第88回ジオダイナミクスセミナー
Geodynamics Seminar
「高圧下でのMg2SiO4リングウッダイトの熱膨張率」
"Thermal expansion of Mg2SiO4 ringwoodite at high pressures"
講師：桂 智男
（岡山大学固体地球研究センター助教授）
主催 ： 愛媛大学地球深部ダイナミクス研究センター
日時 ： ２００４年１月３０日（金）17：00〜
場所 ： 愛媛大学理学部講義棟 ２０１教室
要 旨
Unit cell volumes of Mg2SiO4 ringwoodite have been measured at temperatures to 2000 K and pressure of 15 to 24 GPa, and at temperature of 300 K and pressure of 0 to 21 GPa, using a Kawai-type multi anvil apparatus, which is equipped with an oscillation system to obtain high-quality diffraction pattern against grain growth. We obtained the following parameters describing the P-V-T relations of Mg2SiO4 ringwoodite. Volume at 0 GPa and 300 K is 524.8(1) A3. By assuming the isothermal bulk modulus of 182 GPa, its pressure derivative is 4.6(2). Thermal expansion coefficient at 300 K and its logarithmic volume dependence, Anderson-Gruneisen parameter, are a0 = 2.57(9)×10-5 + 1.42(8) ×10-8 (T-300) /K, where T is absolute temperature in K, and 6.9(4). The temperature derivative of isothermal bulk modulus is = -0.029(1) GPa/K. The Debye temperature is Q = 846(26) K. The Gruneisen parameter and its volume dependence are 1.93(3) and 3.5(3). The adiabatic temperature gradient in the mantle is largely temperature dependent: it increases from 0.29 to 0.40 K/km with increasing temperature from 1600 to 2000 K.
問い合わせ先：山崎 大輔 TEL （089）927-8408
E-mail yamazaki@sci.ehime-u.ac.jp
