Effects of hydrogen on the electrical conductivity in upper mantle and transition zone minerals

将通过高压、高温实验研究水（氢）对地幔矿物电导率的影响。研究的样品包括橄榄石、斜方辉石和石榴石。交流阻抗将在1千赫至1兆赫的范围内测定。在大多数情况下，研究人员将确定具有受控粒度的多晶样品的电导率。所有样品均为控制粒度和含水量的合成样品。合成将在控制氧逸度和氧化物活性的条件下进行。在所有的实验中，在实验前后都将测定颗粒大小和含水量。结果将提供电导率与温度和含水量（+粒度、氧逸度）之间的函数关系。研究所将与东京大学宇多田教授的研究小组合作，研究西太平洋上地幔和过渡带的三维电导率分布，以推断地球上地幔和过渡带的水分布。

The influence of water (hydrogen) on electrical conductivity in mantleMinerals will be investigated through high-pressure, temperatureexperiments. Samples investigated include olivine, orthopyroxene and garnet.The AC impedance will be determined for a range of 1 KHz to 1 MHz. In mostcases, the investigators will determine the electrical conductivity inpolycrystalline samples with controlled grain-size. All the samples aresynthetic samples with controlled grain-size and water content. Thesynthesis will be made under controlled oxygen fugacity and oxide activity.In all runs, both grain-size and water content will bedetermined both before an after the experiment. The results will provide thefunctional relationships between electrical conductivity and temperature andwater content (+ grain-size, oxygen fugacity). The results can be usedto infer the water content in the Earth's upper mantle and transition zone.The PI will collaborate with Professor Utada's group at University of Tokyo,who investigates the three-dimensional distribution of electricalconductivity in Earth's upper mantle and transition zone in the westernPacific to infer the water distribution in this region of the Earth.