Tuesday, February 1, 2011

Volcanoes

This semester in my classes we are learning about volcanoes, and everything that goes with them.  So I thought I would share with you sofig32me of what I learned first off geologist have a index rating for volcanoes that is similar to the rector scale meaning a change from a 1 to a 2 is 10 times more powerful.  This scale is called  Volcanic Explosivity Index (VEI) (check the link for more info)and ranges form 0 to 9 in intensity rating.  Each volcano has a different rating based on the plume height, frequency of eruption, its occurrence, and the total amount of ejected material.  With a little back ground I wanted to share some new knowledge about a type of volcano that I did not know much about they are called a “Maar” volcanoes and are very deadly.  They form like any other volcano by magma rising to the surface however in this case the magma comes into contact with an underground aquifer.  Water is instantly flashed to steam and as a super heated gas it need to expand rapidly but being trapped under ground applies pressure which is quickly over powered in a atomFig1-maehara-5-18-bm_largeic like explosion earning a VEI of 5-6.  Some of these eruptions produce super heated plumes that can rise 55 kilometers in the atmosphere in case you are wondering NASA describes space as starting at 100 kilometers from the surface of the earth just to give you an idea of the height these plumes can reach.  They produce pyroclastic density currents(PDC) which are super heated ash flows that can travel up to 100 miles an hour, destroy anything in there path.  These PDC are what is responsible for the destruction of the city 080710maarof Pompeii and all the people that lived there (note Mt. Vesuvius is not a maar but is a Strato-volcano like Mt St. Helens).  It is common to find maar’s as a shallow lake sometimes as deep as 10 to 200 meters  and as wide as 60 to 8000 meters.  I will describe more volcanoes and what I have learned in upcoming posts but until then get to know what your walking around on.

4 comments:

Crustacean Queen said...

Talk about bad gas! Sheesh!! ☺

That picture of the lake is awesome. Where is it? Hopefully not to close?

Yeah, I don't know what I'm walking around on...all I know about are the faults around here. That's all that's ever on the news.
How do you find out about that stuff?

Rich said...

I tell you if you ever want the planet is tearing its self apart or the sky is falling and the end of the world excitement just take a geology or physics class. Then you can find out all sorts of interesting and deadly things that "could" happen. Sorry on not labeling the photos the first one is from the The Ubehebe Craters at this web site http://geology.fullerton.edu/whenderson/Fal201L2005/Ubehebe/volcano.htm
the second one is the Ukinrek Maar eruption column April 6 1977 at this website http://commons.wikimedia.org/wiki/File:Ukinrek_Maar_eruption_column_April_6_1977.jpg and the last one is Vulkaneifel Geopark Locatedin the middle of Central Europe you can view it at this website http://www.globalgeopark.org/publish/portal1/tab59/info2841.htm

walterh14 said...

Dig the info with Volcano's. Ive done alot of online research for my manuscript. They play a large part in the second part of my series. thewalkerofthewinds.blogspot.com It's a Fantsy tale, just tidbits if the manuscript, 13 to choose from, you should check it out. Cool site man.

walterh14 said...

Cool site man, I do alot of research on Volcanos myself. For my manuscripts .thewalkerofthewinds.blogspot.com you should check it out. It's just tidbits , 13 pieces of the overall tale.