Reviewed by USGSTonga5mo ago
M4.6 earthquake 84 km WSW of Neiafu, Tonga
Saturday, April 4, 2026, 08:33:48 UTC · 19.014°S, 174.686°W
A magnitude 4.6 earthquake struck 84 km WSW of Neiafu, Tonga on Saturday, April 4, 2026, 08:33:48 UTC, at a depth of 79.3 km (intermediate). It is the strongest earthquake within 300 km since an M4.9 on April 3, 2026.
- Magnitude
- 4.6
- Light · mb
- Depth
- 79 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
41 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
79 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 50 km
USGS lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.6 on April 29, 2026. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 2,060 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 · 249 km E of this epicenter
- 8.0TongaJanuary 4, 1903 · 115 km S of this epicenter
- 8.02006 Tonga EarthquakeMay 3, 2006 · 143 km SE of this epicenter
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 146 km SW of this epicenter
- 7.8111 km SSE of Pangai, TongaJune 26, 1913 · 207 km SE of this epicenter
- 7.5158 km W of Neiafu, TongaMarch 24, 2026 · 99 km NW of this epicenter
- 7.5110 km E of ‘Ohonua, TongaSeptember 8, 1948 · 259 km S of this epicenter
- 7.4103 km ESE of Neiafu, TongaFebruary 27, 1921 · 174 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 16 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1919M8.1
Tonga Islands
30 Apr 1919 · 240 km away
Limited damage (under $1M)tsunami
- 1865M8.0
Tonga Islands
18 Nov 1865 · 136 km away
Limited damage (under $1M)tsunami
- 2006M7.9
Tonga Islands
3 May 2006 · 143 km away · intensity VII
Limited damage (under $1M)tsunami
- 1903M8.0
Tonga Islands
4 Jan 1903 · 115 km away
- 1948M7.9
Tonga Islands
8 Sep 1948 · 232 km away
tsunami
- 1902M7.8
Tonga Islands
9 Feb 1902 · 131 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.