Reviewed by USGSIndonesia49y ago
M5.3 earthquake 146 km SSW of Sumbawa Besar, Indonesia
Thursday, October 20, 1977, 11:35:23 UTC · 9.776°S, 117.098°E
A magnitude 5.3 earthquake struck 146 km SSW of Sumbawa Besar, Indonesia on Thursday, October 20, 1977, 11:35:23 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.3 on October 18, 1977.
- Magnitude
- 5.3
- Moderate · ms
- 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: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
1 kilotons of TNT
That is about 1/11 of the Hiroshima bomb. It released about 3 times the energy of a magnitude 5.0.
Tectonic setting
172 km
from the nearest mapped plate boundary, between the Sunda and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
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 75 km
USGS lists 3 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.6 on October 25, 1977. 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 192 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.31977 Sumba, Indonesia EarthquakeAugust 19, 1977 · 208 km SE of this epicenter
- 7.0133 km NNE of Pototano, IndonesiaJuly 5, 1911 · 291 km N of this epicenter
- 7.084 km SSE of Dompu, IndonesiaMay 9, 1922 · 183 km E of this epicenter
- 6.746 km NE of Bima, IndonesiaNovember 2, 1954 · 277 km NE of this epicenter
- 6.57 km WNW of Ubud, IndonesiaJanuary 20, 1917 · 253 km NW of this epicenter
- 6.4248 km S of Taliwang, IndonesiaMay 28, 1972 · 136 km S of this epicenter
- 6.377 km WSW of Waingapu, IndonesiaOctober 15, 1923 · 277 km E of this epicenter
- 6.3161 km S of Sumbawa Besar, IndonesiaOctober 7, 1977 · 31 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 9 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 225 recorded deaths. The most severe:
- 1977M8.3
Sunda Islands
19 Aug 1977 · 208 km away
189 deaths$1 million damagetsunami
- 1857M7.0
Timor Island:: Dilhi, Gera
13 May 1857 · 264 km away
36 deathsModerate damage ($1–5M)tsunami
- 1836M7.5
Flores Sea
28 Nov 1836 · 241 km away
Limited damage (under $1M)tsunami
- 1954M6.8
Sumabawa: Bima,Raba
2 Nov 1954 · 288 km away · intensity VIII
Limited damage (under $1M)
- 1977M5.2
Bali: Kayubihi,Banjar Antugan Jehem
26 Jan 1977 · 272 km away · intensity VI
Limited damage (under $1M)
- 1837
Sumbawa Island: Bima
28 Nov 1837 · 209 km away · intensity IX
Limited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.