Convergent Subduction: Guam

We have arrived at out first stop, Guam!   We are here to explore the Mariana Trench, an example of convergent subduction. 

http://www.theworldsgreatestvacations.com/for-travelers/an-american-in-guam-and-saipan-without-a-passport/

  

At this at this boundary, one oceanic tectonic plate slides under another and sinks into the mantle as they converge.   As they collide, the younger of the two plates, because it is less dense and warmer, will ride over the edge of the older plate. As the older plate very, very slowly moves into the mantle, the heat causes part of it to melt, creating magma.  The magma is less dense, and rises to the surface, creating a volcano. 

https://www.uwgb.edu/dutchs/CostaRica2008/CRAccretion.HTM

Convergent subduction can cause earthquakes, because of the plates colliding, and mountains and volcanoes from the magma pushing from under the top plate. These volcanos then have the potential to form strings of islands, such as the Mariana Islands.  In this situation, the Pacific plate, the largest in the world is subducted under the much smaller Mariana plate. Mariana Trench itself has had no major recorded earthquakes after the 1600s, due to mud.  The mud is a special type of soft rock called serpentine, which allows the stress caused by earth’s movements to be released without causing any earthquakes.  

http://www.ecorazzi.com/2012/03/02/james-cameron-is-diving-the-mariana-trench-soon/