Reviewed by USGSIndonesia50y ago
M5.6 earthquake in Papua, Indonesia
Saturday, July 24, 1976, 23:26:20 UTC · 4.534°S, 139.949°E
A magnitude 5.6 earthquake struck in Papua, Indonesia on Saturday, July 24, 1976, 23:26:20 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.6 on July 17, 1976.
- Magnitude
- 5.6
- Moderate · mb
- Depth
- 33 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- V
- Moderate (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 75 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
4 kilotons of TNT
That is about 1/4 of the Hiroshima bomb. It released about 8 times the energy of a magnitude 5.0.
Tectonic setting
30 km
from the nearest mapped plate boundary, between the Australian and Maoke plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
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 75 km
USGS lists 4 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.2 on July 26, 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 154 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8230 km W of Abepura, IndonesiaJune 1, 1906 · 274 km NW of this epicenter
- 7.8New Guinea, Papua New GuineaSeptember 20, 1935 · 175 km NE of this epicenter
- 7.7120 km SW of Abepura, IndonesiaJanuary 10, 1971 · 149 km N of this epicenter
- 7.6158 km WSW of Abepura, IndonesiaOctober 26, 1926 · 200 km NW of this epicenter
- 7.5143 km WSW of Abepura, IndonesiaMay 28, 1968 · 196 km N of this epicenter
- 7.593 km SW of Aitape, Papua New GuineaJuly 29, 1917 · 218 km NE of this epicenter
- 7.1214 km NW of Kiunga, Papua New GuineaJune 25, 1976 · 18 km SE of this epicenter
- 7.143 km SW of Aitape, Papua New GuineaAugust 7, 1931 · 265 km NE 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 6,138 recorded deaths. The most severe:
- 1976M7.1
New Guinea: Irian Jaya
25 Jun 1976 · 18 km away
6,000 deathsSevere damage ($5–24M)
- 1976M7.1
New Guinea: Irian Jaya: Jayawijaya
29 Oct 1976 · 4 km away · intensity VIII
133 deathsLimited damage (under $1M)
- 1900M6.9
Nw. Irian Jaya
7 Oct 1900 · 60 km away
5 deathsLimited damage (under $1M)tsunami
- 1971M8.1
New Guinea: Irian Jaya:Djajapura,Sentani
10 Jan 1971 · 162 km away · intensity IX
Moderate damage ($1–5M)
- 1921
New Guinea: Irian Jaya: Sentani
10 Oct 1921 · 279 km away · intensity VII
Moderate damage ($1–5M)
- 1951M6.1
Bismarck Sea
22 Feb 1951 · 291 km away
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.