Magnitude4.8

Reviewed by USGSChina50y ago

M4.8 earthquake 111 km WSW of Xichang, China

Friday, November 12, 1976, 21:27:14 UTC · 27.570°N, 101.190°E

A magnitude 4.8 earthquake struck 111 km WSW of Xichang, China on Friday, November 12, 1976, 21:27:14 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.0 on November 8, 1976.

Magnitude
4.8
Light · mb
Depth
33 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

239 tons of TNT

That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.

Tectonic setting

367 km

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

Depth: shallow

33 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.3 on November 16, 1976. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M4.8
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.3104 km NE of Lijiang, China50y ago · 20 km SW of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 100 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 51 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 51,847 recorded deaths. The most severe:

  1. 1850M7.5

    Sichuan: Xichang

    12 Sep 1850 · 112 km away · intensity X

    20,650 deathsExtreme damage ($25M+)

  2. 1974M7.1

    Yunnan And Sichuan Provinces, Chao-T'Ung

    10 May 1974 · 287 km away

    20,000 deathsSevere damage ($5–24M)

  3. 1925M6.9

    Yunnan Province: Talifu

    16 Mar 1925 · 217 km away

    5,800 deathsExtreme damage ($25M+)

  4. 1917M6.8

    Yunnan Province

    30 Jul 1917 · 281 km away · intensity IX

    1,800 deathsExtreme damage ($25M+)

  5. 1751M6.8

    Yunnan Province

    25 May 1751 · 175 km away · intensity IX

    900 deathsExtreme damage ($25M+)

  6. 1948M7.3

    Sichuan Province

    25 May 1948 · 225 km away · intensity X

    800 deathsSevere damage ($5–24M)

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

Nearby trackers

Closest city pages