Pedological and geochemical investigations at the „Red Outcrop“ of Langenlois (Lower Austria)

In einem Aufschluss von Löss-Paläoboden-Sequenzen über Rehberger Amphibolit NW von Langenlois wurden sechs Bodenprofile (Lois 1 bis Lois 6) beprobt und pedologisch, mineralogisch und geochemisch analysiert. Am Profil Lois 7 wurden bodenmikromorphologische Untersuchungen durchgeführt. Zwei Bodenprofile (Lois 1 und 2) haben sich über Amphibolit entwickelt, zwei über einer Amphibolit/Marmor-Wechsellagerung (Lois 5 und 6) und drei Bodenprofile sind Sequenzen von polyzyklischen Paläoböden mit fossilen Bodenhorizonten ohne unterlagerndes kristallines Gestein (Lois 3, 4 und 7). In den Profilen Lois 1–4 und Lois 7 konnten intensive Karbonatanreicherungen beobachtet werden. Diese hohen Mengen an Karbonat können nicht Produkt einer rezenten Bodenbildung sein, sondern sprechen für eine Infiltration von ursprünglich das Profil überlagernden kalzitreichen Sedimenten (Löss), die erodiert wurden. Zudem wurde in Profil Lois 2 ein Kalksinter angetroffen. Dieser Kalksinter könnte aus der Verwitterung der im Profil Lois 6 aufgeschlossenen Marmorlagen stammen. Die Kalksinter-Schicht scheint die Stoffflüsse zwischen unterliegendem Gestein und Solum in den Profilen Lois 1 und 2 mehr oder weniger zu unterbinden, was auch durch die Ergebnisse der geochemischen Analytik unterstrichen wird. In den fossilen Horizonten wurden auch ältere Anzeichen von Tonverlagerung in Form von Tonkutanen über den Aggregaten und darüber hinaus leichte Pseudovergleyungserscheinungen angetroffen. Die mächtigen Profile ohne aufgeschlossenes Grundgebirge (Lois 3, 4 und 7) weisen mehrere polyzyklische Sedimentationsphasen und dadurch mehrere Generationen von fossilen Horizonten auf. Aufgrund der bodenmikromorphologischen Analyse können die Böden vom „Roten Aufschluss“ altersmäßig im unteren bis mittleren Pleistozän oder älter angesiedelt werden.researc

Thermophysical Properties of a Subsoil Drill Core for Geothermal Energy Applications

Urban heat islands (UHI) occur especially in inner-city areas due to small green areas, an excess of high solar heat, and low air circulation. One solution is the “harvesting” of excess solar urban heat through shallow absorber ducts, which are then used in borehole heat exchanger (BHE) fields for later use for heat or cold storage. Knowing the thermophysical properties of the subsurface as accurately as possible is of great importance in the design and configuring of a borehole heat exchanger field as a thermal energy storage system. In this study, a subsoil drill core from a BHE, with a depth of 80 m, was used to determine temperature dependent effective thermal conductivity based on the heat flow meter method, the specific heat capacity based on differential scanning calorimetry, and thermal expansion based on dilatometry in moist and dry states. The results have shown that the actual moisture content of the subsoil sample has a strong impact on the thermal conductivity, as well as on the heat capacity. Thermal expansion measurements have shown the influence of the drying process on the shrinkage of drill core samples and the low thermal expansion of the dry subsoil itself

Article Design Framework and Laboratory Experiments for Helix and Slinky Type Ground Source Heat Exchangers for Retrofitting Projects

The focus of the experimental work was on shallow spiral geothermal heat exchanger configurations. Real-scale experiments were carried out for vertically oriented spiral collectors (helix) in sand and soil. One objective was to develop a measurement concept in laboratory environment to create a framework for a validated database. This database serves as the basis for further and new development of engineering design tools. To achieve the highest possible data-point density in the observed environment, temperature sensors and a fiber-optic temperature measurement system (DTS) were used. Soil probes were taken in situ before and after the measurements and analyzed at a thermophysical laboratory to determine material properties. The heat flow was controlled by an electric heating cable, which was installed in the form of a spiral-shaped heat exchanger in a 1 m3 container. To guarantee constant boundary conditions, the measurements were carried out in a climate chamber at a defined ambient temperature. The evaluation of the transient response behavior is spatially resolved. The results are coordinate-based temperature points, which describe temperature gradients in all axes of the container over time, which are combined with known soil properties. The collected data was used to develop computational fluid dynamic (CFD) models, which are used to extend the variety of geometry and soil configurations for developing new design tools. Raw data available for download here

Scale-fragment formation impairing geothermal energy production: interacting H2S corrosion and CaCO3 crystal growth

Abstract Background Mineral precipitates (scaling) from deep saline thermal waters often constitute a major problem during geothermal energy production. The occurrence of scale-fragments accumulating and clogging pipes, filters, and heat exchangers is of particular concern regarding an efficient energy extraction. Methods Carbonate scale-fragments from different sections of two geothermal power plants were collected and studied in a high-resolution scaling forensic approach comprising of microstructural characterization, elemental mapping, and stable carbon and oxygen isotope transects. The solid-phase analyses were evaluated in the context of natural environmental and technical (man-made) production conditions. Results and discussion Our results indicate an interaction of metal sulfide mineral layers mainly from H2S corrosion of the steel pipes and CaCO3 nucleation and crystal growth. A conceptual model of scale-fragment development addresses the relevance of two key interfaces: 1) the corrosion layer between the steel substrate and calcite scale and 2) the scale surface versus thermal fluid flow. The corrosion products constitute an attractive crystallization substrate of brittle and mechanically weak consistency. A rough carbonate scale surface tends to induce (micro) turbulences and increased flow resistance (frictional forces). These factors promote partial exfoliation, scale-fragment mobilization, and rapid clogging. This investigation highlights the potential of detailed petrographic and geochemical analyses of mineral precipitates for evaluating favorable versus unfavorable processes in geotechnical environmental settings

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Additional file 1. Additional figures and tables

Earthquakes in Switzerland and surrounding regions during 2014

During 2014, 817 earthquakes and 180 quarry blasts were detected and located in the region under consideration. An additional 160 earthquakes with ML≤1.0 were located using supplementary analysis techniques. The number of located earthquakes in 2014 was the largest since the installation of a seismic network in Switzerland in 1975. This unusually large number is mainly due to the occurrence of two vigorous earthquake sequences, and the local reduction of the earthquake detection thresholds of the Swiss seismic network. With a total of 22 earthquakes of ML≥2.5, the seismic activity of larger and potentially felt events was close to the average of 23 earthquakes over the previous 39years. The most noteworthy seismicity was the earthquake sequence near Diemtigen, west of Lake Thun, where more than 270 events were located between April and December. High-precision hypocenter relocation was applied to image the spatio-temporal evolution of this seismicity. The sequence culminated in an M L 3.2 event in October, which was felt in the region of Lake Thun and Bern. Other cases of earthquakes felt by the public include earthquakes in the region of Biel (ML 3.2), in Vallorcine (ML 3.2), and in Stalden (ML 3.0). Finally, a small but unusually deep earthquake was recorded beneath the Jura Mountains. Focal depth, apparent velocities, as well as waveform characteristics of this earthquake are consistent with a source in the uppermost mantle. This earthquake is the first reliable record of a sub-Moho event ever observed in Switzerland. Zusammenfassung: Dieser Bericht des Schweizerischen Erdbebendienstes stellt eine Zusammenfassung der im Vorjahr in der Schweiz und Umgebung aufgetretenen Erdbeben dar. Im Jahr 2014 wurden im erwähnten Gebiet 817 Erdbeben sowie 180 Sprengungen erfasst und lokalisiert. Weitere 160 Beben mit Magnituden ML≤1.0 wurden mit Hilfe von zusätzlichen Auswertungsmethoden lokalisiert. Die Zahl der in 2014 lokalisierten Erdbeben ist die höchste seit der Installation eines seismischen Messnetzes in der Schweiz im Jahre 1975. Diese außergewöhnlich hohe Zahl erklärt sich vor allem durch das Auftreten zweier äußerst aktiver Erdbebensequenzen und der lokalen Absenkung der Detektionsschwelle für Erdbeben durch die Verbesserung des seismischen Messnetzes der Schweiz. Mit 22 Beben der Magnitude ML≥2.5 lag die seismische Aktivität von stärkeren und potentiell spürbaren Ereignissen im Jahr 2014 nahe am Durchschnitt von 23 Beben pro Jahr der vergangenen 39 Jahren. Bemerkenswert war die Erdbebensequenz von Diemtigen, westlich vom Thunersee bei der mehr als 270 Ereignisse zwischen April und Dezember lokalisiert wurden. Hochauflösende Erdbebenlokalisierung wurde verwendet, um die räumliche und zeitliche Entwicklung dieser Erdbebenserie abzubilden. Ein Beben der Magnitude ML 3.2 bildete den Höhepunkt der Sequenz im Oktober. Dieses wurde in der Region des Thunersees und Bern deutlich verspürt. Weitere Erdbeben, die von der Bevölkerung verspürt wurden, waren unter anderem die Beben in der Region Biel (ML 3.2), in Vallorcine (ML 3.2) und in Stalden (ML 3.0). Darüberhinaus wurde ein schwaches, aber ungewöhnlich tiefes Erdbeben unterhalb des Juras registriert. Sowohl Herdtiefe, Scheingeschwindigkeiten und Charakter der Wellenformen weisen auf einen Erdbebenherd im obersten Mantel hin. Damit ist dieses Ereignis die erste verlässliche Beobachtung eines Erdbebens unterhalb der Moho in der Schweiz. Resumé: Ce rapport du Service Sismologique Suisse résume l'activité sismique en Suisse et dans ses régions environnantes au cours de l'année 2014. Pendant cette période, 817 tremblements de terre et 180 tirs de carrière ont été détectés et localisés dans la région. 160séismes additionnels de magnitude ML≤1.0 ont été localisés à l'aide de moyens supplémentaires d'analyse. Le nombre des évènements localisés en 2014 constitue un record depuis 1975, date de l'installation du réseau sismologique en Suisse. Ce grand nombre inhabituel peut être principalement expliqué par l'occurrence de deux séquences sismiques importantes et par la diminution locale des niveaux de détection résultant des améliorations apportées au réseau sismologique suisse. Avec un total de 22séismes de magnitude ML≥2.5, le nombre des évènements les plus forts et potentiellement ressentis est proche de la moyenne annuelle de 23 tremblements de terre enregistrée pendant les 39 dernières années. La sismicité la plus notable est la séquence sismique qui a eu lieu près de Diemtigen, à l'ouest du lac de Thoune, où plus de 270 évènements ont été localisés entre avril et décembre. La relocalisation de grande précision des hypocentres a permis d'imager l'évolution spatio-temporelle de cette sismicité. La séquence est dominée par un séisme de magnitude ML 3.2 en octobre qui a été ressenti dans la région du lac de Thoune et à Berne. D'autres tremblements de terre ont été ressentis par la population, tels que ceux de la région de Bienne (ML 3.2), de Vallorcine (ML 3.2) et de Stalden (ML 3.0). Enfin, un faible mais inhabituel séisme profond a été enregistré dans le Jura. Sa profondeur focale, les vitesses apparentes enregistrées ainsi que les caractéristiques des formes d'ondes de ce tremblement de terre sont en accord avec une source dans le manteau supérieur. Par conséquence, ce tremblement de terre est le premier enregistrement fiable d'un évènement ayant eu lieu sous le Moho en Suisse

Earthquakes in Switzerland and surrounding regions during 2014

During 2014, 817 earthquakes and 180 quarry blasts were detected and located in the region under consideration. An additional 160 earthquakes with ML ≤ 1.0 were located using supplementary analysis techniques. The number of located earthquakes in 2014 was the largest since the installation of a seismic network in Switzerland in 1975. This unusually large number is mainly due to the occurrence of two vigorous earthquake sequences, and the local reduction of the earthquake detection thresholds of the Swiss seismic network. With a total of 22 earthquakes of ML ≥ 2.5, the seismic activity of larger and potentially felt events was close to the average of 23 earthquakes over the previous 39 years. The most noteworthy seismicity was the earthquake sequence near Diemtigen, west of Lake Thun, where more than 270 events were located between April and December. High-precision hypocenter relocation was applied to image the spatio-temporal evolution of this seismicity. The sequence culminated in an M L 3.2 event in October, which was felt in the region of Lake Thun and Bern. Other cases of earthquakes felt by the public include earthquakes in the region of Biel (ML 3.2), in Vallorcine (ML 3.2), and in Stalden (ML 3.0). Finally, a small but unusually deep earthquake was recorded beneath the Jura Mountains. Focal depth, apparent velocities, as well as waveform characteristics of this earthquake are consistent with a source in the uppermost mantle. This earthquake is the first reliable record of a sub-Moho event ever observed in Switzerland.ISSN:1661-8734ISSN:1661-872

GEOCHEMISTRY OF EUROPEAN BOTTLED WATER

In Europe, ca. 1900 "mineral water" brands are officially registered and bottled for drinking. Bottled waters is groundwater and is in large parts of the continent rapidly developing into the main supply of drinking water for the general population. This book is the first state of the art overview of the chemistry of groundwaters from 40 European countries from Portugal to Russia, measured on 1785 bottled water samples, equivalent to 1189 distinct bottled water brands from 1247 wells in 884 locations plus an additional 500 tap water samples acquired in 2008 by the network of EuroGeoSurveys experts all across Europe. In contrast to previously available compilations, all chemical data (contained on the enclosed CD) were measured in a single laboratory, under strict quality control with high internal and external reproducibility, affording a single high quality, internally consistent dataset. More than 70 parameters were determined on every sample using state of the art analytical ..