Earthquakes on August 20, 2023
333
EARTHQUAKES on August 20, 2023
24-hour UTC period · USGS data
LARGEST: M5.7 — South Sandwich Islands region
79 km deep · 4 people felt it
Elevated activitycompared to daily average (~250/day)
Magnitude Breakdown
M5.0+
3
M4.0–4.9
24
M3.0–3.9
21
M2.0–2.9
77
M1.0–1.9
208
Activity Summary
333
Total earthquakes
~250
Daily average
Elevated
Activity level
3
M5.0+ events
Geographic Breakdown
By US State
Significant Earthquakes (M4.5+)
5.7
South Sandwich Islands region
19:59 UTC · 79.0 km deep
Felt by 4
5.2
179 km SE of Nikolski, Alaska
01:48 UTC · 10.0 km deep
5.1
7 km SE of Ojai, CA
21:41 UTC · 4.8 km deep
Felt by 20,504
4.9
Solomon Islands
13:23 UTC · 80.4 km deep
Felt by 1
4.7
103 km N of Dunbage, China
15:28 UTC · 10.0 km deep
4.7
51 km SW of Chauk, Myanmar
07:42 UTC · 61.1 km deep
4.5
79 km SSW of Sand Point, Alaska
20:56 UTC · 45.6 km deep
Felt by 2
4.5
141 km NE of Hihifo, Tonga
01:30 UTC · 10.0 km deep
Earthquake Map — August 20, 2023
All Earthquakes — August 20, 2023
Showing 30 of 125 (filtered from 333)
(Filtered to M2.0+. Change the magnitude filter to see smaller events.)
| Time ↓ | Mag ↕ | Location ↕ | Depth ↕ | Felt ↕ | MMI | Alert | Status | Details |
|---|---|---|---|---|---|---|---|---|
2023-08-20 2023-08-20 23:59:39 UTC | 2.3ml | 5 km SE of Ojai, CA 34.416°, -119.199° | 4.8 km | 9 | - | - | ✓ Reviewed | USGS → |
August 20, 2023 brought a magnitude 2.3 earthquake 5 km SE of Ojai, CA, logged at 23:59 UTC. Coming 2 hours after a magnitude 5.1 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 M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 23:57:19 UTC | 2.7ml | 56 km S of Whites City, New Mexico 31.668°, -104.377° | 4.9 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.7 earthquake 56 km S of Whites City, New Mexico with origin time 23:57 UTC on August 20, 2023. Coming 8 hours after a magnitude 3.4 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 M2.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 23:49:28 UTC | 2.3ml | 6 km SE of Ojai, CA 34.413°, -119.196° | 3.3 km | 5 | - | - | ✓ Reviewed | USGS → |
A magnitude 2.3 earthquake was recorded 6 km SE of Ojai, CA on August 20, 2023 at 23:49 UTC. This event falls inside the aftershock decay of a nearby magnitude 5.1 earthquake that occurred about 2 hours earlier. This very shallow event was close enough to the surface that even modest magnitudes can produce significant local shaking. See the M2.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 23:25:02 UTC | 2.2ml | 7 km E of Hebgen Lake Estates, Montana 44.778°, -111.099° | 8.0 km | - | - | - | ✓ Reviewed | USGS → |
Seismographs logged a magnitude 2.2 earthquake 7 km E of Hebgen Lake Estates, Montana with origin time 23:25 UTC on August 20, 2023. The event was offshore. See the M2.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 23:01:02 UTC | 2.1ml | 6 km SE of Ojai, CA 34.411°, -119.200° | 3.2 km | 9 | - | - | ✓ Reviewed | USGS → |
A magnitude 2.1 earthquake was recorded 6 km SE of Ojai, CA on August 20, 2023 at 23:01 UTC. It arrived roughly 1 hours after a larger magnitude 5.1 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 M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:55:15 UTC | 3.1ml | 8 km E of Ojai, CA 34.443°, -119.159° | 1.2 km | 57 | III | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 3.1 earthquake 8 km E of Ojai, CA at 22:55 UTC on August 20, 2023. It arrived roughly 1 hours after a larger magnitude 5.1 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 M3.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:52:49 UTC | 2.9ml | 8 km ESE of Ojai, CA 34.423°, -119.165° | 2.1 km | 8 | III | - | ✓ Reviewed | USGS → |
A magnitude 2.9 seismic event took place 8 km ESE of Ojai, CA on August 20, 2023 at 22:52 UTC. It arrived roughly 1 hours after a larger magnitude 5.1 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 M2.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:49:48 UTC | 2.5ml | 9 km SE of Desert Aire, Washington 46.621°, -119.824° | 7.5 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2023 at 22:49 UTC, a magnitude 2.5 earthquake struck 9 km SE of Desert Aire, Washington. The event was offshore. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:39:58 UTC | 2.1ml | 5 km SE of Ojai, CA 34.419°, -119.196° | 4.8 km | 13 | - | - | ✓ Reviewed | USGS → |
This magnitude 2.1 event was detected 5 km SE of Ojai, CA on August 20, 2023, with origin time 22:39 UTC. This event falls inside the aftershock decay of a nearby magnitude 5.1 earthquake that occurred about 1 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. | ||||||||
2023-08-20 2023-08-20 22:39:18 UTC | 2.0ml | 6 km ESE of Ojai, CA 34.425°, -119.188° | 4.3 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2023, worldwide seismic activity registered a magnitude 2.0 earthquake 6 km ESE of Ojai, CA at 22:39 UTC. Coming 1 hours after a magnitude 5.1 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 M2.0 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:38:35 UTC | 2.0ml | 7 km ESE of Ojai, CA 34.428°, -119.170° | 1.0 km | 1 | - | - | Auto | USGS → |
Seismographs logged a magnitude 2.0 earthquake 7 km ESE of Ojai, CA with origin time 22:38 UTC on August 20, 2023. This event falls inside the aftershock decay of a nearby magnitude 5.1 earthquake that occurred about 1 hours earlier. 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. | ||||||||
2023-08-20 2023-08-20 22:24:17 UTC | 2.1ml | 6 km ESE of Ojai, CA 34.424°, -119.186° | 3.1 km | 2 | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.1 earthquake 6 km ESE of Ojai, CA at 22:24 UTC on August 20, 2023. It arrived roughly 1 hours after a larger magnitude 5.1 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 M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:23:05 UTC | 2.8ml | 5 km ESE of Ojai, CA 34.438°, -119.186° | 2.0 km | 11 | - | - | ✓ Reviewed | USGS → |
On August 20, 2023 at 22:23 UTC, a magnitude 2.8 earthquake struck 5 km ESE of Ojai, CA. It arrived roughly 1 hours after a larger magnitude 5.1 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 M2.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:18:16 UTC | 3.9mw | 6 km SE of Ojai, CA 34.412°, -119.192° | 9.8 km | 256 | IV | - | ✓ Reviewed | USGS → |
Reports of a magnitude 3.9 earthquake 6 km SE of Ojai, CA came in on August 20, 2023 at 22:18 UTC. It arrived roughly 1 hours after a larger magnitude 5.1 mainshock in the same 20 km area, placing it within the typical aftershock window. The event was offshore. See the M3.9 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:16:12 UTC | 2.2ml | 6 km SE of Ojai, CA 34.415°, -119.192° | 2.4 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2023, worldwide seismic activity registered a magnitude 2.2 earthquake 6 km SE of Ojai, CA at 22:16 UTC. This event falls inside the aftershock decay of a nearby magnitude 5.1 earthquake that occurred about 1 hours earlier. 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. | ||||||||
2023-08-20 2023-08-20 22:15:35 UTC | 2.7ml | 6 km ESE of Ojai, CA 34.425°, -119.182° | 1.7 km | - | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.7 earthquake 6 km ESE of Ojai, CA at 22:15 UTC on August 20, 2023. Coming 1 hours after a magnitude 5.1 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 M2.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:08:52 UTC | 3.7mw | 7 km ESE of Ojai, CA 34.432°, -119.168° | 1.6 km | 189 | IV | - | ✓ Reviewed | USGS → |
August 20, 2023 brought a magnitude 3.7 earthquake 7 km ESE of Ojai, CA, logged at 22:08 UTC. Coming 1 hours after a magnitude 5.1 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 M3.7 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:07:17 UTC | 2.4ml | 8 km E of Ojai, CA 34.447°, -119.154° | 4.4 km | - | - | - | ✓ Reviewed | USGS → |
This magnitude 2.4 event was detected 8 km E of Ojai, CA on August 20, 2023, with origin time 22:07 UTC. Coming 1 hours after a magnitude 5.1 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 M2.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:07:13 UTC | 2.4ml | 6 km SE of Ojai, CA 34.417°, -119.197° | 2.9 km | - | - | - | ✓ Reviewed | USGS → |
A magnitude 2.4 seismic event took place 6 km SE of Ojai, CA on August 20, 2023 at 22:07 UTC. This event falls inside the aftershock decay of a nearby magnitude 5.1 earthquake that occurred about 1 hours earlier. 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. | ||||||||
2023-08-20 2023-08-20 22:05:18 UTC | 3.4ml | 11 km E of Pāhala, Hawaii 19.223°, -155.371° | 32.8 km | 2 | - | - | ✓ Reviewed | USGS → |
This magnitude 3.4 event was detected 11 km E of Pāhala, Hawaii on August 20, 2023, with origin time 22:05 UTC. The event was offshore. See the M3.4 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:05:01 UTC | 2.5ml | 6 km ESE of Ojai, CA 34.423°, -119.192° | 7.6 km | 1 | - | - | ✓ Reviewed | USGS → |
At 22:05 UTC on August 20, 2023, a magnitude 2.5 tremor occurred 6 km ESE of Ojai, CA. Coming 1 hours after a magnitude 5.1 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 22:01:30 UTC | 2.1ml | 5 km SE of Ojai, CA 34.418°, -119.199° | 4.5 km | - | - | - | ✓ Reviewed | USGS → |
At 22:01 UTC on August 20, 2023, a magnitude 2.1 tremor occurred 5 km SE of Ojai, CA. Coming 1 hours after a magnitude 5.1 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 M2.1 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 21:57:46 UTC | 4.3mb | 262 km WNW of Houma, Tonga -19.881°, -177.419° | 376.2 km | 1 | - | - | ✓ Reviewed | USGS → |
At 21:57 UTC on August 20, 2023, a magnitude 4.3 tremor occurred 262 km WNW of Houma, Tonga. This deep-focus earthquake originated far below the brittle crust, deep inside the mantle. See the M4.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 21:57:11 UTC | 2.0ml | 6 km ESE of Ojai, CA 34.420°, -119.181° | 2.4 km | 2 | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.0 earthquake 6 km ESE of Ojai, CA at 21:57 UTC on August 20, 2023. This event falls inside the aftershock decay of a nearby magnitude 5.1 earthquake that occurred about 1 hours earlier. 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. | ||||||||
2023-08-20 2023-08-20 21:56:01 UTC | 2.5ml | 7 km SE of Ojai, CA 34.409°, -119.182° | 10.1 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2023, worldwide seismic activity registered a magnitude 2.5 earthquake 7 km SE of Ojai, CA at 21:56 UTC. This event falls inside the aftershock decay of a nearby magnitude 5.1 earthquake that occurred about 1 hours earlier. The event was offshore. See the M2.5 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 21:55:42 UTC | 3.3ml | 7 km ESE of Ojai, CA 34.429°, -119.171° | 2.0 km | 182 | III | - | ✓ Reviewed | USGS → |
On August 20, 2023 at 21:55 UTC, a magnitude 3.3 earthquake struck 7 km ESE of Ojai, CA. This event falls inside the aftershock decay of a nearby magnitude 5.1 earthquake that occurred about 1 hours earlier. This very shallow event was close enough to the surface that even modest magnitudes can produce significant local shaking. See the M3.3 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 21:49:57 UTC | 2.3ml | 7 km ESE of Ojai, CA 34.419°, -119.180° | 6.3 km | 6 | - | - | ✓ Reviewed | USGS → |
This magnitude 2.3 event was detected 7 km ESE of Ojai, CA on August 20, 2023, with origin time 21:49 UTC. It arrived roughly 1 hours after a larger magnitude 5.1 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. | ||||||||
2023-08-20 2023-08-20 21:47:47 UTC | 2.8ml | 5 km E of Ojai, CA 34.444°, -119.187° | 1.4 km | - | - | - | ✓ Reviewed | USGS → |
On August 20, 2023, worldwide seismic activity registered a magnitude 2.8 earthquake 5 km E of Ojai, CA at 21:47 UTC. Coming 1 hours after a magnitude 5.1 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 M2.8 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 21:47:33 UTC | 3.2ml | 6 km SE of Ojai, CA 34.415°, -119.195° | 6.1 km | 111 | III | - | ✓ Reviewed | USGS → |
A magnitude 3.2 earthquake was recorded 6 km SE of Ojai, CA on August 20, 2023 at 21:47 UTC. Coming 1 hours after a magnitude 5.1 earthquake in the immediate vicinity, it is most likely an aftershock of that larger rupture. The event was offshore. See the M3.2 event page for the full report, ShakeMap, and citizen-reported intensity data. | ||||||||
2023-08-20 2023-08-20 21:47:28 UTC | 2.3ml | 7 km ESE of Ojai, CA 34.421°, -119.177° | 5.2 km | 2 | - | - | ✓ Reviewed | USGS → |
The USGS recorded this magnitude 2.3 earthquake 7 km ESE of Ojai, CA at 21:47 UTC on August 20, 2023. Coming 1 hours after a magnitude 5.1 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. | ||||||||
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 20, 2023. Data includes all events of magnitude 1.0 or greater. Past earthquake data is considered final after review by USGS seismologists.