日時 ： ２００９年６月２６日（金）※16：30〜
場所 ： 愛媛大学理学部講義棟1F101室（理学部構内）←注意!!
要 旨
Water plays an important role in geochemical and geophysical process, and it is therefore important to understand the distribution and transportation of water in the Earth’s interior. Recent seismological studies reported fine elastic wave velocity structures in subduction zones, which give a clue to understanding the water distribution and transportation in subduction zone. Laboratory measurements of elastic wave velocities of blueschists, which is a constituent of oceanic crust, suggested that epidote blueschist subducts at SW Japan, while lawsonite blueschist first exists in subducting oceanic crust at shallow depth in NE Japan. However, the lawsonite blueschist is also metamorphosed to epidote blueschist (or hydrated eclogite phases) at deeper depth than the arc Moho. Consequently, subduction and the resultant dehydration of the epidote blueschist would supply ~3 wt.% water to overlying wedge mantle. In contrast, effect of the released water on elastic wave velocities has been poorly understood, although it is essential to understand the recycling and/or transportation of water in subduction zone. Some previous studies (Ito et al., 1990; Kono et al., 2007) have determined effect of water on Vp at 1 GPa, while those at higher pressures have not been experimentally determined. I will introduce some experimental and calculated data for the effect of water on elastic wave velocities, and show ongoing technical development for measuring elastic wave velocities of fluid/melt-bearing rocks.
問い合わせ先：土屋 卓久 TEL （089）927-8198
E-mail takut@sci.ehime-u.ac.jp
