A strong undersea earthquake struck the Tongan islands early this morning.
Wednesday 25th November 2009
A magnitude 6.8 earthquake located 135 km east-north-east of the Tongan capital Nuku’Alofa was strongly felt early this morning. The quake, located 220 km south of Neiafu, Tonga (2100 km north-east of Auckland), struck at 1:47 a.m. New Zealand Daylight Time, at a depth of 10 km. Shaking was felt at several islands in the Tonga group and at Niue.
The Pacific Tsunami Warning Centre issued a bulletin for the event at 1:57 a.m. reporting the quake at magnitude 6.8 but slightly deeper at 33 km. It determined that a widespread tsunami threat did not exist based on historical data. No related sea disturbance has been indicated on New Zealand tsunami gauges.
Geoscience Australia reports the quake as magnitude 6.9 at a depth of 35 km. It estimates that the quake would have caused damage within 90 km of the epicentre and would have been felt up to 1100 km away.
Aftershocks of magnitude 5.6 and 5.1 were recorded at 2:04 and 2:32 this morning, NZDT.
This morning’s earthquake is the third quake of magnitude six to strike the south-western Pacific since Sunday. On Sunday evening, a very deep magnitude 6.3 event struck near Fiji. Another very deep magnitude 6.2 earthquake was reported 160 km west of L’Esperance Rock in the Kermadec Islands just before midday on Monday. This event was initially reported as magnitude 5.9. The Kermadec quake was felt in Wellington.
[Compiled from data supplied by the U.S. Geological Survey and its contributing agencies; the U.S. National Oceanic & Atmospheric Administration’s Pacific Tsunami Warning Centre, GeoNet and Geoscience Australia.]