Last previous eruption was 1831. Summit blown off removing upper 400 m in one blast of rock and ash. Hawaiian Islands - Part of a 2400 km long chain of volcanic islands stretching across the central Pacific. Oldest islands in the chain are the most heavily eroded and have the oldest rocks. Lie to the northwest.
Youngest islands are still active and lie at the southeast end of the chain.
Postulated that the islands overlie a mantle hot spot. Movement of the Pacific lithospheric plate to the northwest over the stationary hot spot has caused the observed relationships. Iceland - Fissure Eruptions occur as lava flow from a long linear fissure rather than a central volcano. Seem to be associated with spreading centers at constructive plate margins. Erupted lavas consist of voluminous low viscosity basaltic lava.