MAGMA PATHWAYS, CALDERAS, AND PIT CRATERS
View to the northwest across Kilauea Caldera. Halemaumau pit crater is
in the center of the photo. Photograph by Peggy Lim and courtesy of U.S.
Geological Survey.
Calderas dominate the summits of Kilauea and Mauna Loa volcanoes. The
rift zones of these volcanoes are marked by the presence of pit craters.
This lesson describes how these features form and the path that magma
follows from its source to the surface.
Lesson at a glance, Key Concepts, and Lesson Outcomes are available by
clicking here.
Click here for a list of
references about MAGMA PATHWAYS, CALDERAS, AND PIT CRATERS.
Click here for a list of
activities about volcanic landforms.
Background:
The background begins with a description of how magma gets from its
point of origin to the surface. As magma accumulates in a shallow
reservoir near the summit, it exerts more and more force on the
surrounding rocks. If the weight of the rocks pushing down is greater
than the force of the magma pushing up, the summit can collapse to
produce a caldera. The background concludes with a description of how
craters form.
