Eric Valero - Week 5

For this week's travel journal, we will be visiting the Cascade mountain range.

Wherever oceanic and continental plates collide, the dense, thin oceanic plate is crushed down by the weight of the thicker continental plate. Known as "subduction," this process results in the lower plate being forced down into the Earth's mantle. These convergent plate boundaries create continuous compressive forces, and as the oceanic plate drops further and further into the mantle, its temperature increases. Around 100 miles below the Earth's surface, rocks begin to melt. 

These melting rocks can form magma chambers, which are less dense than surrounding rock, making them buoyant. These collections of molten rock rise through their surroundings towards the surface of the Earth, often resulting in a volcanic eruption. One such example of a subducting oceanic plate creating a range of volcanoes is our weekly destination- the Cascade mountain range. Located along the U.S. western coast, the Juan de Fuca oceanic plate diving beneath the continental border of the United States has created a range of volcanoes over the melting oceanic plate. Mount Saint Helens is one of these volcanoes!

The vast majority of the volcanoes in the Cascades are long dormant and also rather small, although over the ages volcanic debris has built up much of the area. The result is an astonishingly beautiful and geologically significant near-ocean coast for us to visit and appreciate.