Another
type of gas release occurs when lava flows reach the ocean. Extreme heat from
molten lava boils and vaporises seawater, leading to a series of chemical
reactions.
The
boiling and reactions produce a large white plume, locally known as lava haze,
containing a mixture of hydrochloric acid and seawater. (see picture below)
Picture obtained from http://volcanoes.usgs.gov/Hazards/What/VolGas/volgas.html
without permission.