Geodynamic factors

It has been postulated that changes in the distribution and volume of land ice and the rise and fall in eustatic sea-level during glacial-interglacial cycles could have affected the momentum of the Earth (deceleration of the Earth's rotation during periods of sea-level rise, and acceleration during low sea-level stands; Morner (1993)). This could have led to variations in the direction and velocity of the major ocean currents, e.g. the North Atlantic Current (and the Gulf Stream), the Labrador Current and the Humbolt Current. Morner

(1993) argued that such changes may explain some short-term global variations during the last millennium and at the Weichselian-Holocene boundary. However, due to lack of proxy data directly linked to geodynamic variations, it is difficult to test this hypothesis. In addition, the cyclic nature of the most significant climatic variations during the Quaternary is difficult to explain entirely by geodynamic factors. Changes in the spin velocity of the Earth and related effects may have contributed to modulating Late Quaternary climate changes (e.g. Lowe and Walker, 1997).

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