Reviewed by USGSTonga90y ago
M7.3 earthquake 227 km WNW of Haveluloto, Tonga
Friday, April 16, 1937, 03:01:38 UTC · 20.596°S, 177.315°W
A magnitude 7.3 earthquake struck 227 km WNW of Haveluloto, Tonga on Friday, April 16, 1937, 03:01:38 UTC, at a depth of 330.0 km (deep). It is the strongest earthquake within 300 km since an M7.8 on January 1, 1919.
- Magnitude
- 7.3
- Major · mw
- Depth
- 330 km
- Deep
- 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
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
114 km
from the nearest mapped plate boundary, between the Tonga and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: deep
330 km
Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.
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 has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 20 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0TongaJanuary 4, 1903 · 250 km E of this epicenter
- 7.8Fiji regionJanuary 1, 1919 · 163 km NW of this epicenter
- 7.2241 km WNW of Houma, TongaAugust 21, 1911 · 66 km N of this epicenter
- 7.2280 km WNW of Houma, TongaDecember 14, 1910 · 62 km NW of this epicenter
- 7.2Fiji regionMarch 31, 1907 · 282 km N of this epicenter
- 7.1Fiji regionFebruary 25, 1915 · 249 km SW of this epicenter
- 7.1Fiji regionMay 4, 1924 · 164 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1937M8.1
Fiji Islands
16 Apr 1937 · 106 km away
- 1903M8.0
Tonga Islands
4 Jan 1903 · 250 km away
- 1919M7.8
Fiji Islands
1 Jan 1919 · 163 km away
tsunami
- 1853
Tonga Trench
24 Dec 1853 · 232 km away
tsunami
- 1907
S Of Tonga
1907 · 177 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.