Several
types of volcanic eruptions—during which
lava,
tephra (
ash,
lapilli,
volcanic bombs and
blocks), and assorted gases are expelled from a
volcanic vent or
fissure—have been distinguished by
volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series.