Reviewed by USGSIndonesia52y ago
M6.9 earthquake 181 km SW of Sibolga, Indonesia
Wednesday, December 4, 1974, 03:07:46 UTC · 0.393°N, 97.843°E
A magnitude 6.9 earthquake struck 181 km SW of Sibolga, Indonesia on Wednesday, December 4, 1974, 03:07:46 UTC, at a depth of 20.0 km (shallow). It is the strongest earthquake within 300 km since an M7.0 on February 4, 1971.
- Magnitude
- 6.9
- Strong · ms
- Depth
- 20 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
338 kilotons of TNT
That is about 22 times the Hiroshima bomb. It released about 708 times the energy of a magnitude 5.0.
Tectonic setting
96 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
20 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 has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 77 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.6212 km W of Pariaman, IndonesiaDecember 28, 1935 · 87 km SE of this epicenter
- 7.0122 km W of Pariaman, IndonesiaMay 8, 1946 · 181 km SE of this epicenter
- 7.0102 km SW of Padangsidempuan, IndonesiaFebruary 4, 1971 · 103 km E of this epicenter
- 6.928 km NNE of Sinabang, IndonesiaNovember 4, 1917 · 297 km NW of this epicenter
- 6.7214 km SW of Sibolga, IndonesiaMay 29, 1914 · 36 km SW of this epicenter
- 6.768 km SE of Singkil, IndonesiaApril 1, 1921 · 160 km N of this epicenter
- 6.6142 km WNW of Pariaman, IndonesiaJanuary 2, 1936 · 135 km SE of this epicenter
- 6.6150 km WNW of Pariaman, IndonesiaMay 24, 1952 · 133 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,355 recorded deaths. The most severe:
- 1861M8.5
Lagundi, Simuk, Tello I
16 Feb 1861 · 160 km away · intensity IX
1,105 deathsModerate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 46 km away
950 deathsSevere damage ($5–24M)tsunami
- 1797M8.0
Sw. Sumatra
10 Feb 1797 · 136 km away · intensity IX
300 deathsModerate damage ($1–5M)tsunami
- 1843M7.3
Sw. Sumatra
5 Jan 1843 · 124 km away · intensity XI
Severe damage ($5–24M)tsunami
- 1935M7.9
N Sumatera: Batu I,Padang,Sibolga
28 Dec 1935 · 63 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1971M7.1
Natal, Sibolga, Tarutung, Pasaman
4 Feb 1971 · 109 km away · intensity VI
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.