Earthquakes on July 21, 2023
243
EARTHQUAKES on July 21, 2023
24-hour UTC period · USGS data
LARGEST: M5.7 — 151 km S of ‘Ohonua, Tonga
10 km deep
Normal activitycompared to daily average (~250/day)
Magnitude Breakdown
M5.0+
1
M4.0–4.9
34
M3.0–3.9
7
M2.0–2.9
44
M1.0–1.9
157
Activity Summary
243
Total earthquakes
~250
Daily average
Normal
Activity level
1
M5.0+ events
Geographic Breakdown
By US State
Top Countries (International)
Significant Earthquakes (M4.5+)
5.7
151 km S of ‘Ohonua, Tonga
19:01 UTC · 10.0 km deep
4.9
south of Tonga
22:09 UTC · 10.0 km deep
4.9
155 km SSW of ‘Ohonua, Tonga
19:06 UTC · 10.0 km deep
4.9
97 km N of Finschhafen, Papua New Guinea
09:31 UTC · 139.9 km deep
Felt by 2
4.9
36 km NW of Labuan Bajo, Indonesia
08:10 UTC · 157.1 km deep
Felt by 1
4.8
south of Tonga
18:57 UTC · 10.0 km deep
4.8
176 km S of Bengkulu, Indonesia
03:40 UTC · 24.9 km deep
Felt by 2
4.7
86 km NE of Sanana, Indonesia
00:33 UTC · 10.0 km deep
Earthquake Map — July 21, 2023
All Earthquakes — July 21, 2023
Showing 30 of 86 (filtered from 243)
(Filtered to M2.0+. Change the magnitude filter to see smaller events.)
| Time ↓ | Mag ↕ | Location ↕ | Depth ↕ | Felt ↕ | MMI | Alert | Status | Details |
|---|---|---|---|---|---|---|---|---|
2023-07-21 2023-07-21 23:43:21 UTC | 2.0ml | 15 km SW of Trapper Creek, Alaska 62.236°, -150.468° | 11.5 km | - | - | - | ✓ Reviewed | USGS → |
At 23:43 UTC on July 21, 2023, a magnitude 2.0 tremor occurred 15 km SW of Trapper Creek, Alaska. The event was offshore. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 23:22:22 UTC | 2.7ml | Rat Islands, Aleutian Islands, Alaska 51.813°, 178.533° | 104.1 km | - | - | - | ✓ Reviewed | USGS → |
July 21, 2023 brought a magnitude 2.7 earthquake near Rat Islands, Aleutian Islands, Alaska, logged at 23:22 UTC. See the M2.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 23:18:17 UTC | 2.6md | 2 km SE of Palmarejo, Puerto Rico 18.023°, -67.059° | 7.7 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.6 seismic event took place 2 km SE of Palmarejo, Puerto Rico on July 21, 2023 at 23:18 UTC. This event falls inside the aftershock decay of a nearby magnitude 2.8 earthquake that occurred about 23 hours earlier. The event was offshore. See the M2.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 22:41:40 UTC | 4.4mb | 86 km S of Banjar, Indonesia -7.980°, 107.401° | 54.7 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 4.4 event was detected 86 km S of Banjar, Indonesia on July 21, 2023, with origin time 22:41 UTC. The event was offshore. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 22:09:14 UTC | 4.9mb | south of Tonga -24.550°, -175.715° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.9 earthquake was recorded south of Tonga on July 21, 2023 at 22:09 UTC. See the M4.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 22:05:51 UTC | 4.1mb | 221 km SE of Attu Station, Alaska 51.541°, 175.639° | 30.0 km | - | I | - | ✓ Reviewed | USGS → |
A magnitude 4.1 earthquake was recorded 221 km SE of Attu Station, Alaska on July 21, 2023 at 22:05 UTC. The event was offshore. See the M4.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 21:42:21 UTC | 3.1ml | 21 km S of Antelope Valley-Crestview, Wyoming 44.038°, -105.436° | 0.0 km | - | - | - | ✓ Reviewed | USGS → |
July 21, 2023 brought a magnitude 3.1 earthquake 21 km S of Antelope Valley-Crestview, Wyoming, logged at 21:42 UTC. This very shallow event was close enough to the surface that even modest magnitudes can produce significant local shaking. See the M3.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 21:38:11 UTC | 4.3mb | 74 km ENE of Kainantu, Papua New Guinea -5.915°, 146.427° | 92.4 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 4.3 earthquake was recorded 74 km ENE of Kainantu, Papua New Guinea on July 21, 2023 at 21:38 UTC. See the M4.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 21:30:52 UTC | 4.4mb | off the west coast of northern Sumatra 0.561°, 92.350° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 4.4 earthquake near off the west coast of northern Sumatra came in on July 21, 2023 at 21:30 UTC. See the M4.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 21:29:26 UTC | 2.6ml | 8 km SE of Gardendale, Texas 31.969°, -102.312° | 7.9 km | 7 | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.6 earthquake 8 km SE of Gardendale, Texas with origin time 21:29 UTC on July 21, 2023. The event was offshore. See the M2.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 21:09:07 UTC | 2.5ml | 40 km ENE of Healy, Alaska 63.941°, -148.173° | 108.6 km | - | - | - | ✓ Reviewed | USGS → |
July 21, 2023 brought a magnitude 2.5 earthquake 40 km ENE of Healy, Alaska, logged at 21:09 UTC. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 21:09:05 UTC | 3.5ml | 32 km WNW of Kalifornsky, Alaska 60.491°, -151.868° | 77.9 km | - | II | - | ✓ Reviewed | USGS → |
This magnitude 3.5 event was detected 32 km WNW of Kalifornsky, Alaska on July 21, 2023, with origin time 21:09 UTC. See the M3.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 21:07:57 UTC | 2.6ml | 5 km SSE of Floriston, California 39.349°, -119.999° | 7.3 km | 2 | - | - | ✓ Reviewed | USGS → |
On July 21, 2023, worldwide seismic activity registered a magnitude 2.6 earthquake 5 km SSE of Floriston, California at 21:07 UTC. See the M2.6 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 20:10:21 UTC | 2.0ml | 48 km SW of Karluk, Alaska 57.243°, -154.985° | 52.3 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.0 earthquake 48 km SW of Karluk, Alaska at 20:10 UTC on July 21, 2023. The event was offshore. See the M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 20:05:46 UTC | 4.0mb | 75 km SE of Phek, India 25.164°, 95.008° | 86.9 km | - | - | - | ✓ Reviewed | USGS → |
At 20:05 UTC on July 21, 2023, a magnitude 4.0 tremor occurred 75 km SE of Phek, India. The event was offshore. See the M4.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 19:57:19 UTC | 3.2ml | Eastern Montana 45.501°, -108.854° | 5.0 km | 34 | - | - | ✓ Reviewed | USGS → |
A magnitude 3.2 seismic event took place near Eastern Montana on July 21, 2023 at 19:57 UTC. See the M3.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 19:45:21 UTC | 3.1ml | 65 km ENE of Adak, Alaska 52.161°, -175.802° | 156.6 km | - | - | - | ✓ Reviewed | USGS → |
On July 21, 2023 at 19:45 UTC, a magnitude 3.1 earthquake struck 65 km ENE of Adak, Alaska. See the M3.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 19:32:44 UTC | 4.5mb | 121 km E of ‘Ohonua, Tonga -21.371°, -173.781° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
On July 21, 2023 at 19:32 UTC, a magnitude 4.5 earthquake struck 121 km E of ‘Ohonua, Tonga. The event was offshore. See the M4.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 19:26:56 UTC | 2.3md | 10 km SSW of Guánica, Puerto Rico 17.893°, -66.960° | 11.8 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.3 seismic event took place 10 km SSW of Guánica, Puerto Rico on July 21, 2023 at 19:26 UTC. Coming 19 hours after a magnitude 2.8 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 19:24:48 UTC | 4.3mb | 26 km ESE of Bobon, Philippines 6.744°, 126.538° | 74.3 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 4.3 earthquake 26 km ESE of Bobon, Philippines with origin time 19:24 UTC on July 21, 2023. See the M4.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 19:21:37 UTC | 2.4md | 4 km NNE of La Parguera, Puerto Rico 18.011°, -67.038° | 13.1 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.4 earthquake 4 km NNE of La Parguera, Puerto Rico at 19:21 UTC on July 21, 2023. Coming 19 hours after a magnitude 2.8 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M2.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 19:06:56 UTC | 4.9mb | 155 km SSW of ‘Ohonua, Tonga -22.679°, -175.426° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 4.9 earthquake 155 km SSW of ‘Ohonua, Tonga with origin time 19:06 UTC on July 21, 2023. See the M4.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 19:01:43 UTC | 5.7mww | 151 km S of ‘Ohonua, Tonga -22.701°, -175.119° | 10.0 km | - | III | green | ✓ Reviewed | USGS → |
On July 21, 2023 at 19:01 UTC, a magnitude 5.7 earthquake struck 151 km S of ‘Ohonua, Tonga. The USGS PAGER system assigned a green alert level for this event, signalling no significant casualties or damage expected. It is the largest earthquake currently listed for worldwide seismic activity on July 21, 2023. See the M5.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 18:59:02 UTC | 2.8md | 43 km WNW of Petrolia, CA 40.405°, -124.784° | 19.2 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.8 seismic event took place 43 km WNW of Petrolia, CA on July 21, 2023 at 18:59 UTC. See the M2.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 18:57:17 UTC | 4.8mb | south of Tonga -24.518°, -175.815° | 10.0 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 4.8 earthquake south of Tonga at 18:57 UTC on July 21, 2023. See the M4.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 18:27:17 UTC | 2.9md | 47 km NW of Aguadilla, Puerto Rico 18.700°, -67.497° | 7.8 km | 1 | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.9 earthquake 47 km NW of Aguadilla, Puerto Rico with origin time 18:27 UTC on July 21, 2023. The event was offshore. See the M2.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 17:39:03 UTC | 2.5ml | 11 km SW of Brinnon, Washington 47.607°, -123.013° | 48.2 km | - | - | - | ✓ Reviewed | USGS → |
On July 21, 2023 at 17:39 UTC, a magnitude 2.5 earthquake struck 11 km SW of Brinnon, Washington. The event was offshore. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 17:27:26 UTC | 4.3mb | Banda Sea -6.651°, 129.813° | 160.6 km | - | - | - | ✓ Reviewed | USGS → |
On July 21, 2023, worldwide seismic activity registered a magnitude 4.3 earthquake near Banda Sea at 17:27 UTC. See the M4.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 17:26:07 UTC | 2.1ml | 19 km S of Nikolski, Alaska 52.761°, -168.834° | 45.0 km | - | - | - | ✓ Reviewed | USGS → |
Reports of a magnitude 2.1 earthquake 19 km S of Nikolski, Alaska came in on July 21, 2023 at 17:26 UTC. The event was offshore. See the M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-07-21 2023-07-21 17:25:10 UTC | 2.1md | 5 km ENE of Bonadelle Ranchos-Madera Ranchos, CA 37.001°, -119.819° | -0.6 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.1 earthquake 5 km ENE of Bonadelle Ranchos-Madera Ranchos, CA with origin time 17:25 UTC on July 21, 2023. 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. | ||||||||
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 July 21, 2023. Data includes all events of magnitude 1.0 or greater. Past earthquake data is considered final after review by USGS seismologists.