Deep desert aquifers as an archive for Mid-to Late Pleistocene hydroclimate

• Verfasst von: Ram, Roi [VerfasserIn]
• Verfasst von: Adar, Eilon M. [VerfasserIn]
• Verfasst von: Yechieli, Yoseph [VerfasserIn]
• Verfasst von: Yokochi, Reika [VerfasserIn]
• Verfasst von: Aeschbach, Werner [VerfasserIn]
• Verfasst von: Armon, Moshe [VerfasserIn]
• Verfasst von: Solomon, D. Kip [VerfasserIn]
• Verfasst von: Purtschert, Roland [VerfasserIn]
• Verfasst von: Seltzer, Alan [VerfasserIn]
• Verfasst von: Urbach, Kerstin L. [VerfasserIn]
• Verfasst von: Bishof, Michael [VerfasserIn]
• Verfasst von: Mueller, Peter [VerfasserIn]
• Verfasst von: Zappala, Jake C. [VerfasserIn]
• Verfasst von: Jiang, Wei [VerfasserIn]
• Verfasst von: Lu, Zheng-Tian [VerfasserIn]
• Verfasst von: Reznik, Itay J. [VerfasserIn]
• Titel: Deep desert aquifers as an archive for Mid-to Late Pleistocene hydroclimate
• Titelzusatz: an example from the southeastern Mediterranean
• Verf.angabe: Roi Ram, Eilon M. Adar, Yoseph Yechieli, Reika Yokochi, Werner Aeschbach, Moshe Armon, D. Kip Solomon, Roland Purtschert, Alan M. Seltzer, Kerstin L. Urbach, Michael Bishof, Peter Mueller, Jake C. Zappala, Wei Jiang, Zheng-Tian Lu, Itay J. Reznik
• E-Jahr: 2024
• Jahr: November 2024
• Umfang: 14 S.
• Illustrationen: Illustrationen
• Fussnoten: Online verfügbar: 24. August 2024, Artikelversion: 31. August 2024 ; Gesehen am 10.03.2025
• Titel Quelle: Enthalten in: The science of the total environment
• Ort Quelle: Amsterdam [u.a.] : Elsevier Science, 1972
• Jahr Quelle: 2024
• Band/Heft Quelle: 951(2024) vom: Nov., Artikel-ID 175737, Seite 1-14
• ISSN Quelle: 1879-1026
• DOI: doi:10.1016/j.scitotenv.2024.175737
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Desert aquifers
• Sach-SW: Excess air
• Sach-SW: Hydroclimate archives
• Sach-SW: Moisture sources
• Sach-SW: Paleohydrology
• Sach-SW: Recharge temperature
• K10plus-PPN: 1919422781

Abstract

Many efforts have been made to illuminate the nature of past hydroclimates in semi-arid and arid regions, where current and future shifts in water availability have enormous consequences on human subsistence. Deep desert aquifers, where groundwater is stored for prolonged periods, might serve as a direct record of major paleo-recharge events. To date, groundwater-based paleoclimate reconstructions have mainly focused on a relatively narrow timescale (up to ∼40 kyr), limited by the relatively short half-life of the widely used radiocarbon (5.73 kyr). Here we demonstrate the usage of deep regional aquifers in the arid southeastern Mediterranean as a hydroclimate archive for earlier Mid-to-Late Pleistocene epochs. State-of-the-art dating tools, primarily the 81Kr radioisotope (t1/2 = 229 kyr), were combined with other atmosphere-derived tracers to illuminate the impact of four distinguishable wetter episodes over the past 400 kyr, with differences in climatic conditions and paleo-recharge locations. Variations in stable water isotope composition suggest moisture transport from more proximal (Mediterranean) and distal (Atlantic) sources to different parts of the region at distinct times. Large variability in the computed noble gas-based recharge temperature (NGT), ranging ~15-30 °C, cannot be explained by climate variations solely, and points to different recharge pathways, including geothermal heating in the deep unsaturated zone and recharge from high-elevation (colder) regions. The obtained groundwater record complements and enhances the interpretation of other terrestrial archives in the arid region, including a contribution of valuable information regarding the moisture source origin as reflected in the deuterium-excess values, which is unattainable from the common practice analysis of calcitic cave deposits. We conclude that similar applications in other deep (hundred-m-order) regional groundwater systems (e.g., the Sahara desert aquifers) can significantly advance our understanding of long-term (up to 1 Myr) paleo-hydroclimate in arid regions, including places where no terrestrial remnants, such as cave, lake, and spring sediments, are available.