Question

plate tectonics: convergent boundaries dehydration. essentially, it remelts. this process takes place at what is known as a subduction zone, characterized by a trench below sea level and a chain of volcanoes, such as the andes mountain range. how does oceanic crust change as it descends into the earths mantle at a subduction zone? it remelts. it explodes. it becomes very cold.

Explanation:

The text states that as oceanic crust descends into the Earth's mantle at a subduction - zone, it undergoes dehydration and essentially remelts.

Answer:

It remelts.