scholarly journals Strong stratification in the Makarov Basin, Arctic Ocean, observed via intimate means

2020 ◽  
Author(s):  
Adrian McCallum ◽  
Kabir Suara
Keyword(s):  
Arctic Ocean ◽  
Makarov Basin

A sedimentary record from the Makarov Basin, Arctic Ocean, reveals changing middle to Late Pleistocene glaciation patterns

2021 ◽  
Vol 270 ◽  
pp. 107176
Author(s):  
Wenshen Xiao ◽  
Leonid Polyak ◽  
Rujian Wang ◽  
Christelle Not ◽  
Linsen Dong ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Late Pleistocene ◽  
Pleistocene Glaciation ◽  
Sedimentary Record ◽  
Makarov Basin

scholarly journals Assessment of variability of the thermohaline structure and transport of Atlantic water in the Arctic Ocean based on NABOS CTD data

2019 ◽  
Author(s):  
Nataliya Zhurbas ◽  
Natalia Kuzmina
Keyword(s):  
Arctic Ocean ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Atlantic Water ◽  
Volume Flow ◽  
The Arctic ◽  
Makarov Basin ◽  
The Arctic Ocean ◽  
Anna Trough ◽  
Eurasian Basin

Abstract. Data of CTD transects across continental slope of the Eurasian Basin and the St. Anna Trough performed during NABOS (Nansen and Amundsen Basins Observing System) project in 2003–2015 are used to assess transport and propagation features of the Atlantic Water (AW) in the Arctic Ocean. Estimates of θ-S indices and volume flow rate of the current carrying the AW in the Eurasian Basin were obtained. The assessments were based on the analysis of CTD data including 33 sections in the Eurasian Basin, 4 transects in the St. Anna Trough and 2 transects in the Makarov Basin; additionally a CTD transect of the PolarStern-1996 expedition (PS-96) was considered. Using spatial distributions of temperature, salinity, and density on the transects and applying θ-S analysis, the variability of thermohaline pattern on the AW pathway along the slope of Eurasian Basin was investigated. The Fram Strait branch of the Atlantic Water (FSBW) was satisfactorily identified on all transects, including two transects in the Makarov Basin (along 159° E), while the сold waters, which can be associated with the influence of the Barents Sea branch of the Atlantic water (BSBW), on the transects along 126° E, 142° E and 159° E, were observed in the depth range below 800 m and had a negligible effect on the spatial structure of isopycnic surfaces. Special attention was paid to the variability of the volume flow rate of the AW propagating along the continental slope of the Eurasian Basin. The geostrophic volume flow rate was calculated using the dynamic method. An interpretation of the spatial and temporal variability of hydrological parameters characterizing the flow of the AW in the Eurasian Basin is presented. The geostrophic volume flow rate decreases significantly farther away from the areas of the AW inflow to the Eurasian Basin. Thus, the geostrophic estimate of the volume rate for the AW flow in the Makarov Basin at 159° E was found to be more than an order of magnitude smaller than the estimates of the volume flow rate in the Eurasian Basin, implying that the major part of the AW entering the Arctic Ocean circulates cyclonically within the Nansen and Amundsen Basins. There is an absolute maximum of θmax (AW core temperature) in 2006–2008 time series and a maximum in 2013, but only at 103° E. Salinity S(θmax) (AW core salinity) time series display an increase of the AW salinity in 2006–2008 and 2013 (at 103° E) that can be referred to as a AW salinization in the early 2000-ies. The maxima of θmax and S(θmax) in 2006–2008 and 2013 were accompanied by the volume flow rate highs. Additionally the time average volume rates were calculated for the FSBW flow (in the longitude range 31–92° E), for the BSBW flow in the St. Anna Trough and for a combined FSBW and BSBW flow in longitude range 94–107° E. A detailed discussion of the results is presented.

scholarly journals Sedimentation rates in the Makarov Basin, central Arctic Ocean: A paleomagnetic and rock magnetic approach

2001 ◽  
Vol 16 (4) ◽  
pp. 368-389 ◽  
Author(s):  
Norbert R. Nowaczyk ◽  
Thomas W. Frederichs ◽  
Heidi Kassens ◽  
Nils Nørgaard-Pedersen ◽  
Robert F. Spielhagen ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Sedimentation Rates ◽  
Central Arctic Ocean ◽  
Makarov Basin

scholarly journals Structural studies near Pevek, Russia: implications for formation of the East Siberian Shelf and Makarov Basin of the Arctic Ocean

2009 ◽  
Vol 4 ◽  
pp. 223-241 ◽  
Author(s):  
E. L. Miller ◽  
V. E. Verzhbitsky
Keyword(s):  
Arctic Ocean ◽  
Sedimentary Cover ◽  
Volcanic Belt ◽  
The Arctic ◽  
Tectonic Activity ◽  
Magnetic Data ◽  
Makarov Basin ◽  
The Arctic Ocean ◽  
Uplift And Erosion ◽  
Siberian Shelf

Abstract. The Pevek region of Arctic Russia provides excellent beach cliff exposure of sedimentary and igneous rocks that yield detailed information on the nature, progression and timing of structural events in this region. Regional folding and thrust faulting, with the development of a south-dipping axial plane cleavage/foliation developed during N-S to NE-SW directed shortening and formation of the Chukotka-Anyui fold belt. This deformation involves strata as young as Valanginian (136–140 Ma, Gradstein et al., 2004). Fold-related structures are cut by intermediate to silicic batholiths, plutons and dikes of Cretaceous age. Reported K-Ar whole rock and mineral ages on the granitoids range from 144 to 85 Ma, but to the south, more reliable U-Pb zircon ages on compositionally similar plutons yield a much narrower age range of ~120–105 Ma (Miller et al., this volume) and a pluton in Pevek yields a U-Pb age on zircon of 108.1±1.1 Ma with evidence for inheritance of slightly older 115 Ma zircons. Magmas were intruded during an episode of E-W to ENE-WSW directed regional extension based on the consistent N-S to NNW-SSE orientation of over 800 mapped dikes and quartz veins. Analysis of small-offset faults and slickensides yield results compatible with those inferred from the dikes. Younger tectonic activity across this region is minor and the locus of magmatic activity moved southward towards the Pacific margin as represented by the <90 Ma Okhotsk-Chukotsk volcanic belt (OCVB). A lengthy period of uplift and erosion occurred after emplacement of Cretaceous plutons and produced the peneplain beneath the younger OCVB. Based on our studies, we speculate that ~120–105 Ma magmatism, which heralds a change in tectonic regime from compression to extension, could represent one of the consequences of the inception of rifting in the Amerasian Basin of the Arctic, forming the Makarov Basin north of the Siberian shelf at this longitude. A synthesis of available seismic reflection, gravity and magnetic data for the offshore Siberian Shelf reveals a widespread, seismically mappable basement-sedimentary cover contact that deepens northward towards the edge of the shelf with few other significant basins. Various ages have been assigned to the oldest strata above the unconformity, ranging from Cretaceous (Albian – 112–100 Ma) to Tertiary (Paleocene–Eocene – ~60–50 Ma). The period of uplift and erosion documented along the Arctic coast of Russia at this longitude could represent the landward equivalent of the (yet undrilled) offshore basement-sedimentary cover contact, thus overlying sedimentary sequences could be as old as early Late Cretaceous. Although quite speculative, these conclusions suggest that land-based geologic, structural, petrologic and geochronologic studies could provide useful constraints to help resolve the plate tectonic history of the Arctic Ocean.

scholarly journals Evolution of the Deep Water in the Canadian Basin in the Arctic Ocean

2006 ◽  
Vol 36 (5) ◽  
pp. 866-874 ◽  
Author(s):  
M-L. Timmermans ◽  
Chris Garrett
Keyword(s):  
Arctic Ocean ◽  
Deep Water ◽  
Bottom Layer ◽  
Canada Basin ◽  
The Arctic ◽  
Lomonosov Ridge ◽  
Geothermal Heat ◽  
Makarov Basin ◽  
The Arctic Ocean ◽  
Canadian Basin

Abstract An overflow of magnitude 0.25 Sv (Sv ≡ 106 m−3 s−1) has been predicted to enter the Makarov Basin (part of the Canadian Basin in the Arctic Ocean) from the Eurasian Basin via a deep gap in the dividing Lomonosov ridge. The authors argue that this overflow does not ventilate the deep Makarov Basin (below 2400 m) where the water is too warm and salty to be compatible with such a large cold fresh inflow. However, complete isolation of the homogeneous bottom layer of the Makarov Basin must be ruled out because changes there are too small to arise from more than a small fraction of the measured geothermal heat flux into the basin. A small cold fresh inflow of about 0.01 Sv from the Amundsen Basin seems to be required. This could occur if the gap in the dividing Lomonosov Ridge is shallower than previously thought. It could also occur if there is active mixing and dilution of the predicted overflow in the gap, leaving only a small fraction to descend into the deep Makarov Basin. Hydraulic theory and hydrographic observations are used to rule out any significant flow of dense water from the Makarov Basin into the deep Canada Basin, confirming previous hypotheses of isolation of the deep water in the Canada Basin.

scholarly journals Variability of the thermohaline structure and transport of Atlantic water in the Arctic Ocean based on NABOS (Nansen and Amundsen Basins Observing System) hydrography data

Ocean Science ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 405-421
Author(s):  
Nataliya Zhurbas ◽  
Natalia Kuzmina
Keyword(s):  
Time Series ◽  
Arctic Ocean ◽  
Atlantic Water ◽  
Volume Transport ◽  
The Arctic ◽  
Makarov Basin ◽  
The Arctic Ocean ◽  
Anna Trough ◽  
Eurasian Basin ◽  
Volume Transports

Abstract. Conductivity–temperature–depth (CTD) transects across continental slope of the Eurasian Basin and the St. Anna Trough performed during NABOS (Nansen and Amundsen Basins Observing System) project in 2002–2015 and a transect from the 1996 Polarstern expedition are used to describe the temperature and salinity characteristics and volume flow rates (volume transports) of the current carrying the Atlantic water (AW) in the Arctic Ocean. The variability of the AW on its pathway along the slope of the Eurasian Basin is investigated. A dynamic Fram Strait branch of the Atlantic water (FSBW) is identified in all transects, including two transects in the Makarov Basin (along 159∘ E), while the cold waters on the eastern transects along 126, 142, and 159∘ E, which can be associated with the influence of the Barents Sea branch of the Atlantic water (BSBW), were observed in the depth range below 800 m and had a negligible effect on the spatial structure of isopycnic surfaces. The geostrophic volume transport of AW decreases farther away from the areas of the AW inflow to the Eurasian Basin, decreasing by 1 order of magnitude in the Makarov Basin at 159∘ E, implying that the major part of the AW entering the Arctic Ocean circulates cyclonically within the Nansen and Amundsen basins. There is an absolute maximum of θmax (AW core temperature) in 2006–2008 time series and a maximum in 2013, but only at 103∘ E. Salinity S(θmax) (AW core salinity) time series display a trend of an increase in AW salinity over time, which can be referred to as an AW salinization in the early 2000s. The maxima of θmax and S(θmax) in 2006 and 2013 are accompanied by the volume transport maxima. The time average geostrophic volume transports of AW are 0.5 Sv in the longitude range 31–92∘ E, 0.8 Sv in the St. Anna Trough, and 1.1 Sv in the longitude range 94–107∘ E.

scholarly journals Cyclostratigraphic age constraining for Quaternary sediments in the Makarov Basin of the western Arctic Ocean using manganese variability

2020 ◽  
Vol 55 ◽  
pp. 101021 ◽  
Author(s):  
Kwangkyu Park ◽  
Jung-Hyun Kim ◽  
Hirofumi Asahi ◽  
Leonid Polyak ◽  
Boo-Keun Khim ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Quaternary Sediments ◽  
Western Arctic Ocean ◽  
Makarov Basin ◽  
Western Arctic

Distribution, ecology, and oxygen and carbon isotope characteristics of modern planktonic foraminifers in the Makarov Basin of the Arctic Ocean

2014 ◽  
Vol 59 (7) ◽  
pp. 674-687 ◽  
Author(s):  
Xuan Ding ◽  
Rujian Wang ◽  
Haifeng Zhang ◽  
Zhencheng Tao
Keyword(s):  
Arctic Ocean ◽  
Carbon Isotope ◽  
The Arctic ◽  
Planktonic Foraminifers ◽  
Oxygen And Carbon Isotope ◽  
Makarov Basin ◽  
The Arctic Ocean
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