Reviewed by USGSChina18y ago
M4.2 earthquake 33 km NNW of Tianpeng, China
Thursday, September 11, 2008, 10:30:21 UTC · 31.269°N, 103.819°E
A magnitude 4.2 earthquake struck 33 km NNW of Tianpeng, China on Thursday, September 11, 2008, 10:30:21 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
312 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 7 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.6 on October 3, 2008. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.348 km N of Tianpeng, China18y ago · 22 km NE of this epicenter
- 4.662 km NW of Deyang, China18y ago · 37 km NE of this epicenter
- 3.739 km N of Tianpeng, China18y ago · 14 km NE of this epicenter
- 4.466 km NW of Deyang, China18y ago · 40 km N of this epicenter
- 3.820 km N of Tianpeng, China18y ago · 19 km SE of this epicenter
- 4.529 km NW of Tianpeng, China18y ago · 18 km SW of this epicenter
- 4.057 km NW of Deyang, China18y ago · 30 km NE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 148 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 · 56 km SW of this epicenter
- 7.4101 km WNW of Jiangyou, ChinaAugust 25, 1933 · 78 km N of this epicenter
- 7.119 km WSW of Kangding, ChinaApril 14, 1955 · 245 km SW of this epicenter
- 7.0184 km NW of Kangding, ChinaMarch 24, 1923 · 292 km W of this epicenter
- 6.9121 km NNW of Jiangyou, ChinaAugust 16, 1976 · 168 km N of this epicenter
- 6.892 km SSW of Luocheng, ChinaMay 16, 1936 · 295 km S of this epicenter
- 6.8131 km NW of Kangding, ChinaJanuary 23, 1981 · 262 km W of this epicenter
- 6.793 km SSW of Luocheng, ChinaApril 26, 1936 · 296 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 48 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 129,415 recorded deaths. The most severe:
- 2008M7.9
Sichuan Province
12 May 2008 · 52 km away · intensity IX
87,652 deaths$86 billion damagetsunami
- 1879M8.0
Gansu Province
1 Jul 1879 · 230 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
- 1933M7.4
Sichuan Province
25 Aug 1933 · 78 km away · intensity X
9,300 deathsExtreme damage ($25M+)
- 1923M7.3
Sichuan Province
24 Mar 1923 · 269 km away · intensity X
4,800 deathsSevere damage ($5–24M)
- 1816M6.5
Sichuan Province
8 Dec 1816 · 297 km away · intensity VIII
2,854 deathsSevere damage ($5–24M)
- 1881M6.5
Gansu Province
20 Jul 1881 · 269 km away · intensity VIII
480 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.