Serious question about tectonic plates.

James07

James07

James07

Soldato
Joined
6 Dec 2006
Posts
5,914
Location
West Yorkshire
This evening i watched a program on volcanos on the beeb, these have always intrigued me, but something that crossed my mind (google has no answers) is couldnt the plates move in such a way to cause oceans to slowly drain? They move in such a way to create volcanos, i.e. hawaii

They create mountains when they smashed together thousands of years ago and opened at the summit hense causing volcanos, so in theory couldnt they work in the opposite direction?

This is a serious question, im intrigued now.
 
The mid Atlantic fault is two plates moving apart. This is known as a constructive fault as new crust is constructed from the molten magma that flows up through the fault and is cooled by the ocean.
 
My understanding is there is nowhere for them to drain to. Everywhere they could go to has been filled with water, so if tectonic plates were to open up somewhere for the sea to drain into, it wouldn't make much difference as they'd also be moving into where the sea was.
 
Hawaii is an exception to the rule as it is a hot spot based land mass, and has formed in the centre of a plate that is moving, due to mantle plumes.

The plates move apart and hot magma flows upward from the pressurized mantle and is instantly cooled by the water forming new crust.
 
Last edited:
Yeah ive just been told this by someone, apparently they cant invert, as there is nowhere to invert to, so the pressure forces it in the only way possible, upwards.

Dull end to an interesting thought.
 
so... your thinking is the earth is hollow?

its not hollow its lots of rock, then melted rock then melted heavier stuff.. (i dont know what but it seems logical the heaviest stuff sinks to the bottom)

when the plates separate magma fills the gap to create more crust..
 
No, new crust is formed at constructive boundaries (Boundary where two plates move away from each other) as magma from beneath the surface rises into the gap left and cools to form the new crust.
 
edscdk said:
so... your thinking is the earth is hollow?

its not hollow its lots of rock, then melted rock then melted heavier stuff.. (i dont know what but it seems logical the heaviest stuff sinks to the bottom)

when the plates separate magma fills the gap to create more crust..
Click to expand...

Im an engineer, not a geologist, i like to find out what i can though :)

I dont think the earth is hollow no, i just dont understand how such a huge pressure cant be forced in the opposite direction. I also didnt know that the plates are constantly separating, surely this could create larger areas for the oceans to lay? Which would lower ocean levels. Im probably right there, but the plates dont move fast enough i assume. Theories theories..
 
James07 said:
Im an engineer, not a geologist, i like to find out what i can though :)

I dont think the earth is hollow no, i just dont understand how such a huge pressure cant be forced in the opposite direction. I also didnt know that the plates are constantly separating, surely this could create larger areas for the oceans to lay? Which would lower ocean levels. Im probably right there, but the plates dont move fast enough i assume. Theories theories..
Click to expand...

At mid ocean ridges where the plates pull apart, hot magma comes up and forms new oceanic crust.

At destructive margins, at the other edge of the plate, two plates collide; if it is oceanic crust colliding with continental crust, the oceanic crust will be subducted (due to it's higher density) under the continental crust, where it is pushed back into the magma and eventually remelted, thus maintaining a fairly constant area of ocean. (fairly basic explanation, but you get the gist)

It's why the oldest oceanic crust is about 180ma, whereas the oldest continental crust is 4Ga.

Source; I'm a geology/environmental geoscience student.
 
from my basic GCSE Geography some moons I think Plates can

Collide (1 over the top of the other)
Separate (pull apart)
and Shear (tear along each other)

and if memory serves me correctly the Shear Action is the most Destructive in terms of us ontop
 
James07 said:
Serious question about tectonic plates
Click to expand...

James07 said:
This is a serious question
Click to expand...

nfk51t.jpg
 
Komedy said:
Isn't Yellowstone a "Super Volcano" and if/when it goes we're shafted !
Click to expand...

It will be a particularly bad day if it goes up. For a while in the mid 2000's, it started to look a bit suspect as the caldera was rising faster than ever. It has slowed down now though, and the chances of an eruption have receded.

Although you can never be sure. If it goes up, it will block out sunlight for a long time, so most things would die.
 
Supervolcano?

For goodness sake, i was off to bed before i read that! Plus im on the phone to a pretty girl who is less than impressed! Ohhh baby good chat up lines! Luckily for me shes a geek, yet still with zero interest in this subject lol
 
If you took notice of where they are filming you would have noted they were in Iceland.
This Island is born through the fact that the plates are moving away from each other. It is some of the youngest "land" on earth.
Just north of Rekyavik is valley where the eurasian plate and the North American plate are moving apart from each other at about 2cm a year. You can see all around the land sinking to fill in the fissure below, last August they had to close a footpath built near a historic site (the place where the first government of the world was formed) because the ground opened up below it.
and for the iceing on the cake, yes the sea does try to fill in the gap left behind. A lake is forming in that valley and where the actual crack starts I have got in it with my scuba gear and dived in it.

This is it in a dive watch advert, I'm still waiting to get my hands on the pics of me actually in there. :D (Dive buddies with the camera don't get home until later this month)
silfra.jpg
 
Fuzz said:
(Dive buddies with the camera don't get home until later this month)
Click to expand...

If thats genuine then that is epic!

And about the plates moving about 2cm s year, is that on the east coast? I remember been amazed by the way the country has changed shape through history and how it will always change.
 
You must log in or register to reply here.
Back
Top Bottom