Reviewed by USGSChina52y ago
M4.5 earthquake 79 km WSW of Xunchang, China
Saturday, July 13, 1974, 21:01:21 UTC · 28.072°N, 104.034°E
A magnitude 4.5 earthquake struck 79 km WSW of Xunchang, China on Saturday, July 13, 1974, 21:01:21 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M4.8 on July 13, 1974.
- Magnitude
- 4.5
- 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
85 tons of TNT
That is about 1/178 of the Hiroshima bomb. A magnitude 5.0 releases about 6 times more energy.
Tectonic setting
91 km
from the nearest mapped plate boundary, between the Eurasian and Yangtze 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 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 62 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 · 44 km NE of this epicenter
- 6.892 km SSW of Luocheng, ChinaMay 16, 1936 · 70 km NW of this epicenter
- 6.872 km WSW of Xunchang, ChinaMay 10, 1974 · 19 km N of this epicenter
- 6.793 km SSW of Luocheng, ChinaApril 26, 1936 · 70 km NW of this epicenter
- 6.711 km SE of Dadukou, ChinaSeptember 23, 1955 · 285 km SW of this epicenter
- 6.659 km N of Xichang, ChinaSeptember 30, 1952 · 179 km W of this epicenter
- 6.3eastern Sichuan, ChinaDecember 18, 1935 · 103 km NW of this epicenter
- 6.129 km SE of Kangding, ChinaJune 25, 1952 · 265 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 28 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 43,304 recorded deaths. The most severe:
- 1850M7.5
Sichuan: Xichang
12 Sep 1850 · 173 km away · intensity X
20,650 deathsExtreme damage ($25M+)
- 1974M7.1
Yunnan And Sichuan Provinces, Chao-T'Ung
10 May 1974 · 19 km away
20,000 deathsSevere damage ($5–24M)
- 1917M6.8
Yunnan Province
30 Jul 1917 · 9 km away · intensity IX
1,800 deathsExtreme damage ($25M+)
- 1786M7.5
Sichuan Province: S Of Kangding
1 Jun 1786 · 269 km away · intensity IX
435 deathsSevere damage ($5–24M)
- 1933M5.0
Sichuan Province
20 Sep 1933 · 218 km away · intensity VI
200 deathsLimited damage (under $1M)
- 1935M6.0
Sichuan Province
18 Dec 1935 · 82 km away · intensity VIII
100 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.