GEOL 306 Lecture Notes - Lecture 11: Eurasian Plate, Krakatoa, Volcanic Arc
14 Feb 2018
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Document Summary
Indo-australian plate is subducting under eurasian plate. Merapi, bromo, ijen, sinabung, kelut, toba, tambora, Krakatau island in middle of sunda strait, very shallow waters. Intense seismicity in region in the years before (felt as far. Regular stream of perboewatan in may 1883 but activity died shly as australia) after. Activity in june on island, unusually strong tides, some pumice rafts obverced. Some activity observed in between existing cones. Climactic eruption started on august 26, paroxysmal phase at about 13:00 continuously. 27 km high plinian column rising in atmosphere, eruptions. Small tsunami recorded in java and sumatra. Four major eruptions on august 27 created pyroclastic flows and tsunamis (30m high) Third eruption was heard 3,110km away from volcano (1/12 of the earth) Loudest sound ever produced on surface of earth. Pressure wave caused by fourth eruption was recorded all around the world. Collapse of roof of chamber forming a caldera. Volume of eruption 18-21 km3 (even more than novarupta)
