Focus Areas Detail

G@GPS: Groundwater and Global Palaeoclimate Signals

(Leader: Jianyao Chen;

1. History and Scope

Aquifers may archive environmental information acquired before the water was recharged into the aquifer. The recharge processes incorporate different signals (recharge temperatures, rainfall sources, dissolved components, etc.). Analysis of stable and radioactive isotopes is commonly used to estimate palaeorecharge temperatures and residence time of the groundwater. Other geochemical parameters are used to identify the groundwater transport pathways. The groundwater in large aquifers may consist of water recharged over long time intervals and during different climate conditions. This is in particular the case for low-recharge aquifers, where groundwater has long transit times. However, dispersion processes and/or water-rock interaction affect the groundwater during its transport and make it difficult to interpret the palaeoclimate signals. The impact of such processes, which occur along the whole groundwater pathway from its recharge area to its discharge area is difficult to estimate. Therefore, palaeoclimate information deduced from groundwater is inherently a low resolution record. Despite of this, groundwater may have the potential to provide a regionally integrated proxy of climatic variations at the times of recharge.

Over the last few years lots of high resolution continental palaeoclimate records have been published. However, not much work has been dedicated to match continental records with groundwater-derived palaeoclimate data. While the groundwater signal resolution can be limited, recharge follows major climatic events and more importantly it shows how aquifers and their associated recharge vary under climatic forcing. Over the last few years with improved analytical technique and wider use of environmental isotopes a wealth of information is emerging globally from a number of groundwater basins. Some studies are reported in main-stream scientific publications, but a great number is found in less accessible governmental reports. Most studies offer a good understanding of regional groundwater flow and residence times. That is generally complemented with environmental isotopes or in some cases by direct noble gases palaeorecharge temperature estimates. However, few studies have incorporated findings on a continental scale and none (to our knowledge) have attempted to identify common features on a global scale.

2. Objectives and Activities

   2.1. Objectives

(1) Use isotopic and geochemical data from large aquifers to estimate recharge times and palaeorecharge temperatures. The project will initially target one or two emblematic aquifers ("flag basins") in most continents but expects to increase the number of basins targeted as new collaborations and research projects are developed.

(2) Compare and potentially correlate major climatic events derived from groundwater basins with those obtained from higher resolution continental proxy records. This will be done at a continental scale (individual basins) and global scale (between different basins). Several conceptualizations of basin response from the palaeogroundwater record will be modeled and compared. The model's response will be calibrated against available data. Calculated response of modeled basins will also be used to identify additional data needs.

(3) Discuss and improve the methods of age determination and palaeoclimate interpretation based on groundwater signals (e.g. stable and radioactive isotopes, noble gases, other geochemical parameters).

   2.2. Activities in this inter-congress period
            Geographic correlations
G@GPS applies available data from a number of aquifers in the world to interpret the periods of major and long-lasting recharge periods. We focus in particular on low-recharge aquifers where there are old (pre-modern) groundwater components.
            1) The data from one site will be compared with data from other sites within the same aquifer along the groundwater pathways.
            2) The estimated age of groundwater and its associated palaeorecharge temperatures will be compared with the same parameters from the continental records.
            3) Data from one aquifer will be compared with data from other aquifers in the same region and with continental records from the same region.
            4) In the final phase data on a continental scale will be correlated with global palaeoclimate records. Collaboration with INQUA PALCOMM is important.

            Laboratory analyses
The second important aspect of the IFP is to discuss methods for dating groundwater and estimating palaeorecharge climate conditions. Palaeoclimatic signals derived from geochemical characteristics and features of stable isotopes and noble gases, and groundwater dating calculated from naturally occurring radioactive isotopes of varied half-lives (3H, 35S (modern water short half life), 3H/3He (for identification of modern groundwater components), 14C, 32Si, 39Ar, , 85Kr, 81Kr and 36Cl) will constitute the chronological framework. There are also different models used, that takes the diffusion processes and water-rock interactions into account. New methods are developed and G@GPS will involve collaboration between the participating laboratories. Several laboratories have already confirmed that they will participate (see Appendix 1): This will ensure that:
            i) Samples from different flag basins are analyzed in the same laboratory.
            ii) The laboratory scientists can discuss their methods and interpretations.
            iii) Many different types of analyses will be available. The analytical aspect makes G@GPS interesting and useful also for scientists who are not directly involved in the study of large groundwater basins. This part of the work has strong links to INQUA SACCOM.

            Societal importance
The results and knowledge from this IFP will be used in applied groundwater studies to estimate:
-The mixture between old and modern groundwater recharge
-The mixture between old groundwater and modern seawater. This includes the distinction between old formation water and modern intrusion of seawater, and the impact of sea level changes in the past.
- To achieve a better understanding of the impact of future global change on important groundwater basins. Ultimately, the knowledge gained from G@GPS can be used for the best management and policy decisions toward the sustainability of global groundwater resources. These applied aspects will be highlighted in the applications for additional research funding from national and international research foundations and other funding sources.
- G@GPS has a strong skill enhancement component. INQUA-supported training courses focused on isotopes and groundwater recharge were organized in Tunisia in 2010 and China in 2011. Comprehensive training courses take place in Mozambique in 2013 and in Argentina in 2014.

3. Initial correspondents

   3.1. Leaders
Dr. Jianyao Chen (Corresponding leader)
Department of Water Resources and Environment,
School of Geography and Planning. Sun Yatsen University. CHINA.
E-mail: or

   3.2. Regional and thematic groups

African G@GPS Basins
Najiba Chkir Ben Jemâa, Maître Assistante Habilité au Dép. De Géographie
Fac des Lettres et Sciences Humaines de Sfax, TUNISIE,

Dr. Mussa Achimo, Professor, Department of Geology,
Dr. Univ. of Edurado Mondlane, MOZAMBIQUE,

North American G@GPS Basins
Dr. Jason J. Gurdak, Assistant Professor,
Department of Geosciences, San Francisco State University, USA.

South American G@GPS Basins
Dr. Ofelia Tujchneider. Researcher of the National Council of Scientific and Technical Research,
Faculty of Engineering and Water Sciences. National University El Litoral, ARGENTINA.

Asian G@GPS Basins
Dr. Jianyao Chen, Department of Water Resources and Environment,
School of Geography and Planning. Sun Yatsen University. CHINA.
E-mail: or

Australian G@GPS Basins
Dr. Dioni I. Cendón, Senior Research Scientist.
Australian Nuclear Science and Technology Organization (ANSTO), AUSTRALIA.

European G@GPS Basins
Dr. Rein Vaikmäe.
Institute of Geology, Tallinn University of Technology, ESTONIA.

Datings (including Krypton-81) and geochemical methods
Dr. Roland Purtschert,
Climate and Environmental Physics, Physics Institute University of Bern, SWITZERLAND.

Dr. Dioni I. Cendón, Senior Research Scientist.
Australian Nuclear Science and Technology Organization (ANSTO), AUSTRALIA.

Modelling of G@GPS Basins
Dr. Martine J van der Ploeg,
Wageningen University, Centre for Water and Climate Soil Physics,
Ecohydrology and Groundwater Management Group P.O, THE NETHERLANDS,

   3.3. Full list of corresponding members


Surname Name Country e-mail
Dr. Asrat AsfawossenEthiopia
Dr. Bouchaou LhoussaineMorocco,
PhD student ChikiraIbrahimuTanzania
Dr. Christelis Gregory M.Namibia
PhD student DhaouiZahraTunisia
Prof HarrisChrisSouth Africa
Dr. Kebede Seifu Ethiopia
Prof Kirchner Jürgen Namibia
Dr. Kortatsi Benony Ghana
Dr. Matondo Jonathan Swaziland
Dr. Momade Fatima Mozambique,
Dr. Moulla Adnane Algeria
Dr. Ouda Bouchra Morocco
PhD student Totin Henri Benin
Prof Zouari Kamel Tunisia

Surname Name Country e-mail
Dr. Seeboonruang UmaThailand,
Prof Jun ShimadaJapan
Dr. Yechieli YossiIsrael

Surname Name Country e-mail
Senior Scientist AireyPeterAustralia
Dr. Baker Andy Australia
Prof Cartwright Ian Australia
Dr. Currell Matthew Australia
Prof Dodson John Australia
Dr. Graham Ian Australia
Dr Hughes Cath Australia
PhD student Larsen Josh Australia
Dr Meredith Karina Australia
Dr. Pigois Jon-Philippe Australia
Dr. Raiber Matthias Australia
PhD student van der Ley Mira Australia

Surname Name Country e-mail
Prof. Aeschbach-HertigWernerGermany
PhD student Alise Latvia
Dr. Darling George United Kingdom
Prof Edmunds Mike United Kingdom
Dr. Haarstad Ketil Norway
Dr. Hinsby Klaus Denmark
Dr Jones Matthew D. United Kingdom
Dr. Jost Anne France
Dr. Kooi Henk Netherlands
Prof Leijnse Toon Netherlands
Dr. Martma Tõnu Estonia
Dr. Mas-Pla Josep Spain
Dr. Re Viviana Italy
Dr. Saks Tomas Latvia
Dr. Schroder Niels Denmark
Dr. Stone Abi United Kingdom
Dr. Thorn Paul Denmark
Prof van der Zee Sjoerd Netherlands
Dr. van Lanen Henny Netherlands

North America
Surname Name Country e-mail
Prof. AllenDianaCanada
Prof. Gibson John Canada,
Prof. Lu Zheng-Tian USA
Dr. McMahon Pete B. USA

South America
Surname Name Country e-mail
PhD student D'Elía Mónica P. Argentina
Dr. Diaz Ucha Eduardo LuisArgentina