Japan Geoscience Union Meeting 2022

Presentation information

[E] Oral

S (Solid Earth Sciences ) » S-CG Complex & General

[S-CG45] Frontier of Earth's Interior and Dynamics

Sun. May 22, 2022 10:45 AM - 12:15 PM 301A (International Conference Hall, Makuhari Messe)

convener:Hiroko Watanabe(Research Center for Neutrino Science, Tohoku University), convener:Natsue Abe(Mantle Drilling Promotion Office, MarE3, Japan Agency for Marine-Earth Science and Technology ), Tamano Omata(Japan Agency for Marine-Earth Science and Technology), convener:William F McDonough(Department of Earth Science and Research Center for Neutrino Science, Tohoku University, Sendai, Miyagi 980-8578, Japan), Chairperson:Natsue Abe(Mantle Drilling Promotion Office, MarE3, Japan Agency for Marine-Earth Science and Technology), Hiroko Watanabe(Research Center for Neutrino Science, Tohoku University)

10:45 AM - 11:00 AM

[SCG45-01] Study of Ocean Bottom Detector for observation of geo-neutrino from the mantle

★Invited Papers

*Taichi Sakai1, Hiroko Watanabe1, Kunio Inoue1, William F McDonough1,2,3, Natsue Abe4, Eiichiro Araki4, Takafumi Kasaya4, Masanori Kyo4, Noriaki Sakurai4, Kenta Ueki4, Hiroshi Yoshida4 (1.Tohoku University,Research Center for Neutrino Science, 2.Tohoku University, 3.Maryland University, 4.JAMSTEC)

Keywords:geo-neutrino

Observation of geo-neutrinos originating from radioactive isotopes in the Earth (238U,232Th, etc.) can be converted to the amount of radioactive isotopes and the heat generated by their decays which governs the Earth dynamics.
KamLAND experiment achieved world's first observation of geo-neutrinos in 2005. Improvement of observation accuracy allowed us to reach the level where we can obtain geoscientific knowledge. However, it is hard to obtain information on the mantle because 70% of neutrinos observed by detector currently operating or planned are derived from the crust.

Given that the oceanic crust is thinner than the continental crust and has lower densities of U and Th, Ocean Bottom Detector (OBD) makes it sensitive to geo-neutrinos originating from Earth's mantle. OBD is expected to provide transformative insights into the deep Earth.Unique feature of OBD is separation from the reactors which are the main background sources of continental detectors. In addition, this movable detector can observe at multiple points in the ocean.
Scientists at the University of Hawaii started to discuss the idea of observing the geo-neutrinos on the sea floor 15 years ago as the detector called "Hanohano". Unfortunately, the idea has not been realized yet.
In 2019 joint research between Tohoku University and JAMSTEC was started to lead the comprehensive research relating to understanding the Earth's deep interior and realize OBD.
In this talk, I will present development of detector components and estimation of observation sensitivity based on the simulation.