M5.5 earthquake 288 km ENE of Lospalos, Timor Leste

Thursday, October 26, 2023, 05:44:18 UTC · 7.150°S, 129.224°E

A magnitude 5.5 earthquake struck 288 km ENE of Lospalos, Timor Leste on Thursday, October 26, 2023, 05:44:18 UTC, at a depth of 154.0 km (intermediate). USGS received 9 “Did You Feel It?” reports, with a maximum reported intensity of III (weak). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M5.8 on September 22, 2023.

Magnitude: 5.5; Moderate · mww
Depth: 154 km; Intermediate
Felt reports: 9; Max intensity III
Est. shaking: IV; Light (ShakeMap)
PAGER alert: Green; Impact estimate
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 75 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

3 kilotons of TNT

That is about 1/6 of the Hiroshima bomb. It released about 6 times the energy of a magnitude 5.0.

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

154 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

Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.

Place	Intensity	Reports	Distance
Darwin, Northern Territory, Australia	III · Weak	3	628 km
Dare, Dili, East Timor	III · Weak	1	461 km
Humpty Doo-MacMinns Lagoon, Northern Territory, Australia	III · Weak	1	645 km

I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

Modelled from the ShakeMap and population data. Alert level green: low likelihood of casualties and damage.

IV · Light shaking: 13,000 people
III · Weak shaking: 93,000 people

Estimated shaking in nearby towns

TiakurPopulation 0III · Weak

After the main event

Aftershocks within 75 km

USGS lists 5 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M4.6 on November 7, 2023. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,504 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 14 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 · 219 km away · intensity IX
60 deathsSevere damage ($5–24M)tsunami
1763
Bandaneira
12 Sep 1763 · 154 km away · intensity X
7 deathsModerate damage ($1–5M)tsunami
2023M7.6
Banda Sea
9 Jan 2023 · 90 km away · intensity V
1 deathModerate damage ($1–5M)tsunami
1975M5.9
Maluku: Bandanaira
15 Jan 1975 · 254 km away · intensity VII
Moderate damage ($1–5M)tsunami
1963M8.3
Banda Sea
4 Nov 1963 · 51 km away
Limited damage (under $1M)
1852M7.0
Bandaneira
24 Dec 1852 · 278 km away
Limited damage (under $1M)tsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers