Reviewed by USGSMyanmar81y ago
M7.1 earthquake 129 km ENE of Mawlaik, Myanmar
Thursday, September 12, 1946, 15:17:24 UTC · 24.104°N, 95.575°E
A magnitude 7.1 earthquake struck 129 km ENE of Mawlaik, Myanmar on Thursday, September 12, 1946, 15:17:24 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.6 on January 27, 1931.
- Magnitude
- 7.1
- Major · 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 earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
607 kilotons of TNT
That is about 40 times the Hiroshima bomb. It released about 1,274 times the energy of a magnitude 5.0.
Tectonic setting
47 km
from the nearest mapped plate boundary, between the Indian and Eurasian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
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 1 M2.5+ earthquake within 200 km in the following 30 days; the largest was M7.6 on September 12, 1946. 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 42 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.637 km S of Sarupathar, IndiaJanuary 27, 1931 · 230 km NE of this epicenter
- 7.362 km S of Bhamo, MyanmarFebruary 17, 1905 · 169 km E of this epicenter
- 7.031 km SE of Falam, MyanmarAugust 16, 1938 · 229 km SW of this epicenter
- 6.510 km S of Mokokchūng, IndiaMay 12, 1906 · 259 km NW of this epicenter
- 6.528 km SSW of Sarupathar, IndiaAugust 31, 1937 · 237 km NE of this epicenter
- 6.596 km SSW of Sarupathar, IndiaMarch 28, 1914 · 168 km NE of this epicenter
- 6.221 km SE of Wāngjing, IndiaApril 12, 1917 · 145 km W of this epicenter
- 6.213 km NW of Imphal, IndiaSeptember 22, 1930 · 195 km NW 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 400 recorded deaths. The most severe:
- 1839
Ava, Amarapura
23 Mar 1839 · 249 km away · intensity XI
400 deathsSevere damage ($5–24M)
- 1838
Ava (Innwa)
1838 · 260 km away
Severe damage ($5–24M)
- 1932M7.0
Assam
14 Aug 1932 · 211 km away
Moderate damage ($1–5M)
- 1929M5.5
Htawgaw
19 Jan 1929 · 290 km away · intensity IX
Moderate damage ($1–5M)
- 1929
Myitkyina
4 Jun 1929 · 204 km away
Moderate damage ($1–5M)
- 1931
Kamaing
28 Jan 1931 · 190 km away · intensity IX
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.