At the beginning of the Cenozoic,the atmospheric CO_(2)concentration increased rapidly from~2000 ppmv at 60 Ma to~4600 ppmv at 51 Ma,which is 5–10 times higher than the present value,and then continuous declined from...At the beginning of the Cenozoic,the atmospheric CO_(2)concentration increased rapidly from~2000 ppmv at 60 Ma to~4600 ppmv at 51 Ma,which is 5–10 times higher than the present value,and then continuous declined from~51 to 34 Ma.The cause of this phenomenon is still not well understood.In this study,we demonstrate that the initiation of Cenozoic west Pacific plate subduction,triggered by the hard collision in the Tibetan Plateau,occurred at approximately 51 Ma,coinciding with the tipping point.The water depths of the Pacific subduction zones are mostly below the carbonate compensation depths,while those of the Neo-Tethys were much shallower before the collision and caused far more carbonate subducting.Additionally,more volcanic ashes erupted from the west Pacific subduction zones,which consume CO_(2).The average annual west Pacific volvano eruption is 1.11 km~3,which is higher than previous estimations.The amount of annual CO_(2)absorbed by chemical weathering of additional west Pacific volcanic ashes could be comparable to the silicate weathering by the global river.We propose that the initiation of the western Pacific subduction controlled the long-term reduction of atmospheric CO_(2)concentration.展开更多
As important parts of the Belt and Road Initiative,West Asia and North Africa have rich resources and prominent strategic position.Anti-poverty has always been a crucial social issue of China,West Asia and North Afric...As important parts of the Belt and Road Initiative,West Asia and North Africa have rich resources and prominent strategic position.Anti-poverty has always been a crucial social issue of China,West Asia and North Africa. Through literature review and data analysis,this paper analyzed the current situations of anti-poverty in West Asia and North Africa and the causes of poverty,and objectively summarized the realistic foundation of anti-poverty cooperation between China and West Asian and North African countries. On the basis of current situations,it put forward a path for anti-poverty cooperation between China and West Asian and North African countries,in the hope of providing decisionmaking basis and policy recommendations for China to undertake anti-poverty cooperation in the worldwide range.展开更多
Compression is required for all kinds of subduction initiations,which may cause either subsidence or uplift,depending on the ages of the oceanic plates.Subduction initiations associated with the old oceanic crust tend...Compression is required for all kinds of subduction initiations,which may cause either subsidence or uplift,depending on the ages of the oceanic plates.Subduction initiations associated with the old oceanic crust tend to amplify preexisting subsidence by compression,whereas those associated with young oceanic plates may result in uplift.展开更多
基金supported by NSFC Major Research Plan on‘‘West-Pacific Earth System Multispheric Interactions’’to Prof.Weidong Sun(Grant No.92258303)AND Prof.Tianyu Chen(Grant No.91858105)。
文摘At the beginning of the Cenozoic,the atmospheric CO_(2)concentration increased rapidly from~2000 ppmv at 60 Ma to~4600 ppmv at 51 Ma,which is 5–10 times higher than the present value,and then continuous declined from~51 to 34 Ma.The cause of this phenomenon is still not well understood.In this study,we demonstrate that the initiation of Cenozoic west Pacific plate subduction,triggered by the hard collision in the Tibetan Plateau,occurred at approximately 51 Ma,coinciding with the tipping point.The water depths of the Pacific subduction zones are mostly below the carbonate compensation depths,while those of the Neo-Tethys were much shallower before the collision and caused far more carbonate subducting.Additionally,more volcanic ashes erupted from the west Pacific subduction zones,which consume CO_(2).The average annual west Pacific volvano eruption is 1.11 km~3,which is higher than previous estimations.The amount of annual CO_(2)absorbed by chemical weathering of additional west Pacific volcanic ashes could be comparable to the silicate weathering by the global river.We propose that the initiation of the western Pacific subduction controlled the long-term reduction of atmospheric CO_(2)concentration.
基金Supported by Key Project of National Social Science Foundation "Path Design and Policy Synergy Study on the Integration of Precision Poverty Alleviation and Rural Revitalization in the Western Region of China"(18ASH006)
文摘As important parts of the Belt and Road Initiative,West Asia and North Africa have rich resources and prominent strategic position.Anti-poverty has always been a crucial social issue of China,West Asia and North Africa. Through literature review and data analysis,this paper analyzed the current situations of anti-poverty in West Asia and North Africa and the causes of poverty,and objectively summarized the realistic foundation of anti-poverty cooperation between China and West Asian and North African countries. On the basis of current situations,it put forward a path for anti-poverty cooperation between China and West Asian and North African countries,in the hope of providing decisionmaking basis and policy recommendations for China to undertake anti-poverty cooperation in the worldwide range.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDA22050103,XDB42020203)。
文摘Compression is required for all kinds of subduction initiations,which may cause either subsidence or uplift,depending on the ages of the oceanic plates.Subduction initiations associated with the old oceanic crust tend to amplify preexisting subsidence by compression,whereas those associated with young oceanic plates may result in uplift.
