Speaker
Description
The chemical composition of the bottom sediments of Bering Sea (north-west of the Pacific) was measured by method of X-ray fluorescence analysis using synchrotron radiation (SRXRF) at the collective station, VEPP 3 (Institute of Nuclear Physics, SB RAS). Column length is 560 cm. The study of the chemical composition of this column is a continuation of large-scale work aimed at studying the climate of the North Pacific.
The aim of the work is to construct several climate change schemes for the Bering Sea and the subarctic of the Pacific for the characteristic time slices of the last two glacier-ice cycles: the maximum of the last glaciation, the Marine Isotope Stage 4 (MIS 4), the maximum of the last interglacial glaciation (MIS 5.5), the maximum of the penultimate glaciation (Heinrich event 11, MIS 6.2) and the warmest possible MIS 6.5. The general characteristic patterns of orbital and millennial environmental, climate and ventilation changes in the Bering Sea and the Pacific subarctic that have occurred during global climate change over the last two glaciation-ice cycles (190-0 thousand years ago) will be established. Analysis of mutual influence of environment and climate parameters between the subarctic of the Pacific Ocean and the Bering Sea over the last 190 thousand years.
The experiment is aimed at studying the distribution of chemical elements, markers of paleoclimatic changes along the core of bottom sediments in order to identify orbital and rapid climate changes in the last two cycles of glaciation-icing. And also to clarify the role of the region in changes in the palaeoceanology of the world's oceans and in the interaction of water and atmosphere that had occurred during orbital and millennial climate changes.
As part of the work were obtained distributions of chemical elements (from K to Mo for K-series and U, Th, Pb for L-series) along the column under study in 1 cm steps. The conducted cluster analysis showed the presence of two large groups of elements. The first one reflects the terrigenous component of the sediment (K, Rb, Nb, Th, Y, Zr, Mo, Ti, Fe, etc.) and the second - biogenic (Ca, Sr, U, Ge, As, Br). In the Fourier and wavelet spectra of the distribution of the chemical elements were found periodically components comparable with periods of D-O events.
This work was supported of the grant "Interaction of orbital and millennial changes in the environment and hydrology of the Bering Sea and Sub-Arctic, Pacific Ocean for the last two cycles of glaciation and glaciation under global climate variations" № 19-05-00663
