High-resolution investigation of upper mantle discontinuities

不同构造背景下410 ~ 660 km深度地幔过渡带地震不连续面的结构对地幔的热、化学和动力学状态提供了重要的制约。我们的目的是研究上地幔不连续，这是由地幔物质的固-固相变形成的，使用高分辨率的地震阵列分析方法和矿物物理实验，以探讨其精细尺度结构和不同的动力学制度的局部变化。台阵地震学的应用将提高地震构造的横向和纵向分辨率。特别是，我们的目标是解决有争议的问题的锐度（即垂直厚度）的上地幔不连续性：这些结果的解释，在压力温度间隔和矿物相变动力学方面可以产生重要的约束地幔对流的地球动力学模型。第二个问题，我们的目标是解决的深度410公里的不连续性在不同的构造环境，从压力温度斜率的相变，可以解释在横向温度不均匀性。与此相关的是，我们打算寻找与地幔的其他次要成分，这是更敏感的化学相变相关的反射。

The structure of the seismic discontinuities of the mantle transition zone between 410 and 660 km depth in different tectonic settings provides important constraints on the thermal, chemical and dynamical state of the Earth’s mantle. We aim to study the upper mantle discontinuities, which are formed by solid-solid phase transitions of the mantle material, using high-resolution seismic array analysis methods and mineral physics experiments to investigate their fine-scale structure and local variations in different dynamic regimes. The use of array seismology will improve lateral and vertical resolution of the seismic structures. In particular we aim to resolve controversial issues about sharpness (i.e. vertical thickness) of the upper mantle discontinuities: the interpretation of these results in terms of pressuretemperature interval and kinetics of mineral phase transitions can yield important constraints on geodynamical models of mantle convection. The second issue that we aim to address is the depth of the 410 km discontinuity in different tectonic settings which, from the pressuretemperature slope of the phase transition, can be interpreted in terms of lateral temperature heterogeneities. Related to this, we intend to search for reflections associated with phase transitions from other minor constituents of the mantle, which are more sensitive to chemistry.