3D imaging of the crust and upper mantle beneath the Arctic Ocean from Rayleigh-wave group-velocity analysis

2018 ◽  
Vol 54 (1) ◽  
pp. 1-9 ◽  
Author(s):  
V. Corchete
2019 ◽  
pp. 58-70
Author(s):  
L. V. Seredkina

The results of studying the deep structure of the Earth’s crust and upper mantle of the Arctic from surface wave data are presented. For this purpose, based on the frequency-time analysis procedure, a representative dataset of group velocity dispersion curves of seismic Rayleigh and Love waves (1555 and 1265 paths, respectively) in the period range from 10 to 250 s is obtained. With the use of a two-dimensional tomography technique for a spherical surface, group velocity distributions are calculated at separate periods. Overall, 18 maps for each type of surface waves are constructed and the horizontal resolution of the mapping is estimated. For four tectonically different regions of the Arctic, the dispersion curves calculated from the tomography results are inverted for the velocity sections of the SV- and SH-waves. Based on the obtained distributions, the main large-scale features are analyzed in the deep structure of the Earth’s crust and upper mantle of the Arctic, and the revealed velocity irregularities are correlated to various geological structures. The results of the study are of considerable interest for further constructing the three-dimensional model of the shear wave velocity distributions and for studying the anisotropic properties of the upper mantle of the Arctic, as well as for building the geodynamical models of the region.


Data Series ◽  
10.3133/ds862 ◽  
2014 ◽  
Author(s):  
Lisa L. Robbins ◽  
Jonathan Wynn ◽  
Paul O. Knorr ◽  
Bogdan Onac ◽  
John T. Lisle ◽  
...  

2020 ◽  
Vol 29 (1) ◽  
pp. 138-154
Author(s):  
R.V. Smirnov ◽  
O.V. Zaitseva ◽  
A.A. Vedenin

A new species of Pogonophora obtained from one station at a depth of 25 m from near the Dikson Island in the Kara Sea is described. Galathealinum karaense sp. nov. is one of the largest pogonophorans, the first known representative of the rare genus Galathealinum Kirkegaard, 1956 in the Eurasian part of the Arctic Ocean and a highly unusual finding for the desalted shallow of the Yenisey Gulf. Several characters occurring in the new species are rare or unique among the congeners: under-developed, hardly discernible frills on the tube segments, extremely thin felted fibres in the external layer of the tube, and very faintly separated papillae in the anterior part of the trunk. Morphological characters useful in distinguishing species within the genus Galathealinum are defined and summarised in a table. Diagnosis of the genus Galathealinum is emended and supplemented by new characters. Additionally, three taxonomic keys are provided to the species of Galathealinum and to the known species of the Arctic pogonophorans using either animals or their empty tubes only, with the brief zoogeographical information on each Arctic species.


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