M5.5 earthquake 35 km NNE of Ruteng, Indonesia

Monday, September 21, 2026, 01:41:36 UTC · 8.307°S, 120.579°E

A magnitude 5.5 earthquake struck 35 km NNE of Ruteng, Indonesia on Monday, September 21, 2026, 01:41:36 UTC, at a depth of 10.0 km (shallow). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M5.6 on August 20, 2026.

Magnitude: 5.5; Moderate · mb
Depth: 10 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: VII; Very strong (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

1 km

from the nearest mapped plate boundary, between the Sunda and Timor plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

10 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

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

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

VII · Very strong shaking: 2,800 people
VI · Strong shaking: 23,000 people
V · Moderate shaking: 64,000 people
IV · Light shaking: 989,000 people
III · Weak shaking: 167,000 people

Estimated shaking in nearby towns

RutengPopulation 54,000IV · Light
PajoPopulation 13,000IV · Light
JaongPopulation 2,200IV · Light
LungarPopulation 1,200IV · Light
Labuan BajoPopulation 5,800IV · Light
MaunuraPopulation 5,000III · Weak

After the main event

Aftershocks within 75 km

USGS lists 3 M2.5+ earthquakes within 75 km since this event; the largest was M5.0 on September 26, 2026. 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 616 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 21 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,167 recorded deaths. The most severe:

1992M7.8
Flores Region, Maumere, Babi
12 Dec 1992 · 146 km away · intensity XI
2,500 deaths$100 million damagetsunami
1820M7.5
Sulawesi: Makasar
29 Dec 1820 · 227 km away · intensity X
500 deathsModerate damage ($1–5M)tsunami
2026M7.7
Flores Region
14 Aug 2026 · 85 km away · intensity VII
142 deathsExtreme damage ($25M+)tsunami
1982M5.9
Flores Island: Eastern
25 Dec 1982 · 275 km away
13 deaths$1 million damagetsunami
2003M6.5
Flores: Reo
25 Mar 2003 · 18 km away
4 deathsLimited damage (under $1M)
2007M6.5
Sumbawa Island
25 Nov 2007 · 247 km away
3 deathsModerate damage ($1–5M)

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

Nearby trackers