Reviewed by USGSTonga55y ago
M7.0 earthquake 146 km NW of Neiafu, Tonga
Monday, May 22, 1972, 20:45:57 UTC · 17.777°S, 175.026°W
A magnitude 7.0 earthquake struck 146 km NW of Neiafu, Tonga on Monday, May 22, 1972, 20:45:57 UTC, at a depth of 223.7 km (intermediate). It is the strongest earthquake within 300 km since an M7.8 on December 14, 1950.
- Magnitude
- 7.0
- Major · mw
- Depth
- 224 km
- Intermediate
- 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
567 kilotons of TNT
That is about 38 times the Hiroshima bomb. It released about 1,189 times the energy of a magnitude 5.0.
Tectonic setting
47 km
from the nearest mapped plate boundary, between the Tonga and Niuafo'ou plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
224 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 140 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11919 Tonga EarthquakeApril 30, 1919 · 280 km E of this epicenter
- 8.0TongaJanuary 4, 1903 · 247 km S of this epicenter
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 232 km S of this epicenter
- 7.4103 km ESE of Neiafu, TongaFebruary 27, 1921 · 244 km SE of this epicenter
- 7.385 km ESE of Neiafu, TongaJanuary 2, 1907 · 232 km SE of this epicenter
- 7.2108 km SE of Neiafu, TongaDecember 19, 1906 · 255 km SE of this epicenter
- 7.2Fiji regionMarch 31, 1907 · 207 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1919M8.1
Tonga Islands
30 Apr 1919 · 273 km away
Limited damage (under $1M)tsunami
- 1865M8.0
Tonga Islands
18 Nov 1865 · 250 km away
Limited damage (under $1M)tsunami
- 1903M8.0
Tonga Islands
4 Jan 1903 · 247 km away
- 1902M7.8
Tonga Islands
9 Feb 1902 · 270 km away
- 1950M7.7
Tonga Islands
14 Dec 1950 · 217 km away · intensity VI
- 1913M7.6
Tonga Islands
26 Jun 1913 · 270 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.