Earthquakes on August 21, 2023
372
EARTHQUAKES on August 21, 2023
24-hour UTC period · USGS data
LARGEST: M5.4 — 6 km N of Machala, Ecuador
40 km deep · 37 people felt it
Elevated activitycompared to daily average (~250/day)
Magnitude Breakdown
M5.0+
2
M4.0–4.9
32
M3.0–3.9
13
M2.0–2.9
79
M1.0–1.9
246
Activity Summary
372
Total earthquakes
~250
Daily average
Elevated
Activity level
2
M5.0+ events
Geographic Breakdown
By US State
Top Countries (International)
Significant Earthquakes (M4.5+)
5.4
6 km N of Machala, Ecuador
05:24 UTC · 40.4 km deep
Felt by 37
5.2
Flores Sea
10:01 UTC · 515.4 km deep
4.8
Vanuatu
04:15 UTC · 51.9 km deep
4.8
196 km SE of Pondaguitan, Philippines
02:54 UTC · 153.1 km deep
4.6
75 km NE of Sanana, Indonesia
22:55 UTC · 10.0 km deep
4.6
South Sandwich Islands region
22:28 UTC · 10.0 km deep
4.6
west of the Galapagos Islands
22:06 UTC · 10.0 km deep
4.6
125 km NNE of Tobelo, Indonesia
14:55 UTC · 235.3 km deep
0Earthquake Map — August 21, 2023
All Earthquakes — August 21, 2023
Showing 30 of 126 (filtered from 372)
(Filtered to M2.0+. Change the magnitude filter to see smaller events.)
| Time ↓ | Mag ↕ | Location ↕ | Depth ↕ | Felt ↕ | MMI | Alert | Status | Details |
|---|---|---|---|---|---|---|---|---|
2023-08-21 2023-08-21 23:55:57 UTC | 2.8ml | 55 km S of Whites City, New Mexico 31.671°, -104.398° | 7.4 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2023 at 23:55 UTC, a magnitude 2.8 earthquake struck 55 km S of Whites City, New Mexico. The event was offshore. See the M2.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 23:50:25 UTC | 3.3ml | 6 km SE of Ojai, CA 34.415°, -119.198° | 6.2 km | 146 | III | - | ✓ Reviewed | USGS → |
A magnitude 3.3 earthquake was recorded 6 km SE of Ojai, CA on August 21, 2023 at 23:50 UTC. Coming 18 hours after a magnitude 3.9 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. The event was offshore. See the M3.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 23:08:00 UTC | 2.0md | 9 km ENE of French Gulch, CA 40.736°, -122.533° | 15.6 km | - | - | - | ✓ Reviewed | USGS → |
At 23:08 UTC on August 21, 2023, a magnitude 2.0 tremor occurred 9 km ENE of French Gulch, CA. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 22:55:34 UTC | 4.6mb | 75 km NE of Sanana, Indonesia -1.530°, 126.413° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
At 22:55 UTC on August 21, 2023, a magnitude 4.6 tremor occurred 75 km NE of Sanana, Indonesia. The event was offshore. See the M4.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 22:34:59 UTC | 2.3md | 14 km WSW of Ferndale, CA 40.517°, -124.407° | 18.5 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2023 at 22:34 UTC, a magnitude 2.3 earthquake struck 14 km WSW of Ferndale, CA. See the M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 22:28:17 UTC | 4.6mb | South Sandwich Islands region -59.552°, -27.635° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.6 earthquake in the South Sandwich Islands region at 22:28 UTC on August 21, 2023. See the M4.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 22:14:48 UTC | 4.4mb | 56 km ENE of Kainantu, Papua New Guinea -6.102°, 146.345° | 94.6 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.4 earthquake 56 km ENE of Kainantu, Papua New Guinea at 22:14 UTC on August 21, 2023. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 22:06:19 UTC | 4.6mb | west of the Galapagos Islands 2.273°, -99.941° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 4.6 event was detected west of the Galapagos Islands on August 21, 2023, with origin time 22:06 UTC. See the M4.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 22:05:23 UTC | 3.7md | 32 km SE of Boca de Yuma, Dominican Republic 18.186°, -68.383° | 131.0 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 3.7 event was detected 32 km SE of Boca de Yuma, Dominican Republic on August 21, 2023, with origin time 22:05 UTC. The event was offshore. See the M3.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 22:02:34 UTC | 4.3mb | Mindanao, Philippines 7.831°, 126.888° | 9.6 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.3 seismic event took place near Mindanao, Philippines on August 21, 2023 at 22:02 UTC. See the M4.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 21:52:49 UTC | 2.7ml | Fox Islands, Aleutian Islands, Alaska 52.666°, -170.926° | 10.7 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2023, worldwide seismic activity registered a magnitude 2.7 earthquake near Fox Islands, Aleutian Islands, Alaska at 21:52 UTC. See the M2.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 21:32:27 UTC | 2.0md | 2 km ENE of Cantua Creek, CA 36.512°, -120.290° | 2.3 km | - | - | - | ✓ Reviewed | USGS → |
August 21, 2023 brought a magnitude 2.0 earthquake 2 km ENE of Cantua Creek, CA, logged at 21:32 UTC. 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. | ||||||||
2023-08-21 2023-08-21 21:15:43 UTC | 4.2mb | Fiji region -21.140°, -178.374° | 545.9 km | - | - | - | ✓ Reviewed | USGS → |
At 21:15 UTC on August 21, 2023, a magnitude 4.2 tremor occurred in the Fiji region. This is the deepest earthquake in the current dataset — a deep-focus event. See the M4.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 20:36:40 UTC | 2.1ml | 61 km W of Akhiok, Alaska 56.865°, -155.162° | 29.3 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2023 at 20:36 UTC, a magnitude 2.1 earthquake struck 61 km W of Akhiok, Alaska. The event was offshore. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 20:08:13 UTC | 2.4ml | 5 km NNW of Marble Falls, Texas 30.624°, -98.294° | 2.9 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 2.4 event was detected 5 km NNW of Marble Falls, Texas on August 21, 2023, with origin time 20:08 UTC. 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. | ||||||||
2023-08-21 2023-08-21 20:01:18 UTC | 2.1ml | 284 km WSW of Adak, Alaska 51.437°, 179.322° | 56.2 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.1 earthquake was recorded 284 km WSW of Adak, Alaska on August 21, 2023 at 20:01 UTC. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 19:47:29 UTC | 2.0ml | 78 km ENE of Ugashik, Alaska 57.728°, -156.142° | 104.2 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.0 earthquake 78 km ENE of Ugashik, Alaska with origin time 19:47 UTC on August 21, 2023. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 19:01:29 UTC | 2.0ml | 110 km WSW of Adak, Alaska 51.517°, -178.123° | 6.6 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2023, worldwide seismic activity registered a magnitude 2.0 earthquake 110 km WSW of Adak, Alaska at 19:01 UTC. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 19:00:58 UTC | 2.0ml | 85 km SSW of Kaktovik, Alaska 69.382°, -144.077° | 9.6 km | - | - | - | ✓ Reviewed | USGS → |
At 19:00 UTC on August 21, 2023, a magnitude 2.0 tremor occurred 85 km SSW of Kaktovik, Alaska. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 18:54:09 UTC | 2.1ml | 45 km NW of Island Park, Idaho 44.696°, -111.804° | 10.4 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 2.1 event was detected 45 km NW of Island Park, Idaho on August 21, 2023, with origin time 18:54 UTC. The event was offshore. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 18:29:57 UTC | 4.3mb | 72 km W of Masachapa, Nicaragua 11.804°, -87.178° | 49.3 km | - | - | - | ✓ Reviewed | USGS → |
August 21, 2023 brought a magnitude 4.3 earthquake 72 km W of Masachapa, Nicaragua, logged at 18:29 UTC. The event was offshore. See the M4.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 18:12:13 UTC | 2.0md | 4 km WSW of Guánica, Puerto Rico 17.953°, -66.944° | 10.5 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.0 earthquake 4 km WSW of Guánica, Puerto Rico at 18:12 UTC on August 21, 2023. This event falls inside the aftershock decay of a nearby magnitude 2.7 earthquake that occurred about 18 hours earlier. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 18:06:10 UTC | 2.5md | 6 km E of La Parguera, Puerto Rico 17.985°, -66.984° | 9.6 km | - | - | - | ✓ Reviewed | USGS → |
At 18:06 UTC on August 21, 2023, a magnitude 2.5 tremor occurred 6 km E of La Parguera, Puerto Rico. This event falls inside the aftershock decay of a nearby magnitude 2.7 earthquake that occurred about 18 hours earlier. The event was offshore. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 18:03:48 UTC | 3.5ml | 24 km ENE of Wright, Wyoming 43.826°, -105.211° | 0.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 3.5 seismic event took place 24 km ENE of Wright, Wyoming on August 21, 2023 at 18:03 UTC. This very shallow event was close enough to the surface that even modest magnitudes can produce significant local shaking. See the M3.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 17:41:34 UTC | 4.3mb | 50 km ESE of Onagawa Chō, Japan 38.264°, 141.976° | 51.4 km | - | - | - | ✓ Reviewed | USGS → |
On August 21, 2023 at 17:41 UTC, a magnitude 4.3 earthquake struck 50 km ESE of Onagawa Chō, Japan. See the M4.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 17:39:01 UTC | 2.4md | 14 km NW of Aguada, Puerto Rico 18.468°, -67.287° | 19.9 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.4 earthquake 14 km NW of Aguada, Puerto Rico at 17:39 UTC on August 21, 2023. The event was offshore. See the M2.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 17:37:04 UTC | 4.1mb | 110 km NNW of Manado, Indonesia 2.336°, 124.332° | 294.1 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.1 seismic event took place 110 km NNW of Manado, Indonesia on August 21, 2023 at 17:37 UTC. See the M4.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 17:26:07 UTC | 2.1ml | 7 km SE of Ojai, CA 34.405°, -119.189° | 1.6 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.1 seismic event took place 7 km SE of Ojai, CA on August 21, 2023 at 17:26 UTC. This event falls inside the aftershock decay of a nearby magnitude 3.9 earthquake that occurred about 12 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. | ||||||||
2023-08-21 2023-08-21 17:20:39 UTC | 4.2mb | 183 km NNE of Codrington, Antigua and Barbuda 19.231°, -61.323° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.2 earthquake 183 km NNE of Codrington, Antigua and Barbuda at 17:20 UTC on August 21, 2023. See the M4.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-21 2023-08-21 17:17:35 UTC | 2.6ml | 70 km SSE of Perryville, Alaska 55.291°, -158.896° | 10.4 km | - | - | - | ✓ Reviewed | USGS → |
August 21, 2023 brought a magnitude 2.6 earthquake 70 km SSE of Perryville, Alaska, logged at 17:17 UTC. See the M2.6 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 August 21, 2023. Data includes all events of magnitude 1.0 or greater. Past earthquake data is considered final after review by USGS seismologists.