scholarly journals Lithological and biogeochemical investigations of the North Atlantic sediment system (data from the 49th cruise of the R/V Akademik Ioffe)

2019 ◽  
Vol 59 (4) ◽  
pp. 641-655
Author(s):  
E. A. Novichkova ◽  
A. S. Savvichev ◽  
L. D. Bashirova ◽  
N. V. Kozina ◽  
A. A. Klyuvitkin ◽  
...  
Keyword(s):  
North Atlantic ◽  
General Pattern ◽  
Sediment Supply ◽  
Marine Phytoplankton ◽  
Middle Pleistocene ◽  
The North ◽  
Suspended Particulate ◽  
49Th Cruise ◽  
System Data ◽  
The North Atlantic

Marine sediments and samples of suspended particulate matter from the North Atlantic were studied. It is shown that modern sedimentation in this area is controlled mainly by the efficiency of autochthonous marine phytoplankton and sediment supply by the system of near-bottom currents, as well as by means of the ice-rafting. The studied sediment sections were formed in the North Atlantic during the Middle Pleistocene to Holocene. The highest sedimentation rate, up to 58.3 cm/kyr, is established for AI-3359 core, collected in the area of the Gardar and Björn Drifts. This makes the core very interesting for detailed paleoreconstructions. AI-3378 and AI-3415 cores are characterized by low sedimentation rates. Nevertheless, they are of interest for spatial paleoreconstructions on a continuous timeline. The general pattern is established for the first time for the sediments from the central North Atlantic: biogeochemically significant processes are detected only in the thin surface layer (0–2 cm) and almost completely cease at depths of 90–180 cm. The processes are probably controlled by the position of the sampling stations and the composition of organic matter (OM) but not related to the age of the sedimentary layer. The low microbial activity in the sediments is most likely the result of a lack of OM.

Lithological and Biogeochemical Investigations of the North Atlantic Sediment System (Data from the 49th Cruise of the R/V Akademik Ioffe)

Oceanology ◽  
2019 ◽  
Vol 59 (4) ◽  
pp. 577-590 ◽  
Author(s):  
E. A. Novichkova ◽  
A. S. Savvichev ◽  
L. D. Bashirova ◽  
N. V. Kozina ◽  
A. A. Klyuvitkin ◽  
...  
Keyword(s):  
North Atlantic ◽  
The North ◽  
49Th Cruise ◽  
System Data ◽  
The North Atlantic

scholarly journals Insolation forcing of coccolithophore productivity in the North Atlantic during the Middle Pleistocene

2018 ◽  
Vol 191 ◽  
pp. 318-336 ◽  
Author(s):  
C. Cavaleiro ◽  
A.H.L. Voelker ◽  
H. Stoll ◽  
K.-H. Baumann ◽  
D.K. Kulhanek ◽  
...  
Keyword(s):  
North Atlantic ◽  
Middle Pleistocene ◽  
The North ◽  
The North Atlantic ◽  
Insolation Forcing

Pre-basaltic sediments (Aptian–Paleocene) of the Kangerlussuaq Basin, southern East Greenland

2001 ◽  
pp. 99-106 ◽  
Author(s):  
Michael Larsen ◽  
Morten Bjerager ◽  
Tor Nedkvitne ◽  
Snorre Olaussen ◽  
Thomas Preuss
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Sediment Supply ◽  
Basin Evolution ◽  
East Greenland ◽  
Sea Floor ◽  
North West ◽  
The North ◽  
The North Atlantic ◽  
Sea Floor Spreading

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Larsen, M., Bjerager, M., Nedkvitne, T., Olaussen, S., & Preuss, T. (2001). Pre-basaltic sediments (Aptian–Paleocene) of the Kangerlussuaq Basin, southern East Greenland. Geology of Greenland Survey Bulletin, 189, 99-106. https://doi.org/10.34194/ggub.v189.5163 _______________ The recent licensing round in the deep-water areas south-east of the Faeroe Islands has emphasised the continued interest of the oil industry in the frontier areas of the North Atlantic volcanic margins. The search for hydrocarbons is at present focused on the Cretaceous– Paleocene succession with the Paleocene deepwater play as the most promising (Lamers & Carmichael 1999). The exploration and evaluation of possible plays are almost solely based on seismic interpretation and limited log and core data from wells in the area west of the Shetlands. The Kangerlussuaq Basin in southern East Greenland (Fig. 1) provides, however, important information on basin evolution prior to and during continental break-up that finally led to active sea-floor spreading in the northern North Atlantic. In addition, palaeogeographic reconstructions locate the southern East Greenland margin only 50–100 km north-west of the present-day Faeroe Islands (Skogseid et al. 2000), suggesting the possibility of sediment supply to the offshore basins before the onset of rifting and sea-floor spreading. In this region the Lower Cretaceous – Palaeogene sedimentary succession reaches almost 1 km in thickness and comprises sediments of the Kangerdlugssuaq Group and the siliciclastic lower part of the otherwise basaltic Blosseville Group (Fig. 2). Note that the Kangerdlugssuaq Group was defined when the fjord Kangerlussuaq was known as ‘Kangerdlugssuaq’. Based on field work by the Geological Survey of Denmark and Greenland (GEUS) during summer 1995 (Larsen et al. 1996), the sedimentology, sequence stratigraphy and basin evolution of the Kangerlussuaq Basin were interpreted and compared with the deep-water offshore areas of the North Atlantic (Larsen et al. 1999a, b).

Biochemical Characteristics of Suspended Particulate Matter on a Latitudinal Transect in the North Atlantic

Oceanology ◽  
2018 ◽  
Vol 58 (4) ◽  
pp. 573-582
Author(s):  
N. V. Politova ◽  
A. S. Savvichev ◽  
A. A. Klyuvitkin ◽  
M. D. Kravchishina ◽  
A. B. Demidov ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Suspended Particulate Matter ◽  
North Atlantic ◽  
Biochemical Characteristics ◽  
The North ◽  
Suspended Particulate ◽  
Latitudinal Transect ◽  
The North Atlantic

scholarly journals Spring bloom onset in the Nordic Seas

2016 ◽  
Vol 13 (11) ◽  
pp. 3485-3502 ◽  
Author(s):  
Alexandre Mignot ◽  
Raffaele Ferrari ◽  
Kjell Arne Mork
Keyword(s):  
North Atlantic ◽  
Spring Bloom ◽  
Large Fraction ◽  
Biomass Accumulation ◽  
Marine Phytoplankton ◽  
The Arctic ◽  
Nordic Seas ◽  
In Situ Data ◽  
The North ◽  
The North Atlantic

Abstract. The North Atlantic spring bloom is a massive annual growth event of marine phytoplankton, tiny free-floating algae that form the base of the ocean's food web and generates a large fraction of the global primary production of organic matter. The conditions that trigger the onset of the spring bloom in the Nordic Seas, at the northern edge of the North Atlantic, are studied using in situ data from six bio-optical floats released north of the Arctic Circle. It is often assumed that spring blooms start as soon as phytoplankton cells daily irradiance is sufficiently abundant that division rates exceed losses. The bio-optical float data instead suggest the tantalizing hypothesis that Nordic Seas blooms start when the photoperiod, the number of daily light hours experienced by phytoplankton, exceeds a critical value, independently of division rates. The photoperiod trigger may have developed at high latitudes where photosynthesis is impossible during polar nights and phytoplankton enters into a dormant stage in winter. While the first accumulation of biomass recorded by the bio-optical floats is consistent with the photoperiod hypothesis, it is possible that some biomass accumulation started before the critical photoperiod but at levels too low to be detected by the fluorometers. More precise observations are needed to test the photoperiod hypothesis.

Dynamics of the potential photosynthetic activity of marine phytoplankton during illumination change in the North Atlantic

2019 ◽  
pp. 35-45
Author(s):  
Sergey A. Mosharov ◽  
Irina V. Mosharova
Keyword(s):  
Surface Layer ◽  
North Atlantic ◽  
Photosynthetic Activity ◽  
Vertical Mixing ◽  
Experimental Studies ◽  
Marine Phytoplankton ◽  
Light Conditions ◽  
Illumination Change ◽  
The North ◽  
The North Atlantic

The results of experimental studies of the magnitude and rate of variability of the potential photosynthetic activity of marine phytoplankton under variations in light conditions simulating the vertical mixing of phytoplankton within the euphotic layer are considered. It has been shown that photoinhibition of phytoplankton in the surface layer occurs fairly quickly, but is reversible with mixing of water.

The North Atlantic Organized Track Structure

1982 ◽  
Vol 35 (3) ◽  
pp. 497-499 ◽  
Author(s):  
V. W. Attwooll
Keyword(s):  
North Atlantic ◽  
General Pattern ◽  
Local Times ◽  
Main Stream ◽  
Diurnal Pattern ◽  
Traffic System ◽  
The North ◽  
Transit Times ◽  
The North Atlantic ◽  
The Difference

The first point to note about the North Atlantic air traffic system is the diurnal pattern of flow. This is strongly tidal, with westbound flow predominant during daylight hours and eastbound flow overnight. There is some traffic which flows against the main stream, particularly during the day, but the strong tendency for one-way traffic results from the difference in local times on opposite sides of the ocean, together with the transit times of flight at current speeds. This means that the general pattern will probably persist, unless and until aircraft speeds change radically.

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