Day 5 - Mariana Trench 15°10'N 145°45'E

I arrived in the Philippines the other day, and immediately was taken to my hotel to get some rest. When I awoke, I set out to explore the city and find how to get to the trench. While in the city I met with a group of fishermen. They spoke in broken English, but I could still get what they were saying. They told me they were heading to the Mariana Trench and would take me out there on a fishing excursion.  I gladly agreed! This might be the only chance I get.

Sapian Island - environment.nationalgeographic.com

I met with them the next day while the sun was still rising, and set off. These men had been doing this for a long time; they cast and reeled with expertise. After a couple hours of fishing we came upon it. It was magnificent. The water was dark, almost black, and the surface glinted in the sunlight. In the distant I made out a group of islands. They were known as the Mariana Islands, a group of volcanic islands that marked the overriding Philippine Plate.

After fishing, we landed on Sapian Island, an island that is part of the Mariana Islands. The villagers there were very helpful and kind, taking care of our boat and treating us to a feast. I stayed there one night in one of the villagers huts, and then sailed off in the morning. It was such a wonderful experience!

The Mariana Trench formed over millions of years ago through a process called subduction, which occurs when one tectonic plate moves over another. In subduction, the older plate subducts under the newer due to density. In the Mariana Trench, the Pacific Plate subducted under the Philippine Plate, and the Pacific Plate is pulled down to form the Mariana Trench. This process is also responsible for the chain of volcanic islands known as the Mariana Islands. These volcanic islands form when the subducting rock melts due to the extreme temperatures and percolates up towards the surface. Since tectonic plates only move a few centimeters every year, it would have taken tens of thousands of years for the subduction to occur.

Subduction - katherine-tectonictour.blogspot.com