[IIOE2-EP63] R/V Hakuho-Maru Central Indian Ridge Cruise 2024 "MOWALL-CIR" (KH-24-4)

Lead Investigator :

1. Kyoko OKINO Atmosphere and Ocean Research Institute, The University of Toyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-0852, JAPAN
     okino[at]aori[dot]u-tokyo[dot]ac[dot]jp

Period of Project: October 2024 - March 2027

Brief description of the Project:

Formation of oceanic plate at mid-ocean ridges is a key concept of plate tectonics. The project MOWALL (Moho observation along transform fault WALLs) aims to reveal the temporal variation of mid-ocean ridge process along long oceanic transforms. The geophysical and geochemical structures of oceanic plates show a large variation over the global ridge system and this variation is mainly controlled by the melt supply ratio (=melt supply/separation). However, we have not yet understood what constrains the melt supply. Long oceanic transform is unique place where we can access the whole vertical section of oceanic crust and its temporal variation continuously. The objectives of the project are, 1) to reveal the million-years scale variation of crustal structure, and 2) to investigate the spatio-temporal variation of chemical/physical properties of underlying mantle. Our working hypothesis is that the diversity and temporal variation of crustal structure are controlled by spatial heterogeneity of chemical composition of upper mantle. The target area of the R/V Hakuho-maru cruise is the Marie Celeste Transform, that offsets the Central Indian Ridge about 220km, where 11 million years history of crustal formation is recorded.

Region(s) of study:

The Marice Celeste Transform Fault and the adjacent areas 17°S-18°S, 65°E-67.5°E