• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Geosciences >Role of Salt Migration in Destabilization of Intra Permafrost Hydrates in the Arctic Shelf: Experimental Modeling
【24h】

Role of Salt Migration in Destabilization of Intra Permafrost Hydrates in the Arctic Shelf: Experimental Modeling

机译：盐迁移在北极架内多年冻土层水合物失稳中的作用：实验模型

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Destabilization of intrapermafrost gas hydrate is one possible reason for methane emission on the Arctic shelf. The formation of these intrapermafrost gas hydrates could occur almost simultaneously with the permafrost sediments due to the occurrence of a hydrate stability zone after sea regression and the subsequent deep cooling and freezing of sediments. The top of the gas hydrate stability zone could exist not only at depths of 200–250 m, but also higher due to local pressure increase in gas-saturated horizons during freezing. Formed at a shallow depth, intrapermafrost gas hydrates could later be preserved and transform into a metastable (relict) state. Under the conditions of submarine permafrost degradation, exactly relict hydrates located above the modern gas hydrate stability zone will, first of all, be involved in the decomposition process caused by negative temperature rising, permafrost thawing, and sediment salinity increasing. That’s why special experiments were conducted on the interaction of frozen sandy sediments containing relict methane hydrates with salt solutions of different concentrations at negative temperatures to assess the conditions of intrapermafrost gas hydrates dissociation. Experiments showed that the migration of salts into frozen hydrate-containing sediments activates the decomposition of pore gas hydrates and increase the methane emission. These results allowed for an understanding of the mechanism of massive methane release from bottom sediments of the East Siberian Arctic shelf.
机译：多年冻土层中天然气水合物的失稳是北极大陆架上甲烷排放的可能原因之一。这些永久冻土气中水合物的形成几乎与永久冻土沉积物同时发生，这是由于海退后出现了水合物稳定区，随后对沉积物进行了深度冷却和冻结。天然气水合物稳定区的顶部可能不仅存在于200–250 m的深度，而且由于冻结期间天然气饱和层中局部压力的增加而可能更高。多年冻土层内的天然气水合物在浅深度形成，以后可以保存并转变为亚稳态（遗迹）状态。在海底多年冻土退化的条件下，位于现代天然气水合物稳定区上方的确切残留水合物将首先参与由负温度升高，多年冻土融化和沉积物盐度增加引起的分解过程。这就是为什么在负温度下对包含残留甲烷水合物的冷冻沙质沉积物与不同浓度的盐溶液之间的相互作用进行特殊实验，以评估多年冻土层中天然气水合物解离条件的原因。实验表明，盐类向冻结的含水合物沉积物中迁移会激活孔隙气体水合物的分解并增加甲烷排放量。这些结果有助于了解东西伯利亚北极大陆架底部沉积物中大量甲烷的释放机理。

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