Magma contains dissolved gases that are released
into the atmosphere during eruptions. Gases are also released from magma
that either remains below ground (for example, as an intrusion) or rises
toward the surface. In such cases, gases may escape continuously into the
atmosphere from the soil, volcanic vents, fumaroles,
and hydrothermal systems.
|Sulfur dioxide and other volcanic gases rise from
the Pu'u O'o vent on Kilauea Volcano, Hawai'i. During periods of sustained
eruption from Pu`u O'o between 1986 and 2000, Kilauea emitted about
2,000 to 1,000 metric tonnes of irritating sulfur dioxide each day.
Credit: K. A. McGee / U.S. Geological Survey
The most common gas released by magma is steam (H2O), followed
by CO2 (carbon dioxide), SO2 (sulfur dioxide), (HCl)
hydrogen chloride, and other compounds.
AND PLANETARY SCIENCE
Source: U.S. Geological Survey