M6.1 earthquake 263 km SW of Waingapu, Indonesia

Friday, August 19, 1977, 05:08:41 UTC · 11.145°S, 118.388°E

A magnitude 6.1 earthquake struck 263 km SW of Waingapu, Indonesia on Friday, August 19, 1977, 05:08:41 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M6.3 on January 2, 1977.

Magnitude: 6.1; Strong · mb
Depth: 33 km; Shallow
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: 100 km aftershock search area

In context

How big was it, and why here?

Energy released

21 kilotons of TNT

That is about the energy of the Hiroshima bomb. It released about 45 times the energy of a magnitude 5.0.

Tectonic setting

26 km

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

Depth: shallow

33 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

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 100 km

USGS lists 67 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M8.3 on August 19, 1977. 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 46 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 2 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 189 recorded deaths. The most severe:

1977M8.3
Sunda Islands
19 Aug 1977 · 2 km away
189 deaths$1 million damagetsunami
1837
Sumbawa Island: Bima
28 Nov 1837 · 294 km away · intensity IX
Limited damage (under $1M)

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

Nearby trackers