第125回ジオダイナミクスセミナー
Geodynamics Seminar
"Global P-wave tomography: on the effect of various mantle
and core phases"
講師：Jianshe LEI (GRC研究機関研究員)
主催 ： 愛媛大学地球深部ダイナミクス研究センター
日時 ： ２００５年５月１３日（金）17：00〜
場所 ： 愛媛大学理学部講義棟 １０１教室 ←今年度より変更
要 旨
In this work, many global tomographic inversions and resolution tests are carried out to investigate the influence of various mantle and core phase data from the International Seismological Center (ISC) data set on the determination of 3-D velocity structure of the Earth’s interior. Our results show that, when only the direct P data are used, the resolution is good for most of the mantle except for the oceanic regions down to about 1000 km depth and for most of the D” layer, and PP rays can provide a better constraint on the structure down to the middle mantle, in particular for the upper mantle under the oceans. PcP can enhance the ray sampling of the middle and lower mantle around the Pacific rim and Europe, while Pdiff can help improve the spatial resolution in the lowermost mantle. The outer core phases (PKP, PKiKP and PKKP) can improve the resolution in the lowermost mantle of the southern hemisphere and under oceanic regions. When finer blocks or grid nodes are adopted to determine a high-resolution model, pP data are very useful for improving the upper mantle structure. The resulting model inferred from all phases not only displays the general features contained by the previous global tomographic models, but also reveals some new features. Our results suggested that later seismic waves are of great importance in better understanding the structure and dynamics of the Earth’s interior.
Keywords: Mantle and core phases; ISC data; Global tomography; Hotspot;
Mantle plume; Subducting slab
問い合わせ先：土屋 卓久 TEL （089）927-8198
E-mail takut@sci.ehime-u.ac.jp