DOI: 10.5194/cp-10-1363-2014
Scopus记录号: 2-s2.0-84904822440
论文题名: Constraining Holocene hydrological changes in the Carpathian-Balkan region using speleothem δ18O and pollen-based temperature reconstructions
作者: Drǎguşin V. ; Staubwasser M. ; Hoffmann D.L. ; Ersek V. ; Onac B.P. ; Veres D.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2014
卷: 10, 期: 4 起始页码: 1363
结束页码: 1380
语种: 英语
英文摘要: Here we present a speleothem isotope record (POM2) from Ascunsǎ Cave (Romania) that provides new data on past climate changes in the Carpathian-Balkan region from 8.2 ka until the present. This paper describes an approach to constrain the effect of temperature changes on calcite δ18O values in stalagmite POM2 over the course of the middle Holocene (6-4 ka), and across the 8.2 and 3.2 ka rapid climate change events. Independent pollen temperature reconstructions are used to this purpose. The approach combines the temperature-dependent isotope fractionation of rain water during condensation and fractionation resulting from calcite precipitation at the given cave temperature. The only prior assumptions are that pollen-derived average annual temperature reflects average cave temperature, and that pollen-derived coldest and warmest month temperatures reflect the range of condensation temperatures of rain above the cave site. This approach constrains a range of values between which speleothem δ18O changes should be found if controlled only by surface temperature variations at the cave site. Deviations of the change in δ18Ocspel values from the calculated temperature-constrained range of change are interpreted towards large-scale variability of climate-hydrology. Following this approach, we show that an additional ∼0.6‰ enrichment of δ18Oc in the POM2 stalagmite was caused by changing hydrological patterns in SW Romania across the middle Holocene, most likely comprising local evaporation from the soil and an increase in Mediterranean moisture δ18O. Further, by extending the calculations to other speleothem records from around the entire Mediterranean basin, it appears that all eastern Mediterranean speleothems recorded a similar isotopic enrichment due to changing hydrology, whereas all changes recorded in speleothems from the western Mediterranean are fully explained by temperature variation alone. This highlights a different hydrological evolution between the two sides of the Mediterranean. Our results also demonstrate that during the 8.2 ka event, POM2 stable isotope data essentially fit the temperature-constrained isotopic variability. In the case of the 3.2 ka event, an additional climate-related hydrological factor is more evident. This implies a different rainfall pattern in the Southern Carpathian region during this event at the end of the Bronze Age. © Author(s) 2014. 资助项目: EC, European Commission Service
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49244
Appears in Collections: 气候变化与战略
There are no files associated with this item.
Recommended Citation:
Drǎguşin V.,Staubwasser M.,Hoffmann D.L.,et al. Constraining Holocene hydrological changes in the Carpathian-Balkan region using speleothem δ18O and pollen-based temperature reconstructions[J]. Climate of the Past,2014-01-01,10(4)