | 2.3ml | 4 km WNW of Bondurant, Wyoming 43.216°, -110.462° | 5.0 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 2.3 event was detected 4 km WNW of Bondurant, Wyoming on October 21, 2023, with origin time 19:50 UTC. See the M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 19:49:49 UTC | 2.6md | 8 km S of Pole Ojea, Puerto Rico 17.895°, -67.175° | 12.4 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.6 earthquake was recorded 8 km S of Pole Ojea, Puerto Rico on October 21, 2023 at 19:49 UTC. The event was offshore. See the M2.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 19:17:48 UTC | 2.4ml | 11 km S of Big Bear Lake, CA 34.144°, -116.903° | 12.2 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.4 earthquake was recorded 11 km S of Big Bear Lake, CA on October 21, 2023 at 19:17 UTC. The event was offshore. See the M2.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 18:44:29 UTC | 3.5mb | 10 km NW of Apollo Bay, Australia -38.687°, 143.587° | 10.0 km | 15 | - | - | ✓ Reviewed | USGS → |
At 18:44 UTC on October 21, 2023, a magnitude 3.5 tremor occurred 10 km NW of Apollo Bay, Australia. Coming 4 hours after a magnitude 4.8 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. The event was offshore. See the M3.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 18:25:11 UTC | 2.5md | 39 km N of Tierras Nuevas Poniente, Puerto Rico 18.813°, -66.441° | 30.0 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 2.5 earthquake 39 km N of Tierras Nuevas Poniente, Puerto Rico came in on October 21, 2023 at 18:25 UTC. The event was offshore. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 18:14:35 UTC | 2.3ml | 110 km ESE of Akutan, Alaska 53.748°, -164.223° | 25.6 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 2.3 earthquake 110 km ESE of Akutan, Alaska came in on October 21, 2023 at 18:14 UTC. See the M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 18:04:45 UTC | 4.0mb | 175 km E of Hicks Bay, New Zealand -37.348°, -179.746° | 20.4 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.0 earthquake was recorded 175 km E of Hicks Bay, New Zealand on October 21, 2023 at 18:04 UTC. The event was offshore. See the M4.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 18:03:30 UTC | 2.2ml | 138 km N of Nikolski, Alaska 54.180°, -168.864° | 19.3 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.2 earthquake 138 km N of Nikolski, Alaska with origin time 18:03 UTC on October 21, 2023. The event was offshore. See the M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 17:16:08 UTC | 4.1mb | 92 km NW of Madang, Papua New Guinea -4.701°, 145.133° | 194.6 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 4.1 event was detected 92 km NW of Madang, Papua New Guinea on October 21, 2023, with origin time 17:16 UTC. The event was offshore. See the M4.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 17:10:01 UTC | 5.1mww | 121 km WSW of Puerto Madero, Mexico 14.194°, -93.410° | 9.8 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 5.1 earthquake was recorded 121 km WSW of Puerto Madero, Mexico on October 21, 2023 at 17:10 UTC. See the M5.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 17:05:14 UTC | 4.6mb | 120 km WSW of Puerto Madero, Mexico 14.311°, -93.454° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
On October 21, 2023 at 17:05 UTC, a magnitude 4.6 earthquake struck 120 km WSW of Puerto Madero, Mexico. See the M4.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 17:03:17 UTC | 3.5md | 58 km NNE of Luquillo, Puerto Rico 18.850°, -65.474° | 28.0 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 3.5 event was detected 58 km NNE of Luquillo, Puerto Rico on October 21, 2023, with origin time 17:03 UTC. See the M3.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 17:00:53 UTC | 2.1ml | 58 km E of Juneau, Alaska 58.341°, -133.420° | 0.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.1 earthquake was recorded 58 km E of Juneau, Alaska on October 21, 2023 at 17:00 UTC. This event falls inside the aftershock decay of a nearby magnitude 2.4 earthquake that occurred about 13 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. | ||||||||
2023-10-21 2023-10-21 16:56:29 UTC | 2.2md | 1 km SSW of Indios, Puerto Rico 17.982°, -66.822° | 14.9 km | - | - | - | ✓ Reviewed | USGS → |
On October 21, 2023, worldwide seismic activity registered a magnitude 2.2 earthquake 1 km SSW of Indios, Puerto Rico at 16:56 UTC. Coming 9 hours after a magnitude 2.5 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 16:47:55 UTC | 2.9ml | 45 km E of Yakutat, Alaska 59.484°, -138.925° | 5.8 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.9 earthquake 45 km E of Yakutat, Alaska at 16:47 UTC on October 21, 2023. The event was offshore. See the M2.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 16:44:28 UTC | 3.2ml | 280 km ESE of Attu Station, Alaska 51.745°, 176.878° | 66.6 km | - | - | - | ✓ Reviewed | USGS → |
October 21, 2023 brought a magnitude 3.2 earthquake 280 km ESE of Attu Station, Alaska, logged at 16:44 UTC. See the M3.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 16:41:33 UTC | 4.4mb | 63 km W of Labuan, Indonesia -6.486°, 105.264° | 62.2 km | - | - | - | ✓ Reviewed | USGS → |
October 21, 2023 brought a magnitude 4.4 earthquake 63 km W of Labuan, Indonesia, logged at 16:41 UTC. The event was offshore. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 16:31:25 UTC | 2.5ml | 5 km WNW of Halibut Cove, Alaska 59.615°, -151.305° | 45.4 km | 1 | - | - | ✓ Reviewed | USGS → |
On October 21, 2023 at 16:31 UTC, a magnitude 2.5 earthquake struck 5 km WNW of Halibut Cove, Alaska. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 16:22:47 UTC | 4.5mb | 135 km E of Kokopo, Papua New Guinea -4.394°, 153.492° | 117.8 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.5 earthquake 135 km E of Kokopo, Papua New Guinea at 16:22 UTC on October 21, 2023. The event was offshore. See the M4.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 15:40:21 UTC | 4.7mb | Izu Islands, Japan region 31.744°, 142.366° | 18.2 km | - | - | - | ✓ Reviewed | USGS → |
At 15:40 UTC on October 21, 2023, a magnitude 4.7 tremor occurred in the Izu Islands, Japan region. See the M4.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 15:36:59 UTC | 2.5ml | 14 km SSW of Volcano, Hawaii 19.335°, -155.308° | 3.8 km | 1 | - | - | ✓ Reviewed | USGS → |
A magnitude 2.5 seismic event took place 14 km SSW of Volcano, Hawaii on October 21, 2023 at 15:36 UTC. 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 M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-10-21 2023-10-21 15:21:42 UTC | 4.6mb | 39 km ENE of La Paz, Philippines 9.122°, 126.591° | 35.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.6 earthquake was recorded 39 km ENE of La Paz, Philippines on October 21, 2023 at 15:21 UTC. Coming 10 hours after a magnitude 4.7 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. | ||||||||
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 October 21, 2023. Data includes all events of magnitude 1.0 or greater. Past earthquake data is considered final after review by USGS seismologists.