DOI: 10.5194/cp-9-99-2013
Scopus记录号: 2-s2.0-84873821556
论文题名: Stable isotopes in caves over altitudinal gradients: Fractionation behaviour and inferences for speleothem sensitivity to climate change
作者: Johnston V.E. ; Borsato A. ; Spötl C. ; Frisia S. ; Miorandi R.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2013
卷: 9, 期: 1 起始页码: 99
结束页码: 118
语种: 英语
Scopus关键词: altitude
; calcite
; carbon dioxide
; cave
; climate change
; evaporation
; isotopic composition
; isotopic fractionation
; isotopic ratio
; speleothem
; stable isotope
; supersaturation
; temperature gradient
; ventilation
; Alps
; Italy
英文摘要: The interpretation of stable isotope ratios in speleothem calcite is complex, and only in a few cases, unequivocal relationships with palaeoclimate parameters have been attained. A major issue is temperature, which has an effect on both the isotope incorporation into calcite and on environmental processes. Here, a field approach is taken, by studying the isotopic composition of calcites from monitored caves located in steep altitudinal topography in the northern Italian Alps. These create a thermal gradient (3-12 °C) apt to study the effects of temperature on the speleothem isotope record. Our data indicate that the magnitude of oxygen isotope disequilibrium effects, calculated as an offset from the experimentally determined equilibrium, decreases with increased elevation (cooler temperatures) and faster drip rate. Carbon isotope values exhibit 13C enrichment at high altitudes (colder temperatures) and slow drip rates. The results obtained support modelling and laboratory cave analogue experiments that indicate temperature, drip rate, pCO2 and supersaturation are important factors controlling stable isotope fractionation, but also stress the significance of ventilation and evaporation in the cave environment. It is proposed that the effects on stable isotope ratios observed along the altitudinal gradient can be analogues for glacial to interglacial temperature changes in regions which were extensively glaciated in the past. © Author(s) 2013. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49485
Appears in Collections: 气候变化与战略
There are no files associated with this item.
Recommended Citation:
Johnston V.E.,Borsato A.,Spötl C.,et al. Stable isotopes in caves over altitudinal gradients: Fractionation behaviour and inferences for speleothem sensitivity to climate change[J]. Climate of the Past,2013-01-01,9(1)