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Quick DSOK if you can answer this

PostPosted: Wed Oct 13, 2004 3:05 pm
by Porter
How can Mount Erebus in antartica be an active stratovolcano if it doesn't even lie on a convergent plate boundry?

Re: Quick DSOK if you can answer this

PostPosted: Wed Oct 13, 2004 3:37 pm
by DSOK
Porter wrote:How can Mount Erebus in antartica be an active stratovolcano if it doesn't even lie on a convergent plate boundry?

I don't think the complete answer to this is known. It is evidently a hot spot volcano of some sort, since the source of the magma is not a nearby subduction zone. I believe that there are other hot spot stratovolcanoes, although they are rare.

This rest is more speculative.
In the case of Mt. Erebus, its proximity to the south magnetic pole may be part of the answer. The magnetohydrodynamics of the magma are different near the magnetic poles, and this could affect the composition of various ions in the fluid. Perhaps this may lead to a buildup of silica relative to what is usually found at hot spots; this could lead to the occasional explosive eruptions required to build up the mountain's height. However, most of the peak's activity is actually more typical of hot spot volcanoes. Mt. Erebus' crater contains a persistent convective lava lake, which is made up of fairly low-viscosity material, like the material produced by shield volcanoes. Also, cores taken on the mountain indicate that the preponderance of the eruptions have been basaltic.

PostPosted: Wed Oct 13, 2004 3:42 pm
by Alundra
:shock: DSoK ... did you swallow an encyclopedia when you were a child??

PostPosted: Wed Oct 13, 2004 3:44 pm
by Flibbo
he was dropped on his head in a library as a child

PostPosted: Wed Oct 13, 2004 3:44 pm
by Porter
i've done some research now and really I'm seeing no such evidence of a shield volcano similar to that of Mt. Kiluwaya. (mantle plume)

Erebus erupts several times a day and throws the lava bombs all over the damn place, also it discharges ash and gas almost all the time, which usually means silica material is in the lava and its very sticky.

I guess what I need to know is, what is causing all the seismic activity below Erebus since there is no real subduction zone nearby, in fact, the closet deal is rifting and spreading.

PostPosted: Wed Oct 13, 2004 4:17 pm
by DSOK
Porter wrote:i've done some research now and really I'm seeing no such evidence of a shield volcano similar to that of Mt. Kiluwaya. (mantle plume)

Erebus erupts several times a day and throws the lava bombs all over the damn place, also it discharges ash and gas almost all the time, which usually means silica material is in the lava and its very sticky.

I guess what I need to know is, what is causing all the seismic activity below Erebus since there is no real subduction zone nearby, in fact, the closet deal is rifting and spreading.

My impression was that the daily strombolic eruptions were caused by very small explosive events underneath the lava lake. These events would then spray the basaltic material up into the air. So, while the mountain's capacity for explosive eruptions is necessary for these events, most of the actual material expelled is the low-viscosity basalt.

Frankly, I don't think anybody knows what exactly is going on with Mt. Erebus. My theory (and it's just something that occured to me today and could be wildly inaccurate) is that it may be related to the magnetized flow of the mantle near the south pole.


Alundra wrote: DSoK ... did you swallow an encyclopedia when you were a child??

I read a lot. Earth science has always been one of my interests, and I knew a bit about Mt. Erebus. I had to refresh my memory about the details though.

PostPosted: Wed Oct 13, 2004 4:20 pm
by Porter
Geology is truely the bomb science

PostPosted: Wed Oct 13, 2004 5:04 pm
by Excell
Okay.....this is completely ridiculous. He could've just looked it up online......

There is no way to successfully question someone about something in test form like this over the internet.

PostPosted: Wed Oct 13, 2004 5:41 pm
by Porter
actually, he does know about it

PostPosted: Wed Oct 13, 2004 5:52 pm
by Excell
How do you know?

PostPosted: Wed Oct 13, 2004 6:18 pm
by Porter
i've been researching answers to the plate tectonics to Mt Erebus' eruptive style for 2 weeks now and have NEVER seen that information before.

His speculations make perfect sense.

PostPosted: Wed Oct 13, 2004 6:45 pm
by Excell
Okay DSOK....answer this one. It's pretty easy but I'll know if you've done internet research on it.

Who invaded Parthia during the First Triumvirate? Why was he important? What enabled him to be part of the First Triumvirate? Did he win or lose? Why?

Anyone try for it.....I don't really care. Just no internet research....it spoils the fun.

PostPosted: Wed Oct 13, 2004 6:50 pm
by Glenn47
It was obviously Ghengis Kahn. DUH :lol:

wow i never noticed this box up here

PostPosted: Wed Oct 13, 2004 6:57 pm
by Iteroth
Better yet, answer the skill testing question on the back of a lottery card.


(3 *50) + 20/5

PostPosted: Thu Oct 14, 2004 2:18 am
by Impossible
FORTY-TWO!