A pervasive tropical climate in SE Tibet 35.5 Ma ago

A global cooling of the Earth climate has characterized the Eocene-Oligocene transition that initiated the Antarctic glaciation ca. 33.7 Ma and a shift from greenhouse to icehouse conditions. What was the impact of these climatic changes in the continental realm, particularly in tropical regions affected by a monsoonal regime? A recent study published in Scientific Reports shows prevalent wet conditions in SE Tibet 35.5 Ma while a dry arid climate dominates the northern part of the Xining Basin. These results suggest a redistribution of moisture in tropical Asia most probably forced by a northern migration of the Intertropical Convergence Zone (ITCZ) around 35.5 Ma. This is in agreement with recent reconstructions of Sea Surface Temperatures (SST) in marine sediments in equatorial regions.

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September 18, 2017