在过去的两次冰川结束期间,加强了东太平洋的热水活动
D C Lund1, P D Asimow2, K A Farley2
1Deptartment of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.
概括
在海平面的影响下,中海岩可能会对冰盖产生反. 在冰川终结期间增强的热水活动表明地幔融化促进了脱冰.
科学领域:
- 地球科学
- 地质学
- 海洋学
背景情况:
- 海洋中山脉的 magma 源于海底的扩散和地幔的解压.
- 融化产量可能受到冰川间海平面变化的调节,可能将岩流与冰盖大小联系起来.
- 之前的研究缺乏精确的时间来将岩与纪气候变化联系起来.
研究的目的:
- 调查中海岩层与过去气候变化之间的关系.
- 在中海系统中限制融化的时间变化.
- 探索岩石流作为冰川周期中的反机制的潜在作用.
主要方法:
- 分析了来自东太平洋起的定年沉积物记录.
- 过去的热水活动水平的重建.
- 岩石异常与冰川间时期的相关性.
主要成果:
- 沉积物记录显示,在过去的两次冰川结束期间,水热活动增强.
- 证据表明,异常的上层地幔融化发生在冰川最大时,海平面较低.
- 在中海山脊上的岩石异常与脱冰期相吻合.
结论:
- 冰川周期期间的海平面波动影响了上层地幔的融化和中海岩.
- 在脱冰过程中增强的岩可能导致冰盖通过热量和碳释放而退缩.
- 海洋中部岩可能会对冰盖大小产生负面反,影响全球气候转变.
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