Download file (2.03MB)
Download as zip (1.59MB)

コレクション

引用

説明:

A cold silica (SiO2)-rich subducted slab creates notable heterogeneity above the core-mantle boundary (CMB), influencing the evolution of the Earth’s mantle. This slab may exhibit characteristic anomalies in the longitudinal and shear wave seismic velocity above the CMB, attributed to the SiO2 phase transition into its dense polymorph, seifertite. However, the transition depth remains unclear due to the often-observed metastable phases in experiments. To address this long-standing challenge, we conducted laser-heated diamond anvil cell experiments with synchronised rapid X-ray diffraction measurements alongside theoretical calculations. The slope of the seifertite phase boundary was less steep than previously estimated, and consequently, the temperature profile of the slab crosses the boundary twice, like the post-perovskite transition. We observed a decrease in shear wave velocity beneath Hawaii and Central America, and we found anti-correlation in seismic wave velocities matching the depth range of the seifertite transition in a cold slab beneath Central America. This may provide evidence that a cold SiO2-rich slab descends towards the CMB.

権利情報:

• Creative Commons BY Attribution 4.0 International
  

キーワード: DFT, Seifertite

刊行年月日: 2026-05-30

出版者: Springer Science and Business Media LLC

掲載誌:

• Scientific Reports (ISSN: 20452322) vol. 16 issue. 1 26394

研究助成金:

• Japan Society for the Promotion of Science JPJS00420230010

原稿種別: 出版者版 (Version of record)

MDR DOI:

公開URL: https://doi.org/10.1038/s41598-026-54731-6

関連資料:

その他の識別子:

連絡先:

更新時刻: 2026-08-31 17:52:18 +0900

MDRでの公開時刻: 2026-09-01 10:26:48 +0900