Reviewed by USGSTonga20y ago
M4.6 earthquake 47 km NE of ‘Ohonua, Tonga
Tuesday, July 25, 2006, 10:06:21 UTC · 21.058°S, 174.604°W
A magnitude 4.6 earthquake struck 47 km NE of ‘Ohonua, Tonga on Tuesday, July 25, 2006, 10:06:21 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M4.6 on July 25, 2006.
- Magnitude
- 4.6
- Light · mb
- Depth
- 10 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
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
95 km
from the nearest mapped plate boundary, between the Tonga and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
10 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 50 km
USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,206 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0TongaJanuary 4, 1903 · 125 km N of this epicenter
- 8.02006 Tonga EarthquakeMay 3, 2006 · 109 km NE of this epicenter
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 200 km NW of this epicenter
- 7.8192 km WSW of Haveluloto, TongaOctober 14, 1997 · 252 km SW of this epicenter
- 7.8111 km SSE of Pangai, TongaJune 26, 1913 · 93 km NE of this epicenter
- 7.5110 km E of ‘Ohonua, TongaSeptember 8, 1948 · 76 km E of this epicenter
- 7.4103 km ESE of Neiafu, TongaFebruary 27, 1921 · 290 km NE of this epicenter
- 7.385 km ESE of Neiafu, TongaJanuary 2, 1907 · 259 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1 recorded deaths. The most severe:
- 1977M7.2
Tonga Trench
22 Jun 1977 · 243 km away · intensity IV
1 death$1 million damagetsunami
- 1865M8.0
Tonga Islands
18 Nov 1865 · 208 km away
Limited damage (under $1M)tsunami
- 2006M7.9
Tonga Islands
3 May 2006 · 109 km away · intensity VII
Limited damage (under $1M)tsunami
- 1937M8.1
Fiji Islands
16 Apr 1937 · 253 km away
- 1903M8.0
Tonga Islands
4 Jan 1903 · 125 km away
- 1948M7.9
Tonga Islands
8 Sep 1948 · 63 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.