Reviewed by USGSIndonesia42y ago
M4.8 earthquake 182 km SSW of Sibolga, Indonesia
Wednesday, December 5, 1984, 05:36:00 UTC · 0.315°N, 97.948°E
A magnitude 4.8 earthquake struck 182 km SSW of Sibolga, Indonesia on Wednesday, December 5, 1984, 05:36:00 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.0 on November 17, 1984.
- Magnitude
- 4.8
- Light · mb
- Depth
- 33 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 earthquake
In context
How big was it, and why here?
Energy released
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
102 km
from the nearest mapped plate boundary, between the Sunda and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
33 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 50 km
USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 126 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 · 74 km SE of this epicenter
- 7.1190 km SSW of Sibolga, IndonesiaNovember 17, 1984 · 16 km SE of this epicenter
- 7.0122 km W of Pariaman, IndonesiaMay 8, 1946 · 167 km SE of this epicenter
- 7.0102 km SW of Padangsidempuan, IndonesiaFebruary 4, 1971 · 94 km E of this epicenter
- 6.9181 km SW of Sibolga, IndonesiaDecember 4, 1974 · 15 km NW of this epicenter
- 6.7214 km SW of Sibolga, IndonesiaMay 29, 1914 · 44 km W of this epicenter
- 6.768 km SE of Singkil, IndonesiaApril 1, 1921 · 166 km N of this epicenter
- 6.6142 km WNW of Pariaman, IndonesiaJanuary 2, 1936 · 121 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 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 · 154 km away · intensity IX
1,105 deathsModerate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 35 km away
950 deathsSevere damage ($5–24M)tsunami
- 1797M8.0
Sw. Sumatra
10 Feb 1797 · 122 km away · intensity IX
300 deathsModerate damage ($1–5M)tsunami
- 1843M7.3
Sw. Sumatra
5 Jan 1843 · 132 km away · intensity XI
Severe damage ($5–24M)tsunami
- 1935M7.9
N Sumatera: Batu I,Padang,Sibolga
28 Dec 1935 · 49 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1971M7.1
Natal, Sibolga, Tarutung, Pasaman
4 Feb 1971 · 100 km away · intensity VI
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.