Burial and Origin of Permafrost Derived Carbon in the Nearshore Zone of the Southern Canadian Beaufort Sea
Burial and Origin of Permafrost Derived Carbon in the Nearshore Zone of the Southern Canadian Beaufort Sea
复制标题
加拿大南部波弗特海近岸区永久冻土衍生碳的埋藏和起源
DOI：
10.3997/2214-4609.201902741
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
M. Fritz
中科院分区：
文献类型：
--
作者：
H. Grotheer;V. Meyer;T. Riedel;J. Hefter;T. Gentz;G. Mollenhauer;M. Fritz
对受海岸侵蚀影响的多年冻土沉积物（加拿大博福特海赫歇尔岛）和邻近海洋沉积物（赫歇尔盆地）进行了详细的有机地球化学和碳同位素（δC和ΔC）分析，以了解有机碳在北极近岸环境中的命运。我们使用一个端元模型的基础上的碳同位素组成的散装有机质，以确定有机碳的来源。蒙特卡罗模拟应用于量化的贡献，沿海永久冻土侵蚀沉积碳收支。模型表明，当地沿海永久冻土侵蚀释放的所有碳中，约40%被有效地捕获和封存在近岸地区。这突出了沉积陷阱的重要性，如盆地，泻湖，槽和峡谷的环境中的碳固存在以前调查不足，近岸地区。高纬度地区空气和海洋表面温度的升高导致常年冻土的加速解冻、不稳定和侵蚀（即，永久冻土），通常富含有机碳。海岸侵蚀导致更多的有机碳进入北冰洋，在那里可以转化为温室气体，因此可能导致进一步变暖。如果有机物有效地沉积在海底，埋藏在海洋沉积物中，从而从短期碳循环中去除，那么碳的分解就会受到限制。靠近海岸线的盆地、峡谷和海槽可以作为沉积物的捕获器，并有可能容纳沿着北极海岸的大量有机碳。在这里，我们使用生物标志物（源特异性分子），稳定的碳同位素和放射性碳，以确定有机碳的来源在赫歇尔岛附近的加拿大南部博福特海的近岸区。我们量化了沿海永久冻土侵蚀对该地区沉积碳预算的贡献，并估计当地永久冻土侵蚀释放的所有碳中有三分之一以上有效地被困在海洋沉积物中。这突出了区域沉积物收集器对固碳的重要性。
Detailed organic geochemical and carbon isotopic (δC and ΔC) analyses are performed on permafrost deposits affected by coastal erosion (Herschel Island, Canadian Beaufort Sea) and adjacent marine sediments (Herschel Basin) to understand the fate of organic carbon in Arctic nearshore environments. We use an end‐member model based on the carbon isotopic composition of bulk organic matter to identify sources of organic carbon. Monte Carlo simulations are applied to quantify the contribution of coastal permafrost erosion to the sedimentary carbon budget. The models suggest that ~40% of all carbon released by local coastal permafrost erosion is efficiently trapped and sequestered in the nearshore zone. This highlights the importance of sedimentary traps in environments such as basins, lagoons, troughs, and canyons for the carbon sequestration in previously poorly investigated, nearshore areas. Plain Language Summary Increasing air and sea surface temperatures at high latitudes leads to accelerated thaw, destabilization, and erosion of perennially frozen soils (i.e., permafrost), which are often rich in organic carbon. Coastal erosion leads to an increased mobilization of organic carbon into the Arctic Ocean, which there can be converted into greenhouse gases and may therefore contribute to further warming. Carbon decomposition can be limited if organic matter is efficiently deposited on the seafloor, buried in marine sediments, and thus removed from the short‐term carbon cycle. Basins, canyons, and troughs near the coastline can serve as sediment traps and potentially accommodate large quantities of organic carbon along the Arctic coast. Here we use biomarkers (source‐specific molecules), stable carbon isotopes, and radiocarbon to identify the sources of organic carbon in the nearshore zone of the southern Canadian Beaufort Sea near Herschel Island. We quantify the contribution of coastal permafrost erosion to the sedimentary carbon budget of the area and estimate that more than a third of all carbon released by local permafrost erosion is efficiently trapped in marine sediments. This highlights the importance of regional sediment traps for carbon sequestration.
影响因子：
5.2
作者：
Guenther, F.;Overduin, P. P.;Grigoriev, M. N.
通讯作者：
Grigoriev, M. N.
影响因子：
4
作者：
Hoerner, T.;Stein, R.;Birgel, D.
通讯作者：
Birgel, D.
影响因子：
12.1
作者：
Strauss, Jens;Schirrmeister, Lutz;Veremeeva, Alexandra
通讯作者：
Veremeeva, Alexandra