Reviewed by USGSChina18y ago
M5.1 earthquake 41 km WNW of Guangyuan, China
Tuesday, December 9, 2008, 18:53:11 UTC · 32.518°N, 105.395°E
A magnitude 5.1 earthquake struck 41 km WNW of Guangyuan, China on Tuesday, December 9, 2008, 18:53:11 UTC, at a depth of 24.5 km (shallow). USGS received 7 “Did You Feel It?” reports, with a maximum reported intensity of IV (light). It is the strongest earthquake within 300 km since an M5.1 on September 11, 2008.
- Magnitude
- 5.1
- Moderate · mwc
- Depth
- 25 km
- Shallow
- Felt reports
- 7
- Max intensity IV
- Est. shaking
- V
- Moderate (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 75 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
674 tons of TNT
That is about 1/22 of the Hiroshima bomb. It released about 1 times the energy of a magnitude 5.0.
Tectonic setting
351 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
25 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
Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.
| Place | Intensity | Reports | Distance |
|---|---|---|---|
| Chengdu, Sichuan, China | III · Weak | 5 | 241 km |
| Guangyuan, Sichuan, China | IV · Light | 1 | 51 km |
| Ziyang, Sichuan, China | III · Weak | 1 | 274 km |
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 75 km
USGS lists 4 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.0 on December 29, 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 · 259 km SW of this epicenter
- 7.4101 km WNW of Jiangyou, ChinaAugust 25, 1933 · 174 km W of this epicenter
- 6.9121 km NNW of Jiangyou, ChinaAugust 16, 1976 · 119 km W of this epicenter
- 6.794 km NNW of Jiangyou, ChinaAugust 23, 1976 · 114 km W of this epicenter
- 6.499 km NNW of Jiangyou, ChinaAugust 21, 1976 · 108 km W of this epicenter
- 6.3146 km NW of Jiangyou, ChinaNovember 9, 1960 · 167 km W of this epicenter
- 6.261 km S of Tianshui, ChinaAugust 1, 1936 · 171 km N of this epicenter
- 6.1127 km WNW of Jiangyou, ChinaMarch 14, 1938 · 186 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 33 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 194,769 recorded deaths. The most severe:
- 2008M7.9
Sichuan Province
12 May 2008 · 255 km away · intensity IX
87,652 deaths$86 billion damagetsunami
- 1718M7.5
Gansu Province
19 Jun 1718 · 277 km away · intensity X
73,000 deathsExtreme damage ($25M+)
- 1879M8.0
Gansu Province
1 Jul 1879 · 100 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
- 1933M7.4
Sichuan Province
25 Aug 1933 · 174 km away · intensity X
9,300 deathsExtreme damage ($25M+)
- 1765M6.5
Gansu Province: Wushan, Gangu
2 Sep 1765 · 256 km away · intensity IX
2,068 deathsExtreme damage ($25M+)
- 1881M6.5
Gansu Province
20 Jul 1881 · 141 km away · intensity VIII
480 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.