Groundwater and Global Palaeoclimate Signals (G@GPS)

Abstract

Groundwater sources supply fresh drinking water to almost half of the World's population and are a main source of water for irrigation across world. Characterization of groundwater resources, surfacegroundwater interactions and their link to the global water cycle and modern global change are important themes in hydrogeological research, whereas little attention has been given to the relation between groundwater and past climate variations. A groundwater system's history is vital to assess its vulnerability under future and potentially adverse climatic changes. The scientific initiative Groundwater and Global Palaeoclimate Signals (G@GPS) investigates major recharge periods of large groundwater aquifers worldwide. We describe the findings for a major basin on each permanently inhabited continent and one with coastal influences in Australia. As palaeo-signals in groundwater are inherently low-resolution records, they can only be related to considerable amounts of recharge. Long periods with substantial groundwater recharge ought to be well identifiable in terrestrial records. Correlation with regional and global climate records may give ideas of the conditions under which such large amounts of recharge were initiated.

Global Isotope Hydrogeology―Review

“…Fossil groundwater recharged during the late‐Pleistocene has been identified in over 100 aquifer systems around the globe (e.g., Münnich & Vogel, ; Edmunds & Wright, ; Fontes, ; Edmunds et al, , ; Darling, ; Haldorsen et al, ; Figure ; Table ). Measurements of fossil groundwater δ 18 O values can provide information about Pleistocene climate conditions (Andrews et al, ; Bertrand et al, ; Haggaz & Kheirallah, ; Joussaume & Jouzel, ) or the fate of paleo‐meltwaters derived from large Pleistocene ice sheets (e.g., the Laurentide ice sheet—Desaulniers et al, ; Siegel & Mandle, ; Bottomley et al, ; Siegel, ; Remenda et al, ; Grasby & Betcher, , ; Clark et al, ; Grasby & Chen, ; Ferguson et al, ; Person et al, ; Jasechko et al, ; McIntosh et al, ; Stotler et al, ; Ferguson & Jasechko, ; Vetter et al, ; Ellis & Jasechko, ; Birks et al, —and the Fennoscandian ice sheet—Boulton et al, ; Vaikmäe, Vallner, et al, ; Vaikmäe, Edmunds, et al, ; Raidla et al, ; Pärn et al, , ; Gerber et al, ).…”

Groundwater in catchments headed by temperate glaciers: A review

“…Present offshore fresh groundwater stocks could be the relics of periods when glaciers were more extended and recharge more important due to glacial meltwater (Baltic Artesian Basin, Pleistocene: Haldorsen et al, 2016; Baltic Artesian Basin under the Scandinavian Ice Sheet: Pärn et al, 2016). The concerned periods could either be recent (e.g.…”