ALBERT

Description: Tectonothermal evolution in the core of an arcuate fold and thrust belt: the south-eastern sector of the Cantabrian Zone (Variscan belt, north-western Spain) María Luz Valín, Susana García-López, Covadonga Brime, Fernando Bastida, and Jesús Aller Solid Earth, 7, 1003-1022, doi:10.5194/se-7-1003-2016, 2016 The tectonothermal evolution of an area located in the core of the Ibero-Armorican Arc (Variscan belt) has been determined by using the conodont colour alteration index (CAI), Kübler index of illite (KI), the Árkai index of chlorite (AI) and the analysis of clay minerals and rock cleavage. The area is part of the Cantabrian Zone (CZ), which represents the foreland fold and thrust belt of the orogen. It has been thrust by several large units of the CZ, what resulted in the generation of a large number of synorogenic Carboniferous sediments. CAI, KI and AI values show an irregular distribution of metamorphic grade, independent of stratigraphic position. Two tectonothermal events have been distinguished in the area. The first one, poorly defined, is mainly located in the northern part. It gave rise to very-low-grade metamorphism in some areas and it was associated with a deformation event that resulted in the emplacement of the last large thrust unit and development of upright folds and associated cleavage ( S 1 ). The second tectonothermal event gave rise to low-grade metamorphism and cleavage ( S 2 ) crosscutting earlier upright folds in the central, western and southern parts of the study area. The event continued with the intrusion of small igneous rock bodies, which gave rise to contact metamorphism and hydrothermal alteration. This event was linked to an extensional episode due to a gravitational instability at the end of the Variscan deformation. This tectonothermal evolution occurred during the Gzhelian–Sakmarian. Subsequently, several hydrothermal episodes took place and local crenulation cleavage developed during the Alpine deformation.

Description: Microstructures and deformation mechanisms in Opalinus Clay: insights from scaly clay from the Main Fault in the Mont Terri Rock Laboratory (CH) Ben Laurich, Janos L. Urai, and Christophe Nussbaum Solid Earth Discuss., doi:10.5194/se-2016-94,2016 Manuscript under review for SE (discussion: open, 0 comments) Scaly clay is a well-known rock fabric that can develop in tectonic systems and that can alter the physical rock properties of a formation. However, internal microstructure and evolution of this fabric remains poorly understood. We examined the scaly microstructure of progressively faulted Opalinus Clay using optical as well as scanning electron microscopy. We present an evolutionary model for scaly clay that is of interest in the evaluation of Opalinus Clay to host radioactive waste.

Description: Structure of Suasselkä Postglacial Fault in northern Finland obtained by analysis of local events and ambient seismic noise Nikita Afonin, Elena Kozlovskaya, Ilmo Kukkonen, and DAFNE/FINLAND Working Group Solid Earth Discuss., doi:10.5194/se-2016-90,2016 Manuscript under review for SE (discussion: open, 0 comments) Understanding inner structure of seismogenic faults and their ability to reactivate is particularly important in investigating continental intraplate seismicity regime. In our study we address this problem using analysis of local seismic events and ambient seismic noise recorded by the temporary DAFNE array in northern Fennoscandian Shield. The main purpose of the DAFNE/FINLAND passive seismic array experiment was to characterize the present-day seismicity of the Suasselkä post-glacial fault (SPGF) that was proposed as one potential target for the DAFNE (Drilling Active Faults in Northern Europe) project. The DAFNE/FINLAND array comprised the area of about 20 to 100 km and consisted of 8 short-period and 4 broad-band 3-component autonomous seismic stations installed in the close vicinity of the fault area. The array recorded continuous seismic data during September, 2011–May, 2013. Recordings of the array have being analyzed in order to identify and locate natural earthquakes from the fault area and to discriminate them from the blasts in the Kittilä Gold Mine. As a result, we found several dozens of natural seismic events originating from the fault area, which proves that the fault is still seismically active. In order to study the inner structure of the SPGF we use cross-correlation of ambient seismic noise recorded by the array. Analysis of azimuthal distribution of noise sources demonstrated that during the time interval under consideration the distribution of noise sources is close to the uniform one. The continuous data were processed in several steps including single station data analysis, instrument response removal and time-domain stacking. The data were used to estimate empirical Green’s functions between pairs of stations in the frequency band of 0.1–1 Hz and to calculate correspondent surface wave dispersion curves. The S-wave velocity models were obtained as a result of dispersion curves inversion. The results suggest that the area of the SPGF corresponds to a narrow region of low S-wave velocities surrounded by rocks with high S-wave velocities. We interpret this low velocity region as a non-healed mechanically weak fault damage zone (FDZ) that remained after the last major earthquake that occurred after the last glaciation.

Description: 4-D imaging of sub-second dynamics in pore-scale processes using real-time synchrotron X-ray tomography Katherine J. Dobson, Sophia B. Coban, Samuel A. McDonald, Joanna N. Walsh, Robert C. Atwood, and Philip J. Withers Solid Earth, 7, 1059-1073, doi:10.5194/se-7-1059-2016, 2016 State-of-the-art synchrotron x-ray imaging was used to observe micron scale transport processes in real time. The 20 Hz 3-D image acquisition rates give experimental data free from motion artefacts, and suitable for detailed quantitative analysis of the dynamic fluid distribution, flow pathways and processes. The method marks a major breakthrough in our ability to capture both sub-second and lower frequency non-equilibrium process in many geological or engineering systems.

Description: Studying local earthquakes in the area Baltic-Bothnia Megashear using the data of the POLENET/LAPNET temporary array Olga Usoltseva and Elena Kozlovskaya Solid Earth, 7, 1095-1108, doi:10.5194/se-7-1095-2016, 2016 We address the problem of seismicity in the intraplate area of northern Fennoscandia using the information on local events recorded by the POLENET/LAPNET seismic array. We relocate the seismic events, calculate a 3-D tomographic P wave velocity model of the uppermost crust and investigate a focal mechanism of the event. Our results demonstrate that the Baltic-Bothnia Megashear is an important large-scale, reactivated tectonic structure that has to be taken into account when estimating seismic hazard.

Description: Combined deep sampling and mass-based approaches to assess soil carbon and nitrogen losses due to land-use changes in karst area of southwestern China Yecui Hu, Zhangliu Du, Qibing Wang, and Guichun Li Solid Earth, 7, 1075-1084, doi:10.5194/se-7-1075-2016, 2016 We quantified the SOC and TN losses induced by land-use changes in a typical karst region of southwestern China. Converting from natural forest to croplands greatly led to SOC and TN losses (as higher as 37.8 %), but the magnitude depended on sampling depth and calculation method. We recommend to account for SOC and TN stocks on equivalent soil mass basis together with deep sampling. This study has significant implications on the projected land management in the degraded karst areas.

Description: Phase segmentation of X-ray computer tomography rock images using machine learning techniques: an accuracy and performance study Swarup Chauhan, Wolfram Rühaak, Hauke Anbergen, Alen Kabdenov, Marcus Freise, Thorsten Wille, and Ingo Sass Solid Earth, 7, 1125-1139, doi:10.5194/se-7-1125-2016, 2016 Machine learning techniques are a promising alternative for processing (phase segmentation) of 3-D X-ray computer tomographic rock images. Here the performance and accuracy of different machine learning techniques are tested. The aim is to classify pore space, rock grains and matrix of four distinct rock samples. The porosity obtained based on the segmented XCT images is cross-validated with laboratory measurements. Accuracies of the different methods are discussed and recommendations proposed.

Description: Pore-scale tomography and imaging: applications, techniques and recommended practice Matthias Halisch, Holger Steeb, Steven Henkel, and Charlotte M. Krawczyk Solid Earth, 7, 1141-1143, doi:10.5194/se-7-1141-2016, 2016 No abstract available.

Description: Active faulting, 3-D basin architecture and Plio-Quaternary structural evolution of extensional basins: a 4-D perspective on the central Apennine chain evolution, Italy Stefano Gori, Emanuela Falcucci, Chiara Ladina, Simone Marzorati, and Fabrizio Galadini Solid Earth Discuss., doi:10.5194/se-2016-103,2016 Manuscript under review for SE (discussion: open, 0 comments) We perfomed geological field survey and seimic recordings of ambient noise to study the evolution of a portion of the central Apennines, in central Italy, over the past few million years. The adopted approach and the analysis of the available information allowed to decipher how the investigated areas evolved, in terms of activity of the faults present there. We also defined that some of the investigated faults are no more major faults, i.e. they are no more able to produce strong earthquakes.

Description: Porosity and permeability determination of organic-rich Posidonia shales based on 3-D analyses by FIB-SEM microscopy Georg H. Grathoff, Markus Peltz, Frieder Enzmann, and Stephan Kaufhold Solid Earth, 7, 1145-1156, doi:10.5194/se-7-1145-2016, 2016 This study improves our understanding of the evolution of pores in shales for modelling transport properties. 3-D microscopy on early and postmature Posidonia Shales showed similar porosities and pore size distributions. Large isolated pore clusters are within carbonates and clay minerals. Pores form during maturation in the postmature-matrix-filling organic matter. Modelled permeabilities are lowest perpendicular to bedding. They decrease with increasing maturity and are comparable to experimental data.

Description: Arrested development – a comparative analysis of multilayer corona textures in metamorphic rocks Paula P. Ogilvie and Roger Lawrence R. L. Gibson Solid Earth Discuss., doi:10.5194/se-2016-97,2016 Manuscript under review for SE (discussion: open, 0 comments) Coronas are vital clues to the presence of arrested reaction in metamorphic rocks. We review formation mechanisms of coronas and approaches utilised to model their evolution in P - T - X space. Forward modelling employing calculated chemical potential gradients allows a far more nuanced understanding of the intricacies that govern metamorphic reaction. These models have critical implications for the limitations and opportunities coronas afford in interpreting the evolution of metamorphic terranes.

Description: Archie's law – a reappraisal Paul W. J. Glover Solid Earth, 7, 1157-1169, doi:10.5194/se-7-1157-2016, 2016 In 1942 Archie discovered equations which have been used ever since to calculate reserves of oil and gas around the world. Two equations exist, one which is theoretically justified, and one which is not. Unfortunately it is the one which is not justified that often gives the best results. This research examines the extent to which the two approaches give differing results, concluding that the Winsauer et al. form of Archie's equations is better for use with data containing systematic errors.

Description: Digital carbonate rock physics Erik H. Saenger, Stephanie Vialle, Maxim Lebedev, David Uribe, Maria Osorno, Mandy Duda, and Holger Steeb Solid Earth, 7, 1185-1197, doi:10.5194/se-7-1185-2016, 2016 Modern estimation of rock properties combines imaging with advanced numerical simulations, an approach known as digital rock physics (DRP). In this paper we suggest a specific segmentation procedure of X-ray micro-computed tomography data with two different resolutions for two sets of carbonate rock samples. These carbonates were already characterized in detail in a previous laboratory study, which we complement with nanoindentation experiments.

Description: Experimental sand burial affects seedling survivorship, morphological traits, and biomass allocation of Ulmus pumila var. sabulosa in the Horqin Sandy Land, China Jiao Tang, Carlos Alberto Busso, Deming Jiang, Ala Musa, Dafu Wu, Yongcui Wang, and Chunping Miao Solid Earth, 7, 1085-1094, doi:10.5194/se-7-1085-2016, 2016 In order to test the tolerance of sandy elm after emergence, an experiment was conducted to evaluate the changes of survivorship, morphological traits and biomass allocation buried by various experimental burial depths. The results showed that partial sand burial did not influence survivorship but increased seedling height, diameter, taproot length, total biomass, and relative growth rates. It decreased total leaf area and changed biomass allocation, transferring more biomass to aboveground.

Description: Simulating stress-dependent fluid flow in a fractured core sample using real-time X-ray CT data Tobias Kling, Da Huo, Jens-Oliver Schwarz, Frieder Enzmann, Sally Benson, and Philipp Blum Solid Earth, 7, 1109-1124, doi:10.5194/se-7-1109-2016, 2016 A method is introduced to implement medical CT data of a fractured sandstone under varying confining pressures into fluid flow simulations to reproduce experimental permeabilities. The simulation results reproduce plausible fracture flow features (e.g. flow channeling, fracture closing/opening) and approximate the actual permeabilities, which are affected by the CT resolution and compositional matrix heterogeneities. Additionally, some recommendations are presented concerning future studies.

Description: Effects of topsoil treatments on afforestation in a dry-Mediterranean climate (southern Spain) P. Hueso-González, J. F. Martínez-Murillo, and J. D. Ruiz-Sinoga Solid Earth Discuss., doi:10.5194/se-2016-98,2016 Manuscript under review for SE (discussion: open, 0 comments) The development of alternative low cost and low environmental impact revegetation methods is necessary for the effective management of Mediterranean forest environments. This research assessed the effects of five types of soil amendment on the success of afforestation processes. In terms of land management, the study shows that the addition of mulch or hydroabsorbent polymer can reduce transplanting stress, and improve the success of afforestation programs.

Description: X-ray computed tomography investigation of structures in Opalinus Clay from large-scale to small-scale after mechanical testing Annette Kaufhold, Matthias Halisch, Gerhard Zacher, and Stephan Kaufhold Solid Earth, 7, 1171-1183, doi:10.5194/se-7-1171-2016, 2016 The OPA material has been intensively studied by a variety of multiple scale and non-destructive 3-D X-ray CT investigations, following a consequent top-down approach to identify specific regions of interest. According to the mechanical experiment, it has been observed that the shear failure is located in a clay-rich area. Within the intersecting area of the two main fractures, a so called mylonitic zone with a particle reduction was observed on the open shear failure using CT and SEM techniques.

Description: Seismic structure beneath the Gulf of Aqaba and adjacent areas based on the tomographic inversion of regional earthquake data Sami El Khrepy, Ivan Koulakov, Nassir Al-Arifi, and Alexey G. Petrunin Solid Earth, 7, 965-978, doi:10.5194/se-7-965-2016, 2016 Three-dimensional seismic structures beneath the Gulf of Aqaba are presented for the first time for the southern part of the Dead Sea. A regional earthquake tomography method is applied to P and S waves data. The new results indicate new perspectives suggesting an oceanic nature of the crust in the northern part of the Red Sea, disagreeing with the hypothesis of a gradual stretching of the continental crust.

Description: A multi-stage 3D stress field modelling approach exemplified in the Bavarian Molasse Basin Moritz O. Ziegler, Oliver Heidbach, John Reinecker, Anna M. Przybycin, and Magdalena Scheck-Wenderoth Solid Earth Discuss., doi:10.5194/se-2016-92,2016 Manuscript under review for SE (discussion: open, 0 comments) Subsurface engineering relies on sparsely distributed datapoints of the stress state of the earth's crust. 3D geomechanical numerical modelling is applied to estimate the stress state in the entire volume of a large area. We present a multi-stage approach of differently sized models which provide the stress state in an area of interest derived from few and widely scattered data records. Furthermore we demonstrate the changes in reliability of the model depending on different input parameters.

Description: Defining a Mid-Holocene earthquake through speleoseismological and independent data: constraints for the outer Central Apennines (Italy) seismotectonic framework Alessandra Di Domenica and Alberto Pizzi Solid Earth Discuss., doi:10.5194/se-2016-77,2016 Manuscript under review for SE (discussion: open, 0 comments) Speleoseismological investigations have been adopted to characterize a complex tectonically active area in the easternmost sector of the Central Apennines. Evidence of earthquake damages have been recognized in the analyzed cave. Radiocarbon dating and the correspondence with independent data collected outside the cave, provide constraints for the individuation of a M~7 Mid-Holocene earthquake and for the identification of the nearby Sulmona normal fault as the most likely causative structure.

Description: Vegetation greenness response to water availability in northern China from 1982 to 2006 Fengtai Zhang and Youzhi An Solid Earth, 7, 995-1002, doi:10.5194/se-7-995-2016, 2016 The relationship between satellite-observed normalized difference vegetation index (NDVI) data as a proxy for vegetation greenness and water availability (rainfall and soil moisture) can greatly improve our understanding of how vegetation greenness responds to water availability fluctuations. Using Sen and Pearson’s correlation methods, we analyzed the spatiotemporal variation of vegetation greenness for both the entire year and the growing season (GS,4–10) in northern China from 1982 to 2006.

Description: 3D GPS velocity field and its implications on the present-day postorogenic deformation of the Western Alps and Pyrenees Hai Ninh Nguyen, Philippe Vernant, Stephane Mazzotti, Giorgi Khazaradze, and Eva Asensio Solid Earth Discuss., doi:10.5194/se-2016-78,2016 Manuscript under review for SE (discussion: open, 0 comments) We present a new 3D GPS velocity solution for 182 sites for the region encompassing the Western Alps, Pyrenees. The only significant horizontal deformation (0.2 mm yr −1 over a distance of 50 km) is a NNE-SSW extension in the western Pyrenees. In contrast, significant uplift rates up to 2 mm yr −1 occur in the Western Alps but not in the Pyrenees. A correlation between site elevations and fast uplift rates in the Western Alps suggests that part of this uplift is induced by postglacial rebound.

Description: Development of a numerical workflow based on μ -CT imaging for the determination of capillary pressure–saturation-specific interfacial area relationship in 2-phase flow pore-scale porous-media systems: a case study on Heletz sandstone Aaron Peche, Matthias Halisch, Alexandru Bogdan Tatomir, and Martin Sauter Solid Earth, 7, 727-739, doi:10.5194/se-7-727-2016, 2016 In this case study, we compute georeservoir specific capillary pressure-saturation- interfacial area relationships by implementing a FEM-based two-phase flow model on μ-CT-based modelling domains. We propose a recommended practice for deriving a model and model setup for the successful modelling of such types of problems on micro-CT obtained geometries.

Description: Geopotential field anomalies and regional tectonic features – two case studies: southern Africa and Germany Monika Korte and Mioara Mandea Solid Earth, 7, 751-768, doi:10.5194/se-7-751-2016, 2016 We investigated characteristics of magnetic anomalies over southern Africa (South Africa, Namibia, and Botswana) and Germany on different scales and also compared them to gravity gradient anomalies. Such anomalies provide information relevant to understanding geological and tectonic structures. Our results indicate a better agreement between anomalies caused by shallow and deeper structures in the southern African area than in the German area.

Description: Discussing the genesis of karst rocky desertification research based on the correlations between cropland and settlements in typical peak-cluster depressions Yang Bing Li, Qiong Yao Li, Guang Jie Luo, Xiao Yong Bai, Yong Yan Wang, Shi Jie Wang, Jing Xie, and Guang Bin Yang Solid Earth, 7, 741-750, doi:10.5194/se-7-741-2016, 2016 In karst mountainous areas in Southwest China, sloping land is overly reclaimed. Why are farmers doing this? Through typical case studies of peak-cluster depression areas, we found that low land carrying capacity and high population pressure where farmers carry out extreme steep reclamation activities are the main reasons for desert-like landscapes; this is a kind of land degradation which occurs in vulnerable karst dryland socioecological systems.

Description: The Pollino 2012 seismic sequence: clues from continuous radon monitoring Antonio Piersanti, Valentina Cannelli, and Gianfranco Galli Solid Earth Discuss., doi:10.5194/se-2016-72,2016 Manuscript under review for SE (discussion: open, 0 comments) We investigate in an innovative way the dynamics of radon emanation in a seismically active area. We analyzed three years of data, collected during a long term radon monitoring experiment. The complexity of the relationships among the investigated variables led us to consider the problem both from a phenomenological point of view and by means of original numerical analyses. Different approaches converge on the existence of a physical relation between soil radon emanation and seismicity.

Description: Nitrogen and Warming Control the Vegetation in Inner Mongolia Tourist Area Qiong Sun, Xiaobing Hu, and Chi Zhang Solid Earth Discuss., doi:10.5194/se-2016-52,2016 Manuscript under review for SE (discussion: open, 0 comments) The global warming and atmospheric nitrogen deposition problem has become more and more serious under the influence of human activities, and it has become one of the hot issues in this field, which will have far-reaching impact on all kinds of vegetation, thus the functioning of the ecosystem will be changed, which will be reflected in climate warming process. Inner Mongolia Autonomous Region is mainly composed of desert grasslands, so the development and protection of vegetation has considerable significance on the region. However, in the current environment of global warming, few studies have been carried out on desert grassland plants. In this paper, an in-depth study was carried out on the impact of warming and nitrogen addition on soil temperature, vegetation reproductive phenology and vegetation community seed rain under natural conditions during five-year period from 2011 to 2015. During the experimental period, we found that soil temperature and soil moisture decreased with the increase of soil layer, and warming obviously shortened the time of budding, flowering and fruiting of vegetation. However, no significant effect was found on nitrogen addition. Meanwhile, the impact of interaction effect of warming and nitrogen addition on seed rain was not obvious, but the year difference of all relevant indicators was significant.

Description: Fixation kinetics of chelated and non-chelated zinc in semi-arid alkaline soils: application to zinc management Theophilus K. Udeigwe, Madeleine Eichmann, and Matthew C. Menkiti Solid Earth, 7, 1023-1031, doi:10.5194/se-7-1023-2016, 2016 Micronutrient fixation leads to the reduction of plant-available portions. This study examined the fixation kinetics of chelated and non-chelated zinc (Zn) in semi-arid soils. About 30 % more Zn was fixed in the non-chelated system in the first 14 days. Slope of change of Zn to Cu (i.e., Cu–Zn) was higher than other micronutrients. Zn fixation kinetics were better described by a power-function model. Tools developed from this study will be used to advance micronutrient management.

Description: sUAS and their application in observing geomorphological processes Jozef Gallik and Lenka Bolešová Solid Earth, 7, 1033-1042, doi:10.5194/se-7-1033-2016, 2016 Technology is moving ahead very fast, and so researchers have new possibilities for their research. We tried to demonstrate benefits of using remote-sensing technology (Phantom 1 drone) such as its accuracy in the terrain, easy access to hardly accessible areas, and the possibility to collect data even during unfavourable weather conditions. The high mountainous environment provided us great conditions for testing the drone as a device for very easy and accurate mapping of natural phenomena.

Description: Alpine tectonic wedging and crustal delamination in the Cantabrian Mountains (NW Spain) Jorge Gallastegui, Javier A. Pulgar, and Josep Gallart Solid Earth, 7, 1043-1057, doi:10.5194/se-7-1043-2016, 2016 We present the interpretation of deep seismic reflection profile ESCIN-2 across the boundary between the Cantabrian Mountains and the Cenozoic Duero Basin (NW Spain). 2-D seismic modelling allowed us to construct a N-S geological cross section which is compatible with the rest of the geophysical data. This profile shows the importance of the N-S Alpine deformation. A wedge of Cantabrian margin crust indented southwards into the delaminated Iberian crust, forcing its northward subduction.

Description: Stepwise drying of Lake Turkana at the end of the African Humid Period: an example of forced regression modulated by solar activity? Alexis Nutz and Mathieu Schuster Solid Earth Discuss., doi:10.5194/se-2016-95,2016 Manuscript under review for SE (discussion: open, 0 comments) From the geomorphology of a paleo-delta complex of Lake Turkana (Kenya), we explore the end of the Holocene African Humid Period (AHP) that corresponded to a major change in climate of Africa and that had important environmental impacts. Here, we propose that the transition from a wet to a dry period at the end of the AHP is stepwise, discussing a potential control by short-term evolution of solar activity. Understanding of this climate event is crucial to anticipate a future climate change.

Description: POLENET/LAPNET teleseismic P wave travel time tomography model of the upper mantle beneath northern Fennoscandia Hanna Silvennoinen, Elena Kozlovskaya, and Eduard Kissling Solid Earth, 7, 425-439, doi:10.5194/se-7-425-2016, 2016 POLENET/LAPNET broadband seismic network was deployed in northern Fennoscandia 2007–2009. In our study we estimate the 3D architecture of the upper mantle beneath the network using high-resolution teleseismic P-wave tomography. Our study reveals a highly heterogeneous lithospheric mantle. The most significant feature seen in the obtained velocity model is a large elongated low-velocity anomaly beneath the crust, separating the three cratonic units that formed the region in the early Proterozoic.

Description: Calculating structural and geometrical parameters by laboratory measurements and X-ray microtomography: a comparative study applied to a limestone sample before and after a dissolution experiment Linda Luquot, Vanessa Hebert, and Olivier Rodriguez Solid Earth, 7, 441-456, doi:10.5194/se-7-441-2016, 2016 To evaluate oil and gas production, accurate characterization (usually based on laboratory experiments) of reservoir rock properties needs to be performed. X-ray scanning samples enable obtaining 3-D images of the rock inner structure from which those properties can be obtained using images processing. This article shows that these two approaches are complementary and yield consistent results. Moreover, image-based calculations allow to save a huge amount of time compared to lab-based measures.

Description: Phase Segmentation of X-Ray Computer Tomography Rock Images using Machine Learning Techniques: an Accuracy and Performance Study Swarup Chauhan, Wolfram Rühaak, Hauke Anbergen, Alen Kabdenov, Marcus Freise, Thorsten Wille, and Ingo Sass Solid Earth Discuss., doi:10.5194/se-2016-44,2016 Manuscript under review for SE (discussion: open, 0 comments) Machine learning techniques are a promising alternative for processing (phase segmentation) of 3D X-Ray computer tomographic (XCT) rock images. Here, the performance and accuracy of different machine learning techniques is tested. Aim is to classify pore space, rock grains and matrix of four distinct rock samples. The porosity obtained based on the segmented XCT images is cross-validated with laboratory measurements. Accuracies of the different methods are discussed and recommendation proposed.

Description: The Mohr–Coulomb criterion for intact rock strength and friction – a re-evaluation and consideration of failure under polyaxial stresses Abigail Hackston and Ernest Rutter Solid Earth, 7, 493-508, doi:10.5194/se-7-493-2016, 2016 This was an experimental study of the strength of two rock types, over a range of pressure conditions that correspond to depths in the Earth’s crust ranging up to 12 km. Tests were carried out under different stress regimes to simulate extremes of the range of loading geometries encountered in the Earth and hence how these affect failure strength and resistance to frictional slip on faults. These experiments will promote understanding of rock behaviour in oil, gas and water reservoirs.

Description: Tectonothermal evolution in the core of an arcuate fold and thrust belt: the southeastern sector of the Cantabrian Zone (Variscan belt, NW Spain) M. L. Valín, S. García-López, C. Brime, F. Bastida, and J. Aller Solid Earth Discuss., doi:10.5194/se-2016-53,2016 Manuscript under review for SE (discussion: open, 0 comments) Abstract. The tectonothermal evolution of an area located in the core of the Ibero-Armorican arc (Variscan belt) has been determined by using the conodont color alteration index (CAI), Kübler index of illite (KI), the Árkai index of chlorite (AI), and the analysis of clay minerals and rock cleavage. The area is part of the Cantabrian Zone (CZ), which represents the foreland fold and thrust belt of the orogen. It has been thrust by several large units of the CZ, what resulted in the generation of a large amount of synorogenic Carboniferous sediments. CAI, KI and AI values show an irregular distribution of metamorphic grade, independent of stratigraphic position. Two tectonothermal events have been distinguished in the area. The first one, poorly defined, is mainly located in the northern part. It gave rise to very low-grade metamorphism in some areas and it was associated with a deformation event that resulted in the emplacement of the last large thrust unit and development of upright folds and associated cleavage (S 1 ).The second tectonothermal event gave rise to low-grade metamorphism and cleavage (S 2 ) crosscutting earlier upright folds in the central, western and southern parts of the study area. The event continued with the intrusion of small igneous rock bodies, which gave rise to contact metamorphism and hydrothermal alteration. The second event was linked to an extensional episode due to a gravitational instability at the end of the Variscan deformation. This tectonothermal evolution occurred during the Gzhelian-Sakmarian. Subsequently, several hydrothermal episodes took place, in association with local development of crenulation cleavage during the Alpine deformation.

Description: Development of a numerical workflow based on μ-CT-imaging for the determination of capillary pressure-saturation-specific interfacial area relationship in two-phase flow pore-scale porous media systems: A case study on Heletz sandstone Aaron Peche, Matthias Halisch, and Alexandru Bogdan Tatomir Solid Earth Discuss., doi:10.5194/se-2016-39,2016 Manuscript under review for SE (discussion: open, 0 comments) In this case study, we compute georeservoir specific capillary pressure-saturation- interfacial area relationships by implementing a FEM-based two-phase flow model on μ-CT-based modelling domains. We propose a recommended practice for deriving a model and model setup for the successful modelling of such types of problems on micro-CT obtained geometries.

Description: 3-D visualisation of palaeoseismic trench stratigraphy and trench logging using terrestrial remote sensing and GPR – a multiparametric interpretation Sascha Schneiderwind, Jack Mason, Thomas Wiatr, Ioannis Papanikolaou, and Klaus Reicherter Solid Earth, 7, 323-340, doi:10.5194/se-7-323-2016, 2016 Palaeoseismological research uses historical earthquakes to verify seismic hazard assessment. Earthquakes of magnitude M 〉 5.5 likely produce surface ruptures that can be preserved in the subsurface. Buried soils or progressive displacements are the main targets of trenching studies. However, the recognition of these features is challenging for inexperienced researchers. Here a workflow is presented which applies remote sensing and geophysical techniques to verify layer distinction.

Description: Visualization and Quantification of the Penetration Behavior of Bentonite Suspensions into the Pore Network of non-cohesive Media by using μ-CT Imaging Britta Schoesser, Atefeh Ghorbanpour, Matthias Halisch, and Markus Thewes Solid Earth Discuss., doi:10.5194/se-2016-42,2016 Manuscript under review for SE (discussion: open, 0 comments) In summary, the µ-CT technique delivers a valuable contribution for the research on the interaction of bentonite suspensions penetration the pore space of non-cohesive media. This study shows the missing visual evidence concerning the theoretical interaction models of the bentonite suspension in the pore space on microscale. The Imaging results have been cross-validated with laboratory experiments and are in good agreement with each other.

Description: Strain localization in ultramylonitic marbles by simultaneous activation of dislocation motion and grain boundary sliding (Syros, Greece) A. Rogowitz, J. C. White, and B. Grasemann Solid Earth, 7, 355-366, doi:10.5194/se-7-355-2016, 2016 This paper discusses the processes resulting in extreme strain localization (gamma up to 1000) in an almost pure calcite marble located in Syros, Greece. We observed grain size reduction by bulging recrystallization, followed by the simultaneous activation of grain boundary sliding and a dislocation motion in conditions (high differential stress, high strain rate, low temperature) in which brittle deformation rather than ductile flow might be suspected.

Description: On the mechanical behaviour of a low angle normal fault: the Altotiberina fault (Northern Apennines, Italy) system case study Luigi Vadacca, Emanuele Casarotti, Lauro Chiaraluce, and Massimo Cocco Solid Earth Discuss., doi:10.5194/se-2016-48,2016 Manuscript under review for SE (discussion: open, 0 comments) Geological and seismological observations have been used to parameterize 2D numerical models to simulate the interseismic deformation of a complex extensional fault system located in the Northern Apennines (Italy). The geological system is dominated by the presence of the Altotiberina fault (ATF), a large (60 km along strike) low-angle normal fault 20° dipping in the brittle crust (0–15 km). The ATF is currently interested by a high and constant rate of microseismic activity and no moderate-to-large magnitude earthquakes have been associated to it for the past 1000 years. Modelling results have been compared with GPS data in order to understand the mechanical behaviour of this fault and a suite of minor syn- and antithetic normal fault segments located in the main fault hanging-wall. The results of the simulations demonstrate the active role played by the Altotiberina fault in accommodating the on going tectonic extension in this sector of the chain. The GPS velocity profile constructed through the fault system cannot be explained without including the ATF's contribution to deformation, indicating that this fault although misoriented has to be considered tectonically active and with a creeping behaviour below 5 km of depth. The low angle normal fault also shows a high degree of tectonic coupling with its main antithetic fault (the Gubbio fault) suggesting that creeping along the ATF may control the observed strain localization and the pattern of microseismic activity.

Description: Vegetation greenness response to water availability in northern China from 1982 to 2006 Zhang Fengtai and An Youzhi Solid Earth Discuss., doi:10.5194/se-2016-46,2016 Manuscript under review for SE (discussion: open, 0 comments) An evaluation of the relationship between satellite-observed Normalized Difference Vegetation Index (NDVI) data as a proxy for vegetation greenness and water availability (rainfall and soil moisture) can greatly improve our understanding of how vegetation greenness responds to water availability fluctuations. Using Sen and Pearson’s correlation methods, we analyzed the spatio-temporal variation of vegetation greenness for both the entire year and the growing season (GS,4-10) in northern China from 1982 to 2006. Although, vegetation greenness and soil moisture during the study period changed significantly for the entire study area, there was no change in rainfall. Linear correlation analysis between NDVI and rainfall revealed higher correlations using data for all seasons. Higher correlations for NDVI and soil moisture were obtained using growing season data. This study highlights how strongly vegetation greenness responds to water availability dynamics, especially in the growing season period.

Description: Multi-phase classification by a least-squares support vector machine approach in tomography images of geological samples Faisal Khan, Frieder Enzmann, and Michael Kersten Solid Earth, 7, 481-492, doi:10.5194/se-7-481-2016, 2016 X-ray microtomography image processing involves artefact reduction and image segmentation. The beam-hardening artefact is removed, applying a new algorithm, which minimizes the offsets of the attenuation data points. For the segmentation, we propose using a non-linear classifier algorithm. Statistical analysis was performed to quantify the improvement in multi-phase classification of rock cores using and without using our advanced beam-hardening correction algorithm.

Description: The effectiveness of jute and coir blankets for erosion control in different field and laboratory conditions Jana Kalibová, Lukáš Jačka, and Jan Petrů Solid Earth, 7, 469-479, doi:10.5194/se-7-469-2016, 2016 Jute and coir geotextiles (GTXs) significantly reduced the volume of surface run-off induced by simulated rainfall. “No-soil” conditions used during the laboratory experiment guarantee data based on GTX properties only. Contrary to our expectations, the performance ranking of GTXs in the laboratory did not match the field records. Soil did not influence all GTX samples equally. Further research may shed light on the variability of GTX effectiveness reported in available studies.

Description: The Subduction Dichotomy of Strong Plates and Weak Slabs Robert I. Petersen, Dave R. Stegman, and Paul J. Tackley Solid Earth Discuss., doi:10.5194/se-2016-56,2016 Manuscript under review for SE (discussion: open, 0 comments) In this study we propose a dichotomy in the strength profile of tectonic plates. This apparent dichotomy suggests that plates at the Earth's surface are significantly, orders of magnitude, stronger than the subducted slabs in the Earth's interior. Strong plates promote single sided, Earth-like subduction. Once subducted strong slabs transmit dynamic stresses and disrupt subduction. Slabs which are weakened do not disrupt subduction and furthermore exhibit a variety of observed morphologies.

Description: Archie's Law – A reappraisal Paul W. J. Glover Solid Earth Discuss., doi:10.5194/se-2016-47,2016 Manuscript under review for SE (discussion: open, 0 comments) In 1942 Archie examined data on the electrical properties of rocks containing oil and discovered equations which have been used ever since to calculate reserves of oil and gas around the world. Two equations exist, one which is theoretically justified, and one which is not. Unfortunately it is the one which is not justified that often gives the best results. It was the goal of this research to discover the extent to which the two approaches give differing results and to find the reason why.

Description: Feathery and network-like filamentous textures as indicators for the crystallization of quartz from a silica gel precursor at the Rusey Fault, Cornwall, UK Tim I. Yilmaz, Florian Duschl, and Danilo Di Genova Solid Earth Discuss., doi:10.5194/se-2016-61,2016 Manuscript under review for SE (discussion: open, 1 comment) Quartz crystals from a hydrothermal shear-zone-hosted quartz deposit (Rusey Fault, Cornwall, UK) show feathery textures and network-like filamentous textures. Optical hot-cathodoluminescence (CL) analysis and LA-ICP-MS investigations on quartz samples revealed that positions exhibiting feathery textures (violet luminescence) incorporate higher amounts of Ca, As, Na, Mg, and K than quartz positions without feathery textures (blue luminescence). Raman spectroscopy investigations revealed the presence of a weak peak ("shoulder") at 507–509 cm −1 in quartz affected by feathery textures, which we attribute to the presence of moganite, a microcrystalline silica variety. The combined occurrence of feathery textures and network-like filamentous textures in quartz samples from the Rusey fault zone points to the presence of a silica gel precursor before or during the crystallization.

Description: Combined deep sampling and mass-based approaches to assess soil carbon and nitrogen losses due to land-use changes in karst area of Southwestern China Yecui Hu, Zhangliu Du, Qibing Wang, and Guichun Li Solid Earth Discuss., doi:10.5194/se-2016-57,2016 Manuscript under review for SE (discussion: open, 0 comments) We quantified the SOC and TN losses induced by land-use changes in a typical karst region of southwestern China. Converting from natural forest to croplands greatly led to SOC and TN losses (as higher as 37.8 %), but the magnitude depended on sampling depth and calculation method. We recommend to account for SOC and TN stocks on equivalent soil mass basis together with deep sampling. This study has significant implications on the projected land management in the degraded karst areas.

Description: Dilatant normal faulting in jointed cohesive rocks: a physical model study Michael Kettermann, Christoph von Hagke, Heijn W. van Gent, Christoph Grützner, and Janos L. Urai Solid Earth, 7, 843-856, doi:10.5194/se-7-843-2016, 2016 We present an analogue modeling study on the interaction of pre-existing joints and normal faults using cohesive powder. We vary the angle between joints and a rigid basement fault and analyze interpreted map-view photographs at maximum displacement for various parameters and compare to nature. Results show a clear effect of increasing angle between joints and faults on fault geometry, fracture density and connectivity. These information can help interpreting fractured layers in the subsurface.

Description: Fully probabilistic seismic source inversion – Part 2: Modelling errors and station covariances Simon C. Stähler and Karin Sigloch Solid Earth Discuss., doi:10.5194/se-2016-87,2016 Manuscript under review for SE (discussion: open, 0 comments) Seismic source inversion is the method of inferring the spatial orientation of an earthquake source from seismic records. The results come with large uncertainties, which we try to estimate with a Bayesian approach. We propose an empirical relationship for a likelihood function based on a large dataset of deterministic solutions. This allows to use the cross-correlation coefficient as a misfit criterion, which is better suited for waveform comparison than the popular root mean square or L 2 -norm.

Description: Ionospheric influence on the seismo-telluric current related to electromagnetic signals observed before the Wenchuan M S  = 8.0 earthquake Mei Li, Handong Tan, and Meng Cao Solid Earth Discuss., doi:10.5194/se-2016-89,2016 Manuscript under review for SE (discussion: open, 0 comments) The results got in this investigation probably give a supplementary to the problem of lithosphere-atmosphere-ionosphere electromagnetic coupling and it maybe also helps us to understand the "energy source" of the same problem. In addition, the ionosphere can facilitate the electromagnetic wave propagation, as if the detectability of the observing system is improved effectively, which makes it reasonable that sometimes electromagnetic signals are recorded at a seeming unreasonable distance.

Description: High-resolution shear wave reflection seismics as tool to image near-surface subrosion structures – a case study in Bad Frankenhausen, Germany Sonja Wadas, Ulrich Polom, and Charlotte Krawczyk Solid Earth Discuss., doi:10.5194/se-2016-91,2016 Manuscript under review for SE (discussion: open, 0 comments) Subrosion is the subsurface leaching of soluble rocks. It is a global phenomenon and a geohazard in urban areas, because it causes depressions and sinkholes. This is the case in the study area, the town of Bad Frankenhausen, in northern Thuringia, Germany. Using shear-wave reflection seismics we are able to image these structures at high resolution to a depth of ca. 100 m. We observe that the underground is strongly fractured and there are indications of cavities.

Description: Geoscientific process monitoring with positron emission tomography (GeoPET) Johannes Kulenkampff, Marion Gründig, Abdelhamid Zakhnini, and Johanna Lippmann-Pipke Solid Earth, 7, 1217-1231, doi:10.5194/se-7-1217-2016, 2016 Transport processes can be observed with input–output experiments, disregarding the impact of heterogeneities, or they can be modelled, based on structural images. In contrast, positron emission tomography (PET) directly yields the spatio-temporal distribution of tracer concentration. PET benefits from its molecular sensitivity together with a reasonable resolution. We illustrate its use with examples of process monitoring of advection and diffusion processes, and we discuss benefits and limits.

Description: The deep Earth origin of the Iceland plume and its effects on regional surface uplift and subsidence N. Barnett-Moore, R. Hassan, N. Flament, and R. D. Müller Solid Earth Discuss., doi:10.5194/se-2016-118,2016 Manuscript under review for SE (discussion: open, 0 comments) We use a 3D mantle flow model to investigate the evolution of the Iceland plume in the North Atlantic. Our results show that over the last ~ 100 Myr a remarkably stable pattern of mantle flow in the lowermost mantle made it an ideal plume nucleation site beneath the region. At the surface, the model plume compared to published observables indicates that its large plume head, ~ 2000 km in diameter, arriving beneath Western Greenland in the Paleocene, can account for widespread topographic uplift.

Description: Determination of critical pH and Al concentration of acidic Ultisols for wheat and canola crops Abdulaha-Al Baquy, Jiu-Yu Li, Chen-Yang Xu, Khalid Mehmood, and Ren-Kou Xu Solid Earth Discuss., doi:10.5194/se-2016-126,2016 Manuscript under review for SE (discussion: open, 1 comment) Al toxicity to plants and soil infertility in acidic soils are the main limiting factors for crop growth. To establish which acid soils need to be ameliorated for plant growth, the parameters of critical soil pH and soil Al concentration must be determined. The critical soil pH and exchangeable aluminium of two Ultisols for wheat and canola production were determined in this study. The results obtained will provide useful references for the utilization and management of acid soils.

Description: Spatial variability of some soil properties varies in oil palm ( Elaeis guineensis Jacq.) plantations of west coastal area of India Sanjib Kumar Behera, Kancherla Suresh, Bezawada Narsimha Rao, Ravi Kumar Mathur, Arvind Kumar Shukla, Kamireddy Manorama, Kummari Ramachandrudu, Parasa Harinarayana, and Chandra Prakash Solid Earth, 7, 979-993, doi:10.5194/se-7-979-2016, 2016 This study analyzed the spatial variability of some soil properties in surface and subsurface soil layers of oil palm plantations in the south Goa district of Goa situated in western coastal area of India. The studied soil properties in surface and subsurface layers varied widely. Geostatistical analysis revealed different spatial distribution patterns for the soil properties. The generated prediction maps are useful for site-specific soil nutrient management in the area.

Description: Preface: From orogenesis to geoscience in the service of society: the scientific legacy of Prof. Andrés Pérez-Estaún Joaquina Alvarez-Marrón, Fernando Bastida, Ernest Rutter, Ramon Carbonell, and Charlotte M. Krawczyk Solid Earth, 7, 1199-1205, doi:10.5194/se-7-1199-2016, 2016 No abstract.

Description: Cooperative effects of field traffic and organic matter treatments on some compaction-related soil properties Metin Mujdeci, Ahmet Ali Isildar, Veli Uygur, Pelin Alaboz, Husnu Unlu, and Huseyin Senol Solid Earth Discuss., doi:10.5194/se-2016-84,2016 Manuscript under review for SE (discussion: open, 1 comment) Organic matter addition is an efficient way of reducing the effects of field traffic. The depth dependent (0–10 and 10–20 cm) changes of some soil physical traits such as penetration resistance, bulk density and porosity as a function of tractor passes and organic matter addition to a clay soil. The enhancing effects of treatmenst on the investigated parameteres were C 〉 GM 〉 FYM). The increase in tramlines made the soil properties worse and corresponded with the type of organic matter.

Description: Estimations of soil fertility in physically degraded agricultural soils through selective accounting of fine earth and gravel fractions Mavinakoppa S. Nagaraja, Ajay Kumar Bhardwaj, G. V. Prabhakara Reddy, Chilakunda A. Srinivasamurthy, and Sandeep Kumar Solid Earth, 7, 897-903, doi:10.5194/se-7-897-2016, 2016 Three nutrient stock estimation methods, generalized soil mass (GSM), bulk-density-based soil mass (BDSM) and the proportion of fine earth volume (FEV) method, were compared to estimate organic C and major available nutrient stocks in physically degraded agricultural soils of southern India. The stocks were lowest using FEV method followed by GSM and BDSM method. The study highlights the importance of estimation methods to obtain realistic estimates for the development of degraded land areas.

Description: Desertification of forest, range and desert in Tehran province, affected by climate change Hadi Eskandari, Moslem Borji, Hassan Khosravi, and Tayebeh Mesbahzadeh Solid Earth, 7, 905-915, doi:10.5194/se-7-905-2016, 2016 Climate change has been identified as a leading human and environmental crisis of the twenty-first century. Drylands throughout the world have always undergone periods of degradation due to naturally occurring fluctuation in climate. Persistence of widespread degradation in arid and semiarid regions of Iran necessitates monitoring and evaluation. This paper aims to monitor the desertification trend in three types of land use, including range, forest and desert, affected by climate change in Tehran province for the 2000s and 2030s. For assessing climate change at Mehrabad synoptic station, the data of two emission scenarios, including A2 and B2, were used, utilizing statistical downscaling techniques and data generated by the Statistical DownScaling Model (SDSM). The index of net primary production (NPP) resulting from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images was employed as an indicator of destruction from 2001 to 2010. The results showed that temperature is the most significant driving force which alters the net primary production in rangeland, forest and desert land use in Tehran province. On the basis of monitoring findings under real conditions, in the 2000s, over 60 % of rangelands and 80 % of the forest were below the average production in the province. On the other hand, the long-term average changes of NPP in the rangeland and forests indicated the presence of relatively large areas of these land uses with a production rate lower than the desert. The results also showed that, assuming the existence of circumstances of each emission scenarios, the desertification status will not improve significantly in the rangelands and forests of Tehran province.

Description: Combined effects of grain size, flow volume and channel width on geophysical flow mobility: 3-D discrete element modeling of dry and dense flows of angular rock fragments Bruno Cagnoli and Antonio Piersanti Solid Earth Discuss., doi:10.5194/se-2016-79,2016 Manuscript under review for SE (discussion: open, 0 comments) The purpose of our research is to understand the mechanisms that determine the mobility of granular flows of rock fragments. Since rock avalanches and pyroclastic flows are too dangerous to be studied at close range, we use numerical modelling and laboratory experiments. We focus on the fundamentals upon which new numerical simulations able to predict the behaviours of natural flows will be built. These fundamentals include the effects of grain size, flow volume and channel width.

Description: Land use and land cover change based on historical space-time model Qiong Sun, Chi Zhang, Min Liu, and Yongjing Zhang Solid Earth Discuss., doi:10.5194/se-2016-70,2016 Manuscript under review for SE (discussion: open, 0 comments) Land use and cover change is a leading edge topic in the current research field of global environmental changes and case study of typical areas is an important approach understanding global environmental changes. Taking Qiantang River (Zhejiang, China) as an example, this study explores automatic classification of land use using remote sensing technology and analyzes historical space-time change by remote sensing monitoring, which provide new methods for optimizing land use structure and realize the optimal allocation of land resources as well as intensive utilization. It is of great importance to the sustainable development of Qiantang River basin and the whole Zhejiang province. This study combines spectral angle mapping (SAM) with multi-source information and creates a convenient and efficient high precision land use computer automatic classification method which meets the application requirements and is suitable for complex landform of the studied area. This work analyzes the histological space-time characteristic of land use and cover change in 2001, 2007 and 2014, providing a strong information support and new research method for optimizing Qiantang River land use structure and achieving optimal allocation of land resources and scientific management.

Description: Responses of aeolian desertification to a range of climate scenarios in China Xunming Wang, Ting Hua, and Wenyong Ma Solid Earth, 7, 959-964, doi:10.5194/se-7-959-2016, 2016 Aeolian desertification plays an important role in earth-system processes and ecosystems, and has the potential to greatly impact global food production. The occurrence of aeolian desertification has traditionally been attributed to increases in wind speed and temperature and decreases in rainfall. In this study, by integrating the aeolian desertification monitoring data and climate and vegetation indices, we found that although aeolian desertification is influenced by complex climate patterns and human activities, increases in rainfall and temperature and decreases in wind speed may not be the key factors of aeolian desertification controls in some regions of China. Our results show that, even when modern technical approaches are used, different approaches to desertification need to be applied to account for regional differences. These results have important implications for future policy decisions on how best to combat desertification.

Description: Structural geology and geophysics as a support to build a hydrogeologic model of granite rock Lurdes Martinez-Landa, Jesús Carrera, Andrés Pérez-Estaún, Paloma Gómez, and Carmen Bajos Solid Earth, 7, 881-895, doi:10.5194/se-7-881-2016, 2016 In the present study we present a methodology of how structural geology and geophysics techniques, together with hydrochemical and hydraulic data, can help in identifying the main fractures that conduct most of the groundwater flow in a granitic pluton (low-permeability fractured media). Using the values of transmissivities obtained from 3-D numerical models of the local hydraulic test interpretation, we have been able to reproduce the effect of a large-scale and long-term pumping test.

Description: Oblique collision and deformation partitioning in the SW Iberian Variscides Irene Pérez-Cáceres, José Fernando Simancas, David Martínez Poyatos, Antonio Azor, and Francisco González Lodeiro Solid Earth, 7, 857-872, doi:10.5194/se-7-857-2016, 2016 Different transpressional scenarios have been proposed to relate kinematics and complex deformation patterns. We apply the most suitable of them to the Variscan orogeny in SW Iberia, which is characterized by a number of successive left-lateral transpressional structures developed in the Devonian to Carboniferous period. These structures resulted from the oblique convergence between three continental terranes (Central Iberian Zone, Ossa-Morena Zone and South Portuguese Zone), whose amalgamation gave way to both intense shearing at the suture-like contacts and transpressional deformation of the continental pieces in-between, thus showing strain partitioning in space and time. We have quantified the kinematics of the collisional convergence by using the available data on folding, shearing and faulting patterns, as well as tectonic fabrics and finite strain measurements. Given the uncertainties regarding the data and the boundary conditions modeled, our results must be considered as a semi-quantitative approximation to the issue, though very significant from a regional point of view. The total collisional convergence surpasses 1000 km, most of them corresponding to left-lateral displacement parallel to terrane boundaries. The average vector of convergence is oriented E–W (present-day coordinates), thus reasserting the left-lateral oblique collision in SW Iberia, in contrast with the dextral component that prevailed elsewhere in the Variscan orogen. This particular kinematics of SW Iberia is understood in the context of an Avalonian plate salient currently represented by the South Portuguese Zone.

Description: Investigation of the relationship between landform classes and electrical conductivity (EC) of water and soil using a fuzzy model in a GIS environment Marzieh Mokarram and Dinesh Sathyamoorthy Solid Earth, 7, 873-880, doi:10.5194/se-7-873-2016, 2016 In this study, the relationship between landform classes and electrical conductivity (EC) of water and soil for wheat crops was determined using a combination of a GIS and a fuzzy model. The results show that EC of water is high for valley classes while the EC of soil is high in upland drainage.

Description: Folding and necking across the scales: a review of theoretical and experimental results and their applications Stefan Markus Schmalholz and Neil Mancktelow Solid Earth Discuss., doi:10.5194/se-2016-80,2016 Manuscript under review for SE (discussion: open, 0 comments) About 200 years ago in 1815 Sir James Hall made his famous analogue experiments which showed probably for the first time that natural folds in ductile rock are the result of a horizontal compression. If such rocks are extended, then the rock layers can thin only locally which is a process termed necking and the resulting structure is often termed pinch-and-swell. We review here theoretical and experimental results on folding and necking on all geological scales.

Description: X-ray CT analyses, models and numerical simulations: a comparison with petrophysical analyses in an experimental CO 2 study Steven Henkel, Dieter Pudlo, Frieder Enzmann, Viktor Reitenbach, Daniel Albrecht, Leonhard Ganzer, and Reinhard Gaupp Solid Earth, 7, 917-927, doi:10.5194/se-7-917-2016, 2016 This study investigates the experimentally induced effects of CO 2 storage on underground reservoir sandstones by applying high-resolution computer tomography and standard petrophysical methods. The results of digital rock physic calculations derived from the µ -CT scans are compared with measurements achieved by the standard methods. Both approaches lead to similar results for coarse- and medium-grained sandstones but differ for fine-grained sediments.

Description: Joint interpretation of magnetotelluric, seismic, and well-log data in Hontomín (Spain) Xènia Ogaya, Juan Alcalde, Ignacio Marzán, Juanjo Ledo, Pilar Queralt, Alex Marcuello, David Martí, Eduard Saura, Ramon Carbonell, and Beatriz Benjumea Solid Earth, 7, 943-958, doi:10.5194/se-7-943-2016, 2016 This paper explores the compatibility of seismic and magnetotelluric methods across scales highlighting the importance of joint interpretation in reservoir characterisation. The combination of the two methods together with well-log data at the Hontomín CO 2 storage pilot plant (Spain) allowed a detailed characterisation of the shallow subsurface and defined the structural and fluid flow characteristics of the existing faults, which are key aspects for the risk assessment of the site.

Description: X-ray CT analysis of pore structure in sand Toshifumi Mukunoki, Yoshihisa Miyata, Kazuaki Mikami, and Erika Shiota Solid Earth, 7, 929-942, doi:10.5194/se-7-929-2016, 2016 In this study, a specimen of sand was scanned to evaluate pore structure quantitatively using a micro-focused X-ray CT scanner. The representative volume to perform reasonable image analysis for sand was discussed, and then the spatial distribution of pore diameter in 3-D was visualized and evaluated quantitatively by granulometric image analysis. Also, the voxel-percolation analysis was newly proposed in this study to assess capillary pressure and saturation degree by pore diameter analyzed.

Description: Nitrogen addition alters elemental stoichiometry within soil aggregates in a temperate steppe Jinfei Yin, Ruzhen Wang, Heyong Liu, Xue Feng, Zhuwen Xu, and Yong Jiang Solid Earth Discuss., doi:10.5194/se-2016-129,2016 Manuscript under review for SE (discussion: open, 0 comments) In this manuscript we report on changes in elemental stoichiometry as affected by nitrogen addition effect within three soil aggregate fractions of large macro- (〉 2000 μm), small macro- (250–2000 μm), and microaggregates (

Description: Cultivated grasslands present a higher soil organic carbon sequestration efficiency under leguminous than under gramineous species Yu Liu, Fu-Ping Tian, Peng-Yan Jia, Jing-Ge Zhang, and Gao-Lin Wu Solid Earth Discuss., doi:10.5194/se-2016-109,2016 Manuscript under review for SE (discussion: open, 0 comments) The establishment of grassland on abandoned cropland has been proposed as an effective method of mitigating climate change by increasing soil organic carbon (SOC) storage. In this study, five cultivated grasslands were established (three leguminous species – Coronilla varia , Onobrychis viciaefolia , Medicago sativa , and two gramineous species – Poa annua , Agropyron cristatum ), one uncultivated, one natural grassland to examine how the SOC storage, sequestration rate and sequestration efficiency to change for 5 years restoration in semi-arid area. Our results showed that the cultivated leguminous grasslands had greater total biomass, SOC storage, SOC sequestration rate and efficiency than gramineous grasslands. The greater soil carbon (C) accumulation in leguminous grassland was mainly attributed to higher biomass production. Leguminous grasslands accumulated more SOC than gramineous grasslands by 0.64 Mg C ha −1  yr −1 . The average SOC sequestration efficiency in leguminous grassland (1.00) was about 2 times greater than gramineous grassland (0.34). The results indicate that cultivated leguminous grasslands sequestered more SOC with higher SOC sequestration efficiency than cultivated gramineous grasslands in arid and semi-arid areas.

Description: A geological model for the management of subsurface data in the urban environment of Barcelona and surrounding area Enric Vázquez-Suñé, Miguel Ángel Marazuela, Violeta Velasco, Marc Diviu, Andrés Pérez-Estaún, and Joaquina Álvarez-Marrón Solid Earth, 7, 1317-1329, doi:10.5194/se-7-1317-2016, 2016 This study shows the need for a symbiotic relationship between government and research groups for efficient management of geologic data in urban environments. Through its implementation, both the city administration and private companies benefit from the feedback of geologic knowledge acquired during this process, thereby substantially reducing the cost of construction projects and facilitating the development of aquifer management plans.

Description: Mid-crustal shear zone development under retrograde conditions: pressure–temperature–fluid constraints from the Kuckaus Mylonite Zone, Namibia Johann F. A. Diener, Åke Fagereng, and Sukey A. J. Thomas Solid Earth, 7, 1331-1347, doi:10.5194/se-7-1331-2016, 2016 The Kuckaus Mylonite Zone (KMZ) forms part of the larger Marshall Rocks–Pofadder shear zone system, a 550 km-long, crustal-scale strike-slip shear zone system that is localized in high-grade granitoid gneisses and migmatites of the Namaqua Metamorphic Complex. Shearing along the KMZ occurred ca. 40 Ma after peak granulite-facies metamorphism during a discrete tectonic event and affected the granulites that had remained at depth since peak metamorphism. Isolated lenses of metamafic rocks within the shear zone allow the P – T –fluid conditions under which shearing occurred to be quantified. These lenses consist of an unsheared core that preserves relict granulite-facies textures and is mantled by a schistose collar and mylonitic envelope that formed during shearing. All three metamafic textural varieties contain the same amphibolite-facies mineral assemblage, from which calculated pseudosections constrain the P – T conditions of deformation at 2.7–4.2 kbar and 450–480 °C, indicating that deformation occurred at mid-crustal depths through predominantly viscous flow. Calculated T – M H 2 O diagrams show that the mineral assemblages were fluid saturated and that lithologies within the KMZ must have been rehydrated from an external source and retrogressed during shearing. Given that the KMZ is localized in strongly dehydrated granulites, the fluid must have been derived from an external source, with fluid flow allowed by local dilation and increased permeability within the shear zone. The absence of pervasive hydrothermal fractures or precipitates indicates that, even though the KMZ was fluid bearing, the fluid/rock ratio and fluid pressure remained low. In addition, the fluid could not have contributed to shear zone initiation, as an existing zone of enhanced permeability is required for fluid infiltration. We propose that, following initiation, fluid infiltration caused a positive feedback that allowed weakening and continued strain localization. Therefore, the main contribution of the fluid was to produce retrograde mineral phases and facilitate grain-size reduction. Features such as tectonic tremor, which are observed on active faults under similar conditions as described here, may not require high fluid pressure, but could be explained by reaction weakening under hydrostatic fluid pressure conditions.

Description: New data on geology of the Southern Urals: a concise summary of research after the period of EUROPROBE activity Victor N. Puchkov Solid Earth, 7, 1269-1280, doi:10.5194/se-7-1269-2016, 2016 The period between 1991 and 2005 was a time when many western geologists came to the Urals to get a closer look at this famous and extraordinarily rich region. The main reason was an openness policy of the USSR government, when foreigners were admitted to this area that was formerly almost closed. The co-operation of the western geologists with local specialists was very fruitful. The author aimed to describe the most interesting findings in Uralian geology after the learned guests left.

Description: First magmatism in the New England Orogen, Australia: Forearc and arc-backarc components in the Bakers Creek Suite gabbros Seann J. McKibbin, Bill Landenberger, and Mark C. Fanning Solid Earth Discuss., doi:10.5194/se-2016-123,2016 Manuscript under review for SE (discussion: open, 0 comments) The youngest, eastern-most part of continental Australia formed in an ancient subduction zone by rifting of the crust. This drove melting of the underlying mantle, producing basaltic magmas that intruded the crust. We determined the composition and ages of these intrusives, finding that they predate other types of magma in the area. This indicates a progression in magma types from basaltic (mantle origin), through mixed, to granitic (crust recycling) during the growth of this region.

Description: Recent developments in neutron imaging with applications for porous media research Anders P. Kaestner, Pavel Trtik, Mohsen Zarebanadkouki, Daniil Kazantsev, Michal Snehota, Katherine J. Dobson, and Eberhard H. Lehmann Solid Earth, 7, 1281-1292, doi:10.5194/se-7-1281-2016, 2016 Experiments to determine the location and displacement of fluids in porous media are of high interest to verify flow and transport models. Neutron imaging presents, due to the high sensitivity to hydrogen, an ideal method to provide 3-D information about fluid distribution on the scale of a few tens of microns in a dense matrix of a sample container. We report instrumentation and method developments that increase spatial or temporal resolution, and demonstrate the performance in case studies.

Description: The Pollino 2012 seismic sequence: clues from continuous radon monitoring Antonio Piersanti, Valentina Cannelli, and Gianfranco Galli Solid Earth, 7, 1303-1316, doi:10.5194/se-7-1303-2016, 2016 We investigate in an innovative way the dynamics of radon emanation in a seismically active area. We analysed 3 years of data, collected during a long-term radon monitoring experiment. The complexity of the relationships among the investigated variables led us to consider the problem both from a phenomenological point of view and by means of original numerical analyses. Different approaches converge on the existence of a physical relation between soil radon emanation and seismicity.

Description: On the path to the digital rock physics of gas hydrate-bearing sediments – processing of in situ synchrotron-tomography data Kathleen Sell, Erik H. Saenger, Andrzej Falenty, Marwen Chaouachi, David Haberthür, Frieder Enzmann, Werner F. Kuhs, and Michael Kersten Solid Earth, 7, 1243-1258, doi:10.5194/se-7-1243-2016, 2016 To date, very little is known about the distribution of natural gas hydrates in sedimentary matrices and its influence on the seismic properties of the host rock, in particular at low hydrate concentration. Digital rock physics offers a unique approach to this issue yet requires good quality, high-resolution 3-D representations for the accurate modeling of petrophysical and transport properties. Although such models are readily available via in situ synchrotron radiation X-ray tomography, the analysis of such data asks for complex workflows and high computational power to maintain valuable results. Here, we present a best-practice procedure complementing data from Chaouachi et al. (2015) with data post-processing, including image enhancement and segmentation as well as exemplary numerical simulations of an acoustic wave propagation in 3-D using the derived results. A combination of the tomography and 3-D modeling opens a path to a more reliable deduction of properties of gas hydrate-bearing sediments without a reliance on idealized and frequently imprecise models.

Description: Geochemical mass-balance, weathering and evolution of soils formed on a Quaternaryage basaltic toposequences Hüseyin Şenol, Tülay Tunçay, and Orhan Dengiz Solid Earth Discuss., doi:10.5194/se-2016-105,2016 Manuscript under review for SE (discussion: open, 0 comments) In this study the features of pedogenic evolution of four soil profiles formed in topographically different positions of the southwestern–northeastern direction were investigated. The results of the study showed a strong relationship between the topography and some of the soil’s morphological, mineralogical, physical and chemical characteristics. Soil depth and physical soil features such as texture, structure and bulk density were found to improve downwards within the toposequence.

Description: Geopotential field anomalies and regional tectonic features – two case studies: southern Africa and Germany Monika Korte and Mioara Mandea Solid Earth Discuss., doi:10.5194/se-2015-132,2016 Manuscript under review for SE (discussion: open, 0 comments) We investigated characteristics of magnetic anomalies over southern Africa (South Africa, Namibia and Botswana) and Germany on different scales and also compared them to gravity gradient anomalies. Such anomalies provide information relevant to understanding geologcial and tectonic structures. Our results indicate a better agreement between anomalies caused by near-surface and deeper structures in the southern African than the German area.

Description: Effects of pumice mining on soil quality A. Cruz-Ruíz, E. Cruz-Ruíz, R. Vaca, P. Del Aguila, and J. Lugo Solid Earth, 7, 1-9, doi:10.5194/se-7-1-2016, 2016 The main aim was to assess agriculture soils differing in elapsed time since pumice mining in Mexico. The study sites in 0, 4, 10 and 15 year old reclaimed soils were compared with an adjacent undisturbed site. A general trend of recovery towards the undisturbed condition with reclamation age was found after disturbance. The multivariate analysis applied indicates that the most appropriate indicators to diagnose the quality of the soils were total N, urease and available phosphorus.

Description: The Imbert Formation of northern Hispaniola: a tectono-sedimentary record of arc–continent collision and ophiolite emplacement in the northern Caribbean subduction–accretionary prism J. Escuder-Viruete, Á. Suárez-Rodríguez, J. Gabites, and A. Pérez-Estaún Solid Earth, 7, 11-36, doi:10.5194/se-7-11-2016, 2016 New stratigraphical, structural, geochemical, and geochronological data from the northern Caribbean orogenic belt indicate that the Imbert Fm constitutes a coarsening-upward stratigraphic sequence that records the transition of the sedimentation from a pre-collisional forearc to a syn-collisional piggy-back basin in the lower-to-middle Eocene. This piggy-back basin was transported to the top of the Puerto Plata ophiolitic slab as it was emplaced onto the North America continental margin units.

Description: Grazing effects on soil characteristics and vegetation of grassland in northern China Z. Wang, D. A. Johnson, Y. Rong, and K. Wang Solid Earth, 7, 55-65, doi:10.5194/se-7-55-2016, 2016 Grazing increased diversity, but heavy grazing decreased aboveground biomass and increased the non-grass component. Overgrazing homogenized soil characteristics at a 10m scale. Therefore, moderate grazing was recommended as the preferred management alternative for grasslands in northern China because of increased plant diversity without negative consequences related to decreased forage quality forage quantity and soil heterogeneity in northern China's grasslands.

Description: The challenge and future of rocky desertification control in karst areas in southwest China J. Y. Zhang, M. H. Dai, L. C. Wang, C. F. Zeng, and W. C. Su Solid Earth, 7, 83-91, doi:10.5194/se-7-83-2016, 2016 Karst rocky desertification occurs after vegetation deteriorates as a result of intensive land use, which leads to severe water loss and soil erosion and exposes basement rocks, creating a rocky landscape. Karst rocky desertification is found in humid areas in southwest China, the region most seriously affected by rocky desertification in the world. In order to promote ecological restoration and help peasants out of poverty, the Chinese government carried out the first phase of a rocky desertification control project from 2006 to 2015, which initially contained the expansion of rocky desertification. Currently, the Chinese government is prepared to implement the second phase of the rocky desertification control project, and therefore it is essential to summarise the lessons learned over the last 10 years of the first phase. In this paper, we analyse the driving social and economic factors behind rocky desertification, summarise the scientific research on rocky desertification in the region, and finally identify the main problems facing rocky desertification control. In addition, we put forward several policy suggestions that take into account the perspective of local peasants, scientific research, and China's economic development and urbanisation process. These suggestions include promoting the non-agriculturalization of household livelihoods, improving ecological compensation, strengthening the evaluation of rocky desertification control and dynamic monitoring, and strengthening research on key ecological function recovery technologies and supporting technologies.

Description: Quantifying the impact of land degradation on crop production: the case of Senegal B. G. J. S. Sonneveld, M. A. Keyzer, and D. Ndiaye Solid Earth, 7, 93-103, doi:10.5194/se-7-93-2016, 2016 We found a plausible relationship between crop yield and a land degradation index based on expert judgements and affected area share. A pseudo-experiment was designed that for sites with otherwise similar circumstances compares the yield of a site with and one without land degradation. Our overall conclusion is that yield reduction is associated with higher levels of land degradation, irrespective of whether fertilizer is being applied or not.

Description: Effects of vegetation restoration on the aggregate stability and distribution of aggregate-associated organic carbon in a typical karst gorge region F. K. Tang, M. Cui, Q. Lu, Y. G. Liu, H. Y. Guo, and J. X. Zhou Solid Earth, 7, 141-151, doi:10.5194/se-7-141-2016, 2016 A study of vegetation restoration's effects on soil aggregate stability and SOC sequestration was carried out in a typical karst region (China). We found that revegetation promoted soil stability and accumulation of total SOC and SOC associated in water stable aggregates (WSA). WSA 〈 0.25 mm has the greatest contribution to total SOC. Fractal dimensions could objectively and comprehensively reflect soil stability. Promoting natural restoration is the ideal method to restore ecology in karst region.

Description: Qualitative and quantitative changes in detrital reservoir rocks caused by CO 2 –brine–rock interactions during first injection phases (Utrillas sandstones, northern Spain) E. Berrezueta, B. Ordóñez-Casado, and L. Quintana Solid Earth, 7, 37-53, doi:10.5194/se-7-37-2016, 2016 The aim of this article is to describe and interpret qualitative and quantitative changes at the rock matrix scale of Cretaceous sandstones (northern Spain) exposed to supercritical CO2 and brine. Experimental CO2-rich brine injection was performed in a reactor chamber under realistic conditions of deep saline formations (P ≈ 7.8 MPa, T ≈ 38 °C and 24 h exposure time). SEM and optical microscopy, aided by optical image processing and chemical analyses were used to study the rock samples.

Description: Evolution of rheologically heterogeneous salt structures: a case study from the NE Netherlands A. F. Raith, F. Strozyk, J. Visser, and J. L. Urai Solid Earth, 7, 67-82, doi:10.5194/se-7-67-2016, 2016 3D seismic and well data were used to study the evolution of salt pillows with extreme mechanical stratification to gain a better understanding of layered evaporite deposits. During evaporation an active basement graben caused the local accumulation of thick K-Mg salts. The resulting structure after the following extensional and compressional salt flow was strongly influenced by folding of the ruptured ZIII-AC stringer, leading to thickening and internal deformation of the soft K-Mg salt layers.

Description: Effects of wood chip amendments on the revegetation performance of plant species on eroded marly terrains in a Mediterranean mountainous climate (Southern Alps, France) V. Breton, Y. Crosaz, and F. Rey Solid Earth Discuss., doi:10.5194/se-2016-11,2016 Manuscript under review for SE (discussion: open, 0 comments) This paper presents the results of two experiments of revegetation techniques in context of water erosion and mountainous Mediterranean climate. We studied the interest of a wood chip amendment, applied on soil surface (mulch), and its interaction with plant development. The use of different plant species and the monitoring on three growing seasons (with climatic variations) allow us to specify the interest of wood chip mulch to improve revegetation especially in erosion and drought conditions.

Description: Basement structure of the Hontomín CO 2 storage site (Spain) determined by integration of microgravity and 3D seismic data J. Andres, J. Alcalde, P. Ayarza, E. Saura, I. Marzán, D. Martí, J. R. Martínez Catalán, R. Carbonell, A. Pérez-Estaún, J. L. García-Lobón, and F. M. Rubio Solid Earth Discuss., doi:10.5194/se-2016-13,2016 Manuscript under review for SE (discussion: open, 0 comments) A multidisciplinary study has been carried out in Hontomín (Spain) to determine the basement structural setting/ geometry and that of the sedimentary succession of an area aimed to be the first Spanish pilot plant of CO 2 injection. An integration of coincident 3D seismic results, borehole data and unpublished microgravity 5 maps aims to reproduce the deep structure of the basement and to quantify the thickness of the Triassic Keuper evaporites. All datasets manage to clearly identify two main fault systems compartmentalizing the main structural domains into three differentiated blocks. These have been interpreted to be reactivated normal faults that have led to the formation of 10 the Hontomín dome. The general structure is characterized by a half-graben setting filled with thick Keuper evaporites (up to 2000 m thick) forming an extensional forced fold.

Description: CO 2 emission and structural characteristics of two calcareous soils amended with municipal solid waste and plant residue N. Yazdanpanah Solid Earth, 7, 105-114, doi:10.5194/se-7-105-2016, 2016 Following the application of organic amendment treatments, the increased organic carbon and total porosity values, as compared to the control treatment, were greater in the loamy sand soil than in the clay loam soil. Moreover, compared to the microbial respiration of control plots, the application of municipal solid waste resulted in higher levels of microbial respiration from the clay loam soil than from the loamy sand soil, whereas the reverse was found for alfalfa residue.

Description: Trail impact monitoring in Rocky Mountain National Park, USA J. Svajda, S. Korony, I. Brighton, S. Esser, and S. Ciapala Solid Earth, 7, 115-128, doi:10.5194/se-7-115-2016, 2016 Rocky Mountain National Park is one of the most visited national parks in the United States. 95 % of the park is managed as wilderness. This paper examines the impacts of trampling on the vegetation and soil along selected trails. Trail widening and soil loss are the most visible types of trail degradation. Insights into the influence of different factors (use level, topography) can lead to the selection of appropriate management measures to avoid or minimize negative consequences.

Description: X-ray microtomography analysis of soil structure deformation caused by centrifugation S. Schlüter, F. Leuther, S. Vogler, and H.-J. Vogel Solid Earth, 7, 129-140, doi:10.5194/se-7-129-2016, 2016 A new protocol for digital volume correlation facilitates detailed insights into internal deformation of soil. Structure deformation during centrifugation is revealed by comparing X-ray CT images before and after centrifugation. Quantitative image analysis reveals that soil structure changes are driven by soil shrinkage due to drying and soil compaction due to compression.

Description: Geophysical evidence of pre-sag rifting and post-rifting fault reactivation in the Parnaíba basin, Brazil D. L. de Castro, F. H. R. Bezerra, R. A. Fuck, and Roberta M. Vidotti Solid Earth Discuss., doi:10.5194/se-2016-21,2016 Manuscript under review for SE (discussion: open, 0 comments) We combine new seismic data and well logs with airborne gravity and magnetic data to reveal the internal architecture of the Parnaíba basin. This Phanerozoic sedimentary basin overlies a large region of Precambrian crustal blocks in the South American platform before the break-up of the West Gondwana in Early Cretaceous. The tectonic evolution of this important cratonic basin involved a complex rifting phase followed by a long period of sag subsidence, with multiple fault reactivation.

Description: Stability and biodegradability of organic matter from Arctic soils of Western Siberia: insights from 13 C-NMR spectroscopy and elemental analysis E. Ejarque and E. Abakumov Solid Earth, 7, 153-165, doi:10.5194/se-7-153-2016, 2016 This study presents, for the first time, a characterisation of soil organic matter from the Gydan Peninsula in the Yamal Region, Western Siberia, Russia. We provide evidences that soils in this region accumulate lowly decomposed organic matter with a high mineralisation potential. This emphasises the vulnerability of this soil carbon pool to be remobilised as CO 2 to the atmosphere under climate warming effects.

Description: Integrating a mini catchment with mulching for soil water management in a sloping jujube orchard on the semiarid Loess Plateau of China H. C. Li, X. D. Gao, X. N. Zhao, P. T. Wu, L. S. Li, Q. Ling, and W. H. Sun Solid Earth, 7, 167-175, doi:10.5194/se-7-167-2016, 2016 We integrated fish-scale pits with mulching to test whether this integration could improve soil water conservation. The results showed that integrating fish-scale pits with mulching could conserve significantly more soil water by increasing infiltration and decreasing evaporation, and showed greater soil water storage and degree of soil water compensation compared to fish-scale pits alone. In addition, jujube branches exerted better mulching effects than maize straw.

Description: A new X-ray transparent flow-through reaction cell for a μ-CT-based concomitant surveillance of the reaction progress of hydrothermal mineral-fluid interactions Wolf-Achim Kahl, Christian Hansen, and Wolfgang Bach Solid Earth Discuss., doi:10.5194/se-2016-25,2016 Manuscript under review for SE (discussion: open, 0 comments) A new flow-through reaction cell consisting of an X-ray transparent semicrystalline thermoplastic has been developed for percolation experiments. Core holder, tubing and all confining parts are designed of PEEK (polyetheretherketone) to allow concomitant surveillance of the reaction progress by X-ray microtomography. The reaction progress of the flow-through experiment can be monitored without dismantling the sample from the core holder.

Description: Characterization of a complex near-surface structure using well logging and passive seismic measurements Beatriz Benjumea, Albert Macau, Anna Gabàs, and Sara Figueras Solid Earth Discuss., doi:10.5194/se-2016-19,2016 Manuscript under review for SE (discussion: open, 0 comments) We study the near-surface of a complex study area located in Burgos (Spain) characterized by significant changes in shallow geology. The geophysical techniques include measurements of seismic noise (passive seismic) at different points that provide sediment thickness and seismic velocity of the subsoil. On the other hand, geophysical well data help to interpret the passive seismic results. The product of this methodology can be helpful for planning geophysical field surveys in complex areas.

Description: X-ray CT analysis of pore structure in sand Toshifumi Mukunoki, Yoshihisa Miyata, Kazuaki Mikami, and Erika Shiota Solid Earth Discuss., doi:10.5194/se-2016-16,2016 Manuscript under review for SE (discussion: open, 0 comments) In this study, a specimen of sand was scanned to evaluate pore structure quantitatively using a micro-focused X-ray CT scanner. The representative volume to perform reasonable image analysis for sand was discussed and then, the spatial distribution of pore diameter in 3D was visualized and evaluated quantitatively by granulometric image analysis. Also, the voxel-percolation analysis was newly proposed in this study to assess capillary pressure and saturation degree by pore diameter analyzed.