Reviewed by USGSIndonesia Earthquake49y ago
M8.3 earthquake 1977 Sumba, Indonesia Earthquake
Friday, August 19, 1977, 06:08:54 UTC · 11.154°S, 118.385°E
A magnitude 8.3 earthquake struck 1977 Sumba, Indonesia Earthquake on Friday, August 19, 1977, 06:08:54 UTC, at a depth of 15.9 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 8.3
- Great · mw
- Depth
- 16 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- V
- Moderate (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 400 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
43 megatons of TNT
That is about 2,823 times the Hiroshima bomb. It released about 89,125 times the energy of a magnitude 5.0.
Tectonic setting
25 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
16 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 400 km
USGS lists 124 M2.5+ earthquakes within 400 km in the following 30 days; the largest was M6.1 on August 25, 1977. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 5.1south of Sumba, Indonesia49y ago · 114 km E of this epicenter
- 4.6south of Sumbawa, Indonesia49y ago · 67 km SW of this epicenter
- 5.2219 km S of Sumbawa Besar, Indonesia49y ago · 111 km NW of this epicenter
- 5.5south of Sumbawa, Indonesia49y ago · 40 km SW of this epicenter
- 5.2181 km S of Dompu, Indonesia49y ago · 112 km N of this epicenter
- 4.8South of Lombok, Indonesia49y ago · 207 km SW of this epicenter
- 5.1211 km SSW of Waingapu, Indonesia49y ago · 93 km E of this epicenter
- 5.1211 km S of Sumbawa Besar, Indonesia49y ago · 132 km NW of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 47 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.084 km SSE of Dompu, IndonesiaMay 9, 1922 · 212 km N of this epicenter
- 6.4248 km S of Taliwang, IndonesiaMay 28, 1972 · 158 km W of this epicenter
- 6.377 km WSW of Waingapu, IndonesiaOctober 15, 1923 · 191 km NE of this epicenter
- 6.362 km S of Waingapu, IndonesiaOctober 15, 1923 · 230 km NE of this epicenter
- 6.3139 km SSE of Dompu, IndonesiaDecember 21, 1938 · 161 km N of this epicenter
- 6.3151 km WSW of Waingapu, IndonesiaJanuary 2, 1977 · 128 km NE of this epicenter
- 6.384 km S of Komodo, IndonesiaJanuary 2, 1936 · 238 km NE of this epicenter
- 6.3139 km WSW of Waingapu, IndonesiaApril 13, 1951 · 151 km NE of this epicenter
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 · 1 km away
189 deaths$1 million damagetsunami
- 1837
Sumbawa Island: Bima
28 Nov 1837 · 295 km away · intensity IX
Limited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.