Seminar: CPS Seminar
date: 2017 Feb 17 (Thu) 16:30-18:00
room: CPS Seminar room
speaker: Nobuo Geshi (Research Group Leader, Research Institute Earthquake and Volcano Geology, Geological Survey of Japan, AIST)
organizer: Yoshiyuki Hayashi
title: Development of volcanic conduit and its effects on the variation of volcanic eruption
abstract: Structural variation of volcanic conduit and the internal magmatic processes, such as decompression, vesiculation and fragmentation processes, within the conduit control the wide spectrum about the eruption on the earth’s surface. Combined analysis of the structure of the feeder dike system and their eruption products on the ground surface in Miyakejima and other mafic volcanoes revealed the variation of the fragmentation depth and intensity of the mechanical erosion of the conduit wall. The process of mechanical erosion may also be recorded in the variation of the lithic fragments in the eruption products. Analysis of the lithic fragments in the pumice fall of the caldera-forming eruption of Aira Caldera shows the intense erosion of the conduit wall during the precursory Plinian eruption. In this talk, development process of volcanic conduit and its effects on the eruption process will be discussed.
keywords: volcanic eruption, conduit, development of eruption