Plate data: Bird (2003), PB2002, converted by Hugo Ahlenius, Nordpil (ODC-By 1.0). Land: Natural Earth (India POV).
The Philippine Sea Plate is an oceanic plate in the western Pacific. USGS uses the Marianas Trench as its example of two oceanic plates converging: the fast-moving Pacific Plate converges against the slower Philippine Plate. PB2002 splits a narrow Mariana Plate off the eastern edge, so on this map the Pacific Plate touches the Philippine Sea Plate mostly north of the Marianas.1
At the southern end of that trench, the Challenger Deep plunges to nearly 11,000 m, deeper below sea level than Mount Everest rises above it. Subduction here also builds volcanoes that rise from the seafloor in a curved chain, the Mariana Islands, a classic island arc.
Bird (2003) explains the Mariana split. West of the Mariana volcanic arc, the seafloor of the Mariana Trough is spreading: estimates at 18 degrees north range from 30 to 43 mm per year, and later magnetic surveys found about 50 to 56 mm per year near 13 to 14 degrees north. The strip between the trough and the trench therefore moves as its own plate. Bird ends it near 24 degrees north, where the back-arc basin ends. Farther north, extension behind the Izu arc is only 1 to 2.5 mm per year, below the threshold Bird uses for a new boundary, so the Izu arc stays part of the Philippine Sea Plate (Bird 2003).
USGS reports that in 1991, two volcanoes on the western edge of the Philippine Plate produced major eruptions: Mount Pinatubo in the Philippines and Unzen in Japan. Pinatubo's eruption on 15 June sent an ash cloud 40 km into the air (USGS). PB2002 draws those western edges a little differently, and on this map Pinatubo sits on the Sunda Plate and Unzen on the Amur Plate.2
Philippine Sea Plate in numbers
Measured from its PB2002 outline, the Philippine Sea Plate covers about 5.4 million km², or 1.1% of the
Earth's surface. That makes it number 12 by area of the 52 plates in the model.
It spans from 0°N to 35°N and from 119°E to 145°E.
Its edge is about 11,281 km long, mostly convergent:
19.5%divergentDivergent boundary. Plates pull away from each other and new crust forms between them. Source (2,198 km)
, 70.6%convergentConvergent boundary. Plates move toward each other and crust is destroyed as one plate dives under another. Source (7,966 km)
and 9.9%transformTransform boundary. Plates slide horizontally past each other. Crust is neither made nor destroyed. Source (1,117 km)
.
Countries whose main landmass sits on this plate: Philippines and Taiwan. Countries that straddle a boundary
are listed under the plate that holds the center of their largest landmass.
Philippine Sea Plate fact table
Philippine Sea Plate at a glance, computed from PB2002
Along its boundaries it moves a mean 6.0 cm/yr relative to its neighbors, fastest against the Okinawa Plate. Bird (2003)
Neighboring plates Neighbors. Plates that share a boundary with this plate. Most plate movement happens along these narrow zones between plates. Source
The Philippine Sea Plate shares a boundary with 9 plates in PB2002, longest shared edge first.
The longest, about 2,882 km, is with the Sunda Plate; the shortest, about 313 km, is with the Okhotsk Plate.
