AA_MtStHelen_P5

By speedypiglet
  • Hydrothermal Eruptions
    1989 BCE

    Hydrothermal Eruptions

    During this period, there was a series of ash producing hydrothermal explosions.
  • Ape Canyon Stage
    275 BCE

    Ape Canyon Stage

    During this period, lava domes formed in two stages.
  • Cougar Stage
    28 BCE

    Cougar Stage

    The cougar stage was the most active stage before the spirit lake stage.
  • Swift Creek Stage
    18 BCE

    Swift Creek Stage

    This short period was mostly the construction of the dacite domes.
  • Smith Creek Stage
    3 BCE

    Smith Creek Stage

    Smith Creek was a highly active time the volcano. Some of the eruptions were 4 times bigger than the one in 1980.
  • Pine Creek Eruptive Period
    3 BCE

    Pine Creek Eruptive Period

    During this period the volcano Ejected compacted ash.
  • Castle Creek Eruptive Period
    2 BCE

    Castle Creek Eruptive Period

    This period produced compacted ash, lava flows, and many lava domes.
  • Goat Rocks Eruptive Period

    Goat Rocks Eruptive Period

    This period included the last lava flow and eruptions until 1980.
  • Cataclysmic Eruption Of May 1980

    Cataclysmic Eruption Of May 1980

    This eruption was the biggest since 1857. This eruption was followed by a debris avalanche.
  • Secondary Succession

    Secondary Succession

    After the eruption of 1980 secondary succession begins.