约七亿年前“雪球地球”海洋有多冷

Core Insights - An international research team led by researchers from the Chinese Academy of Sciences has directly measured ocean temperatures from the "Snowball Earth" period, approximately 700 million years ago, revealing that local ocean temperatures could drop to -15°C with extremely high salinity [1][2] Group 1: Research Findings - The study published in "Nature Communications" provides direct quantitative evidence of the extreme marine environment during the "Snowball Earth" period, indicating that despite the cold, liquid water microenvironments may have existed [2] - The research utilized iron isotopes to decode ancient ocean temperature signals, finding that iron formations from this period exhibited a unique isotopic signature indicative of low temperatures [1] - The high salinity of the water, estimated to be over four times that of modern seawater, contributed to a lowered freezing point of approximately -11°C, aligning with the temperature estimates [2] Group 2: Implications - The findings offer new insights into how early life may have survived in extreme climates, contributing to the understanding of Earth's climate system's dramatic changes [2]