Manus Trench is a trench delineating the oceanic boundary between the Caroline Plate

Caroline Plate

The Caroline Plate is a small tectonic plate located north of New Guinea. It forms a subduction zone along the border with the Bird's Head Plate and the Woodlark Plate to the south. A transform boundary forms the northern border with the Pacific Plate. Along the border with the Philippine Sea Plate...

 and North Bismarck Plate

North Bismarck Plate

The North Bismarck Plate is a small tectonic plate located in the Bismarck Sea off the northeast coast of New Guinea.-Tectonics:To the north it collides with the Pacific Plate and the Caroline Plate, part of the western part subducts under the Woodlark Plate of New Guinea, and it is separated from...

s, in Papua New Guinea

Papua New Guinea

Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...

. The Kilinailai Trench

Kilinailai Trench

Kilinailai Trench is a trench delineating the oceanic boundary between the Pacific Plate and North Bismarck Plates, in Papua New Guinea. The Manus Trench, which looks as if it is a Western continuation of the Manus Trench, marks the boundary between the Caroline Plate and North Bismarck...

, which looks as if it is a continuation of the Manus Trench, marks the boundary between the Pacific and North Bismarck Plates. Perpendicular to the two trenches is another trench, the Mussau Trench separating Caroline plate and Pacific Plate.