
| Small, sudden explosions of methane gas occur frequently near the leading edges of a lava flow. 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 90 m from from the leading edge of a flow, blasting rocks and debris in all directions. Large methane gas explosions (above) generate dark tephra-filled explosion clouds and form explosion craters as large as 15 m in diameter and 5 m deep. |