Re-entry of giant-impact fragments and early evolution of the Earth's ocean

Takanori Sasaki

Presentation information

[E] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-OS Ocean Sciences & Ocean Environment

[A-OS11] Continental-Oceanic Mutual Interaction: Planetary scale Material Circulation

Wed. May 29, 2019 9:00 AM - 10:30 AM 301A (3F)

convener:Yosuke Alexandre Yamashiki(Earth & Planetary Water Resources Assessment Laboratory Graduate School of Advanced Integrated Studies in Human Survivability Kyoto University), Yukio Masumoto(Graduate School of Science, The University of Tokyo), Swadhin Behera(Climate Variation Predictability and Applicability Research Group, Application Laboratory, JAMSTEC, 3173-25 Showa-machi, Yokohama 236-0001), Takanori Sasaki(Department of Astronomy, Kyoto University), Chairperson:Yukio Masumoto, Behera Swadhin(JAMSTEC)

9:30 AM - 9:45 AM

[AOS11-03] Re-entry of giant-impact fragments and early evolution of the Earth's ocean

*Takanori Sasaki¹ (1.Department of Astronomy, Kyoto University)

Keywords:Earth, ocean, giant impact

The late stages of Earth's formation remain a mystery. No building blocks remain in Earth's orbit and no geological evidence is available for the first 700 million years Earth's history. Herein we propose that protoplanetary fragments produced by the giant impacts during terrestrial planet formation may give some important clues to the era. Iron-bearing giant impact fragments provide significant reducing agent that could transform primitive CO2–H2O atmosphere and ocean into more reducing H2-bearing atmosphere. Re-entry of the giant-impact fragments into eary Earth would be important for the origin of Earth’s life and its early evolution.