M7.9 earthquake 58 km W of Tianpeng, China

Monday, May 12, 2008, 06:28:01 UTC · 31.002°N, 103.322°E

A magnitude 7.9 earthquake struck 58 km W of Tianpeng, China on Monday, May 12, 2008, 06:28:01 UTC, at a depth of 19.0 km (shallow). USGS received 1,236 “Did You Feel It?” reports, with a maximum reported intensity of IX (violent). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude: 7.9; Major · mwc
Depth: 19 km; Shallow
Felt reports: 1,236; Max intensity IX
Est. shaking: IX; Violent (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

11 megatons of TNT

That is about 709 times the Hiroshima bomb. It released about 22,387 times the energy of a magnitude 5.0.

Tectonic setting

315 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

19 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
Peking, Beijing, China	III · Weak	256	1546 km
Chengdu, Sichuan, China	VII · Very strong	139	82 km
Shanghai, Schanghai, China	III · Weak	123	1731 km
Xian, Shaanxi, China	VI · Strong	94	636 km
Wuhan, Hubei, China	III · Weak	36	1049 km
Chongqing, Chongqing, China	V · Moderate	32	351 km
Taipei, Taipei Hsien, Taiwan	III · Weak	23	1902 km
Zhengzhou, Henan, China	III · Weak	22	1054 km
Lanzhou, Gansu, China	V · Moderate	21	561 km
Kunming, Yunnan, China	III · Weak	20	662 km
Nanjing, Jiangsu, China	II · Weak	18	1472 km
Bangkok, Bangkok, Thailand	II · Weak	16	1934 km

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 200 km

USGS lists 547 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.1 on May 12, 2008. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 102 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 50 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 129,418 recorded deaths. The most severe:

2008M7.9
Sichuan Province
12 May 2008 · 7 km away · intensity IX
87,652 deaths$86 billion damagetsunami
1879M8.0
Gansu Province
1 Jul 1879 · 277 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
1933M7.4
Sichuan Province
25 Aug 1933 · 111 km away · intensity X
9,300 deathsExtreme damage ($25M+)
1923M7.3
Sichuan Province
24 Mar 1923 · 228 km away · intensity X
4,800 deathsSevere damage ($5–24M)
1816M6.5
Sichuan Province
8 Dec 1816 · 253 km away · intensity VIII
2,854 deathsSevere damage ($5–24M)
1811M6.5
Sichuan Province: E. Of Ganze
27 Sep 1811 · 297 km away · intensity VIII
480 deathsModerate damage ($1–5M)

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers