Reviewed by USGSVietnam92y ago
M6.8 earthquake 27 km SE of Dien Bien Phu, Vietnam
Friday, November 1, 1935, 16:22:09 UTC · 21.185°N, 103.177°E
A magnitude 6.8 earthquake struck 27 km SE of Dien Bien Phu, Vietnam on Friday, November 1, 1935, 16:22:09 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
- 6.8
- Strong · mw
- Depth
- 15 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
208 kilotons of TNT
That is about 14 times the Hiroshima bomb. It released about 437 times the energy of a magnitude 5.0.
Tectonic setting
153 km
from the nearest mapped plate boundary, between the Caribbean and North American 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 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 4 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.741 km S of Luang Namtha, LaosDecember 22, 1925 · 190 km W of this epicenter
- 6.350 km NNE of Chiang Klang, ThailandMay 13, 1935 · 273 km SW of this epicenter
- 6.267 km NNW of Sainyabuli, LaosFebruary 12, 1934 · 245 km SW of this epicenter
- 6.231 km SSE of Jinghong, ChinaJuly 1, 1923 · 251 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 6 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,988 recorded deaths. The most severe:
- 1887M6.8
Yunnan Province
16 Dec 1887 · 288 km away · intensity IX
2,000 deathsSevere damage ($5–24M)
- 1814M6.0
Yunnan Province: Siping
24 Nov 1814 · 288 km away · intensity VIII
900 deathsSevere damage ($5–24M)
- 1755M6.0
Yunnan Province
8 Feb 1755 · 295 km away · intensity VIII
70 deathsModerate damage ($1–5M)
- 1884M6.5
Yunnan Province
14 Nov 1884 · 294 km away · intensity VIII
17 deathsModerate damage ($1–5M)
- 1934M6.0
Yunnan Province
12 Jan 1934 · 284 km away · intensity VIII
1 deathModerate damage ($1–5M)
- 1935M6.8
Dien Bien Phu
1 Nov 1935 · 61 km away · intensity IX
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.