Reviewed by USGS107y ago
M6.4 earthquake in Bangladesh
Wednesday, March 30, 1921, 10:26:31 UTC · 22.384°N, 90.659°E
A magnitude 6.4 earthquake struck in Bangladesh on Wednesday, March 30, 1921, 10:26:31 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.1 on July 8, 1918.
- Magnitude
- 6.4
- Strong · mw
- Depth
- 15 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 earthquake
In context
How big was it, and why here?
Energy released
60 kilotons of TNT
That is about 4 times the Hiroshima bomb. It released about 126 times the energy of a magnitude 5.0.
Tectonic setting
502 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
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 1 M5.0+ earthquake within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
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 2,275 recorded deaths. The most severe:
- 1874
Bhola
May 1874 · 176 km away
2,000 deathstsunami
- 1762
Chittagong, Dacca, Arracan
2 Apr 1762 · 145 km away · intensity XI
200 deathsSevere damage ($5–24M)tsunami
- 1885M6.9
Unnamed location
14 Jul 1885 · 293 km away · intensity VII
75 deathsModerate damage ($1–5M)
- 1918M7.6
Srimangal
8 Jul 1918 · 238 km away
Moderate damage ($1–5M)
- 1842M6.0
Unnamed location
11 Nov 1842 · 230 km away
Limited damage (under $1M)tsunami
- 1868M7.5
Sylhet
30 Jun 1868 · 250 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.