Reviewed by USGSChina18y ago
M4.0 earthquake in Sichuan-Gansu border region, China
Thursday, July 10, 2008, 19:36:02 UTC · 32.189°N, 104.166°E
A magnitude 4.0 earthquake struck in Sichuan-Gansu border region, China on Thursday, July 10, 2008, 19:36:02 UTC, at a depth of 8.3 km (shallow).
- Magnitude
- 4.0
- Light · mb
- Depth
- 8 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
15 tons of TNT
That is about 1/998 of the Hiroshima bomb. A magnitude 5.0 releases about 32 times more energy.
Tectonic setting
380 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
8 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.9 on August 7, 2008. 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 97 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.958 km W of Tianpeng, ChinaMay 12, 2008 · 154 km SW of this epicenter
- 7.4101 km WNW of Jiangyou, ChinaAugust 25, 1933 · 53 km SW of this epicenter
- 6.9121 km NNW of Jiangyou, ChinaAugust 16, 1976 · 63 km N of this epicenter
- 6.794 km NNW of Jiangyou, ChinaAugust 23, 1976 · 34 km N of this epicenter
- 6.5128 km NNW of Kangding, ChinaMay 29, 1919 · 271 km SW of this epicenter
- 6.499 km NNW of Jiangyou, ChinaAugust 21, 1976 · 43 km N of this epicenter
- 6.3146 km NW of Jiangyou, ChinaNovember 9, 1960 · 76 km NW of this epicenter
- 6.261 km S of Tianshui, ChinaAugust 1, 1936 · 251 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 35 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 121,989 recorded deaths. The most severe:
- 2008M7.9
Sichuan Province
12 May 2008 · 153 km away · intensity IX
87,652 deaths$86 billion damagetsunami
- 1879M8.0
Gansu Province
1 Jul 1879 · 123 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
- 1933M7.4
Sichuan Province
25 Aug 1933 · 53 km away · intensity X
9,300 deathsExtreme damage ($25M+)
- 1765M6.5
Gansu Province: Wushan, Gangu
2 Sep 1765 · 300 km away · intensity IX
2,068 deathsExtreme damage ($25M+)
- 1881M6.5
Gansu Province
20 Jul 1881 · 162 km away · intensity VIII
480 deathsSevere damage ($5–24M)
- 1792M6.0
Sichuan Province: N Of Qianning
7 Sep 1792 · 285 km away · intensity VIII
205 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.