Convection currents occur in the MANTLE. The mantle is the second layer of the earth after the crust. The mantle is approximately 2900 km thick. Convection currents are triggered or fueled by the heat from the Earth's core.
The part of the mantle closest to the core gets heated. It then becomes less dense than the layers above so it rises. When this rising plume interacts with the crust it cools and becomes more dense than the layers below and so it sinks and this circular motion continues to form convection currents.
Answer:
1. Continental-continental convergence are both <em>continental crust</em> plates.
2. Buoyancy basically means these plates are light float on top of the Asthenosphere.
Explanation:
1. To go a little more into detail, this type of convergence ocurrs when two plates made of continental crust (not oceanic) collide. In the case of ocean-continent convergence, the denser oceanic crust sinks underneath the lighter continental crust.
In this scenario, we have two plates, neither of which want to sink, so instead of going down they just crumple and fold and keep colliding. This collision creates very high mountain ranges such as the Himalaya and usually doesn't contain any volcanic activity because no magma is capable of penetrating through so much crustal material.
2. As for why continental crust is buoyant and doesn't sink has much to do with its composition. Continental crust is made mostly of silicate material. This is very different from oceanic crust which is made of basaltic rocks and is therefore heavier. The term buoyancy refers to the 'floating action' of the continental crust on top of the uppermost mantle.
You would definitely not expect political stability in a state that is being annexed or which does not have a territory - rather the opposite would be true.
Both multinational and souvereign states can have a high lever of political security. However, in a multinational state one can also expect some conflicts between the different ethnic groups - therefore the best answer is "a sovereign state"
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Divergent boundaries move oceanic plates (plates found in the ocean) away from each other, making magma seep in to fill those cracks, thus spreading the sea floor.
Answer:
measures less than 90 degrees
Explanation:
