Question

What is the role of water in an explosive eruption?
Why do felsic magmas erupt explosively?
How do volcanic gases affect the atmosphere?
Why do mafic lavas flow rather than explode?
Compare and contrast lavas from explosive and effusive eruptions.
Why do effusive eruptions sometimes cause a lot of damage?

Answer 1

1) In the Cascade volcanoes, water migrates upward and melts the oceanic crust at the top, causing magma to be produced.