There are 10 active mud volcanoes in the Izu–Bonin–Mariana_Arc which can be found along a north to south trend, parallel to the Mariana trench. The material erupted at these mud volcanoes consists primarily of blue and green serpentinite mud which contains fresh and serpentinized peridotite material from the subduction channel. Serpentinite mud is formed as fluid from the down going Pacific plate is released via prehnite-pumpellyite dehydration, greenschist alteration, and blueschist dehydration. This fluid interacts with mafic and ultramafic rocks in the down going Pacific plate and overriding Philippine plate, resulting in the formation of serpentinite mud. All of these mud volcanoes are associated with faults, indicating that the faults act as conduits for the serpentine mud to migrate from the subduction channel to the surface. These mud volcanoes are large features on the forearc, the largest of which has a diameter of ~50 km and is over 2 km high.