海底热水系统控制海水的长期变化[Li+]:来自液体含的证据
Mebrahtu F Weldeghebriel1, Tim K Lowenstein1
1Department of Geological Sciences and Environmental Studies, Binghamton University, Binghamton, NY 13902, USA.
Science advances
|July 26, 2023
概括
海水度在1.5亿年内显著下降,主要是由于海洋地产量减少和热水活动减少. 这种减少影响了主要的地化学和气候变化,突出了板块构造学.
科学领域:
- 地质化学 地质化学
- 海洋学 海洋学 海洋学
- 古气候学 古气候学
- 板块构造学是一种板块构造学.
背景情况:
- 海水的化学成分和同位素成分在数百万年时间尺度上表现出长期的变化.
- 这些长期海洋变化背后的驱动力仍然是科学辩论的主题.
- 之前的研究已经记录了主要离子和同位素的变化,但缺乏对其原因的统一解释.
研究的目的:
- 调查海水度 ([Li+]SW) 长期世俗变化的原因.
- 模拟的地化学循环,并确定过去1.5亿年的关键控制因素.
- 为了将海水的变化与其他主要的地球化学和气候指标相关联.
主要方法:
- 分析海洋化物中的液体含量,以重建过去的海水度.
- 开发和应用地化学循环模型.
- 将建模的趋势与地质和古海洋学代理的比较 (例如,Mg2+/Ca2+,87Sr/86Sr,蒸发物种,气候指标).
主要成果:
- 在过去的1.5亿年里,海水度 ([Li+]SW) 减少了7倍 (Ma).
- [Li+]SW的下降主要是由于海洋地产量下降和相关的热水流量.
- 大陆气候流不需要解释观察到的[Li+]SW.的减少.
结论:
- 海洋地产量的减少和热水活动是长期海水减少的主要驱动因素.
- 观察到的[Li+]SW的减少与主要变化相关,包括增加的Mg2+/Ca2+和87Sr/86Sr比率,蒸发物组成的变化以及从温室气候转变为冰室气候的转变.
- 板块构造活动在地质时间尺度上调节地球的水球和大气组成方面发挥着至关重要的作用.
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