Reviewed by USGSTimor Leste3y ago
M4.1 earthquake 233 km ENE of Lospalos, Timor Leste
Thursday, August 31, 2023, 10:02:54 UTC · 7.368°S, 128.770°E
A magnitude 4.1 earthquake struck 233 km ENE of Lospalos, Timor Leste on Thursday, August 31, 2023, 10:02:54 UTC, at a depth of 160.7 km (intermediate).
- Magnitude
- 4.1
- Light · mb
- Depth
- 161 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
21 tons of TNT
That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.
Tectonic setting
80 km
from the nearest mapped plate boundary, between the Banda Sea and Timor plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
161 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 50 km
USGS lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.8 on September 25, 2023. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,425 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11963 Banda Sea EarthquakeNovember 4, 1963 · 103 km NE of this epicenter
- 7.7Banda SeaNovember 2, 1950 · 76 km NE of this epicenter
- 7.6Pulau Pulau Tanimbar, IndonesiaJanuary 9, 2023 · 141 km E of this epicenter
- 7.6196 km S of Ambon, IndonesiaJanuary 27, 2006 · 222 km N of this epicenter
- 7.5273 km WSW of Tual, IndonesiaJune 3, 1927 · 209 km E of this epicenter
- 7.3145 km NNE of Lospalos, Timor LesteAugust 30, 1917 · 126 km W of this epicenter
- 7.3125 km NNE of Lospalos, Timor LesteDecember 29, 2021 · 133 km W of this epicenter
- 7.3281 km WSW of Tual, IndonesiaDecember 20, 1992 · 199 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 68 recorded deaths. The most severe:
- 1852M8.3
Maluku: Bandanaira
25 Nov 1852 · 259 km away · intensity IX
60 deathsSevere damage ($5–24M)tsunami
- 1763
Bandaneira
12 Sep 1763 · 204 km away · intensity X
7 deathsModerate damage ($1–5M)tsunami
- 2023M7.6
Banda Sea
9 Jan 2023 · 144 km away · intensity V
1 deathModerate damage ($1–5M)tsunami
- 1975M5.9
Maluku: Bandanaira
15 Jan 1975 · 296 km away · intensity VII
Moderate damage ($1–5M)tsunami
- 1963M8.3
Banda Sea
4 Nov 1963 · 106 km away
Limited damage (under $1M)
- 1908M6.6
Timor
23 Mar 1908 · 294 km away
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.