why would a super continent form and they break up once it formed.?

Question

Studying Plate tectonics

Answer 1

The mantle of the Earth is not solid. It is a thick and slowly flowing material. This magma has convection currents due to temperature differences. When the magma flows, the plates floating on top of it must move along, too. The plates bump and grind together to form different sized land masses over the history of the Earth.

Answer 2

Plate tectonics is a system that continuously recycles itself

the plates are brought together by convergent forces, and the Earth is a sphere so those forces are all connected and aren't perfectly aligned.


The continents are pushing against those forces that brought it together,
and once together they basically can't keep enough pressure to hold them there so the continents start growing apart.

A super continent (as big as Pangea) is unstable. All that continental crust leaves plenty of room for hot spots to grow underneath which eventually create a "hole" in the continent (actually forms oceanic crust and allows for a young ocean to form)...which will grow until it splits the continent apart.




Did you know there was a supercontinent that split apart even before Pangea? it was called Rodinia! and scientists have found evidence of 3 or so different supercontinents!

Answer 3

The pattern that you are talking about is called the Wilson Cycle, after J. Tuzo Wilson who formalized some of the first ideas of plate tectonics. He noted a cyclical pattern of rifting, then ocean basin formation, then closing of the ocean basin and collision.
You asked two questions:
1) why would a super continent form? --A supercontinent forms when old ocean basins between continents get subducted.
When ocean crust gets pretty old and cold it becomes dense; it sinks and disappears in to a subduction zone. Eventually, an old ocean basin will develop a rim of subduction zones around it. The Pacific ocean is the leftover of the once vast ocean that surrounded the supercontinent of Pangea. Now, it is mostly surrounded by subduction zones. The total volume of ocean crust being subducted around the Pacific rim is greater than the volume of crust being created at the East Pacific Rise and other spreading ridges in the eastern Pacific. So, the Pacific Ocean is slowly closing. Eventually, the spreading ridges in the eastern Pacific will disappear at subduction zones and there will be no more new crust being created in the Pacific ocean unless new rift zones form because of an episode of plate reorganize. Subduction around the ocean will continue, and the ocean basin will close. The Americas will collide with Asia/Australia in millions of years and a new supercontinent will be born.
2) Why would a supercontinent break up? The processes that would cause the break up of a supercontinent are probably similar to those that break apart modern continents. They involve extensional faulting, crustal thinning, the rise of plumes of magma, and finally, the creation of ocean crust. Some areas that are rifting: East African Rift zone, Rio Grande Rift, Lake Baikal Russia, Salton trough, California (transtensive), Dead Sea rift (transtensive). More than one model has been developed to explain continental rifting: Burke & Dewey model (plume-generated triple junctions), the Vink and Courtillot model (rift-tip propagation).

Answer 4

It depends on the angle at which their respective plates collide and the movement of their plates relative to each other.

For example, Africa and South America were once joined together, but separated when the respective plates on which they "float" moved apart, creating the South Atlantic Ocean.

In contrast, the subcontinent of India has collided at a right angle with Asia, moving in the opposite direction. The interaction of those two plates formed the Himalaya mountains.

Plates can even move from side to side relative to each other, as they do along the San Andreas Fault which moves in a north-south orientation so no, California is not going to "slide into the ocean"..

Answer 5

The super continent might be the remnants of one of the last super collisions on the planet. The higher masses in that area had a higher altitude before there was a drop of water on the planet. Then the plates moved and mixed everything up and as we can see now add to the existing land masses.

Answer 6

It didn't seem to me that anyone understood your question. I think it was just a coincidence that all the plates were together at one time. They had previously been separated and had all collided in the Mesozoic Era to form Pangea.