What can the gas emissions tell us about a volcano?
Magmatic gas is the driving force of volcanic eruptions. As the magma rises to lower pressure it causes the magma to expand rapidly (think agitated champagne being released from the pressure of the bottle). A primary objective in gas monitoring is to determine changes in the release of certain gases from a volcano, chiefly carbon dioxide and sulfur dioxide. Such changes can be used with other monitoring information to provide eruption warnings and to improve our understanding of how volcanoes work.
- Changes in the gas composition or emission rate may signal changes in the magma supply
- Gas is under high pressure in magma deep below the ground
- That gas can drive an eruption if a pathway to the surface is breeched High-gas eruptions can erupt explosively