Abstract. Lakes act as important sinks for inorganic and organic sediment components. However, investigations of sedimentary carbon budgets within glacial lakes are currently absent from Arctic Siberia. The aim of this paper is to provide the first reconstruction of accumulation rates, sediment and carbon budgets from a lacustrine sediment core from Lake Rauchuagytgyn, Chukotka (Arctic Siberia). We combined multiple sediment-biogeochemical and sedimentological parameters from a radiocarbon-dated 6.5 m sediment core with lake basin hydroacoustic data to derive sediment stratigraphy, sediment volumes, and infill budgets. Our results distinguished three principal sediment and carbon accumulation regimes that could be identified across all measured environmental proxies including Early MIS2 (ca. 29–23.4 cal. ka BP), Mid-to-late MIS2 (ca. 23.4–11.5 cal. ka BP), and Holocene (ca. 11.5–present). Estimated organic carbon accumulation rates (OCARs) were higher within Holocene sediments (average 3.53 g OC m⁻² a⁻¹) than Pleistocene sediments (average 1.09 g OC m⁻² a⁻¹) and are similar to those calculated for boreal lakes from Quebec and Finland and Lake Baikal but significantly lower than Siberian thermokarst lakes and Alberta glacial lakes. Using a bootstrapping approach, we estimated the total organic carbon pool to 0.26 ± 0.02 Mt and a total sediment pool of 25.7 ± 1.71 Mt within a hydroacoustically derived sediment volume of ca. 32990557 m³. The total organic carbon pool is substantially smaller than Alaskan Yedoma, thermokarst lake sediments, and Alberta glacial lakes but shares similarities with Finnish boreal lakes. Temporal variability in sediment and carbon accumulation dynamics at Lake Rauchuagytgyn is controlled predominantly by palaeoclimate variation that regulates lake ice-cover dynamics and catchment glacial, fluvial and permafrost processes through time. These processes, in turn, affect catchment and within-lake primary productivity as well as catchment soil development. Spatial differences to other lake systems at a trans-regional scale likely relates to the high-latitude, mountainous location of Lake Rauchuagytgyn.

中文翻译：

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更新世和全新世晚期楚科奇（北极西伯利亚）冰川湖中的沉积物和碳积聚：结合水声剖面和下层分析

摘要。湖泊是无机和有机沉积物成分的重要汇。但是，北极西伯利亚目前尚无冰川湖内沉积碳收支的调查。本文的目的是从楚科奇（北极西伯利亚）的拉克瓦格吉金湖的湖相沉积岩芯中，对堆积率，沉积物和碳收支进行首次重建。我们将放射性碳年代为6.5 m的沉积岩心的多个沉积物生物地球化学和沉积学参数与湖盆水声数据相结合，以得出沉积物地层，沉积物量和填充预算。我们的研究结果区分了三种主要的沉积物和碳积累机制，可以在所有测得的环境代理中确定，包括早期的MIS2（约29–23.4 cal ka BP），中晚期的MIS2（约23.4-11.5 cal ka BP）。 ），和全新世（约11.5年至今）。全新世沉积物中的有机碳积累速率（OCAR）估计较高（平均3.53 g OC m^-2  a ^-1））比更新世沉积物（平均1.09 g OC m ^-2  a ^-1）要高，与魁北克，芬兰和贝加尔湖的北方湖泊的计算结果相似，但明显低于西伯利亚热喀斯特湖和艾伯塔冰川湖。使用自举法，我们估计在水声法沉积物体积为ca的情况下，总有机碳库为0.26±0.02 Mt，总沉积物池为25.7±1.71Mt。32990557 m ³。总有机碳库比阿拉斯加耶德玛，热喀斯特湖沉积物和艾伯塔冰川湖要小得多，但与芬兰北方湖泊有相似之处。Rauchuagytgyn湖沉积物和碳积累动态的时间变化主要受古气候变化控制，该变化调节湖泊冰盖的动态以及流域冰川，河流和多年冻土过程。这些过程反过来影响集水区和湖内初级生产力以及集水区土壤的发育。在跨区域范围内与其他湖泊系统的空间差异可能与Rauchuagytgyn湖的高纬度山区有关。