M6.9 earthquake 233 km NNW of Qamdo, China

Tuesday, April 13, 2010, 23:49:38 UTC · 33.165°N, 96.548°E

A magnitude 6.9 earthquake struck 233 km NNW of Qamdo, China on Tuesday, April 13, 2010, 23:49:38 UTC, at a depth of 17.0 km (shallow). USGS received 71 “Did You Feel It?” reports, with a maximum reported intensity of VI (strong). It is the strongest earthquake within 300 km since an M7.6 on March 17, 1947.

Magnitude: 6.9; Strong · mwc
Depth: 17 km; Shallow
Felt reports: 71; Max intensity VI
Est. shaking: IX; Violent (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

338 kilotons of TNT

That is about 22 times the Hiroshima bomb. It released about 708 times the energy of a magnitude 5.0.

Tectonic setting

557 km

from the nearest mapped plate boundary, between the Eurasian and Indian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

17 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
Xining, Qinghai, China	VI · Strong	12	612 km
Lasa, Xizang, China	V · Moderate	8	648 km
Qiatou, Qinghai, China	VI · Strong	7	629 km
Thimphu, Thimphu, Bhutan	II · Weak	6	911 km
Urumqi, Xinjiang, China	II · Weak	6	1416 km
Baoji, Gansu, China	II · Weak	4	794 km
Lanzhou, Gansu, China	II · Weak	3	728 km
Punakha, Punakha, Bhutan	III · Weak	2	874 km
Dibrugarh, Assam, India	III · Weak	2	648 km
Daxian, Sichuan, China	III · Weak	2	1055 km
Yaan, Sichuan, China	III · Weak	2	713 km
Zhangye, Gansu, China	IV · Light	1	730 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 100 km

USGS lists 14 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M6.1 on April 14, 2010. 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 60 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 6 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,392 recorded deaths. The most severe:

2010M6.9
Qinghai Province: Yushu
13 Apr 2010 · 0 km away
2,968 deaths$500 million damage
1738M6.5
Qinghai Province
1738 · 16 km away · intensity VIII
336 deaths
1834M5.5
Qinghai Province
1834 · 46 km away · intensity VII
88 deaths
1937M7.5
Qinghai Province
7 Jan 1937 · 277 km away · intensity X
Limited damage (under $1M)
1963M7.0
Qinghai Province
19 Apr 1963 · 285 km away · intensity VIII
Limited damage (under $1M)
1947M7.7
Qinghai Province
17 Mar 1947 · 275 km away

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

Nearby trackers