Reviewed by USGSTonga108y ago
M6.6 earthquake 151 km S of Hihifo, Tonga
Friday, May 2, 1919, 02:07:30 UTC · 17.316°S, 173.643°W
A magnitude 6.6 earthquake struck 151 km S of Hihifo, Tonga on Friday, May 2, 1919, 02:07:30 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M8.1 on April 30, 1919.
- Magnitude
- 6.6
- Strong · mw
- Depth
- 25 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
133 kilotons of TNT
That is about 9 times the Hiroshima bomb. It released about 279 times the energy of a magnitude 5.0.
Tectonic setting
97 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
25 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 11 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 · 169 km SE of this epicenter
- 8.0The 1917 Samoa-Tonga EarthquakeJune 26, 1917 · 261 km N of this epicenter
- 7.385 km ESE of Neiafu, TongaJanuary 2, 1907 · 198 km S of this epicenter
- 7.2108 km SE of Neiafu, TongaDecember 19, 1906 · 219 km S of this epicenter
- 6.915 km WSW of Pangai, TongaFebruary 27, 1905 · 298 km S of this epicenter
- 6.9127 km S of Hihifo, TongaMay 8, 1913 · 44 km NW of this epicenter
- 6.8100 km SE of Hihifo, TongaDecember 20, 1914 · 89 km NE of this epicenter
- 6.7144 km ENE of Hihifo, TongaOctober 20, 1916 · 231 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 3 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2 recorded deaths. The most severe:
- 1917M8.3
Samoa Islands
26 Jun 1917 · 213 km away
2 deathsModerate damage ($1–5M)tsunami
- 1919M8.1
Tonga Islands
30 Apr 1919 · 166 km away
Limited damage (under $1M)tsunami
- 1865M8.0
Tonga Islands
18 Nov 1865 · 243 km away
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.