The upward movement of magma, or molten rock, into a volcano prior to an eruption causes changes that can be detected by geophysical measurements and visual observation.
(The upward movement of magma, or molten rock, into a volcano prior to an eruption; causes; changes that can be detected by geophysical measurements and visual observation) (changes; can be detected; by geophysical measurements and visual observation)
The upward movement of magma, or molten rock, into a volcano prior to an eruption changes
causes can be detected
changes that can be detected by geophysical measurements and visual observation
by geophysical measurements and visual observation