Photograph by J.P. Lockwood on
March 31, 1984
Sketch by J. Johnson,
1998
M
size="+2">ethane explosion
Sudden explosions of methane gas occur frequently near
the edges of active lava flows. Methane gas is generated
when vegetation is covered and heated by molten lava. The
explosive gas travels beneath the ground through cracks
and fills abandoned lava tubes for long distances around
the margins of the flow. Methane gas explosions have
occurred at least 100 m from the leading edge of a
flow, blasting rocks and debris in all directions.
Top photo:
A dark tephra cloud rises from a large methane
gas explosion in front of a slow-moving `a`a flow on Mauna Loa
Volcano, Hawai`i.
Bottom sketch:
Illustration showing methane gas explosion
occurring above an old empty lava tube. Cracks, fractures, and
tubes in older flows beneath an active lava flow (red) serve to
an explosion.
