Greater Seattle Area - Tectonics, Mountains, Shields and Platforms

Juan de Fuca Plate is a part of the Ring of Fire. It used to be part of a much larger plate known as the Farallon Plate. (Farallon Plate) This plate has nearly subducted underneath the North American Plate. The Juan de Fuca Plate is much smaller and is actively subducting underneath the North American Plate. 

If you look at the pictures below, you will notice the volcanism and mountain range being created as a result of these convergent plates coming together with the oceanic crust subducting underneath the continental crust. As a result, the GSA experiences several earthquakes each year. In the past month, two earthquakes have been recorded. You can track these at: http://earthquaketrack.com/r/seattle-tacoma-area-washington/recent


Columbia Plateau and Cascade Range Volcanism

Juan de Fuca Plate

Cascade Range

To the east lies the Cascade Range, a result of the Juan de Fuca subduction (Cascade Volcano Observatory). As the plate is subducted, a chain of volcanoes formed from the rising flow of magma, erupting along the subduction area. Some of these famous volcanoes include Mount St. Helens, Mount Rainier, Mount Baker and Glacier Peak. Tourists travel year-round to get a glimpse of the magnificent, yet deadly volcanoes. After you have reached the heart of parks and glance around at the beauty surrounding the volcano, it is difficult to imagine the actual result if it were to erupt. The beauty makes you forget for a short period of time. Mount Rainier reaches 14,410 ft at it's highest.

In the pictures below, located in the Paradise Jackson Visitor area of Mount Rainier, is Myrtle Falls. The lush greenery is also filled with many wildflowers. The beauty is extremely elusive to the danger that lurks beneath the surface of the earth. These were taken in September 2012.        

Olympic Mountains

To the west lies the Olympic Peninsula. It contains several ecosystems over a relatively small region. For this post, I am going to concentrate on the Olympic Mountains located within Olympic National Park. The park contains a little over 1400 square miles right in the middle of the peninsula. Mount Olympus sits at the highest point just short of 8,000 ft. The formation of the mountains is still under debate. Most agree that a sudden uprising of the crust formed the mountains as chunk of the crust broke off. It folded and smashed into the continent forming the Olympic Mountains. It is mainly composed of basalt, shale, and sandstone; and also contains marine fossils, National Geographic: Olympic National Park.  The mountains were separated from the continent during the glacial period of the Pleistocene, Olympic National Park, and were jaggedly carved by the many glaciers and rivers that whittle down the landscape. Glaciers still sit atop these mountains. Even the coastline is full of twisted, jagged terrain.

The pictures below are from Ruby Beach in March 2013. As you can see, there are sharp, large rock formations on the coastline of the peninsula. My son is standing on the boulder to demonstrate how massive these rocks really are, and well, also to show he wasn't afraid to climb them.

   

The pictures below are from Kalaloch Beach in September 2012. The terrain along the coast is extremely steep, with columnar formations jutting out of the crust in different areas. They are extremely large, as you compare them to the tiny person (again, my son - who tends to be my assistant on many of these trips) climbing on them.

   

Again, I tried to stick with just covering the plate tectonics and the results (mountains, volcanoes, etc) of the subduction of those plates. There is so much more to these areas, but that information doesn't really fall under this particular subject. Hope you enjoy the pictures and are able to take away some information about the tectonics in this region. Also, please do not use my pictures without permission first.

Until next time!

~ Crystal ~