According to the GPS data, at present, the length of parallels in the Southern hemisphere is increasing and in North hemisphere it is decreasing. The formula which relates the rate of change in the length of a parallel with the velocity of the northern drift of the core is given and the velocity of this drift is evaluated (2.6 cm/yr). During the last 600 Ma, the northern component has been characteristic for the continental drift and flow of underlying mantle. The simplest kinematic model of this flow is based on the principle of its balanced arrangement: in the rear of this horizontal tectonic flow (beneath the South Pole), the balancing ascending flow which supports the high standing of Antarctica is inevitable, and at its front (beneath the North Pole), the balancing descending flow which caused the prolonged and completely intensive subsidence of the bottom of Arctic ocean ( the antipode of Antarctica according to its outlines) is inevitable as well. The expansion of the surface of the Southern hemisphere and the reduction of the surface of the Northern hemisphere is the consequence of this meridional convection. The characteristic velocity of the superficial horizontal flow is evaluated (0.25 cm/yr). Like the velocity of the core drift, this value is also evaluated according to the characteristic rate of lengthening of Earth's parallels. A possible reason for convection is the displacement of Earth's core to the North Pole.
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