Speleothems from the Middle East: An Example of Water Limited Environments in the SISAL Database

Abstract

The Middle East spans the transition between temperate Mediterranean climate in the Levant to hyper-arid sub-tropical deserts in the southern part of the Arabian Peninsula, with the complex alpine topography in the northeast feeding the Euphrates and Tigris rivers which support life in the southeastern Fertile Crescent (FC). Climate projections predict severe drying in major parts much of the ME in response to global warming, making it important to understand the controls of hydro-climate perturbations in the region. Here we discuss 23 ME speleothem stable oxygen isotope (δ 18 Occ) records from 16 sites from the SISAL_v1 database, which provide a record of past hydro-climatic variability. Sub-millennial changes in ME speleothem δ 18 Occ values primarily indicate changes in past precipitation amounts superimposed on variations of the main synoptic pattern in the region, specifically Mediterranean cyclones. The coherency (or lack thereof) between regional records is reviewed from Pleistocene to present, covering the Last Glacial Maximum (LGM), prominent events during deglaciation, and transition into the Holocene. The available speleothem δ 18 Occ time-series are investigated by binning and normalizing at 25-year and 200-year time windows over the Holocene. Important Holocene climatic oscillations are discussed, such as the 8.2 ka, 4.2 ka and 0.7 ka (the Little Ice Age) Before Present events. Common trends in the standardized anomalies are tested against different climate archives. Finally, recommendations for future speleothem-based research in the region are given along with comments on the utility and completeness of the SISAL database.

Main controls on the stable carbon isotope composition of speleothems

“…This database was compiled to provide a comprehensive understanding of speleothem δ 18 O and δ 13 C records for climate reconstruction and model evaluation (e.g., Comas-Bru et al, 2019). From this database, several papers have already been published that assess data coverage and investigate regional patterns in stalagmite δ 18 O records from specific regions and continents (e.g., Lechleitner et al, 2018;Oster et al, 2019;Braun et al, 2019;Burstyn et al, 2019). To constrain the governing processes influencing speleothem δ 13 C values in the SISAL records we focus on two subsets of the data of the SISAL_v1 database.…”

Heterogenous Late Holocene Climate in the Eastern Mediterranean—The Kocain Cave Record From SW Turkey

“…Confidently reconstructing this variability requires a dense network of precisely dated and highly resolved palaeoclimate records. Past spatio‐temporal climate variability in the EM is, however, poorly documented due to unevenly distributed records (Burstyn et al., 2019; Luterbacher et al., 2012).…”

The Timing, Duration And Magnitude of The 8.2 Ka Event In Global Speleothem Records

“…records of the event do not always show a well-constrained timing 4,38,39 or a signal with an amplitude larger than the noise of the record 40 Furthermore, the signal of this event sometimes consists of several oscillations rather than one straightforward excursion 4,41 . However, it seems more likely that this event was not of global extent.…”