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Subject: Surtsey

I (would like) basic info about the 1963 eruption of Surtsey. What happened and what is the up to date condition?

    Surtsey, is part of a chain of islands that extend southward from the (main) island of Iceland. The volcano that makes up this island may be older but the island itself was born on 15 Nov, 1963. Eruptions actually started below sea level about a half of a year prior to this. They were detected and located by earthquake activity (seismic tremors) in the area. Earliest indications of an impending eruption at the surface were from water temperature increases of 7-9 °C at the sea surface, about 45 days before the above-sea-level eruptions began. The 1963 eruption actually started at over 100 meters water depth. As the volcano neared the surface, the eruptions created large explosions. When it neared the surface it produced an eruption column composed moslty of volcanic ash. The first observations of an eruption column were by Ólafur Vestman. He observed the volcanic debris from a ship on the morning of Nov. 14, 1963.
    Eventually, the volcano grew above sea level, lava flows were erupted, and a cone formed. Basaltic lava flows first erupted April 4, 1964. All eruptions ceased in 1967. This pyroclastic to lava flow transition occured after the volcano had breached sea level and had built up a cone that was large enough t o keep sea water out of its eruption crater.
    Today, the island is being eroded by the large waves of North Atlantic Ocean and will probably disappear unless it erupts anew. It is presently volcanically quiet.

Drs. Mike Garcia and Ken Rubin
Department of Geology and Geophysics
University of Hawaii, Honolulu, HI 96822
with some info being provided by Dr. Karl Gronvold, of Nordisk Vulkanologisk Institut (the Nordic Volcanological Institute) in Iceland.


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