Numerical simulations of the governing geophysical processes are crucial for geothermal applications in order to characterize the subsurface. This characterization presents us with major challenges ranging from the correct physical and geometrical characterization to the quantification of uncertainties. Quantifying rock physics uncertainties and performing other probabilistic inverse methods is, even with current state-of-the-art finite element solver and high-performance infrastructures, computationally not feasible for complex basin- and reservoir-scale geothermal applications due to the large spatial, temporal,...

Information about the recent stress state of the upper crust is important for understanding tectonic processes and for the use of the underground in general. A currently important topic, the search for a radioactive waste deposit, illustrates this relevance, as the crustal stress state is decisive for the short and long-term safety of a possible repository. For example, the integrity of the host rock due to the activation or reactivation of faults and associated fluid...

Geo.X is the research network for geosciences in the Berlin and Potsdam metropolitan region and integrates five universities and six extramural research institutions. Our partners are committed to a FAIR and sustainable handling of research data and infrastructures. For this purpose, we established a search portal for the geoscientific laboratory infrastructure and related research data of the network partners (LI@Geo.X). The portal aims to increase the visibility and accessibility of the partner institutions’ infrastructures, data,...

Directivity of ground motion in the near-field region of large earthquakes is a well-observed phenomenon whose impacts can be particularly detrimental to structures that sit close to an earthquake rupture. Predictive models of this phenomenon and its amplifying effect on ground motion have been available for more than 20 years, with recent projects such as the Next Generation Attenuation West 2 (NGA-West2) yielding several advanced models for application in probabilistic seismic hazard analysis (PSHA). Despite...

This position paper was drawn up by the Task Group Research Software of the Helmholtz Association Open Science Working Group and adopted by the Open Science Working Group on November 21, 2019.

Speleothems provide a great opportunity for paleoclimate reconstruction because they occur almost worldwide and can be dated very precisely using the U-series disequilibrium method. The most commonly used climate proxies are stable isotope values (δ18O and δ13C) and trace elements. However, these are influenced by a variety of surface and in-cave processes, which results in a non-trivial interpretation of the speleothem proxy signals. The last glacial period and in particular the Marine Isotope Stage (MIS)...

Additional file 1: Table S1. Major (wt%) and trace element (ppm) concentrations of the outcrop and reservoir samples. Table S2. Chemical indices of the outcrop and reservoir samples. Table S3. Cross-correlations of selected major, trace, and rare-earth elements. Table S4. Concentration changes in % of major and trace elements of the reservoir samples. Table S5. P-values obtained during Kruskal–Wallis tests.

Additional file 1: Table S1. Major (wt%) and trace element (ppm) concentrations of the outcrop and reservoir samples. Table S2. Chemical indices of the outcrop and reservoir samples. Table S3. Cross-correlations of selected major, trace, and rare-earth elements. Table S4. Concentration changes in % of major and trace elements of the reservoir samples. Table S5. P-values obtained during Kruskal–Wallis tests.

As the digitalization of research and teaching progresses, the number of software solutions developed at scientific institutions and used for the purpose of knowledge production is increasing. The accessibility and reuse of scientific results called for under the heading “open science” can be ensured in many fields only if, in addition to research data, program code is also made openly accessible. The present guide is addressed to decision-makers at the Helmholtz Centers who deal with...

The distribution of earthquakes in time and space is seldom stationary. In low-seismicity regions, non-stationarity and data scarcity may preclude a significant statistical analysis. We investigate the performance of traditional stationary Poisson forecasts (such as smoothed-seismicity models [SSM]), with applications in Probabilistic Seismic Hazard Assessment, in terms of the available training data. We design bootstrap experiments that use multiple pairs of consecutive training-forecast windows of a catalogue to: (i) analyse the lowest available training data...

In Central Europe, the largest geothermal potential resides in the crystalline basement rock with important hotspots in tectonically stressed areas. To better harvest this energy form under sustainable, predictable and efficient conditions, new focused, scientific driven strategies are needed. Similar to other geo-technologies, the complex processes in the subsurface need to be investigated in large-scale facilities to ensure environmental sustainability. The proposed new underground research laboratory GeoLaB (Geothermal Laboratory in the Crystalline Basement) will address...

Since the discipline of ‘geochemistry’ was first defined in 1838, geochemical data has been pervasively acquired and used in the Earth, environmental and planetary sciences and become fundamental for understanding past, present, and future processes in natural systems. Initially, geochemical data was published in hard-copy literature, but as analytical systems became computerised, major digital databases emerged (EarthChem, PetDB, OZCHEM and GEOROC) which revolutionised data access. They have proven the power of re-use of geochemical data...

Hydro-mechanical (HM) simulations are essential aspects of geothermal reservoir studies to assess the heat production and the associated-environmental impacts, such as seismicity. HM simulations are numerically expensive (especially for large-scale simulations) since they require a relatively fine mesh to capture the complex interplay between the fluid-flow and geomechanical processes. This aspect makes it difficult to perform detailed studies on uncertainties in HM simulations. In this work, we present a comprehensive review and numerical demonstrations about...

Measured data of the Earth’s surface heat flow are rare observables for heat transport processes in the Earth interior. Precise knowledge of heat flow is thus fundamental (i) to describe the Earth’s thermal field, (ii) to decipher plate-tectonic and geodynamic processes and (iii) to understand natural or artificial utilized geological thermal systems – across all spatial scales and timely domains. Heat flow data are documented in more than 1,400 publications and are collected by the...

Nitrate is one of the dominant chemical pollutants of groundwater, and there is a need to mitigate groundwater pollution in rural, urban and industrial terrains in an aquifer system. The study assesses the extent of nitrate pollution in the Densu Basin because of its predominance in agriculture and urbanized vicinities by employing robust techniques for estimating both the natural background and human-induced concentrations. The statistical methods used to estimate these concentrations are the pre-selection method,...

Fractures are the predominant flow pathways in low-permeability rocks. Understanding the fluid-rock interactions that occur in rock fractures and their effects on fracture aperture variations is important for assessing the sustainability of reservoir productivity. This study presents two long-term flow-through experiments with fractured pure quartz sandstones to investigate how fluid composition affects fracture changes over time. One sample was continuously flowed through with fluids (DI or Si-rich fluid), while the other sample was subjected to...

The save and effective storage of hydrogen in geological formations is an important part towards the implementation of renewable energy use. Due to fluctuating power supply from wind or solar plants, it is envisaged to use excess energy for electrolytical hydrogen production and the subsequent temporary storage in geological formations, as buffer for energy at “high-demand-low-production-times”. The preferred geological storage formations are either salt deposits or porous sandstones with a gas-tight caprock. To date, these...

When Western Gondwana broke apart into the South American and African continents ca.120 Ma ago, some of its cratons were broken apart as well. Following the isopycnic hypothesis, their long-term stability and often neutral to positive buoyancy can be explained by the counteracting effects of cooling (density increase) and iron depletion (density decrease). To separate these effects, we created the presented models following an iterative integrated approach using mainly seismic and gravity data. In the...