Week 5 - Converging Plates - Peter Hoffman

    My first thought for this weeks post immediately was of the San Andreas transform fault, however I decided to try and shift gears to something that was closer to somewhere I had lived.  I remember when I lived in the pacific NW I would see groves of trees of dead cedar trees in the middle of what was otherwise a flourishing area.  Further research led me to discover that this is in face what is known as a ghost forest which according to Wikipedia can occur when a portion of forest can be poisoned by salt water due to  a rise in sea level.

Picture of the ghost forest along the Copalis river in Washington courtesy of https://www.atlasobscura.com/places/ghost-forest-of-copalis

This ghost forest is the result of an earthquake that happened in the PNW due to the Juan de Fuca plate.   An oceanic plate that is subducting under the North American plate. 

Juan de Fuca plate and subduction zone. Image courtesy of https://earthquake.usgs.gov/learn/glossary/?term=subduction

The result of this convergent plate (along with another small plate) is the Cascades volcanic arc that was thoroughly went through by our text.

Mount St Helens (left) and Mt Rainer.  Image courtesy of https://www.usgs.gov/media/images/mount-st-helens-left-and-mount-rainier-viewed-toward-north