Department of Earth and Environment, Boston University, 685 Commonwealth Avenue, Boston, MA 02215, USA.
Science. 2014 Apr 4;344(6179):80-3. doi: 10.1126/science.1249466.
The temperature and composition of Earth's mantle control fundamental planetary properties, including the vigor of mantle convection and the depths of the ocean basins. Seismic wave velocities, ocean ridge depths, and the composition of mid-ocean ridge basalts can all be used to determine variations in mantle temperature and composition, yet are typically considered in isolation. We show that correlations among these three data sets are consistent with 250°C variation extending to depths >400 kilometers and are inconsistent with variations in mantle composition at constant temperature. Anomalously hot ridge segments are located near hot spots, confirming a deep mantle-plume origin for hot spot volcanism. Chemical heterogeneity may contribute to scatter about the global trend. The coherent temperature signal provides a thermal calibration scale for interpreting seismic velocities located distant from ridges.
地幔的温度和成分控制着基本的行星特性，包括地幔对流的强度和海洋盆地的深度。地震波速度、海洋山脊深度和中洋脊玄武岩的成分都可用于确定地幔温度和成分的变化，但通常是孤立考虑的。我们表明，这三个数据集之间的相关性与延伸到 >400 公里深度的 250°C 变化一致，与温度恒定的地幔成分变化不一致。异常热的山脊段位于热点附近，这证实了热点火山作用的深部地幔柱起源。化学非均质性可能导致对全球趋势的离散。一致的温度信号为解释远离山脊的地震速度提供了热校准尺度。
