Reviewed by USGSIndonesia71y ago
M6.3 earthquake 75 km SSE of Sinabang, Indonesia
Monday, April 2, 1956, 10:50:00 UTC · 1.864°N, 96.667°E
A magnitude 6.3 earthquake struck 75 km SSE of Sinabang, Indonesia on Monday, April 2, 1956, 10:50:00 UTC, at a depth of 29.9 km (shallow). It is the strongest earthquake within 300 km since an M6.3 on August 29, 1950.
- Magnitude
- 6.3
- Strong · mw
- Depth
- 30 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 earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
44 kilotons of TNT
That is about 3 times the Hiroshima bomb. It released about 92 times the energy of a magnitude 5.0.
Tectonic setting
9 km
from the nearest mapped plate boundary, between the Sunda and Burma plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
30 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 48 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.2The 1907 Sumatra Earthquake and TsunamiJanuary 4, 1907 · 156 km NW of this epicenter
- 7.6212 km W of Pariaman, IndonesiaDecember 28, 1935 · 296 km SE of this epicenter
- 7.186 km WSW of Pangkalan Brandan, IndonesiaSeptember 19, 1936 · 226 km NE of this epicenter
- 7.040 km NE of Meulaboh, IndonesiaAugust 3, 1935 · 281 km N of this epicenter
- 6.928 km NNE of Sinabang, IndonesiaNovember 4, 1917 · 95 km N of this epicenter
- 6.860 km W of Sinabang, IndonesiaNovember 2, 1908 · 119 km NW of this epicenter
- 6.7214 km SW of Sibolga, IndonesiaMay 29, 1914 · 205 km SE of this epicenter
- 6.768 km SE of Singkil, IndonesiaApril 1, 1921 · 167 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,155 recorded deaths. The most severe:
- 1907M8.2
Nw Sumatra: Gunungsitoli, Barus
4 Jan 1907 · 156 km away
2,188 deathsSevere damage ($5–24M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 254 km away
950 deathsSevere damage ($5–24M)tsunami
- 1936
N Sumatera: Tapanuli, Karo
9 Sep 1936 · 204 km away · intensity VIII
17 deathsModerate damage ($1–5M)
- 1843M7.3
Sw. Sumatra
5 Jan 1843 · 154 km away · intensity XI
Severe damage ($5–24M)tsunami
- 1935M7.9
N Sumatera: Batu I,Padang,Sibolga
28 Dec 1935 · 272 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
26 Apr 1861 · 133 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.