I cannot believe the number of you out there that have no idea that there are active Volcanoes right here in River City. I just assumed others were as interested as I am in the geology and workings of our natural world. I am not an expert by any means, but I do know quite a bit about the weather and tectonic plates, and the Ring of Fire, and volcanism.
Our Continent is active seismically, because of forces under the crust of the earth, and the oceans. Tectonic plates are floating pieces of earth that are constantly being transformed. Some are being SUBDUCTED under another plate and remelted into volcanic magma. Without going into a huge geology lesson, this is the part we will deal with today. The area of the planet that we live on is the North American plate. Right off shore here is the San Juan plate. When this plate moves, and slides under the North American Plate, it gets hot and turns into molten rock called Magma. This Magma is under extreme pressure, and like a bad case of acne, needs to erupt into a pimple. This Pimple is called a volcano, and when the pressure gets really bad, it pops. And erupts magma into the atmosphere where it is now called Lava. Lava forms rock, which in turn becomes earth.
All along the Pacific Ocean rim we have Subduction going on, and thus we have what is called the Ring of Fire. I have included a wonderful Website here called the USGS volcanic page. Go at your leisure and read this site, it will help you learn even more. It will amaze you at the number of places RIGHT HERE in the USA that are or will be active some time in the geologic future.
To get on with our geology lesson for the state of Washington, there are 5 active or potentially active Mountains. Mt Baker, Glacier Peak (extinct), Mt. Rainier, Mt St Helens, And Mt Adams. When you cross the border into Oregon there are even more of them the most famous of them being Mt Hood, and Crater Lake. Then of course we cross into California, Where Mt Lassen blew itself to smithereens in early 1900’s, and Mt Shasta. Alaska has so many it is hard to keep track of them all.
map
Mt Baker steams through an open vent in Sherman Crater. It has not erupted in more than 200 years, but it could at any time. Mt Rainier has hot springs, and could become active at any time. IF and When this occurs, Seattle and the surrounding vicinity will be buried under 100’s of feet of mud and ash. (Makes you wonder why people live there). Mt St Helens as you all know, woke up in 1980 and after 2 months of venting and rumbling, and opening cracks, it blew the side out of itself, creating a new landscape and killing 50 or so people. It is active to this day, erupting lava, and doing some new dome building. Mt Adams is quiet and so is Glacier Peak, but they will not always be that way.
The earthquakes that we are so famous for are tectonic plates sliding past each other. There are fault lines all through the area, some not even discovered yet. Brenda said that she just experienced an earthquake along the Madras Fault. This is a huge fault that runs through the middle of The Continent. It experienced a MAJOR earthquake in the early 1800’s. As long as there are small degrees of slippage, and small quakes, and venting of steam and around these areas, the major earthquakes, and Volcanic eruptions are kept at bay. It is when there is no activity at all that we should really worry. SO read the USGS site and get prepared people, because every single one of us is sitting on some kind of geologic time bomb.
Sleep tight!!
No comments:
Post a Comment