Volcanoes are also located where plates are spreading apart. A ridge
forms, and as the two plates separate, the mantle rock from below the
surface flows up into the empty spaces between the plates. The mantle
rock will melt, forming magma. As the magma flows out, it cools, hardening
to form new crust. This fills in the gap created by the plates separating.
Scientists have discovered this type of activity in the Atlantic Ocean
along the Mid-Atlantic Ridge, where Iceland's volcanoes are found.
Some scientists believe that weather affects volcanic
activity. Research seems to show that snow buildup at the North Pole might
spur eruptions in other parts of the world.
What happens at hot spots?
A visit to the Big Island of Hawaii reveals more about volcanoes. Rather
than fleeing from Kilauea, an active Hawaiian volcano that has been erupting
continuously since 1983, tourists flock to the area hoping to glimpse
the oozing lava. Volcanologists refer to Hawaii's volcanic eruptions as
"quiet" eruptions. Gas escapes slowly rather than in one large
violent explosion and visitors can usually safely view the lava flow.
The ongoing flow has destroyed landmarks and beaches, but it has also
created land adding more than 560 acres of new land to the island.