Reviewed by USGSChina5y ago
M7.3 earthquake in Southern Qinghai, China
Friday, May 21, 2021, 18:04:13 UTC · 34.598°N, 98.251°E
A magnitude 7.3 earthquake struck in Southern Qinghai, China on Friday, May 21, 2021, 18:04:13 UTC, at a depth of 10.0 km (shallow). USGS received 28 “Did You Feel It?” reports, with a maximum reported intensity of IX (violent). The USGS PAGER alert is orange: significant casualties and damage are likely. It is the strongest earthquake within 300 km since an M7.6 on March 17, 1947.
- Magnitude
- 7.3
- Major · mww
- Depth
- 10 km
- Shallow
- Felt reports
- 28
- Max intensity IX
- Est. shaking
- IX
- Violent (ShakeMap)
- PAGER alert
- Orange
- Impact estimate
- 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
1.3 megatons of TNT
That is about 89 times the Hiroshima bomb. It released about 2,818 times the energy of a magnitude 5.0.
Tectonic setting
725 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
10 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 | V · Moderate | 4 | 389 km |
| Lanzhou, Gansu, China | II · Weak | 2 | 519 km |
| Wuwei, Gansu, China | V · Moderate | 1 | 554 km |
| Anshun, Guizhou, China | III · Weak | 1 | 1183 km |
| Chengdu, Sichuan, China | III · Weak | 1 | 698 km |
| Rohtak, Haryana, India | III · Weak | 1 | 2148 km |
| Pasighat, Arunachal Pradesh, India | II · Weak | 1 | 775 km |
| Dulia Gaon, Assam, India | II · Weak | 1 | 848 km |
| Changsha, Hunan, China | II · Weak | 1 | 1569 km |
| Xian, Shaanxi, China | II · Weak | 1 | 979 km |
| Peking, Beijing, China | I · Not felt | 1 | 1715 km |
USGS PAGER estimate
Who was exposed to shaking
Modelled from the ShakeMap and population data. Alert level orange: significant casualties and damage are likely.
- VII · Very strong shaking
- 5,900 people
- VI · Strong shaking
- 38,000 people
- V · Moderate shaking
- 301,000 people
- IV · Light shaking
- 54 million people
- III · Weak shaking
- 20 million people
Estimated shaking in nearby towns
- HuanghePopulation 0IX · Violent
- HeihePopulation 0VII · Very strong
- MachaliPopulation 0VI · Strong
- ZhalinghuPopulation 0VI · Strong
- ChangmahePopulation 0VI · Strong
- YouyunPopulation 0VI · Strong
- XiningcapitalPopulation 768,000IV · Light
- ChengducapitalPopulation 7.4 millionIV · Light
After the main event
Aftershocks within 200 km
USGS lists 48 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M5.5 on May 21, 2021. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.4Southern Qinghai, China5y ago · 81 km W of this epicenter
- 4.1Southern Qinghai, China5y ago · 78 km NW of this epicenter
- 4.2Southern Qinghai, China5y ago · 37 km S of this epicenter
- 5.0Southern Qinghai, China5y ago · 42 km W of this epicenter
- 4.5Southern Qinghai, China5y ago · 34 km E of this epicenter
- 5.0Southern Qinghai, China5y ago · 7 km E of this epicenter
- 5.1Southern Qinghai, China5y ago · 6 km NW of this epicenter
- 5.1Southern Qinghai, China5y ago · 80 km E of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 77 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8Southern Qinghai, ChinaJanuary 7, 1937 · 93 km NW of this epicenter
- 7.6Qinghai-Sichuan border region, ChinaMarch 17, 1947 · 167 km SE of this epicenter
- 6.9233 km NNW of Qamdo, ChinaApril 13, 2010 · 224 km SW of this epicenter
- 6.7Southern Qinghai, ChinaApril 19, 1963 · 161 km NW of this epicenter
- 6.5153 km WSW of Xining, ChinaApril 26, 1990 · 238 km NE of this epicenter
- 6.5296 km NE of Qamdo, ChinaAugust 25, 1919 · 174 km SE of this epicenter
- 6.3Southern Qinghai, ChinaJuly 26, 1935 · 294 km SE of this epicenter
- 6.3148 km WSW of Xining, ChinaApril 26, 1990 · 244 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,538 recorded deaths. The most severe:
- 2010M6.9
Qinghai Province: Yushu
13 Apr 2010 · 224 km away
2,968 deaths$500 million damage
- 1738M6.5
Qinghai Province
1738 · 210 km away · intensity VIII
336 deaths
- 1990M6.9
Qinghai Province: Ganghe-Xinghai
26 Apr 1990 · 238 km away
126 deaths$58 million damage
- 1834M5.5
Qinghai Province
1834 · 212 km away · intensity VII
88 deaths
- 2021M7.3
Qinghai Province
21 May 2021 · 0 km away · intensity IX
20 deathsLimited damage (under $1M)
- 2020M5.4
Qinghai Province
1 Apr 2020 · 175 km away
$11 million damage
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.