Reviewed by USGSChina17y ago
M4.9 earthquake 54 km NNW of Linqiong, China
Saturday, February 7, 2009, 21:21:10 UTC · 30.883°N, 103.273°E
A magnitude 4.9 earthquake struck 54 km NNW of Linqiong, China on Saturday, February 7, 2009, 21:21:10 UTC, at a depth of 42.3 km (shallow). USGS received 4 “Did You Feel It?” reports, with a maximum reported intensity of III (weak). It is the strongest earthquake within 300 km since an M5.0 on December 29, 2008.
- Magnitude
- 4.9
- Light · mb
- Depth
- 42 km
- Shallow
- Felt reports
- 4
- Max intensity III
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
338 tons of TNT
That is about 1/45 of the Hiroshima bomb. A magnitude 5.0 releases about 1 times more energy.
Tectonic setting
308 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
42 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 | II · Weak | 3 | 90 km |
| Ziyang, Sichuan, China | III · Weak | 1 | 160 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 50 km
USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 172 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 · 14 km N of this epicenter
- 7.4203 km NW of Kangding, ChinaFebruary 6, 1973 · 263 km W of this epicenter
- 7.4101 km WNW of Jiangyou, ChinaAugust 25, 1933 · 125 km N of this epicenter
- 7.3151 km W of Kangding, ChinaMay 25, 1948 · 289 km W of this epicenter
- 7.1150 km WNW of Kangding, ChinaAugust 30, 1904 · 256 km W of this epicenter
- 7.119 km WSW of Kangding, ChinaApril 14, 1955 · 178 km SW of this epicenter
- 7.0184 km NW of Kangding, ChinaMarch 24, 1923 · 245 km W of this epicenter
- 7.042 km W of Xunchang, ChinaJuly 30, 1917 · 292 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 52 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 129,420 recorded deaths. The most severe:
- 2008M7.9
Sichuan Province
12 May 2008 · 16 km away · intensity IX
87,652 deaths$86 billion damagetsunami
- 1879M8.0
Gansu Province
1 Jul 1879 · 291 km away · intensity XI
22,000 deathsExtreme damage ($25M+)
- 1933M7.4
Sichuan Province
25 Aug 1933 · 125 km away · intensity X
9,300 deathsExtreme damage ($25M+)
- 1923M7.3
Sichuan Province
24 Mar 1923 · 227 km away · intensity X
4,800 deathsSevere damage ($5–24M)
- 1816M6.5
Sichuan Province
8 Dec 1816 · 252 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.