Intense Earthquake Activity, New Caledonia

The burst of earthquake activity that commenced near New Caledonia’s Loyalty Islands this morning has continued, with two larger events occurring in a series of 16 earthquakes.

A magnitude 6.3 earthquake 155 km east of Tadine in the Loyalty Islands (320 km east-north-east of Noumea, New Caledonia) marked the beginning of an intense series of earthquakes at 7:58 this morning, Friday 28th September 2007, New Zealand time.

A series of seven earthquakes with magnitudes between 4.9 and 5.5 followed before activity paused at 10:10 this morning. The relatively consistent strength of the quakes indicated that this was not a normal mainshock/aftershock sequence of events.

At 12:45 this afternoon a magnitude 5.9 quake struck the area and a larger magnitude 6.4 quake followed shortly after at 1:02 p.m. The second event was located 155 km east of Tadine.

A magnitude 5.6 quake at 1:25 p.m. preceded the largest quake of the series so far. The magnitude 6.6 quake, located 160 km east of Tadine struck at 1:36 p.m., triggering a tsunami bulletin from the Pacific Tsunami Warning Centre at 1:51 that advised a widespread tsunami threat was unlikely, despite the quake’s shallow depth.

A further four earthquakes with magnitudes between 5.0 and 5.5 followed before activity again ceased at 2:20 p.m. New Zealand time.

Fifteen of the sixteen quakes to have struck the area today have been in an area east to east-north-east of Tadine at a distance of between 140 and 170 km. A magnitude 5.5 quake at 1:44 this afternoon was located outside this area, being located 280 km south-south-east of Tadine. All of the quakes have been at depths of 15 km or less.

[Compiled from data supplied by the US Geological Survey and its contributing agencies.]

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