学术活动
大气海洋
Tectonics and climate: some illustrations from Neoproterozoic to Cenozoic
浏览次数:
主讲人: Gilles Ramstein
地点: 物理楼北539
时间: 2019年12月18日,周三,10:00—11:00

摘要:

A century ago, the pioneering book published in 1924 DieKlimatedergeologischenVorzeitexplainedbyplatemotion the evolution of vegetation revealed in sedimentary records. Nevertheless, they did notinvokeclimatechanges. In the second part of the 20th century, the intricate relationship between tectonics,longtermcarboncycle, and climate was depicted by Walker (1981). Since these major steps, climate modelingoftheEarth system kept on improving and including more and more components and processes to enabletheinvestigationof deep time periods using general circulation model that can account for atmosphere andoceandynamics. Here we illustrate long but drastic climate changes clearly related with tectonics, throughthreedifferentexamples: (1) the crucial role of paleogeography (continental distribution) to explain thedrawdownofatmospheric carbon dioxide and the huge glaciation associated that occurred during theNeoproterozoicperiod; (2) the shrinkage of largeepicontinentalParatethysthat covered a large part of Eastern EuropeandWesternAsia and its impact on both monsoonal systems (African and Asian) since 40 Ma; and (3) thelargeimpactof mountain range uplifts since Eocene both in Asia (Tibetan Plateau and Himalaya) and in Africa(buildup of the rift), on atmosphere and ocean dynamics. These studies not only allow for testing theabilityofEarth system models to capture long-term changes of Earth climate, but they also pinpoint the pivotalroletectonicsplayed in shaping the long-term evolution of atmospheric CO2 and monsoon patterns.