Reviewed by USGSChina12y ago
M4.1 earthquake 46 km SW of Zhaotong, China
Thursday, November 20, 2014, 23:16:12 UTC · 27.044°N, 103.363°E
A magnitude 4.1 earthquake struck 46 km SW of Zhaotong, China on Thursday, November 20, 2014, 23:16:12 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.1
- Light · mb
- Depth
- 10 km
- Shallow
- Felt reports
- 0
- Max intensity I
- 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
21 tons of TNT
That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.
Tectonic setting
176 km
from the nearest mapped plate boundary, between the Eurasian and Yangtze plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
10 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 lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.4 on December 15, 2014. 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 127 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.042 km W of Xunchang, ChinaJuly 30, 1917 · 176 km NE of this epicenter
- 6.892 km SSW of Luocheng, ChinaMay 16, 1936 · 177 km N of this epicenter
- 6.872 km WSW of Xunchang, ChinaMay 10, 1974 · 148 km NE of this epicenter
- 6.793 km SSW of Luocheng, ChinaApril 26, 1936 · 177 km N of this epicenter
- 6.711 km SE of Dadukou, ChinaSeptember 23, 1955 · 170 km W of this epicenter
- 6.659 km N of Xichang, ChinaSeptember 30, 1952 · 189 km NW of this epicenter
- 6.5115 km NE of Lijiang, ChinaNovember 6, 1976 · 237 km W of this epicenter
- 6.3eastern Sichuan, ChinaDecember 18, 1935 · 206 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 68 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 53,607 recorded deaths. The most severe:
- 1850M7.5
Sichuan: Xichang
12 Sep 1850 · 134 km away · intensity X
20,650 deathsExtreme damage ($25M+)
- 1974M7.1
Yunnan And Sichuan Provinces, Chao-T'Ung
10 May 1974 · 147 km away
20,000 deathsSevere damage ($5–24M)
- 1833M8.0
Yunnan Province
6 Sep 1833 · 208 km away · intensity XI
6,700 deathsExtreme damage ($25M+)tsunami
- 1713M6.8
Yunnan Province: S Of Xundian
26 Feb 1713 · 184 km away · intensity IX
2,100 deathsExtreme damage ($25M+)
- 1917M6.8
Yunnan Province
30 Jul 1917 · 123 km away · intensity IX
1,800 deathsExtreme damage ($25M+)
- 2014M6.2
Yunnan: Ludian: Longtoushan, Zhaotong
3 Aug 2014 · 17 km away · intensity VII
615 deaths$5.0 billion damage
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.