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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2005.12.003 Byline: E. Fahrbach, M. Hoppema, G. Rohardt, M. Schroder, A. Wisotzki Keywords: Antarctica; Weddell Sea; Deep water; Temperature Author Affiliation: Alfred Wegener Institute for Polar and Marine Research, Climate Sciences, Postfach 120161, D-27515 Bremerhaven, Germany Article History: Received 19 July 2005; Revised 16 December 2005; Accepted 21 December 2005

The Al and pH anomalies due to volcanic activities in the Manus Basin may be because the non-steady state volcanic or hydrothermal process cause fluids rich in CO2 and H2S. High temperature and low pH hydrothermal fluid are unlikely to be responsible for these anomalies. Dissolved H2S, CO2, metal oxidation, hydrolysis, sulfide oxidation and metal sulfide formation can provide protons that affect the pH. The Al anomaly may be due to either dissolution of ultrafine hyaloclasites or release of Al as volatile halides.

Longhurst's proposal of the eddy upwelling hypothesis to elucidate the Amazon plume is faulty as the two big plumes of discolored water in the western tropical Atlantic correspond to the geographical location of the deltas of the Orinoco and Amazon Rivers. There is consistency in the two plumes and the advection of river water by nearby ocean currents.

The International Symposium on Andean Geodynamics (ISAG) is an international conference that was held, on average, every 3–4 years in different European cities between 1990 (Grenoble) and 2008 (Nice). These symposia usually offer an opportunity for researchers from Latin American countries and Europe as well as other countries to review the state of knowledge in geosciences on the Andes. After a long period without an edition, the 8th ISAG was organized for the first time in a Latin American country, Ecuador, from 24th to 26th September 2019. The organizing committee led by Pablo Samaniego relied heavily on the Instituto Geofísico of the Escuela Politécnica Nacional (IG-EPN) and the Institut de Recherche pour le Développement (IRD), in particular through its office in Quito, and through the Laboratoire Mixte International in France and Ecuador: "Seismes et Volcans dans les Andes du Nord" (LMI-SVAN); and the French Embassy in Ecuador. Field trips in tectonics, seismotectonics and volcanology at emblematic sites in Ecuador were organized by researchers from the IRD (Isterre and LMV), the Institut de Radio Protection Nucléaire (IRSN), IG-EPN and the University of Geneva. Four invited speakers gave presentations: Peter Molnar (University of Boulder) on the mechanisms of the Andes uplift, Suzanne Kay (Cornell University) on its magmatism, Victor Ramos (University of Buenos Aires) on the scientific approaches developed through time for the Andean orogeny and Eric Calais (Ecole Normale Supérieure de Paris) on the difficulty of dialog between seismic risk specialists and the authorities in Haiti. The symposium also provided an opportunity for more than 250 participants to meet, with more than 80 oral presentations and over 150 posters. As a result of this conference, the Editor of the Journal of South American Earth Sciences proposed to the organizing committee to publish a special issue on the contours of these presentations. Following the peer review process, 19 papers are published in this special issue. These manuscripts reflect the various disciplinary fields, geophysics and deep imaging, tectonics, volcanism, geomorphology and seismic hazard, from the local scale to the Andes as a whole. Not surprisingly, a higher density of works is found in Ecuador and the northern Andes (Figure 1). As this collection of articles reflects the outlines of a symposium and not a specific scientific question, our aim here is not to develop a synthesis of current knowledge on the Andes. We therefore present these articles in sequence, by discipline, although this categorization may appear subjective since some articles are multidisciplinary. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2005.04.022 Byline: P. Varga (a), K.R. Rybicki (b), C. Denis (c) Keywords: Tides, solid body; Prebiotic environments; Earth; Moon Abstract: We show that the fast tidal cycling postulated by Lathe [Lathe, R., 2004. Icarus 168, 18-22] is not a plausible mechanism to explain the origin of life on Earth about 3.9 Ga ago. The value of LOD at this remote epoch was probably comprised between 15 to 17 h, and the Earth-Moon distance was only about 20% smaller than nowadays, implying that the tidal frequencies and amplitudes were not so dramatically different from the present ones as stated in Lathe's paper. Author Affiliation: (a) Geodetic and Geophysical Research Institute of the Hungarian Academy of Sciences, Seismological Observatory, Budapest, Meredek 18, H-1112, Hungary (b) Institute of Geophysics of the Polish Academy of Sciences, ul. K. Janusza 64, PL-01-452 Warszawa, Poland (c) Musee National d'Histoire Naturelle de Luxembourg and European Centre for Geodynamics and Seismology, rue J. Welter 19, L-7256 Walferdange, Luxembourg Article History: Received 16 January 2005; Revised 9 April 2005

The view that either CO mixing ratio decreases with increasing height over several large volcanoes or that an absorbing mineral is present on the surface with coverage correlated with height is justified. However, it fails to consider a third possibility which can explain this mechanism. It is possible that a small error in measurement due to scattered light can affect the results. It is suggested that increasing the continuum level by 0.3% in the low-resolution spectra can bring more accurate results.

Abstract: The discordance between the conceptual de jure delimitation of the world space and the lived territorialities at the sites of the international boundaries is widely accepted in political geography. However, viewing the de facto phenomena as challenging, defying and ignoring the boundaries, or vice versa, is trapped in the modernist dualism. The paper follows Soja''s call for expanding the scope of geographical imagination into three interdependent and interreactive moments of space – conceived, perceived and lived – and through this tri-cameral lens examines the little known spaces on the Sino–Burmese boundary and the territorialities of the Kachin nation delimited into Burma and China. The paper accounts how the power of the ‘conceptual’ controls the perceived moment of space – explicit in the creative adjustments to the boundary by the local actors – while many Kachin spatial practices continue unchanged in the alternative lived space. [Copyright &y& Elsevier]

The article presents a brief introduction of "10th International Symposium in Medical Geography," which was held in Manchester, England in the year of 2003. It represents a selection of papers presented at the Symposium. The conference attracted participants from 23 countries and saw over 100 presentations given over 4 days. The program covered the breadth of contemporary research in medical/health geographies with sessions focusing on issues of health, disease as well as qualitative and quantitative methods. The breadth of papers presented reflected the considerable changes seen in medical geography over the last decade which has, in many ways, reinvigorated our sub-discipline.

In our original paper (Buono et al., 2020), we investigated the dynamics of degassing (e.g., bubble nucleation and growth, degassing styles and regimes) of H 2 O-, CO 2 - and H 2 O-CO 2 -rich evolved alkaline melts over a wide range of variables (final pressures, decompression rates, volatile compositions and contents, temperatures) through a comprehensive review of previous and new HP (high pressure)-HT (high temperature) decompression experiments. The criticism of Allabar and Nowak regards a restricted part of our results, i.e., those concerning homogeneous bubble nucleation from our new experiments on H 2 O-rich melts. Their aim is refusing the classical nucleation theory (CNT), widely accepted in literature to explain homogeneous bubble nucleation in magmas, for evolved alkaline melts in favour of the spinodal decomposition. We found that the Authors of the Comment do not provide any new evidence in support of their thesis, but they keep only arbitrary and erroneous conjectures of our new experimental data. As we stated in our original paper, the evaluation of the specific bubble nucleation mechanism (CNT vs. spinodal decomposition) is beyond the scope of our research, as appropriate studies on both experimental and natural products would be necessary to shed light on this complex issue. [ABSTRACT FROM AUTHOR]

Gierlowski-Kordesch and Cassle (2015, Earth-Science Reviews 148, 209–227) interpreted microconchids (extinct tentaculitoid encrusters) as strictly marine, rejecting the previous conclusions that these organisms occupied a variety of habitats ranging from marine to non-marine. We argue that due to misunderstanding of previous statements concerning the affinity of microconchids, the authors used an actualistic approach and incorrectly compared microconchids with modern phoronids, which led to oversimplifications and misinterpretations. Also their idea that microconchids, as supposedly strictly marine organisms, were preserved in non-marine settings only because of transport by storm surges and tsunamis is unsupported on paleontological grounds. These errors led to mistaken conclusions about microconchid paleoecology that must be discussed in order to avoid an erroneous interpretation of microconchid paleoenvironments. [ABSTRACT FROM AUTHOR]

Preferential concentration of marine particles with small excess density depends on initial conditions and inertia parameter. When the initial velocity of the particle equals that of the fluid at the particle position, the mathematical relation shows that there will be no velocity difference between the fluid and the particle. Particles follow the flow and fail to show any preferential concentration. The preferential concentration of these particles by the turbulence is a transient feature of the flow. The density ratio is a crucial factor for the degree of preferential concentration.

Villaseñor and Olóriz (2019) present a comprehensive review of latest Jurassic to earliest Cretaceous ammonites from Mexico, which previously were ascribed to the genus Kossmatia , and provides evidence that these fossils should be referred to other genera. However, descriptions of two new genera provided by Villaseñor and Olóriz (Burckhardtieia and Aguilerites) are lacking indication of their type species that make these genera unavailable following to ICZN articles 13.3 and 67.4.1. Discussed paper also includes figures of the new species Burckhardtieia westermanni , which is lacking formal description, although illustrated by few figures and its holotype is clearly indicated. The genus Burckhardtieia Villasenor and Oloriz can be considered as a junior synonym of the genus Fierrites Cantu Chapa. The latter genus is suggested to be invalid by Villaseñor and Olóriz (2019), but without strong background in support of this statement. Here the author is follow the proposal by Enay (2009) and consider the genus Fierrites as a correct name, which can be used for all American " Kossmatia ". Discussed article is also lacking detailed biostratigraphic data concerning the range of the Burckhardtieia , although clear indication of its range (and ranges of species included in this taxon) seems to be necessary. [ABSTRACT FROM AUTHOR]

This communication basically comprise replies to the comments raised by Singh and Rajendran (SR) on our paper Malik et al. (2023) published in Journal of Asian Earth Sciences. We would like to bring to the notice of the readers that our studies and findings are based on a robust methodology towards identification and interpretation of active fault traces. Based on detailed satellite data interpretations, field evidence, paleoseismic studies and GNSS Geodesy data we suggested that Khetpurali Taksal Fault (KTF) is a major fault system with prominent dextral strike-slip motion which marks the segment boundary between the Central and NW Himalaya. Further, an attempt was also made to understand the role of KTF in regional context. We disagree with the claims made by SR. The quires raised by SR are completely baseless and expose their lack of experience and understanding. [ABSTRACT FROM AUTHOR]

M. Rogov refers to [5], Treatise Online) to accept Fierrites as proper name for American "Kossmatia", following these authors without any other argumentation to add to the brief text of [5], Treatise Online). Unfortunately, neither [5] nor [13] became aware from their respective contributions, but the occurrence of Mexican "Kossmatia" in Lower Tithonian horizons is known since [8], as reported in [12], [13] but overlooked by M. Rogov. Concerning the first formal mention to the new taxon Buckhardtieia gen. nov. in [13], p. 12), it was preceded by the precise revision, with citations, of all the available information about topics related to the use of genus Kossmatia elsewhere and, especially, in Mexico. [Extracted from the article]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of Publisher/Editor for the below details: Authors submitted a revised paper due to some errors appearing in the paper. Rather than a corrigendum being posted for this original paper, a second version was published: Earth Planet. Sci. Lett. 628 (2024) 118587, https://doi.org/10.1016/j.epsl.2024.118587. We need to retract at least one version of this paper. [ABSTRACT FROM AUTHOR]

• Introduces the nine papers on the theme of subterranean geopolitics. • Offers a wide-ranging review of works related to subterranean geopolitics. • Foregrounds six thematic agendas for future research on subterranean geopolitics. • Argues that subterranean geopolitics needs to be analysed through a relational standpoint. This position paper aims to frame and supplement other papers in this special issue on subterranean geopolitics. We trace the research genealogy that brings together the subterranean with the geopolitical before accounting for the state-of-play in the subfield of subterranean geopolitics. Six research themes and foci that can connect to and enrich the study of subterranean geopolitics are being highlighted and proposed: (i) the three-dimensional conceptualisation of territory, (ii) the political geographies of the environmental, marine and earth sciences, (iii) Anthropocene geopolitics, (iv) lived experiences and intersectional encounters, (v) popular cultures and imaginative possibilities and (vi) moral geographies. These intersect and overlap in complex ways and none are exhaustive. Indeed, along with the collection of papers in the special issue, they serve as invitations to further scholarly reflections and cross-cultural research into understanding the designing, digging, excavating and living of subterranean geopolitics. [ABSTRACT FROM AUTHOR]

Through the Earth's ∼ 4.54 billion year history, icehouse climates have been relatively short-lived but have exerted a significant impact on the evolution of the habitable environment. These icehouse episodes, such as those that occurred in the Cryogenian, mid-Ediacaran, Late Ordovician, and Late Paleozoic, developed through the complex interaction of Earth System processes; however, there is still ongoing debate regarding the causes, processes, and consequences of these glaciations. To improve our understanding of the past history of icehouse climates and the responses of the Earth System, we present this new special issue entitled The Earth System during Icehouse Climate Modes: Contributions from Glacial Records in China. This special issue includes eighteen papers that focus on four major icehouse events: the Cryogenian Snowball Earth glaciations (Sturtian and Marinoan global glaciations), the Ediacaran glaciation, the Ordovician glaciation, and the late Paleozoic Ice Age. This collection of papers provide novel insights into glacial processes, marine environments, and chemical weathering through key intervals of Earth History. We anticipate that this special issue will attract wide interest across the geosciences field. [ABSTRACT FROM AUTHOR]

In recognition of the impacts of climate change and air pollution, a special issue was prepared to address the response and adaptation of agricultural ecosystems to global changes. A total of thirteen papers were published, delving into the mechanisms underlying the effects on crops and agroecosystems and adding important insights into the modeling and adaptation of agroecosystems to global change through optimized management practices. This collection of papers has a broad relevance to numerous areas in agriculture, ecology, and environmental and earth sciences. • A special issue dedicated to 'agricultural ecosystems response and adaptation to global changes'. • A total of thirteen papers were published. • Studies concerned ozone, precipitation, warming, management, and modelling. • This Editorial discusses the content of the publications included in the special issue. [ABSTRACT FROM AUTHOR]

The Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) system is based on a homogeneous global geodetic network. The DORIS ground network is managed and monitored by a core group (CNES & IGN), which made it possible to closely steer its deployment and evolution. Thanks to infrastructure and hardware enhancements, the DORIS network has continuously improved over time in order to meet the performance requirements of satellite altimetry but also strengthen its role as geodetic network to contribute to the International Terrestrial Reference Frame (ITRF). Following the review by Fagard (2006) of the network from its initial deployment to its renovation, this paper aims at showing the advances achieved in the last fifteen years (2006–2021) to better serve the needs for precise orbit determination and geodesy. After reminding the historical background and the different stages of the network development, we zoom in the last decade that enabled the network to achieve improved operability thanks to infrastructure standardization, permanent monitoring and ongoing assessment. Today, the numerous strengths and assets of the DORIS network built up over 30 years give it an important role in contributing to Earth Sciences. This review shows the progress achieved in terms of geographical coverage, co-location with other techniques, data availability, stations equipment, monument stability, and system requirements compliance. Finally, we give an overview of the future prospects and new challenges to continue improvements in the DORIS technique. [ABSTRACT FROM AUTHOR]

The field of citizen science is a rapidly evolving type of scientific research focussing on the collaboration of motivated volunteers (citizen scientists) with professional scientists to generate new knowledge and information. In recent years, there has been a steady growth of Earth Science related citizen science projects that aim to build knowledge, awareness and ultimately resilience to key local- to global-scale environmental issues (e.g., geohazards, environmental monitoring). In addition, there has also been progression from small pilot studies to large data collection Earth Science citizen science initiatives that are used to underpin modelling. However, despite this, numerous operational and strategic challenges exist and whilst the awareness of citizen science has improved markedly, it is clear that the direct impact of citizen science on policy and decision making is still limited. Within this paper, we review these challenges alongside defining citizen science itself, and its benefits. The range of methods and applications of citizen science are explored through a series of case studies centred on geohazards, observations & classification, multi-topic, and education/outreach. The paper also explores future citizen science opportunities within Earth Science. [ABSTRACT FROM AUTHOR]

Understanding the influence of the sampling apparatus on in-situ lunar soil lamination information during the sampling process of the direct push-through lunar weathering layer is of great importance. This paper develops a discrete element model for direct push-through lunar weathering layer sampling using the CUG-1A simulated lunar soil developed by the China University of Geosciences as a simulation object and determines the stress–strain law of the inner wall of a sampling tube. A method for optimizing the inner wall structure of a sampling tube based on the stress–strain law is proposed. The structural disturbance of the marker layer and the lunar soil disturbance rate evaluation function are used to assess the degree of disturbance of the laminar information during the sampling process. The results show that the proposed method can effectively reduce the structural disturbance of the lunar soil in-situ laminar information. In addition, it can also optimize the structural information disturbance of the marker layer. The proposed method can decrease the simulated lunar soil disturbance rate from 0.31 to 0.251 and effectively reduce the penetration force load by 15–20% in the direct push-through sampling process. [ABSTRACT FROM AUTHOR]

A new AMS system (HVEE 4103Bo-AMS) was installed at Tono Geoscience Center, Japan Atomic Energy Agency in November 2019 and AMS experiments started in 2020. The system consists of a SO-110C Cs sputtering ion source, a low-energy spectrometer with an ESA and an injection magnet, a 300 kV tandem accelerator, a high energy spectrometer with two analyzing magnets and an ESA, and a gas ionization chamber for rare isotope measurement. The system is designed for high-sensitivity detection of 10Be, 14C, 26Al and 129I. A comparison with our 5 MV Pelletron is also given in this paper. [ABSTRACT FROM AUTHOR]

Geographical scholarship of the 'digital turn' has refuted the suggestion that digital technologies produce a utopian 'cyberspace' capable of transcending its material attachments. The image of a frictionless 'digital world,' it is argued, merely masks the uneven social and material relationships conditioning that world's possibility. While this is essential criticism, I offer in this paper some reasons for hesitation in collapsing digital space into material practices too quickly. Abstractions may always be attached to their social and material conditions of possibility, but this does not mean that these things are the same. I develop this insight further in the context of the 'volumetric turn,' which has analogously criticized geographers for remaining fixated on surficial formalism while neglecting consideration of the dynamic, material capacities of volumetric space. While again heeding this equally important warning, I question the limits of dynamism as a volumetric analytic insofar as, much like digital technology, this notion can easily be fetishized. In turn, I suggest that these dynamic capacities can be more productively theorized in relation, rather than opposed, to formalistic abstraction, as both are constituent elements of volumetric space. I explore these theoretical considerations through a historical geography of early 20th-century geophysical prospecting in American oilfields, where prospectors produced spatial knowledge that was simultaneously dynamic and formal, material and abstract. In turn, this case study serves to show how the relations between material practices and processes of abstraction can be a fruitful meeting point for theories of digital and volumetric space. [ABSTRACT FROM AUTHOR]

Knowledge concerning the development and evolution of cross-scale discontinuities, such as crevasses, joints, dikes, and faults, caused by crust movement and resultant stress, is essential for geoscience and geo-resources engineering communities. These discontinuities serve as significant conduits for mass and heat transfer, and are associated with magma, meltwater, hydrocarbons, or other ore-forming fluids, which to some extent determine landforms and landscapes, the fate of ice shelves, and the geometry of ore bodies or hydrocarbon reservoirs. Massive endeavors have been made over the last 100 years or even longer in understanding the onset, propagation, and mechanical interaction of cross-scale discontinuities under evolving stress and flow environments. Especially in the past 20 years, various advancements have emerged in elucidating the mechanisms of evolving multi-scale discontinuities. Proposing a proper mechanical model would benefit geoscientists in achieving a deeper understanding of the sequence of existing structures and be valuable for industrial engineers to access the potential of underground resources, which entails complementary studies from geosciences and industries. In this paper, we review state-of-the-art technologies in order to study the evolution of cross-scale discontinuities in: (1) observations from cores and outcrops; (2) in-situ monitoring or geophysical surveys; (3) analogue experiments on scale dependence; and (4) cross-scale numerical models for mechanical analyses. The driving forces, evolving patterns, and geological and engineering importance of cross-scale discontinuities are also discussed in relation to both natural and industrial fluid-driven fracturing processes. This broad review intends to bridge the understanding of the evolution of discontinuities from both Earth science and industrial communities. • The mechanisms, patterns, and modeling approaches of evolving discontinuities in Earth's crust are comprehensively reviewed. • Experimental studies and scaling laws for initiation, propagation, and interaction of fluid-driven fractures are presented. • The current understanding, emerging technologies, and future perspectives concerning evolving discontinuities are summarized. [ABSTRACT FROM AUTHOR]

This paper reports on major outcomes of the ERA-PLANET (The European network for observing our changing planet) project, which was funded under Horizon 2020 ERA-net co-funding scheme. ERA-PLANET strengthened the European Research Area in the domain of Earth Observation (EO) in coherence with the European participation to Group on Earth Observation and the Copernicus European Union's Earth Observation programme. ERA-PLANET was implemented through four projects focused on smart cities and resilient societies (SMURBS), resource efficiency and environmental management (GEOEssential), global changes and environmental treaties (iGOSP) and polar areas and natural resources (iCUPE). These projects developed specific science-policy workflows and interfaces to address selected environmental policy issues and design cost-effective strategies aiming to achieve targeted objectives. Key Enabling Technologies were implemented to enhancing 'data to knowledge' transition for supporting environmental policy making. Data cube technologies, the Virtual Earth Laboratory, Earth Observation ontologies and Knowledge Platforms were developed and used for such applications. SMURBS brought a substantial contribution to resilient cities and human settlements topics that were adopted by GEO as its 4th engagement priority, bringing the urban resilience topic in the GEO agenda on par with climate change, sustainable development and disaster risk reduction linked to environmental policies. GEOEssential is contributing to the development of Essential Variables (EVs) concept, which is encouraging and should allow the EO community to complete the description of the Earth System with EVs in a close future. This will clearly improve our capacity to address intertwined environmental and development policies as a Nexus. iGOSP supports the implementation of the GEO Flagship on Mercury (GOS4M) and the GEO Initiative on POPs (GOS4POPs) by developing a new integrated approach for global real-time monitoring of environmental quality with respect to air, water and human matrices contamination by toxic substances, like mercury and persistent organic pollutants. iGOSP developed end-user-oriented Knowledge Hubs that provide data repository systems integrated with data management consoles and knowledge information systems. The main outcomes from iCUPE are the novel and comprehensive data sets and a modelling activity that contributed to delivering science-based insights for the Arctic region. Applications enable defining and monitoring of Arctic Essential Variables and sets up processes towards UN2030 SDGs that include health (SDG 3), clean water resources and sanitation (SDGs 6 and 14). • Earth Observation can support an efficient science-policy interaction by trusted information. • Policy targets are inherently multidisciplinary, posing challenges on integrating knowledge from different scientific domains. • Specific science-policy workflows and implemented applications were demonstrated through ERA-PLANET. • A comprehensive approach to generate and delivery knowledge from EO and Earth Sciences to policy-makers was developed. [ABSTRACT FROM AUTHOR]

This paper investigates and optimises the thermal performance of deep closed-loop heat exchanger (DCHE) systems by applying a computational numerical approach. The investigated DCHE configuration accounts for two deep vertical boreholes, an injection and a production well, connected by a horizontal borehole at depth and an insulated pipeline at the surface, establishing an effective closed-loop system. First, a parametric sensitivity study explores the effects of the environmental, design and operating variables on the production temperature. The simulation uses realistic geological and geothermal conditions, depths, circulation rates and injection temperatures. Two complex numerical models are then solved for site-specific DCHEs in different geological scenarios: a foreland basin and a convergent margin hosting low-to-intermediate and high-temperature geothermal resources, respectively. Production temperatures beyond 40–60 °C and 100 °C, sustainable for both heat and electric power generation, are obtained, depending on the geothermal conditions and closed-loop dimensions. Furthermore, circulation rates of 0.02–0.04 m3 s−1 are cost-effective, and the system's efficiency and sustainability increase when a fluctuating and periodic heat extraction strategy is employed. When efficiently operated, DCHEs are a viable solution for renewable energy production and should be integrated into the local heat market and distribution network infrastructure. Earth and Planetary Sciences; Energy; Environmental Sciences • Reuse of dry and depleted abandoned wells to boost geothermal energy production. • Deep closed-loop heat exchanger (DCHE) as innovative technological solution. • Computational numerical approach for DCHE performance optimisation. • Sustainable closed-loop configuration for synthetic and real case studies. • Long-term DCHE thermal performance improvement by monthly rotation practice. [ABSTRACT FROM AUTHOR]

Abstract This paper focuses on Kant's account of physical geography and his theory of the Earth. In spelling out the epistemological foundations of Kant's physical geography, the paper examines 1) their connection to the mode of holding-to-be-true, mathematical construction and empirical certainty and 2) their implications for Kant's view of cosmopolitan right. Moreover, by showing the role played by the mathematical model of the Earth for the foundations of Kant's Doctrine of Right, the exact relationship between the latter and physical geography is highlighted. Finally, this paper shows how, in Kant's view, the progress of physical geography can be assured if and only if the free circulation of human beings is established and regulated by law. Therefore, examining the mutual relationship between the theory of Earth and the foundations of right opens new perspectives on the relationship between epistemology and practical philosophy within Kant's system. Highlights • Clarifies Kant's view of physical geography as pragmatic knowledge of the world. • Identifies the main epistemological aspects of Kant's conception of scientific investigation based on empirical certainty. • Sheds light on the connection of Kant's physical geography to the Metaphysics of Morals. [ABSTRACT FROM AUTHOR]

In this paper, we do a critical review of statistical methods for landslide susceptibility modelling and associated terrain zonations. Landslide susceptibility is the likelihood of a landslide occurring in an area depending on local terrain conditions, estimating “where” landslides are likely to occur. Since the first attempts to assess landslide susceptibility in the mid-1970s, hundreds of papers have been published using a variety of approaches and methods in different geological and climatic settings. Here, we critically review the statistically-based landslide susceptibility assessment literature by systematically searching for and then compiling an extensive database of 565 peer-review articles from 1983 to 2016. For each article in the literature database, we noted 31 categories/sub-categories of information including study region/extent, landslide type/number, inventory type and period covered, statistical model used, including variable types, model fit/prediction performance evaluation method, and strategy used to assess the model uncertainty. We present graphical visualisations and discussions of commonalities and differences found as a function of region and time, revealing a significant heterogeneity of thematic data types and scales, modelling approaches, and model evaluation criteria. We found that the range of thematic data types used for susceptibility assessment has not changed significantly with time, and that for a number of studies the geomorphological significance of the thematic data used is poorly justified. We also found that the most common statistical methods for landslide susceptibility modelling include logistic regression, neural network analysis, data-overlay, index-based and weight of evidence analyses, with an increasing preference towards machine learning methods in the recent years. Although an increasing number of studies in recent years have assessed the model performance, in terms of model fit and prediction performance, only a handful of studies have evaluated the model uncertainty. Adopting a Susceptibility Quality Level index, we found that the quality of published models has improved over the years, but top-quality assessments remain rare. We identified a clear geographical bias in susceptibility study locations, with many studies in China, India, Italy and Turkey, and only a few in Africa, South America and Oceania. Based on previous literature reviews, the analysis of the information collected in the literature database, and our own experience on the subject, we provide recommendations for the preparation, evaluation, and use of landslide susceptibility models and associated terrain zonations. [ABSTRACT FROM AUTHOR]

This paper contributes to recent debates in energy geography, especially to energy transition research and literature, by developing a critical and empirically grounded understanding of energy transitions as expressions of contentious socio-spatial politics, past and present. The paper argues that historical struggles and contentious political practices around energy, so called energy struggles, continue to inform the ongoing and dynamic socio-spatial politics of energy transitions today and often manifest themselves in transition narratives. This analysis is supported by qualitative empirical materials derived from recent fieldwork in Berlin, Germany, which was conducted within the broader left-green movement for a socio-ecological and democratic German Energiewende . A historicisation of contentious politics and energy struggles facilitates an empirically robust framing of energy transition projects as dynamic, multi-actor, and more than eco-technical processes. The paper’s contribution to energy geographies is threefold; firstly, utilising an empirically robust and historically sensitive analysis of the German Energiewende , the paper explores the deep entanglements of history, space and struggle in energy transitions. Secondly, the paper emphasises the need to understand energy transitions as constituted by energy struggles and contentious politics, past and present. Thirdly, the paper examines emergent spaces of energy democracy as part of the Energiewende and explores recent energy democracy demands as a spatial politics of energy transitions. [ABSTRACT FROM AUTHOR]

During the past two centuries, the world has undergone deep societal, political, and economical changes that heavily affected human life. The above changes contributed to an increased awareness about the deep impact that policy decisions have at the local and the global level. Therefore, there is a strong need that policy-making and decision-making processes for a sustainable development be based on the best available knowledge about Earth system and environment. The recent advance of information technologies enables running complex models that use the large amount of Earth Observation datasets available. However, data and model interoperability are still limited to the syntactic level allowing to access and process datasets independently of their structural characteristics (data format, coordinate reference systems, service interface, ...) but with no clear reference to their content (the semantic level) and context of use (the pragmatic level). This poses heavy limitations to the reusability of scientific processes and related workflows. The paper presents a general framework to address this issue through the design of a Knowledge Base supporting data and model semantic (and pragmatic) interoperability. In this framework, a general ontology represents the knowledge generation process for policy relevant decision-making, while multiple vocabularies formalize the semantics of data and models, identifying different types of observables, process variables, and indicators/indices. To evaluate the proposed approach to semantic interoperability of data and models, the Knowledge Base has been integrated with an advanced model-sharing framework, and a proof-of-concept has been developed for the assessment of one of the indicators of the Sustainable Development Goals defined by the United Nations. • Earth Observation and Earth Science are essential for environmental decision-making. • Essential Variables play a key role in building environmental scientific processes. • Digital transformations support interoperability of environmental data and models. • Environmental knowledge generation requires addressing semantic and pragmatic aspects. • Knowledge formalization enable transparency and reusability of scientific workflows. [ABSTRACT FROM AUTHOR]

Low-temperature thermal desalination (LTTD) process uses naturally available ocean thermal gradient that is environmentally friendly with the advantage of minimum maintenance. The process deals with evaporating the warmer surface seawater at low pressures and condensing the resultant vapour using deep sea cold water available at about 350-400 m below sea level. Ministry of Earth Sciences (MoES) - National Institute of Ocean Technology (NIOT) has established LTTD plants with fresh water generation capacity of 1 Lakh Liters Per Day (LLPD) at Agatti, Minicoy and Kavaratti Islands and those plants were being run by UT administration using local manpower. The construction works are in progress for setting up the similar plants in six more islands with a capacity of 1.5 LLPD. In the view of rapidly growing population, tourism activities and to meet the long term needs in remote islands, the design studies were carried out for scaled-up LTTD plants, from 1.5 to 7 LLPD. The studies presented in this paper, facilitate us to instantly identify the size of major components and determine the preliminary cost for implementation for any capacity of the plant up to 7 LLPD, which ultimately results in significant reduction in design lead time. [ABSTRACT FROM AUTHOR]

Earth science data are being collected for various science needs and applications, processed using different algorithms at multiple resolutions and coverages, and then archived at different archiving centers for distribution and stewardship causing difficulty in data discovery. Curation, which typically occurs in museums, art galleries, and libraries, is traditionally defined as the process of collecting and organizing information around a common subject matter or a topic of interest. Curating data sets around topics or areas of interest addresses some of the data discovery needs in the field of Earth science, especially for unanticipated users of data. This paper describes a methodology to automate search and selection of data around specific phenomena. Different components of the methodology including the assumptions, the process, and the relevancy ranking algorithm are described. The paper makes two unique contributions to improving data search and discovery capabilities. First, the paper describes a novel methodology developed for automatically curating data around a topic using Earth science metadata records. Second, the methodology has been implemented as a stand-alone web service that is utilized to augment search and usability of data in a variety of tools. [ABSTRACT FROM AUTHOR]

In this paper we provide a critical review of the studies conducted on the geology of Rome since the first half of the 20th century, aimed at presenting an updated state of the art on the stratigraphy of this area. Following this introductory summary, we present a complete reconstruction of the geological evolution and the resulting chrono-litho-stratigraphic setting of the greater area of Rome, according to a series of works that in the last 20 years have adopted an innovative methodological approach based on the conceptual model of aggradational successions deposited in response to sea-level rise during the glacial terminations, and on the strict geochronologic constraints to the sedimentary record achieved by paleomagnetic investigation of clay sections and 40 Ar/ 39 Ar dating of interbedded volcanic materials. We also present a complete overview on the chronostratigraphy of the two volcanic districts of Colli Albani and Monti Sabatini, located SE and NW of Rome respectively, that has been achieved integrating the field work with the large number of radiometric ages provided in these years on their eruptive products. Moreover, we propose a revised stratigraphic column to compare the most recent official 1:50,000 and 1:10,000 geologic mapping of Rome, which is intended as a tool of correlation for an international audience of Quaternary scientists to approach the study of this area. A detailed discussion of the proposed revisions is also provided as supplementary information to this paper. [ABSTRACT FROM AUTHOR]

In this paper some mistakes arising in Singh and Mogi (2010) that are: (1) wrong formulation of the intrinsic impedance of the layers of an N-layered earth (Z i ) and reflection coefficient of the EM wave in TM-mode (r TM ), (2) using wrong and the very same algorithms for computing reflection coefficients of the EM wave in both the TE- and the TM-mode (r TE and r TM ) and (3) using flawed algorithms for computing phase and normalized phase values, relating to electric and magnetic components of the EM wave, are noted and corrected form of these mistakes are presented. Moreover, in order to illustrate how these mistakes can affect forward modeling results different two- and three-layered earth models, the same as the models used in Singh and Mogi (2010), are chosen; afterwards EMDPLER and corrected version of this program, presented in this paper titled "EMDPLER_Corr", are conducted on these models and real and imaginary parts of H z and H y components of the magnetic field intensity, their normalized amplitudes ( | H z / H z 0 | and | H y / H y 0 | ) and the corresponding normalized phases are computed, plotted versus frequency and compared with each other. [ABSTRACT FROM AUTHOR]

Data about the Earth, like in many other domains, are too difficult to access. In order to perform some insight-gaining task a series of steps has to be performed which often require a spectrum of detail technology skills which are not related to the original Earth science task on hand. Special-purpose file formats with sometimes rather peculiar mechanics, juggling with horizontal, vertical, and time reference systems, and scaling up processing to large amounts of data are just a few of such common issues. One reason is that data often are provided in a more generator-centric (where generator can be a sensor or a program, such a weather forecast) than user-centric manner, which might be called "too upstream". As is well-known, this hinders EO exploitation significantly, making such tasks impossible to conquer for non-experts and tedious for experts. For the desirable, user-friendly opposite the term Analysis-Ready Data (ARD) has been coined by the USGS Landsat team and has gone viral since. However, despite significant work, such as in CEOS, and visible progress – ultimately it is by no means clear what ARD exactly means and how it can be achieved. In this paper, we take a fresh look focusing on spatio-temporal raster data, i.e., datacubes, modeled as coverages according to the authoritative OGC and ISO standards. The Holy Grail of this study is automatic data fusion of Earth data. Based on long-term own practice (and suffering) we list shortcomings and propose ways forward, including research and standardization directions. • Spatio-temporal geo data remain underexploited due to the barriers; our research on ARD attempts to overcome this. • While most research is metadata centric we look at both data and metadata and propose solutions and research needs. • Findings are applied to three challenges: systematic for service quality parameters, automated data fusion, and ML. • Based on the OGC/ISO coverage/datacube standards. • Based on own experience in datacube implementation and standardization. [ABSTRACT FROM AUTHOR]

Centroid moment tensor (CMT) determination in intraplate regions like Brazil can be very difficult, because earthquakes are often recorded just at few and distant stations. This paper introduces a methodology for datasets like that. The methodology is based on waveform inversion in which each source-station path has its own velocity model. The 1-D path-specific velocity models are derived from the Rayleigh- and Love-wave dispersion curves. The waveform inversion is accompanied by posterior check of numerous P-wave first-motion polarities. An important innovation is the use of so-called frequency range test. The test basically consists in calculating CMT's for many different frequency ranges to assess the stability and uncertainty of the solution. The method is validated on two Brazilian earthquakes and a well-known Greek event. An offshore event (mb 5.2) in SE Brazil is inverted with four stations, at epicentral distances 300–400 km. The other Brazilian earthquake (mb 4.8 in Central Brazil) is even more challenging – only two broadband stations at 800–1300 km are at disposal for waveform inversion. The paper unambiguously demonstrates that the path-specific velocity models significantly increase the reliability of the CMT's. While standard models (e.g. IASP91) typically allow waveform modeling up to epicentral distances of the order of a few (∼10) minimum shear wavelengths (MSW), using the path-specific velocity models we successfully inverted waveforms up to > 20 MSW. Single-station waveform inversions are thoroughly tested, but multi-station joint inversions are shown to be preferable. The new methodology of this paper, providing a reasonable estimate of focal mechanisms and their uncertainties in case of highly limited waveform data, may find broad applicability in Brazil and elsewhere. [ABSTRACT FROM AUTHOR]

This paper presents the earth science program SinoProbe in China, especially the deep continental scientific drilling equipment: “Crust 1” 10k ultra-deep scientific drilling rig and 4 indigenous key equipment: Topdrive system, Pipe handler, Hydraulic catwalk and Iron roughneck. These equipment can save auxiliary time, improve drilling efficiency and reduce labor intensity. Components and technical parameters were also introduced. “Crust 1” was deployed to drill through the Cretaceous continental strata of continental scientific drilling well: Songliao Basin Drilling Project (CCSD-SKII), which is the deepest scientific drilling program in China. Casing program was also introduced in this paper. Automated equipment performs a critical function in CCSD-SKII, the application can provide experience for furthermore scientific drilling program with designed well depth over 10,000 m in China. [ABSTRACT FROM AUTHOR]

A sound understanding of the various factors influencing and associated with the formation of sinkholes or subsidences on dolomite land is essential for the selection of appropriate rehabilitation methods. The investigation and rehabilitation of numerous sinkholes and subsidences located on dolomite in the East Rand of South Africa, created an opportunity to develop a broad based understanding of different karst environments, their susceptibility to sinkhole and subsidence formation and best practice rehabilitation methods. This paper is based on the guidelines developed whereby the geological model of the sinkhole or subsidence is used to recommend an appropriate rehabilitation method. Nine typical geological models with recommended rehabilitation methods are presented in this paper. [ABSTRACT FROM AUTHOR]

To bibliometrically analyze karst-related studies from 1990 to 2016. We collected data, and our findings revealed that the number of documents, authors, research institutes, participant countries, and English references dominant increased for karst-related studies. While geology, water resources, and ecology were leading categories of karst-related studies, environmental earth science karst-related papers were the highest. To quantitatively and qualitatively examine karst-related research documents, we used spatiotemporal, international collaboration, yields, and GDP characteristics to determine global trends in karst-related studies. This study provides quantitatively and qualitatively examine karst-related research documents to determine global trends in karst-related studies and the direction of future studies. [ABSTRACT FROM AUTHOR]

Over the past decade, physical and chemical analyses have been widely applied to the study of rock art contexts, particularly to examine the composition of rock art paintings and for direct radiometric dating. Different sampling and analytical methods have been applied to rock art from different parts of the world. However, in Africa these analyses are still at an embryonic stage. The results are often problematic in terms of reliability, mainly as concerns the chronology. This is due to a wide range of fossil and active biodegradation processes affecting rock surfaces and pigments; such processes are still widely underestimated. This paper aims to discuss the state of the art of the physical and chemical analyses undertaken on African rock art contexts, and the urgent need to establish protocols and best practices for sampling and analysis. The preliminary results of a new project in southern Ethiopia are presented here as an example of an integrated study of a rock art context, combining Archaeology and Earth Sciences. Preliminary field observations and SEM-EDS analyses, run on samples from two rock shelters in the Borana area, reveal the presence of a complex set of physical, chemical, and biological weathering processes with manifold effects on the rock art evidence. [ABSTRACT FROM AUTHOR]

The Global Navigation Satellite System Reflectometry (GNSS-R) has been proven to be a powerful technique for retrieving geophysical parameters of ocean and land. Airborne GNSS-R is an important experimental platform, because it is not only needed as validation for spaceborne application, but also possesses the advantages to be capable of remote sensing of small and medium scale targets, such as rivers and lakes. This paper presents an overview of China's airborne GNSS-R campaign conducted on May 30, 2014, in Henan. The campaign has two objectives, i.e.: (1) to examine the capability of a GNSS-R payload developed by National Space Science Center, Chinese Academy of Sciences (NSSC, CAS) for airborne observations and (2) to study the algorithms for soil moisture and river remote sensing, including altimetry and flow velocity measurement. A previous paper has presented results of soil moisture retrieval as part I, and in this paper, initial results of the Yellow River remote sensing are presented as part II. This paper presents the river altimetry results and explores a new potential application of GNSS-R technology, which is used to detect the flow velocity of the river. The river surface height results observed by code delay altimetry method were consistent with the height results of GPS dual-frequency differential positioning altimetry. The GNSS-R altimetry results showed that decimeter level heights were achieved in 1-min sliding average. Comparing with in situ measurements, the GNSS-R flow velocity result was reasonable; the error was about 0.027 m/s, which indicated the validity and feasibility of using GNSS-R technique to detect river flow velocity. [ABSTRACT FROM AUTHOR]

Planetary geomorphology is the study of extraterrestrial landscapes. In recognition of the promise for productive interaction between terrestrial and planetary geomorphologists, the 45th annual Binghamton Geomorphology Symposium (BGS) focused on Planetary Geomorphology. The aim of the symposium was to bring planetary and terrestrial geomorphologists together for symbiotic and synthetic interactions that would enrich both subdisciplines. In acknowledgment of the crucial role of terrestrial field work in planetary geomorphology and of the BGS tradition, the symposium began with a field trip to the Appalachian Mountains, followed by a dinner talk of recent results from the Mars Surface Laboratory. On Saturday and Sunday, the symposium was organized around major themes in planetary geomorphology, starting with the geomorphic processes that are most common in our Solar System—impact cratering, tectonism, volcanism—to set the stage for other geomorphic processes, including aeolian, fluvial, lacustrine, and glacial/polar. On Saturday evening, the banquet talk provided an historical overview of planetary geomorphology, including its roots in the terrestrial geosciences. The symposium concluded with a full-afternoon tutorial on planetary geomorphologic datasets. This special issue of Geomorphology consists of papers by invited authors from the 2014 BGS, and this introduction provides some context for these papers. [ABSTRACT FROM AUTHOR]

With the launch of the Gravity field and Ocean Circulation Explorer (GOCE) in 2009 the science in gravity got another boost. After the time-lapse and long-wavelength studies from Gravity Recovery and Climate Experiment (GRACE) a new sensor was available for determination of the Earth's gravity field and geoid with high accuracy and spatial resolution. Equipped with a 6-component gradiometer and flying at an altitude of 260 km and less GOCE provides the most detailed measurements of Earth's gravity from space ever. On top, GOCE also provides gravity gradients, i.e., the three-dimensional second derivatives of the gravitational potential. This paper provides a review of the results presented at the 'GOCE solid Earth workshop' at the University of Twente, The Netherlands (2012), where an overview was given of the present status of the data models, and applications with GOCE which form the basis for this special issue and the review in this paper. An introduction will be given to the GOCE satellite followed by an overview of GOCE data and gravity models. The present state of GOCE related research in geodesy, oceanography and solid Earth sciences indicates the first steps taken to integrate GOCE in the different application fields. For all three fields an overview is given on the most recent scientific results and developments, and first results specifically focusing on these studies where GOCE data has made a unique contribution and provides insights that would not have been possible without GOCE. [ABSTRACT FROM AUTHOR]

Moment magnitude ( M W ) determinations from the online GCMT Catalogue of seismic moment tensor solutions (GCMT Catalog, 2011) have provided the bulk of M W values in the ISC-GEM Global Instrumental Reference Earthquake Catalogue (1900–2009) for almost all moderate-to-large earthquakes occurring after 1975. This paper describes an effort to determine M W of large earthquakes that occurred prior to the start of the digital seismograph era, based on credible assessments of thousands of seismic moment ( M 0 ) values published in the scientific literature by hundreds of individual authors. M W computed from the published M 0 values (for a time period more than twice that of the digital era) are preferable to proxy M W values, especially for earthquakes with M W greater than about 8.5, for which M S is known to be underestimated or “saturated”. After examining 1,123 papers, we compile a database of seismic moments and related information for 1,003 earthquakes with published M 0 values, of which 967 were included in the ISC-GEM Catalogue. The remaining 36 earthquakes were not included in the Catalogue due to difficulties in their relocation because of inadequate arrival time information. However, 5 of these earthquakes with bibliographic M 0 (and thus M W ) are included in the Catalogue’s Appendix. A search for reliable seismic moments was not successful for earthquakes prior to 1904. For each of the 967 earthquakes a “preferred” seismic moment value (if there is more than one) was selected and its uncertainty was estimated according to the data and method used. We used the IASPEI formula (IASPEI, 2005) to compute direct moment magnitudes ( M W [ M 0 ]) based on the seismic moments ( M 0 ), and assigned their errors based on the uncertainties of M 0 . From 1900 to 1979, there are 129 great or near great earthquakes ( M W ⩾ 7.75) – the bibliographic search provided direct M W values for 86 of these events (or 67%), the GCMT Catalog provided direct M W values for 8 events (or 6%), and the remaining 35 (or 27%) earthquakes have empirically determined proxy M W estimates. An electronic supplementary file is included with this paper in order to provide our M 0 / M W catalogue of earthquakes (1904–1978) from the published literature, and a reference list of the 1,123 papers that we examined. [ABSTRACT FROM AUTHOR]

Global geodetic observatories (GGO) play an increasingly important role both for scientific and societal applications, in particular for the maintenance and evolution of the reference frame and those applications that rely on the reference frame for their viability. The International Association of Geodesy (IAG), through the Global Geodetic Observing System (GGOS), is fully involved in coordinating the development of these systems and ensuring their quality, perenniality and accessibility. This paper reviews the current role, basic concepts, and some of the critical issues associated with the GGOs, and advocates for their expansion to enhance co-location with other observing techniques (gravity, meteorology, etc). The historical perspective starts with the MERIT campaign, followed by the creation of international services (IERS, IGS, ILRS, IVS, IDS, etc). It provides a basic definition of observing systems and observatories and the build up of the international networks and the role of co-locations in geodesy and geosciences and multi-technique processing and data products. This paper gives special attention to the critical topic of local surveys and tie vectors among co-located systems in sites; the agreement of space geodetic solutions and the tie vectors now place one of the most significant limitations on the quality of integrated data products, most notably the ITRF. This topic focuses on survey techniques, extrapolation to instrument reference points, computation techniques, systematic biases, and alignment of the individual technique reference frames into ITRF. The paper also discusses the design, layout and implementation of network infrastructure, including the role of GGOS and the benefit that would be achieved with better standardization and international governance. [ABSTRACT FROM AUTHOR]

The availability of Raman spectroscopy in a powerful analytical scanning electron microscope (SEM) allows morphological, elemental, chemical, physical and electronic analysis without moving the sample between instruments. This paper documents the metrological performance of the SEMSCA commercial Raman interface operated in a low vacuum SEM. It provides multiscale and multimodal analyses as Raman/EDS, Raman/cathodoluminescence or Raman/STEM (STEM: scanning transmission electron microscopy) as well as Raman spectroscopy on nanomaterials. Since Raman spectroscopy in a SEM can be influenced by several SEM-related phenomena, this paper firstly presents a comparison of this new tool with a conventional micro-Raman spectrometer. Then, some possible artefacts are documented, which are due to the impact of electron beam-induced contamination or cathodoluminescence contribution to the Raman spectra, especially with geological samples. These effects are easily overcome by changing or adapting the Raman spectrometer and the SEM settings and methodology. The deletion of the adverse effect of cathodoluminescence is solved by using a SEM beam shutter during Raman acquisition. In contrast, this interface provides the ability to record the cathodoluminescence (CL) spectrum of a phase. In a second part, this study highlights the interest and efficiency of the coupling in characterizing micrometric phases at the same point. This multimodal approach is illustrated with various issues encountered in geosciences. [ABSTRACT FROM AUTHOR]

The IUPAC-IUGS joint Task Group "Isotopes in Geosciences" recommends a value of (106.25 ± 0.38) Ga for the half-life of 147Sm, and a corresponding decay constant λ 147 = (6.524 ± 0.024) × 10−12 a−1, both with a coverage factor k = 2. For the extinct radionuclide 146Sm two very different half-lives are used in the scientific community (c. 68 and 103 Ma), to such a degree that no consensus value can be endorsed at present by the Task Group. Pending dedicated re-investigations it is recommended that papers using the 146Sm decay to quantify the cosmo/geological evolution of (extra)terrestrial samples perform a twin set of calculations using both proposed half-lives. [ABSTRACT FROM AUTHOR]

The study of paleogroundwater on a timescale of several thousands to a million years is interesting both in terms of understanding the aquifer system itself and water resource management. It may also provide valuable information about the paleoclimate. In their seminal work, Loosli and Oeschger (1969) identified 81Kr as an ideal age tracer for paleogroundwater up to one million years old. Since then radiokrypton dating has been a desirable tool. Recent developments in the Atom Trap Trace Analysis method have made radiokrypton dating available to the earth science community at large. In this paper we will show the current status for radiokrypton dating with an emphasis on sample size reduction. The latest advancements have allowed analysis with only 20 kg of water. Moreover, we will review selected studies that have been carried out on some large aquifers with old groundwater around the world using this new tool. [ABSTRACT FROM AUTHOR]