洱海近代气候变化的化学记录  

Recent Climatic Change and Its Chemical Records in Lake Erhai

作　　者：陈敬安[1] 万国江[1] 陈振楼[1] 黄荣贵[1] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵州贵阳550002

出　　处：《地理科学》2000年第1期83-87,共5页Scientia Geographica Sinica

基　　金：国家自然科学基金!(批准号 :49894170 );中国科学院重大项目专题资助项目!(KZ95 1-A1-4 0 2 -0 6-0 4)

摘　　要：对洱海现代沉积物进行采样 ,将放射性核素精确计年与沉积物化学记录研究相结合 ,成功地恢复了洱海近6 5 0年来的气候与环境变迁。研究结果表明 ,洱海区域气候主要表现为暖干与冷湿相交替的气候演替类型 ,且存在约 2 0 0年时间尺度的变化准周期 ,目前正处于暖干期末期 -冷湿期初期 ,预计气温将有所下降 ,降雨量将有所增加。As a main lodging of surface substances, the plateau lake sediment continuously records the information of regional climate and environment with high resolution, and has major implications for reconstructing short time scale climatic changes. Through careful sampling of recent sediments and accurate dating by radionuclides, the evolutionary history of the regional climate and environment in recent 650 years is reconstructed successfully by chemical records in sediments of Lake Erhai. The results show that the CaO/(MgO·Al 2O 3)ratio in sediments can indicate palaeotemperature changes while the (CaO+K 2O+Na 2O)/Al 2O 3, Sr/Ba, Ca/Mg ratios have the palaeoclimate implications for revealing the aridity/humidity changes, according to it three climate phases are revealed: the warm dry period within 1340-1570AD,the cold humid period within 1570-1800AD and the warm dry period since 1800AD. This suggestes that the climatic succession type in the region of Lake Erhai is the warm dry and the cold humid alternatively and there exists 200 years time scale climatic quasi periodical changes. At present, it is at the end of the warm dry period and at the beginning of the cold humid period, so the temperature will fall and the precipitation will increase. On the one hand, the regional climate in Lake Erhai shows consistency with the global climate. On the other hand, it takes on specific regional characteristics. Therefore, to strengthen palaeoclimate study in this region is very important and meaningful in theory and reality for extending contents of global changes, realizing climatic change characteristics in the southwest monsoon zone and perfecting the Asian paleomonsoon study.

关 键 词：湖泊沉积物 化学记录 气候变化 洱海 古气候 

分 类 号：P532[天文地球—古生物学与地层学] P512.3[天文地球—地质学]