Reviewed by USGSChina18y ago
M4.0 earthquake 28 km N of Jiangyou, China
Friday, August 1, 2008, 21:03:31 UTC · 32.020°N, 104.691°E
A magnitude 4.0 earthquake struck 28 km N of Jiangyou, China on Friday, August 1, 2008, 21:03:31 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.0
- Light · mb
- Depth
- 10 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
338 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 6 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.0 on August 12, 2008. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 3.767 km NNE of Jiangyou, China18y ago · 45 km NE of this epicenter
- 5.047 km WNW of Jiangyou, China18y ago · 47 km W of this epicenter
- 4.065 km NNE of Jiangyou, China18y ago · 43 km NE of this epicenter
- 4.941 km N of Jiangyou, China18y ago · 14 km N of this epicenter
- 3.648 km NNE of Jiangyou, China18y ago · 30 km NE of this epicenter
- 4.119 km W of Jiangyou, China18y ago · 30 km SW of this epicenter
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 · 172 km SW of this epicenter
- 7.4101 km WNW of Jiangyou, ChinaAugust 25, 1933 · 97 km W of this epicenter
- 6.9121 km NNW of Jiangyou, ChinaAugust 16, 1976 · 96 km NW of this epicenter
- 6.794 km NNW of Jiangyou, ChinaAugust 23, 1976 · 71 km NW of this epicenter
- 6.499 km NNW of Jiangyou, ChinaAugust 21, 1976 · 74 km NW of this epicenter
- 6.3146 km NW of Jiangyou, ChinaNovember 9, 1960 · 126 km NW of this epicenter
- 6.261 km S of Tianshui, ChinaAugust 1, 1936 · 244 km NE of this epicenter
- 6.1127 km WNW of Jiangyou, ChinaMarch 14, 1938 · 118 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 31 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 119,678 recorded deaths. The most severe:
- 2008M7.9
Sichuan Province
12 May 2008 · 169 km away · intensity IX
87,652 deaths$86 billion damagetsunami
- 1879M8.0
Gansu Province
1 Jul 1879 · 131 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
- 1933M7.4
Sichuan Province
25 Aug 1933 · 97 km away · intensity X
9,300 deathsExtreme damage ($25M+)
- 1881M6.5
Gansu Province
20 Jul 1881 · 176 km away · intensity VIII
480 deathsSevere damage ($5–24M)
- 1936M6.0
Gansu Province
1 Aug 1936 · 260 km away · intensity VIII
115 deathsSevere damage ($5–24M)
- 1885M6.0
Gansu Province
14 Jan 1885 · 291 km away · intensity VIII
80 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.