中国团队领衔研究首次揭示约7亿年前“雪球地球”海洋有多冷

Core Insights - The research led by Chinese scientists provides the first quantitative evidence of ocean temperatures during the "Snowball Earth" period, approximately 700 million years ago, indicating that local ocean temperatures could drop to around -15°C, with salinity levels significantly higher than modern seawater [1][2]. Group 1: Research Findings - The study utilized iron isotopes as a "paleothermometer" to determine the ocean temperatures during the "Snowball Earth" period, revealing that the iron isotope values from ancient "iron formations" indicate an extremely low-temperature environment [2]. - The estimated temperature during the "Snowball Earth" period is approximately -15±7°C, which is nearly 20°C lower than the coldest modern deep-sea temperatures [2]. - The research also confirmed that the salinity of the ocean water at that time was so high that it could lower the freezing point to about -11°C, corroborating the temperature estimates [2]. Group 2: Implications of the Research - This groundbreaking research provides quantitative evidence for the extreme cold marine environment during the "Snowball Earth," suggesting the existence of unique microenvironments that could have supported early life in extreme climates [1][2]. - The findings have significant implications for understanding the severe climate changes on Earth and may offer new insights into the mechanisms of life’s survival under extreme conditions [1][2].