Three-dimensional mid-mantle electrical conductivity inferred from a global observatory data set

摘要：

We utilize a non-linear conjugate gradient inversion for the spherical Earth developed by Kelbert et al (2008) to invert C responses with periods from 5.12 107 days estimated for 54 mid-latitude geomagnetic observatories by Fujii & Schultz (2002). Extensive sensitivity analysis (Kelbert et al, 2008) shows that even for the sparse and irregular coverage of this observatory distribution data for this period range provides adequate resolution of large-scale (thousands of km laterally) electrical conductivity features at the depths ~ 670 1600 km, beneath approximately two thirds of the Earths surface. The Fujii & Schultz data set requires substantial levels of heterogeneity, extending through and below the mid-mantle transition zone. To verify that the coarse spatial resolution of near-surface heterogeneities associated with the oceans does not bias deeper structure in the inverse solution, we have implemented a high-resolution correction for the ocean effect, as suggested by Kuvshinov et al (2002). The correction introduces subtle changes in the deep mantle structure. However, the magnitudes and gross patterns of heterogeneity are not affected by this correction.

关键词： global inversion mantle three-dimensional conductivity

作者: Anna Kelbert Adam Schultz Gary Egbert Alexei Kuvshinov

作者单位: College of Oceanic & Atmospheric Sciences,Oregon State University, Corvallis,Oregon, United States Institut für Geophysik, HPP H?nggerberg, Zürich, Switzerland

会议类型: 国际会议

会议名称: The 19th International Workshop on Electromagnetic Induction in the Earth(第十九届国际地球电磁感应学术研讨会)

会议地点: 北京

会议语种:英文

页码: 895-899

在线出版日期: 2008-10-23（万方平台首次上网日期，不代表论文的发表时间）