Japan Geoscience Union Meeting 2015

Presentation information


Symbol B (Biogeosciences) » B-PT Paleontology

[B-PT23] Decoding the history of Earth: From Hadean to Modern

Mon. May 25, 2015 4:15 PM - 6:00 PM 104 (1F)

Convener:*Tsuyoshi Komiya(Department of Earth Science & Astronomy Graduate School of Arts and Sciences The University of Tokyo), Yasuhiro Kato(Department of Systems Innovation, Graduate School of Engineering, University of Tokyo), Katsuhiko Suzuki(Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology), Chair:Koichiro Fujinaga(Frontier Research for Energy and Resources, School of Engineering, University of Tokyo), Yutaro Takaya(Research and Development (R&D) Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology)

5:45 PM - 6:00 PM

[BPT23-27] Statistical characterization of deep-sea sediments within the Minamitorishima EEZ by Independent Component Analysis

*Kazutaka YASUKAWA1, Kazutaka OYA1, Junichiro OHTA1, Yutaro TAKAYA2, Koichiro FUJINAGA3, Kentaro NAKAMURA1, Hikaru IWAMORI2, Yasuhiro KATO3 (1.Sys. Innovation, Univ. of Tokyo, 2.JAMSTEC, 3.FRCER, Univ. of Tokyo)

Rare-earth elements and yttrium (REY) play an essential role in state-of-the-art technologies. Recently, the presence of REY-rich mud, deep-sea sediments containing high concentrations of REY, was confirmed within the Japanese exclusive economic zone (EEZ) surrounding Minamitorishima Island (Kato et al., 2013; Fujinaga et al., 2013; Suzuki et al., 2013). The maximum total REY content in the REY-rich mud within the Minamitorishima EEZ reaches almost 7000 ppm, which strongly attracts our attention as a highly promising new resource for REY of great economic value.
The extremely REY-rich mud has been probably produced by a combination of some processes that functioned in the abyssal ocean, and signatures of them could be preserved as characteristic geochemical compositions of the sediments. Therefore, as a first step to elucidate the REY-enrichment processes, it is quite important to decode geochemical signals derived from the sediments. To this end, multivariate statistical analyses are very useful because they can treat multi-elemental information concurrently and comprehensively.
Here we applied Independent Component Analysis (ICA) to the data set composed of elemental contents of the deep-sea sediments collected from the Minamitorishima EEZ. ICA is a relatively new computational statistical technique established in the past quarter century, which can extract original independent source signals or factors from observed signals on the basis of a fundamental assumption that the observed data consist of mutually independent source signals but do not constitute a joint Gaussian distribution (Hyvärinen et al., 2001). We report the results and interpretation of our new analysis, and statistically characterize the deep-sea sediments within the Minamitorishima EEZ.

-- References --
Fujinaga, K. et al. (2013) JpGU Meeting 2013.
Hyvärinen, A. et al. (2001) Independent Component Analysis. John Wiley and Sons.
Kato, Y. et al. (2013) JpGU Meeting 2013.
Suzuki, K. et al. (2013) JpGU Meeting 2013.