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The intensification of glaciation in the Mid‐Pliocene and the Earth's obliquity variation
Author(s) -
Tsutsumi Tatsuya,
Nakada Masao
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1998gl900027
Subject(s) - geology , glacial period , northern hemisphere , paleoclimatology , myr , geophysics , planet , astrobiology , climate change , paleontology , atmospheric sciences , oceanography , physics , astronomy , biochemistry , chemistry , genome , gene
The intensification of glaciation in the northern hemisphere during the past 3 Myr has clearly been confirmed by δ 18 O record for deep‐sea sediment cores extending over the past 5–6 Myr. For earth models with a lower mantle viscosity of greater than 10 22 Pa s inferred from several geophysical observables, perturbations in the Earth's dynamic ellipticity in response to this long term climatic change might have produced an increase of the average Earth's obliquity 0.06° through the resonant effect associated with the orbits of Jupiter and Saturn. This predicted obliquity change may consequently operate as a negative feedback on solar insolation, resulting in a reduction of the intensification of glaciation.