A Quantitative Analysis of the Decelerating Expansion in the South Hemisphere

Abstract

The closed differences of the latitude length rates at the latitude‐circle direction on the South Hemisphere and the convergent and spreading rates along global active plate boundaries are obtained from space geodetic data in a span of 20 years. Comparing these results with NUVEL1A predictions averaged the past 3 million years (Ma) shows that the closed differences of the latitude length rates at the latitude‐circle direction on the South Hemisphere are all positive. 91 percent of sites on the South Hemisphere move up vertically, except the several sites near the equator region. The present‐day spreading and convergent rates of active plate boundaries on the South Hemisphere are systemically smaller than NUVEL1A predictions averaged 3 Ma, while the changes of relative motions on the North Hemisphere are disorderly and unsystematic. All these show the present‐day motion characteristics of the South Hemisphere that is expanding at a slowing down rate.

Geodynamics

“…11. Graphs of the difference between the large and small semi-major axis of the triaxial ellipsoid with the results of simulation (red colorcorresponds to C. Scotese, blue colorcorresponds to R. Blakey) Сучасні дані ГНСС спостережень на постійних перманентних станціях також підтверджують тенденцію до збільшення середнього радіуса Землі [Shuanggen Jin, Wenyao Zhu, 2002, Tserklevych A., et al, 2017, Wen-Bin Shen W., et al, 2015.…”