Reviewed by USGSIndonesia59y ago
M6.9 earthquake 77 km NNW of Masamba, Indonesia
Friday, June 7, 1968, 11:57:31 UTC · 1.899°S, 120.078°E
A magnitude 6.9 earthquake struck 77 km NNW of Masamba, Indonesia on Friday, June 7, 1968, 11:57:31 UTC, at a depth of 23.6 km (shallow). It is the strongest earthquake within 300 km since an M7.7 on May 19, 1938.
- Magnitude
- 6.9
- Strong · mw
- Depth
- 24 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- Strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
294 kilotons of TNT
That is about 20 times the Hiroshima bomb. It released about 617 times the energy of a magnitude 5.0.
Tectonic setting
60 km
from the nearest mapped plate boundary, between the Molucca Sea and Banda Sea plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
24 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 1 M2.5+ earthquake within 100 km in the following 30 days; the largest was M6.2 on June 7, 1968. 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 41 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.7120 km NE of Palu, IndonesiaMay 19, 1938 · 212 km N of this epicenter
- 6.8161 km S of Luwuk, IndonesiaNovember 19, 1913 · 276 km E of this epicenter
- 6.8109 km WSW of Luwuk, IndonesiaMarch 17, 1909 · 210 km E of this epicenter
- 6.747 km WNW of Luwuk, IndonesiaJune 30, 1964 · 289 km NE of this epicenter
- 6.753 km W of Luwuk, IndonesiaApril 23, 1966 · 269 km NE of this epicenter
- 6.6108 km NNE of Palu, IndonesiaOctober 15, 1959 · 216 km N of this epicenter
- 6.6117 km E of Palopo, IndonesiaFebruary 13, 1924 · 184 km SE of this epicenter
- 6.628 km E of Poso, IndonesiaDecember 5, 1923 · 117 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 346 recorded deaths. The most severe:
- 1968M7.4
Sulawesi: Tambu,Coast Of Mapaga
14 Aug 1968 · 235 km away · intensity VIII
200 deathsSevere damage ($5–24M)tsunami
- 1967M5.5
Makassar Strait
11 Apr 1967 · 218 km away · intensity VIII
71 deathsModerate damage ($1–5M)tsunami
- 1927M6.2
Sulawesi: Donggala
1 Dec 1927 · 136 km away · intensity VII
50 deathsSevere damage ($5–24M)tsunami
- 1938M7.7
Sulawesi Island
19 May 1938 · 212 km away · intensity IX
17 deathsSevere damage ($5–24M)tsunami
- 1964M5.2
Sulawesi: Pinrang
8 Jan 1964 · 214 km away
8 deathsModerate damage ($1–5M)
- 1907
Sulawesi: Lemo, Colo, Anja, Olu Congko
30 Jul 1907 · 103 km away · intensity VIII
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.