There are a lot different kinds of volcanic activity and eruptions: phreatic eruptions, explosive eruption of high-silica lava, effusive eruption of low-silica lava, pyroclastic flows, lahars (debris flow) and carbon dioxide emission.
It concentrate of different volcanic gases can vary consider from one volcano to the next. Water vapor is typically the most abundant volcanic gas, followed by carbon dioxide and sulfur dioxide. Other main volcanic gases include hydrogen chloride, hydrogen sulfide, and hydrogen fluoride. A huge number of minor and trace gases are also found in volcanic emissions, for example, carbon monoxide, halocarbons, organic compounds, and volatile metal chlorides hydrogen.
