lava
The violent release of energy from a volcano is known as an eruption. Gas and magma from beneath the earth's surface are under great pressure. The gas and magma find the path of least resistance and burst through the central vent of the volcano.
Things that can be erupted include volcanic ash, pumice, solid rock fragments, and gas.
A volcano " vents " gas when pressure builds up
Gas is stored in the Magma chamber at the bottom of the volcano, along with the magma.
A volcano is made of solid rock.
The gas was trapped in the magma.
Smoke and sulfuric gas
Something Else - 2004 Gas Leak 5-22 was released on: USA: 24 February 2009
The lava flowed down the volcano and gas got in the side vents
Have someone trigger the release inside the passenger compartment while someone else is prying the gas tank cover with a screwdriver.
A volcano may release smoke, or volcanic gas, both before and after it erupts. This gas can be a sign of increased activity within the volcano and may indicate that an eruption is imminent. It is important to monitor changes in gas emissions along with other volcanic activity to predict eruptions accurately.
Planet Neptune