Reviewed by USGSChina50y ago
M4.9 earthquake 100 km NW of Dadukou, China
Tuesday, December 21, 1976, 18:37:12 UTC · 27.294°N, 101.130°E
A magnitude 4.9 earthquake struck 100 km NW of Dadukou, China on Tuesday, December 21, 1976, 18:37:12 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.0 on December 14, 1976.
- Magnitude
- 4.9
- 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
338 tons of TNT
That is about 1/45 of the Hiroshima bomb. A magnitude 5.0 releases about 1 times more energy.
Tectonic setting
365 km
from the nearest mapped plate boundary, between the Indian and Eurasian 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 80 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.824 km NE of Dali, ChinaMarch 16, 1925 · 187 km SW of this epicenter
- 6.892 km SSW of Luocheng, ChinaMay 16, 1936 · 289 km NE of this epicenter
- 6.8143 km WSW of Kangding, ChinaFebruary 9, 1908 · 240 km N of this epicenter
- 6.793 km SSW of Luocheng, ChinaApril 26, 1936 · 288 km NE of this epicenter
- 6.711 km SE of Dadukou, ChinaSeptember 23, 1955 · 112 km SE of this epicenter
- 6.659 km N of Xichang, ChinaSeptember 30, 1952 · 168 km NE of this epicenter
- 6.5115 km NE of Lijiang, ChinaNovember 6, 1976 · 35 km N of this epicenter
- 6.438 km SSW of Lijiang, ChinaDecember 21, 1951 · 136 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 46 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 40,193 recorded deaths. The most severe:
- 1850M7.5
Sichuan: Xichang
12 Sep 1850 · 128 km away · intensity X
20,650 deathsExtreme damage ($25M+)
- 1833M8.0
Yunnan Province
6 Sep 1833 · 298 km away · intensity XI
6,700 deathsExtreme damage ($25M+)tsunami
- 1925M6.9
Yunnan Province: Talifu
16 Mar 1925 · 187 km away
5,800 deathsExtreme damage ($25M+)
- 1713M6.8
Yunnan Province: S Of Xundian
26 Feb 1713 · 295 km away · intensity IX
2,100 deathsExtreme damage ($25M+)
- 1917M6.8
Yunnan Province
30 Jul 1917 · 293 km away · intensity IX
1,800 deathsExtreme damage ($25M+)
- 1751M6.8
Yunnan Province
25 May 1751 · 151 km away · intensity IX
900 deathsExtreme damage ($25M+)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.