In Arctic East Siberia many remains of mammoths
have been found. In this region there is not sufficient sunlight over the year to allow for the growth of the plants on which these animals feed. Consequently the latitude of these regions must have been lower before the end of the Pleistocene than at present. It is a challenge to reconstruct this g...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2006
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.262.1607 http://arxiv.org/pdf/physics/0604029v1.pdf |
| Summary: | have been found. In this region there is not sufficient sunlight over the year to allow for the growth of the plants on which these animals feed. Consequently the latitude of these regions must have been lower before the end of the Pleistocene than at present. It is a challenge to reconstruct this geographic shift of the poles in a manner compatible with known facts. A possible sequence of events is described here. It assumes an additional planet, which must since have disappeared. This is possible, if it moved in an extremely eccentric orbit and was hot as a result of tidal work and solar radiation. During a few million years evaporation of this planet led to a disk-shaped cloud of ions moving around the Sun. This cloud partially shielded the Earth from the solar radiation, producing the alteration of cold and warm periods characterizing the Pleistocene. The degree of shielding is sensitive to the inclination of Earth’s orbit, which has a period of 100000 years. Two cloud structures are discussed. The first is small and steady. The other builds up to a point where inelastic collisions between particles induce its collapse The resulting near-periodic time dependence of the shielding resembles that of Dansgaard-Oeschger events. The Pleistocene came to an end when the additional planet had a close encounter with the Earth, whereby the Earth suffered a one permil extensional deformation. While this deformation relaxed to an equilibrium shape in a time of one to several years, the globe turned relative to the rotation axis: The North Pole moved from Greenland to the Arctic Sea. The additional planet split into fragments, which subsequently evaporated. Simple estimates are used here for the characterization of the complex processes; more elaborate studies may lead to different scenarios for the indispensable pole shift. |
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