Abstract

We studied sedimentation processes in the Lofoten Basin of the Norwegian Sea based on data of the Automatic Deep-Sea Sedimentation Observatory (ADSO) deployed for a year (August 2017–July 2018). The article presents estimates of the vertical fluxes of total sedimentary material, organic carbon (C_org), calcium carbonate (CaCO₃), biogenic silica (SiO_2bio), aluminum, and the particles of planktonic origin (pteropods, foraminifera, fecal pellets, necrozooplankton). The seasonal pattern of total vertical flux is characterized by a unimodal distribution with a maximum in September 2017 (191 mg dry weight m^–2 day^–1) in the 0–500 m surface water layer. The total flux decreases markedly from November and reaches the minimum (2.6 mg m^–2 day^–1) in March–April 2018. The maximum C_org flux values (5.2 mg C m^–2 day^–1), CaCO₃ (178 mg CaCO₃ m^–2 day^–1), and SiO_2bio (9.1 mg SiO_2bio m^–2 day^–1) are observed in autumn. The value of fluxes and the portion of lithogenic material in it are higher at a depth of 2950 m due to redeposition from the nepheloid layer. The amplitude of flux variations during the year is noticeably smaller at this depth. The highest fluxes are related to the maass sedimentation of juvenile pteropods Limacina retroversa. The contribution of pteropods to vertical fluxes in autumn is 60–100% for CaCO₃ and 56–73% for C_org. The contribution of foraminifera to the total CaCO₃ flux does not exceed 6% and only reaches 60% at a depth of 550 m in October. The flux of fecal pellets, where ostracod pellets dominate, varies from <0.01 to 2.1 mgC m^–2 day^–1, making up from 0.1 to 90% of the C_org flux. The flux of zooplankton carcasses (ZCs) in the 0–550 m water layer varies from 0 to 0.45 mgC m^–2 day^–1, reaching the maximum value in February. The share of ZCs flux was 0–33% in the summer–autumn season, 12–52% in winter, and 23–41% in spring relative to the total (taking into account the ZCs) C_org flux. The ZCs flux varied from 0.04 to 0.22 mgC m^–2 day^–1 in the near-bottom water layer and amounted to 0.7–2% of the total C_org flux. The total contribution of all studied planktonic particles to the annual CaCO₃ flux was 16–47%, and their contribution to the annual C_org flux was 37–45%. Comparative analysis of our results and published data obtained in the 1990s demonstrates that the observed climatic changes (increasing temperature and salinity, as well as an increase in the thickness of the Atlantic water layer) in the Lofoten Basin did not result in significant changes in the quantitative characteristics of sedimentation process.

中文翻译：

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挪威海罗弗敦海盆沉积物的通量：季节动态和浮游动物的作用

摘要

我们根据部署了一年（2017年8月至2018年7月）的自动深海沉积观测站（ADSO）的数据，研究了挪威海罗弗敦海盆的沉积过程。该文章介绍了全部沉积物，有机碳（C _org），碳酸钙（CaCO ₃），生物硅（SiO _2bio），铝和浮游生物来源（翼足类，有孔虫，粪便颗粒， necrozooplankton）。总垂直通量的季节性模式具有单峰分布特征，最大分布在2017年9月（191 mg干重，m ^–2天^–1）在0-500 m的地表水层中。总通量从11月开始显着下降，并在2018年3月至4月达到最小值（2.6 mg m ^–2天^–1）。最大C _org通量值（5.2 mg C m ^–2天^–1），CaCO ₃（178 mg） CaCO ₃ m ^–2天^–1）和SiO _2bio（9.1 mg SiO _2bio m ^–2天^–1））在秋天观察到。由于从星云层的再沉积，通量值和其中的成岩材料部分在2950 m深度较高。在这一深度，一年中通量变化的幅度明显较小。最高的通量与幼翼足纲Limacina retroversa的大量沉积有关。秋季，翼足类对垂直通量的贡献为CaCO ₃为60-100 ％，C _org为56-73％。有孔虫对CaCO ₃总通量的贡献不超过6％，在10月的550 m深度仅达到60％。粪丸的通量（其中以兽药为主导）从<0.01至2.1 mgC m ^–2天^–1，占_Corg通量的0.1％至90％。在0–550 m水层中浮游动物尸体的通量在0至0.45 mgC m ^–2天^{–1之间变化}，在2月达到最大值。ZCS通量的份额是在夏秋季0-33％，冬季12-52％，而相对于总（考虑到ZC）的C型弹簧23-41％_有机熔剂。所述ZCS磁通变化为0.04〜0.22 MGC米^-2天^-1在近底部水层，并达到总的C 0.7-2％_的有机通量。所有研究的浮游粒子年度碳酸钙的总贡献₃流量为16-47％，以及他们对C年贡献_组织通量为37–45％。对我们的结果和1990年代获得的公开数据进行的比较分析表明，在罗弗敦盆地观测到的气候变化（温度和盐度升高，以及大西洋水层厚度的增加）并未导致该地区的显着变化。沉淀过程的定量特征。