The study on global changes is an important international scientific program of IGBP organized by ICSU. It is also one of the most active programs in the area of natural sciences.Obviously, the study of global climate...The study on global changes is an important international scientific program of IGBP organized by ICSU. It is also one of the most active programs in the area of natural sciences.Obviously, the study of global climate change in the past should be a focus of the modern scientific research. Its first task is to reconstruct historical sequences of climate. The research is not only the basis of knowing the climatic change in the past, but also the key to predict the climatic change trend in the coming 21st century. In the past two years, we have carried out some preliminary study of environmental magnetism by systematical sampling of modern sediments at a section in the Kunming Lake in the Sum-展开更多
A sediment sequence,from Fangshan in the Beijing Basin,has been sampled for paleomag-netic studies.The 1430 paleomagnetic samples possess a strong and stable magnetic remanence.A high-res-olution record of secular var...A sediment sequence,from Fangshan in the Beijing Basin,has been sampled for paleomag-netic studies.The 1430 paleomagnetic samples possess a strong and stable magnetic remanence.A high-res-olution record of secular variation in North China over the past 15 ka B.P.has been provided.Spectral anal-yses have shown that main periods of inclination,declination and relative intensity are about 1000,2000 and4000 a;800,1640 and 3300 a;and 820,1200,2200 and 3300 a;respectively.Two excursions have beendiscovered,and the correlation between the geomagnetic intensity variations and the climatic changes hasbeen discussed.展开更多
基金Project supported by the National Natural Science Foundation of China
文摘The study on global changes is an important international scientific program of IGBP organized by ICSU. It is also one of the most active programs in the area of natural sciences.Obviously, the study of global climate change in the past should be a focus of the modern scientific research. Its first task is to reconstruct historical sequences of climate. The research is not only the basis of knowing the climatic change in the past, but also the key to predict the climatic change trend in the coming 21st century. In the past two years, we have carried out some preliminary study of environmental magnetism by systematical sampling of modern sediments at a section in the Kunming Lake in the Sum-
基金the Xi'an Laboratory of Loess and Quaternary Geology,Academia Sinica.
文摘A sediment sequence,from Fangshan in the Beijing Basin,has been sampled for paleomag-netic studies.The 1430 paleomagnetic samples possess a strong and stable magnetic remanence.A high-res-olution record of secular variation in North China over the past 15 ka B.P.has been provided.Spectral anal-yses have shown that main periods of inclination,declination and relative intensity are about 1000,2000 and4000 a;800,1640 and 3300 a;and 820,1200,2200 and 3300 a;respectively.Two excursions have beendiscovered,and the correlation between the geomagnetic intensity variations and the climatic changes hasbeen discussed.
