• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Paleoceanography >Vertical thermal gradient history in the eastern equatorial Pacific during the early to middle Miocene: Implications for the equatorial thermocline development
【24h】

Vertical thermal gradient history in the eastern equatorial Pacific during the early to middle Miocene: Implications for the equatorial thermocline development

机译：早期赤道太平洋的垂直热梯度历史在早期到中间内部：对赤道热水下发的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Knowledge of the equatorial thermocline is essential for understanding climate changes in the tropical Pacific. Multispecies planktic foraminiferal analyses provide a way to examine temperature distributions and thus the structure of the thermocline. Although the secular thermocline development has been documented back to the late Miocene, the early to middle Miocene interval has rarely been examined. In addition, relationships with the dynamic Antarctic ice sheets remain unclear. Here we investigate the vertical thermal gradient in the upper water column at Integrated Ocean Drilling Program Site U1337 in the eastern equatorial Pacific (EEP) throughout the early to middle Miocene (23.1 to 11.7Ma). The gradient increased over the Miocene Climatic Optimum, whereas it decreased during the East Antarctic Ice Sheet Expansion (EAIE). Comparison of the EEP record with its western equatorial Pacific (WEP) counterpart suggests that sea surface temperature was more stable in the WEP than in the EEP. We further estimated equatorial thermocline from two diagonal gradients between the EEP and the WEP: thermocline shoaled from 16.7 to 15.7Ma and tilt weakened between 16.5 and 13.8Ma. The onset of the Monterey Excursion and the reduced Antarctic ice sheet volume would have affected thermocline depth and tilt, respectively. Thermocline depth was likely much deeper compared to Pliocene-to-modern conditions. Furthermore, a 4-point-based distribution of isotherms (4DI index) was used as a metric of the evenness or unevenness of the isotherm distributions. The 4DI index considerably reduced at around the EAIE and other Mi-events, reflecting the evenly distributed isotherms under a more glaciated Antarctica.
机译：了解赤道热水管道对于了解热带太平洋的气候变化至关重要。多数综合性传染率分析提供了一种方法来检查温度分布，从而提供热控的结构。虽然世俗的热水下划线已被记录回后期后期，但早期到中间内部间隔很少被检查。此外，与动态南极冰盖的关系仍然不清楚。在这里，我们在整个早期到中间内海洋（23.1至11.7mA）中，我们在东部赤道太平洋（EEP）中的集成海洋钻井计划网站U1337上的上水柱中的垂直热梯度。梯度增加了内肾气球最佳，而在东南南极冰盖膨胀（EAIE）期间降低。 EEP记录与西方赤道太平洋（WEP）对应的比较表明，海面温度在WEP中比EEP更稳定。我们从EEP和WEP之间的两个对角线梯度进行了估计的赤道热量：ThermoClo期从16.7至15.7mA挖掘，并且倾斜在16.5和13.8mA之间削弱。蒙特利偏移的开始和减少的南极冰块体积分别具有影响热量管制深度和倾斜。与现代化的条件相比，热量管道可能更深入。此外，基于4分的等温（4DI指数）的分布用作等温分布的均匀度或不均匀度的度量。 4DI指数在EAIE和其他MI-event周围大大减少，反映了更烫发的南极下均匀分布的等温。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号