Lava tubes form when the surface
of hot flowing lava cools and crusts over, forming a roof over
the flow. This insulates the lava and keeps it in a hot, liquid
state which allows it to flow for tremendous distances. When
the eruption ends and the lava drains out of the tubes, caves
are left behind. These caves differ from regular caves in that
they can be formed quickly, in a matter of days or weeks rather
than over thousands of years of erosion. This makes for very
interesting formations but also makes the caves more unstable. |