Reviewed by USGSChina23y ago
M4.3 earthquake 273 km SSW of Laojunmiao, China
Sunday, April 20, 2003, 10:04:03 UTC · 37.525°N, 96.626°E
A magnitude 4.3 earthquake struck 273 km SSW of Laojunmiao, China on Sunday, April 20, 2003, 10:04:03 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.3
- Light · mb
- Depth
- 10 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
43 tons of TNT
That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.
Tectonic setting
1,038 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
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 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.1 on May 3, 2003. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 56 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8108 km WSW of Laojunmiao, ChinaDecember 25, 1932 · 215 km N of this epicenter
- 7.8Southern Qinghai, ChinaJanuary 7, 1937 · 264 km SE of this epicenter
- 6.7Southern Qinghai, ChinaApril 19, 1963 · 215 km S of this epicenter
- 6.6northern Qinghai, ChinaMay 21, 1962 · 91 km SW of this epicenter
- 6.5200 km S of Jiuquan, ChinaJuly 13, 1930 · 149 km E of this epicenter
- 6.4278 km SSW of Laojunmiao, ChinaApril 17, 2003 · 13 km W of this epicenter
- 6.2106 km SSW of Laojunmiao, ChinaApril 19, 1941 · 169 km N of this epicenter
- 6.2193 km WSW of Laojunmiao, ChinaDecember 26, 1951 · 238 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 313 recorded deaths. The most severe:
- 1932M7.6
Gansu Province
25 Dec 1932 · 242 km away · intensity X
275 deathsSevere damage ($5–24M)
- 1785M6.0
Gansu Province: Huihuipu
18 Apr 1785 · 290 km away · intensity VIII
36 deathsModerate damage ($1–5M)
- 2002M5.5
Gansu Province: Yumne
14 Dec 2002 · 256 km away
2 deathsSevere damage ($5–24M)
- 1937M7.5
Qinghai Province
7 Jan 1937 · 241 km away · intensity X
Limited damage (under $1M)
- 1963M7.0
Qinghai Province
19 Apr 1963 · 206 km away · intensity VIII
Limited damage (under $1M)
- 1962M6.8
Qinghai Province
21 May 1962 · 73 km away
Limited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.