Instructions: In this task, you are given a paragraph, and your task is to construct a question from the given passage. Construct question in such a way that (i) it is well explained in the paragraph, (ii) the words may/may not be present in the paragraph, (iii) it should start with what/how/describe. Avoid creating a question that (i) is just relevant to one or two sentences, and (ii) not relevant to passage. 
Input: Magma rises through surrounding rock. Gas bubbles form and expand, causing lots of pressure. This pressure pushes the magma through weak spots in the earth's surface,. Magma flows out as lava. This can happen slowly or in a huge explosion. 
Output:
What happens during a vocanic eruption?