Which of the following best describes melting of the mantle at subduction zones that leads to island arc volcanoes?
◦ The subducting plate is cooled as it is carried to depth and the subducted oceanic crust melts.
◦ The subducted plate subsides into the mantle and allows magma from the lower mantle magma ocean to rise toward the surface.
◦ Water released from the subducting plate decreases the melting temperature in the mantle above the downgoing plate to generate magmas from the overlying mantle wedge.
◦ Heat is carried downward with the subducting plate and melts the mantle above the downgoing plate.
Three zones of root growth.
Amsterdam Albatross or Amsterdam Island Albatross, Diomedea amsterdamensis
The island model of migration