Reviewed by USGSChina18y ago
M4.2 earthquake 30 km W of Jiangyou, China
Thursday, December 25, 2008, 22:36:11 UTC · 31.758°N, 104.394°E
A magnitude 4.2 earthquake struck 30 km W of Jiangyou, China on Thursday, December 25, 2008, 22:36:11 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.2
- 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
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
329 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 5 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.7 on January 2, 2009. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.147 km WNW of Jiangyou, China17y ago · 19 km NW of this epicenter
- 4.343 km NNW of Jiangyou, China17y ago · 41 km N of this epicenter
- 4.151 km WNW of Jiangyou, China17y ago · 27 km NW of this epicenter
- 4.752 km WNW of Jiangyou, China17y ago · 25 km NW of this epicenter
- 4.054 km W of Jiangyou, China18y ago · 24 km W of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 109 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 · 132 km SW of this epicenter
- 7.4101 km WNW of Jiangyou, ChinaAugust 25, 1933 · 72 km W of this epicenter
- 6.9121 km NNW of Jiangyou, ChinaAugust 16, 1976 · 113 km N of this epicenter
- 6.794 km NNW of Jiangyou, ChinaAugust 23, 1976 · 84 km N of this epicenter
- 6.5128 km NNW of Kangding, ChinaMay 29, 1919 · 275 km W of this epicenter
- 6.499 km NNW of Jiangyou, ChinaAugust 21, 1976 · 91 km N of this epicenter
- 6.3146 km NW of Jiangyou, ChinaNovember 9, 1960 · 128 km NW of this epicenter
- 6.261 km S of Tianshui, ChinaAugust 1, 1936 · 282 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 32 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 119,842 recorded deaths. The most severe:
- 2008M7.9
Sichuan Province
12 May 2008 · 128 km away · intensity IX
87,652 deaths$86 billion damagetsunami
- 1879M8.0
Gansu Province
1 Jul 1879 · 163 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
- 1933M7.4
Sichuan Province
25 Aug 1933 · 72 km away · intensity X
9,300 deathsExtreme damage ($25M+)
- 1881M6.5
Gansu Province
20 Jul 1881 · 206 km away · intensity VIII
480 deathsSevere damage ($5–24M)
- 1792M6.0
Sichuan Province: N Of Qianning
7 Sep 1792 · 287 km away · intensity VIII
205 deathsModerate damage ($1–5M)
- 1936M6.0
Gansu Province
1 Aug 1936 · 298 km away · intensity VIII
115 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.