Strain localization in magma and its roles in volcanic eruptions

2014 Fiscal Year Final Research Report

• Project/Area Number: 24740299
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Tohoku University
• Principal Investigator: OKUMURA Satoshi 東北大学, 理学(系)研究科(研究院), 助教 (40532213)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: マグマ / 脱ガス / 変形集中 / その場X線CT / 揮発性成分

Outline of Final Research Achievements

The explosivity of volcanic eruptions is controlled by magma vesiculation and outgassing. The rate of outgassing that releases gas phase to the outside is enhanced by magma deformation via the formation of bubble networks. In this study, we observed in-situ magma deformation under high temperature and pressure condition using a synchrotron radiation X-ray imaging, and determined the criterion for the onset of strain localization for vesicular rhyolite. Based on this result, we can predict the change of outgassing rate during magma ascent. We also found that the formation and healing of shear-localized zone in magma depend on magma temperature, pressure, and deformation rate.

Free Research Field

火山学