Atmospheric controlled freshwater release at the Laptev Sea continental margin

Abstract Historical hydrographic data (1940s–2010) show a distinct cross-slope difference of the lower halocline water (LHW) over the Laptev Sea continental margins. Over the slope, the LHW is on average warmer and saltier by 0.2°C and 0.5 psu, respectively, relative to the off-slope LHW. The LHW temperature time series constructed from the on-slope historical records are related to the temperature of the Atlantic Water (AW) boundary current transporting warm water from the North Atlantic Ocean. In contrast, the on-slope LHW salinity is linked to the sea ice and wind forcing over the potential upstream source region in the Barents and northern Kara Seas, as also indicated by hydrodynamic model results. Over the Laptev Sea continental margin, saltier LHW favors weaker salinity stratification that, in turn, contributes to enhanced vertical mixing with underlying AW.

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Structure of the Khatanga-Lomonosov fracture zone according to seismic data

Доклады Академии наук ◽

10.31857/s0869-56524873304-309 ◽

2019 ◽

Vol 487 (3) ◽

pp. 304-309

Author(s):

E. V. Shipilov ◽

L. I. Lobkovsky ◽

S. I. Shkarubo

Keyword(s):

Continental Margin ◽

Seismic Data ◽

Data Interpretation ◽

Structural Features ◽

Laptev Sea ◽

Lomonosov Ridge ◽

Fracture Zones ◽

Geodynamic Evolution ◽

Eurasian Basin ◽

The Laptev Sea

According to the results of geophysical data interpretation considered the structural features of the Khatanga-Lomonosov fracture zones (HLZ), adapted to the strip joint part on the Laptev Sea continental margin with the structures of the spreading of the Eurasian basin and the Lomonosov ridge. Its reflection in anomalous geophysical fields, in a wave seismic picture on sections is shown on the example of separate links of HLZ and the character of its kinematic interrelations with heterogeneous tectonic elements is illustrated. The tectonic nature, role and place of this fault zone in the geodynamic evolution of the region are substantiated.

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Geological structure and seismogeological characteristics of the continental margin of the Siberian Platform and the Laptev Sea shelf

Neftegazovaya Geologiya Teoriya I Praktika ◽

10.17353/2070-5379/39_2020 ◽

2020 ◽

Vol 15 (4) ◽

Author(s):

V.A. Kontorovich ◽

◽

A.Yu. Kalinin ◽

L.M. Kalinina ◽

M.V. Solov'ev ◽

...

Keyword(s):

Continental Margin ◽

Siberian Platform ◽

Complex Analysis ◽

Sedimentary Cover ◽

Geological Structure ◽

Water Area ◽

Laptev Sea ◽

Taimyr Peninsula ◽

Upper Proterozoic ◽

The Laptev Sea

The work is devoted to the analysis of the geological structure of the northern continental margin of the Siberian Platform and the western part of the Laptev Sea. In terms petroleum geological zoning, the study area covers the Anabar-Khatanga and Lena-Anabar petroleum bearing areas of the Lena-Tunguska petroleum province and the West Laptev Sea promising petroleum province. Seismogeological models of sedimentary stratum on the continent and in the water area are considered; the conclusion was made that the Northern Siberian and Laptev Sea basins are separated by a large basement high that extends from the Taimyr Peninsula along the coastline to the Lena River issue. A complex analysis of geological and geophysical data made it possible to conclude that the most probable model is that the western part of the Laptev Sea is a continuation of the Siberian Platform with an Archaean-Proterozoic basement and an Upper Proterozoic-Phanerozoic sedimentary cover.

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A volcanic passive continental margin between the Laptev Sea Shelf and the Eurasia Basin?

10.5194/egusphere-egu21-9428 ◽

2021 ◽

Author(s):

Anatoly Nikishin ◽

Vasily Savin ◽

Sierd Cloetingh ◽

Carmen Gaina ◽

Nikolay Malyshev ◽

...

Keyword(s):

Continental Slope ◽

Continental Margin ◽

Gravity Data ◽

Laptev Sea ◽

The North ◽

Rfbr Grant ◽

Break Up ◽

Seismic Lines ◽

Eurasia Basin ◽

The Laptev Sea

New seismic, magnetic and gravity data of the continental margin of the Laptev Sea shelf indicate: (1) Absence of the Lomonosov-Khatanga transform fault between the Eurasia Basin and Laptev Sea shelf. On a number of new seismic lines we do not observe evidence for transtension or transpressional deformation along this lineament whereas some typical deformation for the continental slopes is recognized. Recent seisimicity is absent along the lineament. (2) The pull-apart Laptev-Gakkel continental basin along the Laptev Sea continental slope is in an orthogonal position to the Gakkel Ridge axial rift. This pull-apart basin was tectonically active during Eocene-Oligocene times. (3) Evidence exists for number possible intrusions just below the rift/postrift (break-up) unconformity (56 Ma) on some seismic lines in the area between the Taimyr Shelf and the continental slope of the Eurasia Basin. Evidence is also found for the existence of possible volcanics just below the break-up unconformity in this area. (4) Intrusions might also be present just below the 56 Ma break-up unconformity recognized on some seismic lines in the area between the Lomonosov Ridge and the continental slope of the Eurasia Basin. Buried volcanoes are likely present as well. These two magmatic provinces are symmetric to each other on both sides of the Eurasia Basin and well expressed on the new magnetic anomaly map.(5) The Eurasia Basin has a conical shape in its Southern near-Laptev domain. Opening of the basin appears to be controlled by propagation of oceanic crust spreading to the south. (6) We assume that the continental margin between the Laptev Sea Shelf and the Eurasian Basin could be a passive volcanic margin. This margin is characterized by a structure that is very similar to the North Atlantic margin of almost the same age. This study was supported by RFBR grant (18-05-70011).

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