Reviewed by USGSTonga106y ago
M6.6 earthquake 110 km NW of Pangai, Tonga
Sunday, January 22, 1922, 03:23:48 UTC · 19.193°S, 175.173°W
A magnitude 6.6 earthquake struck 110 km NW of Pangai, Tonga on Sunday, January 22, 1922, 03:23:48 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.4 on February 27, 1921.
- Magnitude
- 6.6
- 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
124 kilotons of TNT
That is about 8 times the Hiroshima bomb. It released about 260 times the energy of a magnitude 5.0.
Tectonic setting
2 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: 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 16 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0TongaJanuary 4, 1903 · 92 km S of this epicenter
- 7.8111 km SSE of Pangai, TongaJune 26, 1913 · 218 km SE of this epicenter
- 7.4103 km ESE of Neiafu, TongaFebruary 27, 1921 · 227 km E of this epicenter
- 7.385 km ESE of Neiafu, TongaJanuary 2, 1907 · 197 km E of this epicenter
- 7.2108 km SE of Neiafu, TongaDecember 19, 1906 · 212 km E of this epicenter
- 7.2Fiji regionMarch 31, 1907 · 224 km NW of this epicenter
- 7.2241 km WNW of Houma, TongaAugust 21, 1911 · 237 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1919M8.1
Tonga Islands
30 Apr 1919 · 295 km away
Limited damage (under $1M)tsunami
- 1865M8.0
Tonga Islands
18 Nov 1865 · 179 km away
Limited damage (under $1M)tsunami
- 1903M8.0
Tonga Islands
4 Jan 1903 · 92 km away
- 1902M7.8
Tonga Islands
9 Feb 1902 · 152 km away
- 1913M7.6
Tonga Islands
26 Jun 1913 · 152 km away
- 1853
Tonga Trench
24 Dec 1853 · 219 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.