Rainy Rainier

Well this brings me to our last boundary... It also returns me to my home town, Seattle. Rain, rain and more rain is all I can say. It makes me wonder why I ever came back. And then I remember the lovely volcano, Mount Rainier. This local phenomenon is a result of the last boundary type called "convergent subduction". 



http://tasaclips.com/illustrations/Convergent_Boundary.jpg


Well great, but what on earth does that mean? It is when two plates move towards one another (in this case oceanic and  continental) and one slides under the other. (This also forms a trench at the convergence point.) The oceanic plate slides beneath the continental plate because it is denser. You may be thinking "What? How come?" Well here is a simplified explanation. Imagine you have a cup of water with Styrofoam pieces in it. Naturally the Styrofoam will rise to the top because it is lighter. The continental plate is the less dense Styrofoam. 

So now back to how this made a volcano. Well, when the oceanic plate (Juan de Fuca)  slides under the continental plate (North American Plate), it sinks into the Earth's mantle which we all know is extremely hot. It melts the rock, creating magma, which rises because it is less dense than the rock. These magmas continue rising until they get to the earth's surface, producing a volcanic eruption. Subduction zones are a basis for long chains of volcanoes called 'volcanic arcs' that are parallel to the zone.

Mount Rainier is a stratovolcano that is part of the Cascadia Subduction Zone, located in the Cascade Range at 46˚51'10"N 121˚45'37"W.  It happens to be the most prominent mountain in the contiguous U.S. and has an elevation of 14,411 ft. It's prominence is 7 meters greater than that of K2. (WOW!) Because of it's structure and internal chemistry it is one of the most  dangerous volcanoes. If it were to erupt, it could produce massive lahars as it did 5,600 years ago when it's wall of mud covered 130 square miles. Lahars can destroy anything their path because of the extreme force/speed. Even worse, when it finally stops moving, the mud 

solidifies creating even more problems. 

Although it's last eruption was in 1884 it has landed itself on the Decade Volcano list, earning perpetual investigation of its dangers, and future eruption possibilities.

The following volcanoes were selected as the 16 current Decade Volcanoes:  

• Avachinsky-Koryaksky, Kamchatka,Russia
• Colima, Jalisco and Colima, Mexico
• Mount Etna, Sicily, Italy
• Galeras, Nariño, Colombia
• Mauna Loa, Hawaii, USA
• Mount Merapi, Central Java, Indonesia
• Mount Nyiragongo, Democratic Republic of Congo
• Mount Rainier, Washington, USA
• Sakurajima, Kagoshima Prefecture,Japan
• Santa Maria/Santiaguito, Guatemala
• Santorini, Cyclades, Greece
• Taal Volcano, Luzonbatangas,Philippines
• Teide, Canary Islands, Spain
• Ulawun, New Britain, Papua New Guinea
• Mount Unzen, Nagasaki Prefecture,Japan
• Vesuvius, Naples, Italy

  But let's not worry about that right now, and just enjoy the marvelous views it provides:

http://rpmedia.ask.com/ts?u=/wikipedia/commons/thumb/e/eb/Mount_Rainier_from_west.jpg/120px-Mount_Rainier_from_west.jpg

http://www.stanford.edu/~thelero/images/photography/Mount%20Rainier.jpg

http://www.bschool.com/media/images/WA/Tacoma,_Washington-Mount_Rainier_over_Tacoma.jpg

http://www.cornforthimages.com/galleries/Landscape/Washington/Mount%20Rainier/Mt%20Rainier%20Lenticular%20Cloud%20Aerial_Mount%20Rainier%20National%20Park,%20Washington.jpg

http://www.imageof.net/bulkupload/wallpapers13/Landscapes/Mount%20Rainier%20Washington.jpg

So unfortunately this brings me to say goodbye. I have loved being able to share my experiences with you, and with bit of luck, hopefully you learned a little about plate tectonics. 

Thank you for your support! I can't wait to see what the USGS thinks of my travels...

Adieu fellow geologists, and keep up your interests in Earth science! The learning never ends!