Article Geochemistry 3 Volume 9, Number 2 Geophysics 8 February 2008 Q02S02, doi:10.1029/2007GC001791 GeosystemsG G ISSN: 1525-2027 AN ELECTRONIC JOURNAL OF THE EARTH SCIENCES Published by AGU and the Geochemical Society Pacific offshore record of plinian arc volcanism in Central America: 2. Tephra volumes and erupted masses S. Kutterolf SFB574 at Kiel University/IFM-GEOMAR, Wischhofstrasse 1-3, D-24148 Kiel, Germany (
[email protected]) A. Freundt SFB574 at Kiel University/IFM-GEOMAR, Wischhofstrasse 1-3, D-24148 Kiel, Germany IFM-GEOMAR, Wischhofstrasse 1-3, D-24148 Kiel, Germany W. Pere´z SFB574 at Kiel University/IFM-GEOMAR, Wischhofstrasse 1-3, D-24148 Kiel, Germany [1] Sediment gravity cores collected from the Pacific seafloor offshore Central America contain numerous distal ash layers from plinian-type eruptions at the Central American Volcanic Arc dating back to more than 200 ka. In part 1 of this contribution we have correlated many of those ash layers between cores and with 26 tephras on land. The marine ash layers cover areas of up to 106 km2 in the Pacific Ocean and represent a major fraction (60–90%) of the erupted tephra volumes because the Pacific coast lies within a few tens of kilometers downwind from the volcanic arc. Combining our own mapping efforts on land and published mapping results with our marine data yields erupted volumes of all major tephras along the arc that range from 1 to 420 km3. Recalculated to erupted magma mass, the widespread tephras account for 65% of the total magma output at the arc.