Where it is
The Maoke Plate is a tiny microplate of about 115,000 square kilometers, or 0.02% of Earth’s surface. It covers part of the central highlands of western New Guinea, about 6.1% of the land of Indonesia. It takes its name from the Maoke Mountains, the range that includes Puncak Jaya (also called Carstensz Pyramid), at 4,884 m the highest mountain in Oceania.
The crust here is continental. It formed along the northern margin of the Australian continent and was later crumpled and lifted as New Guinea collided with volcanic arcs to the north. That collision built some of the highest ranges in the western Pacific, with glaciers that have shrunk sharply in recent decades.
What happens at its edges
The Maoke Plate has only three neighbors. Its southern boundary, 660 km long, is with the Australian Plate. PB2002 classifies the whole stretch as continental transform, with only about 1.3 cm/yr of relative motion.
A 548 km boundary with the Bird’s Head Plate, on the western side, is much faster, about 8.0 cm/yr, and mixes continental rift and strike-slip segments. To the east, a 440 km boundary with the Woodlark Plate is a continental collision zone moving at about 2.3-3.0 cm/yr.
Earthquakes
The dataset lists 29 earthquakes of magnitude 6.5 or larger on the plate since 1900, none of them magnitude 8. The largest include a 1906 earthquake (M7.8), a 1971 earthquake (M7.7) and a 1926 earthquake (M7.6), all centered west and southwest of Jayapura. Most are shallow, as expected in a zone of continental collision and strike-slip faulting. Shaking in these steep mountains often sets off landslides, which can block rivers and isolate highland villages. The dataset lists no volcanoes on the plate, because there is no active subduction zone directly beneath it.
Why the plate is debated
Peter Bird included the Maoke Plate in PB2002 to describe a block of the highlands that does not fit neatly onto the Australian Plate or onto the microplates around it. The area is remote, and GPS stations there have been sparse, so the plate’s exact shape and motion are less certain than those of larger plates. Treat its boundaries on this map as approximate.