Reviewed by USGSChina94y ago
M7.4 earthquake 101 km WNW of Jiangyou, China
Friday, August 25, 1933, 07:50:32 UTC · 31.957°N, 103.669°E
A magnitude 7.4 earthquake struck 101 km WNW of Jiangyou, China on Friday, August 25, 1933, 07:50:32 UTC, at a depth of 15.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 7.4
- Major · mw
- Depth
- 15 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
1.8 megatons of TNT
That is about 118 times the Hiroshima bomb. It released about 3,715 times the energy of a magnitude 5.0.
Tectonic setting
384 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
15 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 200 km
USGS has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 5 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.0184 km NW of Kangding, ChinaMarch 24, 1923 · 286 km W of this epicenter
- 6.5128 km NNW of Kangding, ChinaMay 29, 1919 · 218 km SW of this epicenter
- 5.6125 km N of Kangding, ChinaJuly 2, 1927 · 181 km SW of this epicenter
- 5.5Qinghai-Sichuan border region, ChinaAugust 25, 1927 · 268 km W of this epicenter
- 5.5197 km N of Kangding, ChinaJuly 19, 1928 · 181 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 22 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 41,439 recorded deaths. The most severe:
- 1879M8.0
Gansu Province
1 Jul 1879 · 169 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
- 1933M7.4
Sichuan Province
25 Aug 1933 · 0 km away · intensity X
9,300 deathsExtreme damage ($25M+)
- 1923M7.3
Sichuan Province
24 Mar 1923 · 257 km away · intensity X
4,800 deathsSevere damage ($5–24M)
- 1816M6.5
Sichuan Province
8 Dec 1816 · 288 km away · intensity VIII
2,854 deathsSevere damage ($5–24M)
- 1881M6.5
Gansu Province
20 Jul 1881 · 202 km away · intensity VIII
480 deathsSevere damage ($5–24M)
- 1786M7.5
Sichuan Province: S Of Kangding
1 Jun 1786 · 283 km away · intensity IX
435 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.