M7.9 earthquake 125 km E of Baiyin, China

Thursday, December 16, 1920, 12:05:52 UTC · 36.358°N, 105.554°E

A magnitude 7.9 earthquake struck 125 km E of Baiyin, China on Thursday, December 16, 1920, 12:05:52 UTC, at a depth of 15.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude: 7.9; Major · mw
Depth: 15 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: VIII; Severe (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

12 megatons of TNT

That is about 814 times the Hiroshima bomb. It released about 25,704 times the energy of a magnitude 5.0.

Tectonic setting

671 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

15 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 200 km

USGS lists 3 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M7.0 on December 25, 1920. 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 no earlier M5.0+ earthquakes within 300 km.

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 363,185 recorded deaths. The most severe:

1920M8.3
Gansu Province, Shanxi Province
16 Dec 1920 · 34 km away · intensity XII
235,502 deaths$25 million damagetsunami
1718M7.5
Gansu Province
19 Jun 1718 · 154 km away · intensity X
73,000 deathsExtreme damage ($25M+)
1739M8.0
Ningxia
3 Jan 1739 · 295 km away · intensity X
50,000 deathsExtreme damage ($25M+)
1765M6.5
Gansu Province: Wushan, Gangu
2 Sep 1765 · 180 km away · intensity IX
2,068 deathsExtreme damage ($25M+)
1709M7.5
Ningxia
14 Oct 1709 · 118 km away · intensity X
2,032 deathsExtreme damage ($25M+)
1852M6.0
Ningxia
26 May 1852 · 131 km away · intensity VIII
300 deathsSevere damage ($5–24M)

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

Nearby trackers