The response of the Arctic Ocean gas hydrate associated with subsea permafrost to natural and anthropogenic climate changes
The response of the Arctic Ocean gas hydrate associated with subsea permafrost to natural and anthropogenic climate changes
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与海底永久冻土有关的北冰洋天然气水合物对自然和人为气候变化的响应
DOI：
10.1088/1755-1315/606/1/012035
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
V. Malakhova
中科院分区：
文献类型：
--
作者：
V. Malakhova
我们提出了与海底永久冻土条件相关的北冰洋天然气水合物稳定带变化的评估。为了评价末次冰期气候条件下天然气水合物的形成和分解，有必要了解海洋淹没后多年冻土厚度的变化情况。为此，我们结合了两个数值模型：一个是基于温度和海平面变化的古气候情景的永久冻土动力学模型，另一个是甲烷水合物稳定带（MHSZ）模型。对海底永久冻土层和MHSZ的厚度变化进行了12万年的计算。研究结果表明，尽管近几十年来海底水温的变化影响了水合物稳定带，但该稳定带的主要变化发生在海水淹没北极大陆架之后。通过对多年冻土和MHSZ状态的联合模拟，发现在洪水后的浅层陆架区（水深低于50 m）， MHSZ上部100 m层的水合物存在条件是不符合的。这表明，来自该储层的甲烷集中在大陆架底部沉积物中，然后释放到水中，继续适应海平面的变化、底部水温的上升和海底永久冻土的融化。
We present an assessment of changes in the gas hydrates stability zone of the Arctic Ocean associated with subsea permafrost conditions. To evaluate the formation and dissociation of gas hydrates under the climatic conditions of the last glacial cycle, it is necessary to understand how the thickness of the permafrost has changed after flooding by the sea. To do this, we have combined two numerical models: a model of permafrost dynamics based on the paleoclimatic scenario of changes in temperature and ocean level, and a model of the methane hydrates stability zone (MHSZ). Calculations of changes in the thickness of the submarine permafrost and the MHSZ were carried out for the period of 120 thousand years. Our results show that, although changes in the bottom water temperature over the last-decades period affect the hydrate stability zone, the main changes with this zone occurring after flooding the Arctic shelf with the seawater. As a result of the combined simulation of the permafrost and state of MHSZ, it was found that in the shallow shelf areas (lower 50 m water depth) after flooding, the hydrate presence conditions in the upper 100-meter layer of the MHSZ are violated. This suggests that the methane coming from this reservoir is concentrated in the bottom sediments of the shelf, and then released into the water, continuing to adapt to changing sea levels, rising bottom water temperatures, and subsea permafrost melting.
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影响因子：
5.2
作者：
Biastoch, A.;Treude, T.;Wallmann, K.
通讯作者：
Wallmann, K.
影响因子：
5.2
作者：
Marin-Moreno, Hector;Minshull, Timothy A.;Sarkar, Sudipta
通讯作者：
Sarkar, Sudipta
影响因子：
5.2
作者：
Kretschmer, Kerstin;Biastoch, Arne;Burwicz, Ewa
通讯作者：
Burwicz, Ewa
末次冰期期间北半球永久冻土冰盖的耦合演化
影响因子：
4.3
作者：
Willeit;Ganopolski
通讯作者：
Ganopolski