Geodynamics

Abstract

The purpose of this work is elaboration of the results of long-term GNSS-observations at permanent stations located on the Antarctic tectonic plate; the determination of the change in its rotational parameters and angular momentum, the calculation of the angular momentum of the Earth, the oceanic and atmospheric masses, and the establishment of the interrelationship between these parameters. Methods. The work represents an improved algorithm for determining the parameters of the Euler pole and the angular velocity of the tectonic plate, taking into account the continuity and unevenness of time series of daily solutions of the spatial location of permanent GNSS-stations. Results. According to the results of daily solutions of 28 permanent GNSS-stations in Antarctica for the period (1996-2014), the average position of Euler pole, the angular velocity of the plate, and their annual changes are determined. The annual parameters of the tensor of inertia and angular momentum of the Antarctic tectonic plate are determined. Using the data of the Earth's rotation service and geophysical observations, the annual changes in the angular momentum of the Earth, the tensors of moment of inertia, and angular momentum of oceanic and atmospheric masses for the period (1996-2014) have been calculated. Scientific novelty. It is established that during the whole observation period the increase of the angular momentum of the Antarctic tectonic plate corresponds to the decrease of the angular momentum of the Earth and the atmosphere. This indicates the conservation of angular momentum. The increases of the angular momentum of Antarctic tectonic plate corresponds to the increases of the angular momentum of the ocean. Explanation of this interrelationship requires additional research.

Tectonic plates moment of inertia and angular momentum determination: the case of the Antarctic plate

“…It is well known that the quality of the initial data (i.e., in our case, time series of daily solutions of continuous GNSS stations) is key to obtaining a correct and reliable result. Therefore, to solve the system of equations, the weights of measurements were taken into account based on data irregularity and data continuity (Tretyak et al, 2018;Savchyn, 2022a). The use of weights during processing helps to minimise the influence of a single station on the quality of the determined rotation poles.…”

“…Lobkovsky and Kerchman (1991) note that this theorem in geodynamics gave the concept of plate tectonics a quantitative character and opened the way for theoretical geology to gradually transform from a descriptive science into an exact scientific discipline. Modern methods of using GNSS measurements to study the rotation poles of tectonic plates are presented in Marchenko et al (2012), Altamimi et al (2017), Tretyak et al (2018, Jagoda (2021), Savchyn (2022a;2022b;2022c), andSavchyn et al (2023). In fact, using GNSS measurements, it is possible to find the location of the pole of rotation to fix the tectonic plate in space, as well as the angular velocity to understand the dynamics of its movement around this location.…”