Reviewed by USGSChina18y ago
M4.0 earthquake 65 km NNE of Jiangyou, China
Saturday, August 9, 2008, 16:12:37 UTC · 32.311°N, 104.991°E
A magnitude 4.0 earthquake struck 65 km NNE of Jiangyou, China on Saturday, August 9, 2008, 16:12:37 UTC, at a depth of 25.6 km (shallow).
- Magnitude
- 4.0
- Light · mb
- Depth
- 26 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
350 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
26 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 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on August 13, 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 95 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 · 215 km SW of this epicenter
- 7.4101 km WNW of Jiangyou, ChinaAugust 25, 1933 · 131 km W of this epicenter
- 6.9121 km NNW of Jiangyou, ChinaAugust 16, 1976 · 92 km NW of this epicenter
- 6.794 km NNW of Jiangyou, ChinaAugust 23, 1976 · 79 km W of this epicenter
- 6.499 km NNW of Jiangyou, ChinaAugust 21, 1976 · 75 km NW of this epicenter
- 6.3146 km NW of Jiangyou, ChinaNovember 9, 1960 · 135 km W of this epicenter
- 6.261 km S of Tianshui, ChinaAugust 1, 1936 · 203 km N of this epicenter
- 6.1127 km WNW of Jiangyou, ChinaMarch 14, 1938 · 145 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 34 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 194,784 recorded deaths. The most severe:
- 2008M7.9
Sichuan Province
12 May 2008 · 211 km away · intensity IX
87,652 deaths$86 billion damagetsunami
- 1718M7.5
Gansu Province
19 Jun 1718 · 300 km away · intensity X
73,000 deathsExtreme damage ($25M+)
- 1879M8.0
Gansu Province
1 Jul 1879 · 103 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
- 1933M7.4
Sichuan Province
25 Aug 1933 · 131 km away · intensity X
9,300 deathsExtreme damage ($25M+)
- 1765M6.5
Gansu Province: Wushan, Gangu
2 Sep 1765 · 277 km away · intensity IX
2,068 deathsExtreme damage ($25M+)
- 1881M6.5
Gansu Province
20 Jul 1881 · 148 km away · intensity VIII
480 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.