Yap Trench

The trench is roughly J-shaped and is 650 kilometres (400 mi) long and 8,527 metres (27,976 ft) deep at its deepest point.

Sato et al. observed in 1997 that microseismic activity in the trench was similar to that of active subduction zones, and Nagihara et al. noted large amounts of negative gravity along the trench, suggesting that a force was being exerted upon the crust beneath it.

The resulting rebound of the partially-subducted material may have caused a previously unexplained burst of volcanism along the Yap Arc sometime around 11-7 Mya.

Researchers also noted that their ocean bottom seismometers showed a two-layer crust, like that found in Chile and Argentina, under much of the area around the Yap Trench.

[3] The rest of the subducted Caroline slab, north of the SCP, can be seen as high-velocity areas in seismic tomographs.

The Caroline Plate, shown in maroon, is moving roughly towards the northwest and subducting through the Yap and Palau trenches, shown together as the pink line bordering the Philippine Sea Plate. This area is directly southwest of the Mariana Trench.