"Major Challenges
in Understanding the Mantle and Core"
Dr. Gerald Schubert
Department of Earth and Space Sciences
Institute of Geophysics and Planetary Physics, UCLA
31 October 2003 17:00-18:00
Meeting room, 6th floor, Advanced Research Building, Ehime University
Although we have made major strides in our understanding of mantle dynamics
over the last four decades, a number of important questions are yet to be answered.
Does mantle convection involve the entire mantle or are parts of it non-participating
and isolated? While the 660-km seismic discontinuity is no longer viewed as
dividing the mantle into separately convecting regions, a currently popular mantle
model hypothesizes the existence of a variable thickness, compositionally distinct,
isolated layer at the bottom of the lower mantle. Is mantle convection thermal or
thermochemical in nature? Some seismological observations seem to require a
chemical compositional explanation. Are the so-called superplumes in the mantle
really clusters of smaller plumes? Have we reconciled geophysical and geochemical
constraints on mantle convection? What is the role of water in the dynamics of the
mantle? Can we integrate the equations of mantle convection backwards in time?
How are tectonic plates generated, and how does subduction initiate? What is the
heat flow from the core, and what are the concentration and distribution of
radiogenic heat sources in the mantle? While there are still some computational
challenges in modeling mantle convection, especially in connection with multi-
rheological and mixing and melting problems, our ability to model mantle
convection has gotten ahead of our observational understanding of the mantle.
お問い合わせ先： irifune@dpc.ehime-u.ac.jp TEL 089-927-9645
詳細情報：http://www.ehime-u.ac.jp/~grc/
主催：愛媛大学地球深部ダイナミクス研究センター