Question

Why do magmas rise toward Earth's surface?

A) Due to gravitational pull
B) Because of increased pressure
C) Driven by buoyancy and lower density
D) Forced by tectonic plate movement

Answer 1

Magmas rise towards Earth's surface due to buoyancy and lower density caused by plate tectonic movements, subduction, and hot mantle plumes.

Step-by-step explanation:

Magmas rise towards Earth's surface mainly due to buoyancy and lower density, which is option C. When tectonic plates diverge, the reduced pressure causes magma to be produced. Additionally, when tectonic plates converge, the subduction of oceanic crust causes the release of water, which lowers the melting temperature of the mantle and leads to magma production. Melting can also occur at hot spots caused by mantle plumes. In all these cases, the magma rises towards the surface due to its lower density compared to the surrounding rocks.