9:00 AM - 9:15 AM
[MIS06-01] Do submarine volcanism in mid-ocean ridges impact global climate change? –Heading toward detection of topographic variation in precisely aged seafloor
Keywords:Submarine volcanism, Mid-ocean ridge, Seafloor bathymetry, Near-seafloor magnetic anomaly, Global climate change
In order to evaluate the impact of the MORs on global climate, our team has submitted a proposal to coming 3-years projects of the R/V Hakuhomaru. The aim of this cruise is to estimate magma and CO2 production rate over 4.3 Myrs based on observed seafloor topography, high-resolution magnetic field, and newly developing model of magma eruption in spreading system. Short-wavelength variation of seafloor topography is detected by shipboard multibeam sonar, and detailed seafloor age is estimated by near-seafloor magnetic field data comparing with global paleo-intensity of the geomagnetic field. The study area is circum-Antarctic ridges, especially the fast-spreading East Pacific Rise and Pacific-Antarctic Ridge, and slow- to intermediate-spreading ridges in the Indian Ocean. In order to investigate “sea-level driven eruption hypothesis”, we aim to catch the signal from the seafloor created 3.4 Myrs ago when amplitude of sea-level change is considered to be small.
Here, we present overview of our geophysical survey plan in the southern ocean and previously obtained knowledge about solid-Earth response to climate. Finally, we discuss a role of the MOR study for understanding global climate change.