The main geodynamic border and seismic visualization of plumes under the East European Platform

• Дата: 2019
• Автори: Tsvetkova, T., Bugaenko, I. V., Zaets, L. N.
• Формат: Стаття
• Мова: rus
• Опубліковано: Subbotin Institute of Geophysics of the NAS of Ukraine 2019
• Теми: seismic tomography; East European platform; main geodynamic boundary; plum (Volyn-Orsha; North-Azov; Moscow; Timan; Belomorsky; Varanger; Shelefteo); super-deep fluids
• Онлайн доступ: https://journals.uran.ua/geofizicheskiy/article/view/158868
• Назва журналу: Geofizicheskiy Zhurnal

According to the Taylor approximation method of the three-dimensional P-velocity mantle model under Eurasia, a seismic imaging of the manifold plumes and super-deep fluid processes of the East European Platform was carried out. As the source data, the time of the first wave of R wave entry according to the ISC bulletins from 1964 to 2006 was used. The fluid domain is defined as the region of distribution of low-speed inhomogeneities from the lower, middle mantle to the upper and spreading laterally in the upper end of its central part. The central, low-speed part of the fluid domain is defined as a plume. On the territory of the East European platform, the North-Azov, Volyn-Orsha, Moscow, Timan, Belomorsky, Varanger and Schelfteo plumes are highlighted. In the area of spreading the data of mantle domains there are 19 super-deep mantle fluids. By the nature of the behaviour of the gradient of velocity with depth, the main geodynamic boundary (the boundary between the upper and middle mantle) is constructed, which within the East European platform ranges from 525 to 700 km. According to the depths of the main geodynamic boundary, the East European platform is divided into Fennoscandia (575 km), Sarmatia (divided into two parts with depths of 575 km and 600—625 km) and Volga-Uralia (625 km). The main geodynamic boundary of the Barents Sea plate is divided into East and West (525—550 km). For the given main geodynamic boundary, the reduction of the gradient of speed (sharpness) from north to south from 0.734 s–1 in the mantle under the archipelago Medvezhy to the average is mostly £ 0.2 s–1 in the mantle North of 55° northern latitude.