Reviewed by USGSIndonesia50y ago
M5.1 earthquake 77 km S of Meulaboh, Indonesia
Saturday, August 21, 1976, 12:46:24 UTC · 3.444°N, 96.182°E
A magnitude 5.1 earthquake struck 77 km S of Meulaboh, Indonesia on Saturday, August 21, 1976, 12:46:24 UTC, at a depth of 45.0 km (shallow). It is the strongest earthquake within 300 km since an M5.2 on July 23, 1976.
- Magnitude
- 5.1
- Moderate · mb
- Depth
- 45 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
674 tons of TNT
That is about 1/22 of the Hiroshima bomb. It released about 1 times the energy of a magnitude 5.0.
Tectonic setting
33 km
from the nearest mapped plate boundary, between the Cocos and Nazca plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
45 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 2 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.1 on August 29, 1976. 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 98 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 · 112 km SW of this epicenter
- 7.5209 km WSW of Sinabang, IndonesiaNovember 21, 1969 · 240 km SW of this epicenter
- 7.186 km WSW of Pangkalan Brandan, IndonesiaSeptember 19, 1936 · 157 km E of this epicenter
- 7.040 km NE of Meulaboh, IndonesiaAugust 3, 1935 · 107 km N of this epicenter
- 7.085 km SSE of Meulaboh, IndonesiaJune 20, 1976 · 16 km E of this epicenter
- 6.928 km NNE of Sinabang, IndonesiaNovember 4, 1917 · 90 km SE of this epicenter
- 6.975 km WSW of Banda Aceh, IndonesiaAugust 23, 1936 · 259 km NW of this epicenter
- 6.95 km W of Banda Aceh, IndonesiaApril 2, 1964 · 254 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 16 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,219 recorded deaths. The most severe:
- 1907M8.2
Nw Sumatra: Gunungsitoli, Barus
4 Jan 1907 · 112 km away
2,188 deathsSevere damage ($5–24M)tsunami
- 1936
N Sumatera: Tapanuli, Karo
9 Sep 1936 · 146 km away · intensity VIII
17 deathsModerate damage ($1–5M)
- 1967M6.1
N Sumatera,Malay Peninsula
12 Apr 1967 · 260 km away
14 deathsSevere damage ($5–24M)tsunami
- 1843M7.3
Sw. Sumatra
5 Jan 1843 · 296 km away · intensity XI
Severe damage ($5–24M)tsunami
- 1964M7.0
Banda Aceh
2 Apr 1964 · 278 km away · intensity VII
Severe damage ($5–24M)tsunami
- 1837M7.3
Banda Atjeh
29 Sep 1837 · 230 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.