The western edge of the Pacific tectonic plate is one of the world's oldest sections of oceanic crust.
It disappears underneath the Philippine plate sometimes at such sharp angles that it is almost going straight down.
The subduction zone there creates the deepest point on Earth's surface, the 7-mile-deep Marianas Trench.
That collision of plates also breathes fire into a volcanic island chain known as IBM, short for Izu-Bonin-Mariana.
The chain begins in the south in islands that comprise a United States commonwealth and extends northward into the
heart of Japan. Scientists have chosen the 1,500-mile-long chain as one of two places in the world to study some of
the most challenging questions in plate tectonics.