| A carbon- and oxygen-isotope record of recent environ- mental change from Qinghai Lake, NE Tibetan Plateau |
| |
| 引用本文： | A.C.G.Henderson,J.A.Holmes,M.J.Leng,L.R.Carvalho. A carbon- and oxygen-isotope record of recent environ- mental change from Qinghai Lake, NE Tibetan Plateau[J]. 科学通报(英文版), 2003, 0(14) |
| |
| 作者姓名： | A.C.G.Henderson J.A.Holmes M.J.Leng L.R.Carvalho |
| |
| 作者单位： | Environmental Change Research Centre (ECRC)，Department of Geography，University College London，26 Bedford Way，London WC1H 0AP，UK，Environmental Change Research Centre (ECRC)，Department of Geography，University College London，26 Bedford Way，London WC1H 0AP，UK，NERC Isotope Geosciences Laboratory (NIGL)，British Geological Survey，Keyworth，Nottingham，NG12 5GG，UK，Environmental Change Research Centre (ECRC)，Department of Geography，University College London，26 Bedford Way，London WC1H 0AP，UK Present address: Centre for Ecology and Hydrology (CEH)，Edinburgh，Bush Estate，Penicuik，Midlothian，EH26 0QB，UK |
| |
| 摘 要： | An understanding of natural climatic variability is essential for evaluating anthropogenic impacts on recent and future climate[1—3]. Due to the lack of lengthy instrumental records, such an understanding must be gained from natural archives of climate change. Palaeolimnological indicators of past lake levels may provide a sensitive record of changes in effective precipitation in closed basins. This approach is particularly relevant on the Tibetan Plateau, where instrumental records are very…
|
A carbon- and oxygen-isotope record of recent environ- mental change from Qinghai Lake, NE Tibetan Plateau |
| |
| A. C. G. Henderson,J. A. Holmes,ZHANG Jiawu,M. J. Leng , L. R. Carvalho, . Environmental Change Research Centre. A carbon- and oxygen-isotope record of recent environ- mental change from Qinghai Lake, NE Tibetan Plateau[J]. Chinese science bulletin, 2003, 0(14) |
| |
| Authors: | A. C. G. Henderson J. A. Holmes ZHANG Jiawu M. J. Leng & L. R. Carvalho . Environmental Change Research Centre |
| |
| Affiliation: | A. C. G. Henderson1,J. A. Holmes1,ZHANG Jiawu2,M. J. Leng3 & L. R. Carvalho1,4 1. Environmental Change Research Centre |
| |
| Abstract: | A c. 300-year oxygen and carbon isotope record derived from fine-grained and ostracod carbonate from Qinghai Lake testifies to dramatic interannual to interdecadal limnological change. Fine-grained carbonates, which are mainly authigenic, are likely to have formed in the epilimnion of the lake and their isotopic composition reflects the summer temperature and, more importantly, the isotopic composition of the near-surface waters, which is mainly a function of evaporative concentration. Ostracod shells are secreted in the benthos of the lake, and their isotopic composition reflects summer bottom-water conditions, together with fractionation effects, which may differ between species. Differences between contemporaneous values from authigenic carbonates and ostracod shells may provide an indication of stratification within the lake and variations in effective precipitation over the northeast part of the Tibetan Plateau over the past 300 years. A period of moderate evaporative concentration, from about 300 to 100 yr BP, was interrupted by a marked wet phase from ~100 to 40 yr BP, which was in turn followed by a return to drier conditions in the most recent part of the record. The increase in d 18O values in the latter part of the record accords well with instrumental records of lake-level lowering and salinity increase since about 1955 AD. |
| |
| Keywords: | Tibetan Plateau Qinghai Lake stable isotopes ostracods monsoon. |
| 本文献已被 CNKI 等数据库收录！ |
|
