Biogenic silica concentration as a marine primary productivity proxy in the Holsteinsborg Dyb, West Greenland, during the last millennium

2020 ◽  
Vol 39 (9) ◽  
pp. 78-85
Author(s):  
Longbin Sha ◽  
Dongling Li ◽  
Yanguang Liu ◽  
Bin Wu ◽  
Yanni Wu ◽  
...  
2020 ◽  
Author(s):  
Christina Treinen-Crespo ◽  
Jose Carriquiry ◽  
Julio Villaescusa ◽  
Elisabet Repiso-Terrones

<p>Changes in marine primary productivity (MPP) over the 21st century are expected to occur under the prevailing climate change scenario. For better understanding of past climate variability, we reconstructed MPP at high resolution (~1-2 years) for the past 2000 years analyzing biogenic silica and total organic carbon (TOC %) on a sediment core collected from Soledad Basin (25°N, 112°W), Baja  California, Mexico. Located in the Eastern Tropical North Pacific, this suboxic basin is ideal for palaeoceanographic reconstructions due to its high sedimentation rate (2 mm/year), which allow us to reconstruct past changes in the ocean and climate at high resolution. Our results show an increasing trend in the variability of MPP for the past 2000 years: biogenic silica content does not show a well-defined trend, but rather it is dominated by strong multidecadal and prominent centennial-scale cycles while TOC (%) shows a slight increasing trend towards the present, starting at least 2000 years ago. Spectral analysis confirms the presence of multidecadal to centennial cycles. These results will be discussed in the context of the Anthropocene and natural climate variability.</p>


2019 ◽  
Author(s):  
Mehrdad Sardar Abadi ◽  
◽  
Jeremy D. Owens ◽  
Xiaolei Liu ◽  
Theodore R. Them ◽  
...  

China Geology ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 112-113 ◽  
Author(s):  
Shao-feng Pei ◽  
◽  
Ya-xuan Zhu ◽  
Si-yuan Ye ◽  
Hong-ming Yuan ◽  
...  

1968 ◽  
Vol 32 (1) ◽  
pp. 131-151 ◽  
Author(s):  
D. H. Cushing ◽  
H. F. Nicholson ◽  
G. P. Fox

Lethaia ◽  
2017 ◽  
Vol 51 (2) ◽  
pp. 187-197 ◽  
Author(s):  
Alexandre Pohl ◽  
David A. T. Harper ◽  
Yannick Donnadieu ◽  
Guillaume Le Hir ◽  
Elise Nardin ◽  
...  

Author(s):  
Jade E. Hatton ◽  
Katharine R. Hendry ◽  
Jonathan R. Hawkings ◽  
Jemma L. Wadham ◽  
Sophie Opfergelt ◽  
...  

Glacial environments play an important role in high-latitude marine nutrient cycling, potentially contributing significant fluxes of silicon (Si) to the polar oceans, either as dissolved silicon (DSi) or as dissolvable amorphous silica (ASi). Silicon is a key nutrient in promoting marine primary productivity, contributing to atmospheric CO 2 removal. We present the current understanding of Si cycling in glacial systems, focusing on the Si isotope (δ 30 Si) composition of glacial meltwaters. We combine existing glacial δ 30 Si data with new measurements from 20 sub-Arctic glaciers, showing that glacial meltwaters consistently export isotopically light DSi compared with non-glacial rivers (+0.16‰ versus +1.38‰). Glacial δ 30 Si ASi composition ranges from −0.05‰ to −0.86‰ but exhibits low seasonal variability. Silicon fluxes and δ 30 Si composition from glacial systems are not commonly included in global Si budgets and isotopic mass balance calculations at present. We discuss outstanding questions, including the formation mechanism of ASi and the export of glacial nutrients from fjords. Finally, we provide a contextual framework for the recent advances in our understanding of subglacial Si cycling and highlight critical research avenues for assessing potential future changes in these environments.


Geology ◽  
2019 ◽  
Author(s):  
Mehrdad Sardar Abadi ◽  
Jeremy D. Owens ◽  
Xiaolei Liu ◽  
Theodore R. Them ◽  
Xingqian Cui ◽  
...  

The importance of dust as a source of iron (Fe) for primary production in modern oceans is well studied but remains poorly explored for deep time. Vast dust deposits are well recognized from the late Paleozoic and provisionally implicated in primary production through Fe fertilization. Here, we document dust impacts on marine primary productivity in Moscovian (Pennsylvanian, ca. 307 Ma) and Asselian (Permian, ca. 295 Ma) carbonate strata from peri-Gondwanan terranes of Iran. Autotrophic contents of samples, detected by both point-count and lipid-biomarker analyses, track concentrations of highly reactive Fe, consistent with the hypothesis that dust stimulated primary productivity, also promoting carbonate precipitation. Additionally, highly reactive Fe tracks the fine-dust fraction. Dust-borne Fe fertilization increased organic and inorganic carbon cycling in low- and mid-latitude regions of Pangaea, maintaining low pCO2.


1974 ◽  
Vol 62 (3) ◽  
pp. 821 ◽  
Author(s):  
T. T. Elkington ◽  
B. M. G. Jones

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