Reviewed by USGSIndonesia44y ago
M4.7 earthquake 71 km W of Banda Aceh, Indonesia
Friday, April 8, 1983, 06:21:24 UTC · 5.656°N, 94.694°E
A magnitude 4.7 earthquake struck 71 km W of Banda Aceh, Indonesia on Friday, April 8, 1983, 06:21:24 UTC, at a depth of 79.7 km (intermediate). It is the strongest earthquake within 300 km since an M5.0 on April 4, 1983.
- Magnitude
- 4.7
- Light · mb
- Depth
- 80 km
- Intermediate
- 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: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
169 tons of TNT
That is about 1/89 of the Hiroshima bomb. A magnitude 5.0 releases about 3 times more energy.
Tectonic setting
66 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: intermediate
80 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 50 km
USGS lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.2 on April 11, 1983. 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 118 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.0190 km WNW of Sabang, IndonesiaMay 17, 1955 · 159 km NW of this epicenter
- 7.040 km NE of Meulaboh, IndonesiaAugust 3, 1935 · 237 km SE of this epicenter
- 6.975 km WSW of Banda Aceh, IndonesiaAugust 23, 1936 · 44 km S of this epicenter
- 6.95 km W of Banda Aceh, IndonesiaApril 2, 1964 · 66 km E of this epicenter
- 6.968 km WSW of Sabang, IndonesiaApril 4, 1983 · 8 km NE of this epicenter
- 6.8238 km WNW of Sabang, IndonesiaJanuary 20, 1917 · 203 km NW of this epicenter
- 6.7171 km W of Meulaboh, IndonesiaDecember 9, 1929 · 170 km S of this epicenter
- 6.77 km SSE of Reuleuet, IndonesiaApril 12, 1967 · 186 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 18 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 23 recorded deaths. The most severe:
- 1967M6.1
N Sumatera,Malay Peninsula
12 Apr 1967 · 289 km away
14 deathsSevere damage ($5–24M)tsunami
- 1936M7.3
Banda Aceh,Lhok Sukon,Lhoksemawe
23 Aug 1936 · 49 km away · intensity VIII
9 deathsModerate damage ($1–5M)tsunami
- 1964M7.0
Banda Aceh
2 Apr 1964 · 115 km away · intensity VII
Severe damage ($5–24M)tsunami
- 1837M7.3
Banda Atjeh
29 Sep 1837 · 146 km away
Moderate damage ($1–5M)tsunami
- 1983M6.6
Sumatera: Banda Aceh
4 Apr 1983 · 8 km away · intensity VII
$1 million damage
- 1982M6.3
Little Nicobar Island
20 Jan 1982 · 163 km away · intensity VIII
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.