M5.7 earthquake 29 km N of Jiangyou, China

Friday, August 1, 2008, 08:32:43 UTC · 32.033°N, 104.722°E

A magnitude 5.7 earthquake struck 29 km N of Jiangyou, China on Friday, August 1, 2008, 08:32:43 UTC, at a depth of 11.0 km (shallow). USGS received 55 “Did You Feel It?” reports, with a maximum reported intensity of VII (very strong). It is the strongest earthquake within 300 km since an M5.7 on July 24, 2008.

Magnitude: 5.7; Moderate · mwb
Depth: 11 km; Shallow
Felt reports: 55; Max intensity VII
Est. shaking: VI; Strong (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

5 kilotons of TNT

That is about 1/3 of the Hiroshima bomb. It released about 11 times the energy of a magnitude 5.0.

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

11 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	15	163 km
Xian, Shaanxi, China	II · Weak	5	462 km
Yibin, Sichuan, China	VII · Very strong	4	362 km
Mianyang, Sichuan, China	IV · Light	4	63 km
Chongqing, Chongqing, China	IV · Light	4	326 km
Ankang, Shaanxi, China	II · Weak	4	411 km
Deyang, Sichuan, China	V · Moderate	3	105 km
Guangyuan, Sichuan, China	VI · Strong	2	117 km
Lanzhou, Gansu, China	VI · Strong	1	455 km
Jiangyou, Sichuan, China	V · Moderate	1	31 km
Hanzhong, Shaanxi, China	IV · Light	1	248 km
Leshan, Sichuan, China	III · Weak	1	288 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 75 km

USGS lists 12 M2.5+ earthquakes within 75 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.

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 94 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 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 · 172 km away · intensity IX
87,652 deaths$86 billion damagetsunami
1879M8.0
Gansu Province
1 Jul 1879 · 130 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
1933M7.4
Sichuan Province
25 Aug 1933 · 100 km away · intensity X
9,300 deathsExtreme damage ($25M+)
1881M6.5
Gansu Province
20 Jul 1881 · 175 km away · intensity VIII
480 deathsSevere damage ($5–24M)
1936M6.0
Gansu Province
1 Aug 1936 · 258 km away · intensity VIII
115 deathsSevere damage ($5–24M)
1885M6.0
Gansu Province
14 Jan 1885 · 289 km away · intensity VIII
80 deathsModerate damage ($1–5M)

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

Nearby trackers