Week 5 - Ryukyu Island Arc - Alexander Nestle

Okinawa, the island that I am currently living on, is an island located in the north Philippine Sea.  It is part of a chain of islands called the Ryukyu Islands.  These islands form an island arc that is a product of the convergent plate boundary of the Philippine and Eurasian plates.  At this boundary, the more dense oceanic crust of the Philippine plate is subducting beneath the less dense Eurasian plate.  The crust from the Philippine plate is melted in the lithosphere into less dense magma, which then raises to the surface to form the Ryukyu Island arc.  The island is formed by a large amount of igneous rock from the hardened rock/magma.  The trench that has formed at the boundary of the two plates is called the Ryukyu trench, which is a reverse or thrust fault.  Obviously I don’t have direct access to the fault, but it is extremely likely that there is a large amount of sediment buildup at the trench.

Oregon State (n.d.)

CAMEMBERU (2012)

References:

Oregon State (n.d.) Tectonics and Volcanoes of Japan. Retrieved from http://volcano.oregonstate.edu/vwdocs/volc_images/north_asia/japan_tec.html

CAMEMBERU (2012).Okinawa: Cape Manzamo and Nago Pineapple Park. Retrieved by http://www.camemberu.com/2012/03/okinawa-cape-manzamo-and-nago-pineapple.html