ALBERT

Description: A Web-based spatial decision supporting system for land management and soil conservation Solid Earth, 6, 903-928, 2015 Author(s): F. Terribile, A. Agrillo, A. Bonfante, G. Buscemi, M. Colandrea, A. D'Antonio, R. De Mascellis, C. De Michele, G. Langella, P. Manna, L. Marotta, F. A. Mileti, L. Minieri, N. Orefice, S. Valentini, S. Vingiani, and A. Basile Today it is evident that there are many contrasting demands on our landscape (e.g. food security, more sustainable agriculture, higher income in rural areas, etc.) as well as many land degradation problems. It has been proved that providing operational answers to these demands and problems is extremely difficult. Here we aim to demonstrate that a spatial decision support system based on geospatial cyberinfrastructure (GCI) can address all of the above, so producing a smart system for supporting decision making for agriculture, forestry, and urban planning with respect to the landscape. In this paper, we discuss methods and results of a special kind of GCI architecture, one that is highly focused on land management and soil conservation. The system allows us to obtain dynamic, multidisciplinary, multiscale, and multifunctional answers to agriculture, forestry, and urban planning issues through the Web. The system has been applied to and tested in an area of about 20 000 ha in the south of Italy, within the framework of a European LIFE+ project (SOILCONSWEB). The paper reports – as a case study – results from two different applications dealing with agriculture (olive growth tool) and environmental protection (soil capability to protect groundwater). Developed with the help of end users, the system is starting to be adopted by local communities. The system indirectly explores a change of paradigm for soil and landscape scientists. Indeed, the potential benefit is shown of overcoming current disciplinary fragmentation over landscape issues by offering – through a smart Web-based system – truly integrated geospatial knowledge that may be directly and freely used by any end user ( www.landconsultingweb.eu ). This may help bridge the last very important divide between scientists working on the landscape and end users.

Description: A fuzzy intelligent system for land consolidation – a case study in Shunde, China Solid Earth, 6, 997-1006, 2015 Author(s): J. Wang, A. Ge, Y. Hu, C. Li, and L. Wang Traditionally, potential evaluation methods for farmland consolidation have depended mainly on the experts' experiences, statistical computations or subjective adjustments. Some biases usually exist in the results. Thus, computer-aided technology has become essential. In this study, an intelligent evaluation system based on a fuzzy decision tree was established, and this system can deal with numerical data, discrete data and symbolic data. When the original land data are input, the level of potential of the agricultural land for development will be output by this new model. The provision of objective proof for decision-making by authorities in rural management is helpful. Agricultural land data characteristically comprise large volumes, complex varieties and more indexes. In land consolidation, it is very important to construct an effective index system. A group of indexes need to be selected for land consolidation. In this article, a fuzzy measure was adopted to accomplish the selection of specific features. A fuzzy integral based on a fuzzy measure is a type of fusion tool. The optimal solution with the fewest non-zero elements was obtained for the fuzzy measure by solving a fuzzy integral. This algorithm provides a quick and optimal way to identify the land-index system when preparing to conduct land consolidation. This new research was applied to Shunde's "Three Old" consolidation project which provides the data. Our estimation system was compared with a conventional evaluation system that is still accepted by the public. Our results prove to be consistent, and the new model is more automatic and intelligent. The results of this estimation system are significant for informing decision-making in land consolidation.

Description: Precision of farmer-based fertility ratings and soil organic carbon for crop production on a Ferralsol Solid Earth, 6, 1063-1073, 2015 Author(s): P. Musinguzi, P. Ebanyat, J. S. Tenywa, T. A. Basamba, M. M. Tenywa, and D. Mubiru Simple and affordable soil fertility ratings are essential, particularly for the resource-constrained farmers in sub-Saharan Africa (SSA), in planning and implementing prudent interventions. A study was conducted on Ferralsols in Uganda to evaluate farmer-based soil fertility assessment techniques, hereafter referred to as farmers' field experiences (FFE), for ease of use and precision, against more formal scientific quantitative ratings using soil organic carbon (SQR-SOC). A total of 30 fields were investigated and rated using both techniques, as low, medium and high in terms of soil fertility – with maize as the test crop. Both soil fertility rating techniques were fairly precise in delineating soil fertility classes, though the FFE was inefficient in distinguishing fields 〉 1.2 % SOC with medium and high fertility. Soil organic carbon, silt and clay were exceptionally influential, accounting for the highest percentage in grain yield of 50 % in the topsoil (0–15 cm) and 67 % for the mean concentrations from 0 to 15 and 15 to 30 cm. Each unit increase in SOC concentration resulted in 966 to 1223 kg ha −1 yield gain. The FFE technique was effective in identifying low-fertility fields, and this was coherent with the fields categorized as low (SOC 〈 1.2 %). Beyond this level, its precision can be remarkably increased when supplemented with the SQR-SOC technique.

Description: Phase change in subducted lithosphere, impulse, and quantizing Earth surface deformations Solid Earth, 6, 1075-1085, 2015 Author(s): C. O. Bowin, W. Yi, R. D. Rosson, and S. T. Bolmer The new paradigm of plate tectonics began in 1960 with Harry H. Hess's 1960 realization that new ocean floor was being created today and is not everywhere of Precambrian age as previously thought. In the following decades an unprecedented coming together of bathymetric, topographic, magnetic, gravity, seismicity, seismic profiling data occurred, all supporting and building upon the concept of plate tectonics. Most investigators accepted the premise that there was no net torque amongst the plates. Bowin (2010) demonstrated that plates accelerated and decelerated at rates 10 −8 times smaller than plate velocities, and that globally angular momentum is conserved by plate tectonic motions, but few appeared to note its existence. Here we first summarize how we separate where different mass sources may lie within the Earth and how we can estimate their mass. The Earth's greatest mass anomalies arise from topography of the boundary between the metallic nickel–iron core and the silicate mantle that dominate the Earth's spherical harmonic degree 2 and 3 potential field coefficients, and overwhelm all other internal mass anomalies. The mass anomalies due to phase changes in olivine and pyroxene in subducted lithosphere are hidden within the spherical harmonic degree 4–10 packet, and are an order of magnitude smaller than those from the core–mantle boundary. Then we explore the geometry of the Emperor and Hawaiian seamount chains and the 60° bend between them that aids in documenting the slow acceleration during both the Pacific Plate's northward motion that formed the Emperor seamount chain and its westward motion that formed the Hawaiian seamount chain, but it decelerated at the time of the bend (46 Myr). Although the 60° change in direction of the Pacific Plate at of the bend, there appears to have been nary a pause in a passive spreading history for the North Atlantic Plate, for example. This, too, supports phase change being the single driver for plate tectonics and conservation of angular momentum. Since mountain building we now know results from changes in momentum, we have calculated an experimental deformation index value (1–1000) based on a world topographic grid at 5 arcmin spacing and displayed those results for viewing.

Description: Responses of vertical soil moisture to rainfall pulses and land uses in a typical loess hilly area, China Solid Earth, 6, 595-608, 2015 Author(s): Y. Yu, W. Wei, L. D. Chen, F. Y. Jia, L. Yang, H. D. Zhang, and T. J. Feng Soil moisture plays a key role in vegetation restoration and ecosystem stability in arid and semiarid regions. The response of soil moisture to rainfall pulses is an important hydrological process, which is strongly influenced by land use during the implementation of vegetation restoration. In this study, vertical soil moisture variations of woodland ( Pinus tabulaeformis ), native grassland ( Stipa bungeana ), shrubland ( Hippophea rhamnoides ), cropland ( Triticum aestivum ) and artificial grassland ( Onobrychis viciaefolia ) in five soil profiles were monitored in a typical loess hilly area during the 2010 growing season. The results demonstrated that rainfall pulses directly affected soil moisture variation. A multi-peak pattern of soil moisture appeared during the growing season, notably in the surface soil layer. Meanwhile, the response of each vegetation type to rainfall was inconsistent, and a time-lag effect before reaching the peak value was detected, following each heavy rainfall event. The response duration of soil moisture, however, varied markedly with the size of rainfall events. Furthermore, higher soil water content was detected in grassland and shrubland. Woodland was characterized by relatively lower soil moisture values throughout the investigation period. Our research suggests that vegetation restoration efforts should give priority to grassland and shrubland at the research site. We suggest that more studies should be focused on the characteristics of community structure and spatial vegetation distribution on soil moisture dynamics, particularly within the grass and shrub ecosystems.

Description: Remediation of degraded arable steppe soils in Moldova using vetch as green manure Solid Earth, 6, 609-620, 2015 Author(s): M. Wiesmeier, M. Lungu, R. Hübner, and V. Cerbari In the Republic of Moldova, non-sustainable arable farming led to severe degradation and erosion of fertile steppe soils (Chernozems). As a result, the Chernozems lost about 40% of their initial amounts of soil organic carbon (SOC). The aim of this study was to remediate degraded arable soils and promote carbon sequestration by implementation of cover cropping and green manuring in Moldova. Thereby, the suitability of the legume hairy vetch ( Vicia sativa ) as cover crop under the dry continental climate of Moldova was examined. At two experimental sites, the effect of cover cropping on chemical and physical soil properties as well as on yields of subsequent main crops was determined. The results showed a significant increase of SOC after incorporation of hairy vetch mainly due to increases of aggregate-occluded and mineral-associated OC. This was related to a high above- and belowground biomass production of hairy vetch associated with a high input of carbon and nitrogen into arable soils. A calculation of SOC stocks based on equivalent soil masses revealed a sequestration of around 3 t C ha −1 yr −1 as a result of hairy vetch cover cropping. The buildup of SOC was associated with an improvement of the soil structure as indicated by a distinct decrease of bulk density and a relative increase of macroaggregates at the expense of microaggregates and clods. As a result, yields of subsequent main crops increased by around 20%. Our results indicated that hairy vetch is a promising cover crop to remediate degraded steppe soils, control soil erosion and sequester substantial amounts of atmospheric C in arable soils of Moldova.

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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: Effect of polluted water on soil and plant contamination by heavy metals in El-Mahla El-Kobra, Egypt Esawy Kasem Mahmoud and Adel Mohamed Ghoneim Solid Earth, 7, 703-711, doi:10.5194/se-7-703-2016, 2016 Delta drains receive high concentrations of organic and inorganic pollutants from industrial, domestic as well as diffuse agricultural waste water. High priority should be given to Zefta and drain no.5 sites which receive high loads of pollutants. This was confirmed by the lower water quality and polluted soils, especially by heavy metals in the El-Mahla El-Kobra area.

Description: Soil wind erosion in ecological olive trees in the Tabernas desert (S.E. Spain): a wind tunnel experiment Carlos Asensio, Francisco Javier Lozano, Pedro Gallardo, and Antonio Giménez Solid Earth Discuss., doi:10.5194/se-2016-65,2016 Manuscript under review for SE (discussion: open, 0 comments) Climate and soil surface conditions influence the erosive capacity of the wind, causing loss of soil productivity. Wind erosion leads soil drying and its loss of nutrients, and this in turn is conditioned by soil surface compaction. The impact of management on most of soil properties and on its wind erodibility determines agricultural productivity and sustainability. We used a new wind tunnel to evaluate all these acts.

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: 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: 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: 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: 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: 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: Livestock redistribute runoff and sediments in semi-arid rangeland areas Solid Earth, 6, 433-443, 2015 Author(s): P. Sarah and M. Zonana Semi-arid areas where grazing is the main land use exhibit a "three-phase-mosaic" pattern of dominant surface patches: shrubs, trampling routes, and intershrub areas. This pattern differs from the "two-phase mosaic" seen in grazing-free semi-arid areas. The patches might create a positive feedback process in which enhanced infiltration beneath shrubs minimizes overland flow from under their canopies, thereby strengthening the sink–source mechanism by which overland flow generated between shrubs rapidly infiltrates into the soil beneath them, where it deposits soil particles, litter, nutrients and organic matter, thereby enhancing infiltration by changing the local microtopography, and improving soil properties. To analyze sink–source relationships among the patches in grazed areas in rangelands of the semi-arid northern Negev region of Israel, we constructed small runoff plots, 0.25–1.0 m 2 in area, of five types: shrub ( Sarcopoterium spinosum ), intershrub, route, route–shrub combination, and intershrub–shrub combination. The shrubs always occupied the downslope part of the plot. Overland flow and sediment deposits were measured in all plots during 2007/8 and 2008/9. The combined plots yielded much less overland flow and sediments than intershrub, routes and shrub ones, indicating that the shrubs absorbed almost all the yields of the upper part of their plots. The shrubs generated less runoff and sediments than routes and intershrubs; runoff flows from the routes and intershrubs were similar; sediment yield was highest in the intershrubs. Thus, runoff yield exhibited a two-phase mosaic pattern, and sediment yield, i.e., soil erosion, a three-phase mosaic pattern.

Description: Tectonic evolution and high-pressure rock exhumation in the Qiangtang terrane, central Tibet Solid Earth, 6, 457-473, 2015 Author(s): Z. Zhao, P. D. Bons, G. Wang, A. Soesoo, and Y. Liu Conflicting interpretations of the 〉 500 km long, east–west-trending Qiangtang metamorphic belt have led to very different and contradicting models for the Permo–Triassic tectonic evolution of central Tibet. We define two metamorphic events, one that only affected pre-Ordovician basement rocks and one subduction-related Triassic high-pressure metamorphism event. Detailed mapping and structural analysis allowed us to define three main units that were juxtaposed due to collision of the north and south Qiangtang terranes after closure of the Ordovician–Triassic ocean that separated them. The base is formed by the Precambrian–Carboniferous basement, followed by non-metamorphic ophiolitic mélange containing mafic rocks that range in age from the Ordovician to Middle Triassic. The top of the sequence is formed by strongly deformed sedimentary mélange that contains up to 〉 10 km size rafts of both unmetamorphosed Permian sediments and high-pressure blueschists. We propose that the high-pressure rocks were exhumed from underneath the south Qiangtang terrane in an extensional setting caused by the pull of the northward subducting slab of the Shuanghu–Tethys. High-pressure rocks, sedimentary mélange and margin sediments were thrust on top of the ophiolitic mélange that was scraped off the subducting plate. Both units were subsequently thrust on top of the south Qiantang terrane continental basement. Onset of Late Triassic sedimentation marked the end of the amalgamation of both Qiangtang terranes and the beginning of spreading between Qiantang and north Lhasa to the south, leading to the deposition of thick flysch deposits in the Jurassic.

Description: An evaluation of different measures of dynamically recrystallized grain size for paleopiezometry or paleowattometry studies Solid Earth, 6, 475-495, 2015 Author(s): M. A. Lopez-Sanchez and S. Llana-Fúnez Paleopiezometry and paleowattometry studies are essential to validate models of lithospheric deformation and therefore increasingly common in structural geology. These studies require a single measure of dynamically recrystallized grain size in natural mylonites to estimate the magnitude of differential paleostress (or the rate of mechanical work). This contribution tests the various measures of grain size used in the literature and proposes the frequency peak of a grain size distribution as the most robust estimator for paleopiezometry or paleowattometry studies. The novelty of the approach resides in the use of the Gaussian kernel density estimator as an alternative to the classical histograms, which improves reproducibility. A free, open-source, easy-to-handle script named GrainSizeTools ( http://www.TEOS-10.org ) was developed with the aim of facilitating the adoption of this measure of grain size in paleopiezometry or paleowattometry studies. The major advantage of the script over other programs is that by using the Gaussian kernel density estimator and by avoiding manual steps in the estimation of the frequency peak, the reproducibility of results is improved.

Description: Litter contribution to soil organic carbon in the processes of agriculture abandon Solid Earth, 6, 425-432, 2015 Author(s): A. Novara, J. Rühl, T. La Mantia, L. Gristina, S. La Bella, and T. Tuttolomondo The mechanisms of litter decomposition, translocation and stabilization into soil layers are fundamental processes in the functioning of the ecosystem, as they regulate the cycle of soil organic matter (SOM) and CO 2 emission into the atmosphere. In this study the contribution of litters of different stages of Mediterranean secondary succession on carbon sequestration was investigated, analyzing the role of earthworms in the translocation of SOM into the soil profile. For this purpose the δ 13 C difference between meadow C 4 -C soil and C 3 -C litter was used in a field experiment. Four undisturbed litters of different stages of succession (45, 70, 100 and 120 since agriculture abandon) were collected and placed on the top of isolated C4 soil cores. The litter contribution to C stock was affected by plant species and it increased with the age of the stage of secondary succession. One year after the litter position, the soil organic carbon increased up to 40% in comparison to soils not treated with litter after 120 years of abandon. The new carbon derived from C 3 litter was decomposed and transferred into soil profile thanks to earthworms and the leaching of dissolved organic carbon. After 1 year the carbon increase attributed to earthworm activity was 6 and 13% in the soils under litter of fields abandoned for 120 and 45 years, respectively.

Description: Spatial variability of soil properties and soil erodibility in the Alqueva reservoir watershed Solid Earth, 6, 383-392, 2015 Author(s): V. Ferreira, T. Panagopoulos, R. Andrade, C. Guerrero, and L. Loures The aim of this work is to investigate how the spatial variability of soil properties and soil erodibility ($K$ factor) were affected by the changes in land use allowed by irrigation with water from a reservoir in a semiarid area. To this end, three areas representative of different land uses (agroforestry grassland, lucerne crop and olive orchard) were studied within a 900 ha farm. The interrelationships between variables were analyzed by multivariate techniques and extrapolated using geostatistics. The results confirmed differences between land uses for all properties analyzed, which was explained mainly by the existence of diverse management practices (tillage, fertilization and irrigation), vegetation cover and local soil characteristics. Soil organic matter, clay and nitrogen content decreased significantly, while the K factor increased with intensive cultivation. The HJ-Biplot methodology was used to represent the variation of soil erodibility properties grouped in land uses. Native grassland was the least correlated with the other land uses. The K factor demonstrated high correlation mainly with very fine sand and silt. The maps produced with geostatistics were crucial to understand the current spatial variability in the Alqueva region. Facing the intensification of land-use conversion, a sustainable management is needed to introduce protective measures to control soil erosion.

Description: Soil aggregation, erodibility, and erosion rates in mountain soils (NW Alps, Italy) Solid Earth, 6, 403-414, 2015 Author(s): S. Stanchi, G. Falsone, and E. Bonifacio Erosion is a relevant soil degradation factor in mountain agrosilvopastoral ecosystems that can be enhanced by the abandonment of agricultural land and pastures left to natural evolution. The on-site and off-site consequences of soil erosion at the catchment and landscape scale are particularly relevant and may affect settlements at the interface with mountain ecosystems. RUSLE (Revised Universal Soil Loss Equation) estimates of soil erosion consider, among others, the soil erodibility factor ( K ), which depends on properties involved in structure and aggregation. A relationship between soil erodibility and aggregation should therefore be expected. However, erosion may limit the development of soil structure; hence aggregates should not only be related to erodibility but also partially mirror soil erosion rates. The aim of the research was to evaluate the agreement between aggregate stability and erosion-related variables and to discuss the possible reasons for discrepancies in the two kinds of land use considered (forest and pasture). Topsoil horizons were sampled in a mountain catchment under two vegetation covers (pasture vs. forest) and analyzed for total organic carbon, total extractable carbon, pH, and texture. Soil erodibility was computed, RUSLE erosion rate was estimated, and aggregate stability was determined by wet sieving. Aggregation and RUSLE-related parameters for the two vegetation covers were investigated through statistical tests such as ANOVA, correlation, and regression. Soil erodibility was in agreement with the aggregate stability parameters; i.e., the most erodible soils in terms of K values also displayed weaker aggregation. Despite this general observation, when estimating K from aggregate losses the ANOVA conducted on the regression residuals showed land-use-dependent trends (negative average residuals for forest soils, positive for pastures). Therefore, soil aggregation seemed to mirror the actual topsoil conditions better than soil erodibility. Several hypotheses for this behavior were discussed. A relevant effect of the physical protection of the organic matter by the aggregates that cannot be considered in $K$ computation was finally hypothesized in the case of pastures, while in forests soil erodibility seemed to keep trace of past erosion and depletion of finer particles. A good relationship between RUSLE soil erosion rates and aggregate stability occurred in pastures, while no relationship was visible in forests. Therefore, soil aggregation seemed to capture aspects of actual vulnerability that are not visible through the erodibility estimate. Considering the relevance and extension of agrosilvopastoral ecosystems partly left to natural colonization, further studies on litter and humus protective action might improve the understanding of the relationship among erosion, erodibility, and structure.

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: Experimental sand burial affects seedling survivorship, morphological traits and biomass allocation of Ulmus pumila var. sabulosa in Horqin Sandy Land Jiao Tang, Carlos Alberto Busso, Deming Jiang, Ala Musa, Dafu Wu, Yongcui Wang, and Chunping Miao Solid Earth Discuss., doi:10.5194/se-2016-55,2016 Manuscript under review for SE (discussion: open, 0 comments) 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 and increased seedling height, diameter, taproot length, total biomass and relative growth rates. But it decreased total leaf area and changed biomass allocation, transferring more biomass to aboveground.

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: 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: 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: X-Ray CT analyses, models and numerical simulations – a comparison with common analytical methods of an experimental CO 2 study Steven Henkel, Dieter Pudlo, Frieder Enzmann, Viktor Reitenbach, Daniel Albrecht, Leonhard Ganzer, and Reinhard Gaupp Solid Earth Discuss., doi:10.5194/se-2016-36,2016 Manuscript under review for SE (discussion: open, 0 comments) This study investigates the 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 leading to similar results for coarse and medium grained sandstones but differ for fine grained sediments.

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: 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: 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: 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: 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 Discuss., doi:10.5194/se-2016-54,2016 Manuscript under review for SE (discussion: open, 0 comments) To date, very little is known about the distribution of gas hydrates in sedimentary matrices and the resulting matrix-pore network affecting the seismic properties at low hydrate concentration. Digital rock physics offers a unique solution to this issue yet requires good quality, high resolution 3D representations for the accurate modelling 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-practise procedure complementing data from Chaouachi et al. ( Geochemistry, Geophysics, Geosystems 2015, 16 (6), 1711–1722) with data post-processing, including image enhancement and segmentation as well as numerical simulations in 3D using the derived results as a direct model input. The method presented opens a path to a model-free deduction of the properties of gas hydrate bearing sediments when aiming for in-situ experiments linked to synchrotron-based tomography and 3D modelling.

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: 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 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: 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: Post-glacial reactivation of the Bollnäs fault, central Sweden – a multidisciplinary geophysical investigation Alireza Malehmir, Magnus Andersson, Suman Mehta, Bojan Brodic, Raymond Munier, Joachim Place, Georgiana Maries, Colby Smith, Jochen Kamm, Mehrdad Bastani, Henrik Mikko, and Björn Lund Solid Earth, 7, 509-527, doi:10.5194/se-7-509-2016, 2016 Glacially induced intraplate faults are conspicuous and confined to northern parts of Fennoscandia. Here we report a multidisciplinary geophysical investigation delineating the newly inferred lidar imagery data from the Bollnäs post-glacial fault in central Sweden. The geophysical data consistently support the presence of a fault in the crystalline basement associated with an earlier structure, possibly a deformation zone that reactive after the Weichselian deglaciation.

Description: 〈b〉Ionian Abyssal Plain: A window into the Tethys oceanic lithosphere〈/b〉〈br〉 Anke Dannowski, Heidrun Kopp, Frauke Klingelhoefer, Dirk Klaeschen, Marc-André Gutscher, Anne Krabbenhoeft, David Dellong, Marzia Rovere, David Graindorge, Cord Papenberg, and Ingo Klaucke〈br〉 Solid Earth Discuss., https//doi.org/10.5194/se-2018-123,2018〈br〉 〈b〉Manuscript under review for SE〈/b〉 (discussion: open, 0 comments)〈br〉 The nature of the Ionian Sea crust has been the subject of scientific debate for more than 30 years. Seismic data, recorded on ocean bottom instruments, have been analysed and support the interpretation of the Ionian Abyssal Plain as a remnant of the Tethys oceanic lithosphere formed roughly 220 to 250 ma. Which places the African margin much further south than previously thought.

Description: 〈b〉Myrmekite and strain weakening in granitoid mylonites〈/b〉〈br〉 Alberto Ceccato, Luca Menegon, Giorgio Pennacchioni, and Luiz Fernando Grafulha Morales〈br〉 Solid Earth, 9, 1399-1419, https://doi.org/10.5194/se-9-1399-2018, 2018〈br〉 Metamorphic fine-grained reaction products make continental crust rocks weaker. Microstructural processes related to the transformation of strong K-feldspar into weak aggregates of plagioclase and quartz during crustal deformation have been investigated through electron microscopy. Rheological calculations show that the occurrence of even small amounts of weak aggregates, whose deformation is mainly diffusion-assisted, would lead to a decrease in rock viscosity of several orders of magnitude.

Description: 〈b〉Time-lapse gravity and levelling surveys reveal mass loss and ongoing subsidence in the urban subrosion prone area of Bad Frankenhausen/Germany〈/b〉〈br〉 Martin Kobe, Gerald Gabriel, Adelheid Weise, and Detlef Vogel〈br〉 Solid Earth Discuss., https//doi.org/10.5194/se-2018-115,2018〈br〉 〈b〉Manuscript under review for SE〈/b〉 (discussion: final response, 2 comments)〈br〉 Subrosion, i.e. the underground leaching of soluble rocks, causes disastrous sinkhole events worldwide. We investigate the accompanying mass-transfer using quarter-yearly time-lapse gravity campaigns over four years in the town of Bad Frankenhausen/Germany. After correcting for seasonal soil water content, we find evidence of underground mass loss and attempt to quantify its amount. This is the first study of its kind to prove the feasibility of this approach in an urban area.

Description: 〈b〉New insights on the early Mesozoic evolution of multiple tectonic regimes in the northeastern North China Craton from the detrital zircon provenance of sedimentary strata〈/b〉〈br〉 Yi Ni Wang, Wen Liang Xu, Feng Wang, and Xiao Bo Li〈br〉 Solid Earth, 9, 1375-1397, https://doi.org/10.5194/se-9-1375-2018, 2018〈br〉 Early Triassic sediments in the northeastern North Chian Craton resulted from the subduction of the Paleo-Asian oceanic plate and collision between the North China and Yangtze cratons. Late Triassic sediments resulted from the final closure of the Paleo-Asian Ocean in the Middle Triassic and exhumation of the Su–Lu Orogenic Belt. Early Jurassic change in provenance was related to the uplift of the Xing'an–Mongolia Orogenic Belt and the subduction of the Paleo-Pacific Plate.

Description: 〈b〉Induced seismicity in geologic carbon storage〈/b〉〈br〉 Víctor Vilarrasa, Jesus Carrera, Sebastià Olivella, Jonny Rutqvist, and Lyesse Laloui〈br〉 Solid Earth Discuss., https//doi.org/10.5194/se-2018-129,2019〈br〉 〈b〉Manuscript under review for SE〈/b〉 (discussion: open, 0 comments)〈br〉 To meet the goal of the Paris Agreement to limit temperature increase below 2 ºC, Geologic Carbon Storage (GCS) will be necessary at the gigatone scale. But to successfully deploy GCS, seismicity induced by CO〈sub〉2〈/sub〉 injection should be controlled and maintained below a threshold that does not generate nuisances to the population. We conclude that felt induced seismicity can be minimized provided that a proper site characterization, monitoring and pressure management are performed.

Description: 〈b〉From widespread Mississippian to localized Pennsylvanian extension in central Spitsbergen, Svalbard〈/b〉〈br〉 Jean-Baptiste P. Koehl and Jhon M. Muñoz-Barrera〈br〉 Solid Earth, 9, 1535-1558, https://doi.org/10.5194/se-9-1535-2018, 2018〈br〉 This research is dedicated to the study of poorly understood coal-bearing Mississippian (ca. 360–325 Ma) sedimentary rocks in central Spitsbergen. Our results suggest that these rocks were deposited during a period of widespread extension involving multiple fault trends, including faults striking subparallel to the extension direction, while overlying Pennsylvanian rocks (ca. 325–300 Ma) were deposited during extension localized along fewer, larger faults.

Description: 〈b〉The effect of rock composition on muon tomography measurements〈/b〉〈br〉 Alessandro Lechmann, David Mair, Akitaka Ariga, Tomoko Ariga, Antonio Ereditato, Ryuichi Nishiyama, Ciro Pistillo, Paola Scampoli, Fritz Schlunegger, and Mykhailo Vladymyrov〈br〉 Solid Earth, 9, 1517-1533, https://doi.org/10.5194/se-9-1517-2018, 2018〈br〉 Muon tomography is a technology, similar to X-ray tomography, to image the interior of an object, including geologically interesting ones. In this work, we examined the influence of rock composition on the physical measurements, and the possible error that is made by assuming a too-simplistic rock model. We performed numerical simulations for a more realistic rock model and found that beyond 300 m of rock, the composition starts to play a significant role and has to be accounted for.

Description: 〈b〉Regional Pliocene Exhumation of the Lesser Himalaya in the Indus Drainage〈/b〉〈br〉 Peter D. Clift, Peng Zhou, Daniel F. Stockli, and Jerzy Blusztajn〈br〉 Solid Earth Discuss., https//doi.org/10.5194/se-2018-132,2018〈br〉 〈b〉Manuscript under review for SE〈/b〉 (discussion: open, 0 comments)〈br〉 Surface processes driven by climate have been linked to the tectonic evolution of mountain belts, with the Himalayas and Asian monsoon being a classic example. Sediments from the Arabian Sea now show an increase in erosion from the Karakoram between 17 and 9.5 Ma, followed by an increase in the relative flux from the Himalayas after 5.7 Ma and especially from the Lesser Himalayas after 1.9 Ma. Lack of correlation with climate histories suggests that tectonic forces dominate control over erosion.

Description: 〈b〉The crossdip correction as a tool to improve imaging of crooked line seismic data: A case study from the post-glacial Burträsk fault, Sweden〈/b〉〈br〉 Ruth A. Beckel and Christopher Juhlin〈br〉 Solid Earth Discuss., https//doi.org/10.5194/se-2018-120,2018〈br〉 〈b〉Manuscript under review for SE〈/b〉 (discussion: open, 0 comments)〈br〉 Scandinavia is crossed by extensive fault scarps that have likely been caused by huge earthquake when the ice sheets of the last glacial melted. Due to the inaccessibility of the terrain, reflection seismic data has to be collected along crooked lines which reduces the imaging quality unless special corrections are applied. We developed a new correction method that is very tolerant to noise and used it to improve the reflection image of the such a fault and refine its geological interpretation.

Description: 〈b〉Submarine groundwater discharge site in the First Salpausselkä ice-marginal formation, south Finland〈/b〉〈br〉 Joonas J. Virtasalo, Jan F. Schröder, Samrit Luoma, Juha Majaniemi, Juha Mursu, and Jan Scholten〈br〉 Solid Earth Discuss., https//doi.org/10.5194/se-2018-131,2018〈br〉 〈b〉Manuscript under review for SE〈/b〉 (discussion: open, 1 comment)〈br〉 This study establishes the local stratigraphy and 3D aquifer geometry of a submarine groundwater discharge site in the Hanko Peninsula, south Finland. The study is based on a rich dataset of marine seismic profiles, multibeam and sidescan sonar images of the seafloor, and onshore ground-penetrating radar and refraction seismic profiles. The groundwater discharge takes place through meter scale pockmarks on the seafloor, confirmed by elevated radon concentrations in the overlying water.

Description: 〈b〉Linked thick to thin – skinned inversion in the central Kirthar Fold Belt of Pakistan〈/b〉〈br〉 Ralph Hinsch, Chloé Asmar, Muhammad Nasim, Muhammad Asif Abbas, and Shaista Sultan〈br〉 Solid Earth Discuss., https//doi.org/10.5194/se-2018-137,2018〈br〉 〈b〉Manuscript under review for SE〈/b〉 (discussion: final response, 3 comments)〈br〉 We use surface and geophysical subsurface data to constrain the structure and evolution of the central Kirthar Fold belt, a mountain belt on the western margin of the Indian plate in Pakistan. It can be shown, that the extension phase prior to the collision of India with Asia has a major impact on how the rocks deform today. The inherited structures in the crystalline basement reactivate in opposite sense and complexly deform the sedimentary rocks that have deposited before collision.

Description: 〈b〉Formation of linear planform chimneys controlled by preferential hydrocarbon leakage and anisotropic stresses in faulted fine-grained sediments, offshore Angola〈/b〉〈br〉 Sutieng Ho, Martin Hovland, Jean-Philippe Blouet, Andreas Wetzel, Patrice Imbert, and Daniel Carruthers〈br〉 Solid Earth, 9, 1437-1468, https://doi.org/10.5194/se-9-1437-2018, 2018〈br〉 A newly discovered type of hydrocarbon leakage structure is investigated following the preliminary works of Ho (2013; et al. 2012, 2013, 2016): blade-shaped gas chimneys instead of classical cylindrical ones. These so-called 〈q〉Linear Chimneys〈/q〉 are hydraulic fractures caused by overpressured hydrocarbon fluids breaching cover sediments along preferential directions. These directions are dictated by anisotropic stresses induced by faulting in sediments and pre-existing salt-diapiric structures.

Description: 〈b〉The influence of detachment strength on the evolving deformational energy budget of physical accretionary prisms〈/b〉〈br〉 Jessica McBeck, Michele Cooke, Pauline Souloumiac, Bertrand Maillot, and Baptiste Mary〈br〉 Solid Earth, 9, 1421-1436, https://doi.org/10.5194/se-9-1421-2018, 2018〈br〉 In order to assess the influence of deformational processes within accretionary prisms, we track the evolution of the energy budget. We track the consumption of energy stored in internal deformation of the host rock, energy expended in frictional slip, energy used in uplift against gravity and total energy input. We find that the energy used in internal deformation is 〈 1% of the total and that the energy expended in frictional slip is the largest portion of the budget.

Description: Instaseis: instant global seismograms based on a broadband waveform database Solid Earth, 6, 701-717, 2015 Author(s): M. van Driel, L. Krischer, S. C. Stähler, K. Hosseini, and T. Nissen-Meyer We present a new method and implementation (Instaseis) to store global Green's functions in a database which allows for near-instantaneous (on the order of milliseconds) extraction of arbitrary seismograms. Using the axisymmetric spectral element method (AxiSEM), the generation of these databases, based on reciprocity of the Green's functions, is very efficient and is approximately half as expensive as a single AxiSEM forward run. Thus, this enables the computation of full databases at half the cost of the computation of seismograms for a single source in the previous scheme and allows to compute databases at the highest frequencies globally observed. By storing the basis coefficients of the numerical scheme (Lagrange polynomials), the Green's functions are 4th order accurate in space and the spatial discretization respects discontinuities in the velocity model exactly. High-order temporal interpolation using Lanczos resampling allows to retrieve seismograms at any sampling rate. AxiSEM is easily adaptable to arbitrary spherically symmetric models of Earth as well as other planets. In this paper, we present the basic rationale and details of the method as well as benchmarks and illustrate a variety of applications. The code is open source and available with extensive documentation at www.instaseis.net .

Description: Comparison of wheat and safflower cultivation areas in terms of total carbon and some soil properties under semi-arid climate conditions Solid Earth, 6, 719-725, 2015 Author(s): B. Turgut The aim of this study was to compare the soils of the wheat cultivation area (WCA) and the safflower cultivation area (SCA) within semi-arid climate zones in terms of their total carbon, nitrogen, and sulphur contents, particle size distribution, aggregate stability, organic matter content, and pH values. This study presents the results from the analyses of 140 soil samples taken at two soil layers (0–10 and 10–20 cm) in the cultivation areas. At the end of the study, it was established that there were significant differences between the cultivation areas in terms of soil physical properties such as total carbon (TC), total nitrogen (TN), total sulphur (TS) contents and pH, while only the TN content was significantly different between the two soil layers. Moreover, significant differences were identified between the cultivation areas in terms of soil physical properties including clay and sand contents, aggregate stability, and organic matter content, whereas the only significant difference found among the soil layers was that of their silt content. Since safflower contains higher amounts of biomass than wheat, we found higher amounts of organic matter content and, therefore, higher amounts of TN and TS content in the soils of the SCA. In addition, due to the fact that wheat contains more cellulose – which takes longer to decompose – the TC content of the soil in the WCA was found to be higher than that in the SCA. The results also revealed that the WCA had a higher carbon storage capacity.

Description: Three-dimensional approach to understanding the relationship between the Plio–Quaternary stress field and tectonic inversion in the Triassic Cuyo Basin, Argentina Solid Earth, 6, 747-763, 2015 Author(s): L. Giambiagi, S. Spagnotto, S. M. Moreiras, G. Gómez, E. Stahlschmidt, and J. Mescua The Cacheuta sub-basin of the Triassic Cuyo Basin is an example of rift basin inversion contemporaneous to the advance of the Andean thrust front, during the Plio–Quaternary. This basin is one of the most important sedimentary basins in a much larger Triassic NNW-trending depositional system along the southwestern margin of the Pangea supercontinent. The amount and structural style of inversion is provided in this paper by a three-dimensional approach to the relationship between inversion of rift-related structures and spatial variations in late Cenozoic stress fields. The Plio–Quaternary stress field exhibits important N–S variations in the foreland area of the southern Central Andes, between 33 and 34° S, with a southward gradual change from pure compression, with σ 1 and σ 2 being horizontal, to a strike-slip type stress field, with σ 2 being vertical. We present a 3-D approach for studying the tectonic inversion of the sub-basin master fault associated with strike-slip–reverse to strike-slip faulting stress regimes. We suggest that the inversion of Triassic extensional structures, striking NNW to WNW, occurred during the Plio–Pleistocene in those areas with strike-slip–reverse to strike-slip faulting stress regime, while in the reverse faulting stress regime domain they remain fossilized. Our example demonstrates the impact of the stress regime on the reactivation pattern along the faults.

Description: Socioeconomic modifications of the universal soil loss equation Solid Earth, 6, 1025-1035, 2015 Author(s): A. Erol, Ö. Koşkan, and M. A. Başaran While social scientists have long focused on socioeconomic and demographic factors, physical modelers typically study soil loss using physical factors. In the current environment, it is becoming increasingly important to consider both approaches simultaneously for the conservation of soil and water, and the improvement of land use conditions. This study uses physical and socioeconomic factors to find a coefficient that evaluates the combination of these factors. It aims to determine the effect of socioeconomic factors on soil loss and, in turn, to modify the universal soil loss equation (USLE). The methodology employed in this study specifies that soil loss can be calculated and predicted by comparing the degree of soil loss in watersheds, with and without human influence, given the same overall conditions. A coefficient for socioeconomic factors, therefore, has been determined based on adjoining watersheds (WS I and II), employing simulation methods. Combinations of C and P factors were used in the USLE to find the impact of their contributions to soil loss. The results revealed that these combinations provided good estimation of soil loss amounts for the second watershed, i.e., WS II, from the adjoining watersheds studied in this work. This study shows that a coefficient of 0.008 modified the USLE to reflect the socioeconomic factors, such as settlement, influencing the amount of soil loss in the studied watersheds.

Description: Rainfall and human activity impacts on soil losses and rill erosion in vineyards (Ruwer Valley, Germany) Solid Earth, 6, 823-837, 2015 Author(s): J. Rodrigo Comino, C. Brings, T. Lassu, T. Iserloh, J. M. Senciales, J. F. Martínez Murillo, J. D. Ruiz Sinoga, M. Seeger, and J. B. Ries Vineyards are one of the eco-geomorphological systems most conditioned by human activity in Germany. The vineyards of the Ruwer Valley (Germany) are characterized by high soil erosion rates and rill problems on steep slopes (between 23 and 26°) caused by the increasingly frequent heavy rainfall events as well as deterioration due to incorrect land use managements. The objective of this paper is to determine and to quantify the hydrological and erosive phenomena in one vineyard in Germany during different seasons and under different management conditions (before, during and after vintage). For this purpose, a combined methodology was applied. Climatic (rainfall depth distributions and return periods), pedological (soil analysis and classification), geomorphological (sediment movements and rills evolution) and biological (botanic marks on the vines) variables were used on the two experimental plots in the village of Waldrach (Trier, region of Rhineland-Palatinate). The results showed high infiltration rates (near 100 %) and subsurface flow which were detected by rainfall simulations performed at different times of the year (between September and December). The highest variations of the monitored rills (lateral and frontal movements) were noted before and during vintage, when footsteps occurred concentrated during a short period of time (between September and October). Finally, two maps of soil loss were generated, indicated by botanic marks on the graft union of the vines. 62.5 t ha −1 yr −1 soil loss was registered in the experimental plots of the new vineyards (2 years), while 3.4 t ha −1 yr −1 was recorded in the old one (35 years).

Description: Brittle–viscous deformation of vein quartz under fluid-rich lower greenschist facies conditions Solid Earth, 6, 681-699, 2015 Author(s): H. J. Kjøll, G. Viola, L. Menegon, and B. E. Sørensen We studied by Electron BackScatter Diffraction (EBSD) and optical microscopy a coarse-grained (ca. 0.5–6 mm) quartz vein embedded in a phyllonitic matrix to gain insights into the recrystallization mechanisms and the processes of strain localization in quartz deformed under lower greenschist facies conditions, broadly coincident with the brittle–viscous transition. The vein deformed during faulting along a phyllonitic thrust of Caledonian age within the Porsa Imbricate Stack in the Paleoproterozoic Repparfjord Tectonic Window in northern Norway. The phyllonite hosting the vein formed at the expense of a metabasaltic protolith through feldspar breakdown to form interconnected layers of fine, synkinematic phyllosilicates. In the mechanically weak framework of the phyllonite, the quartz vein acted as a relatively rigid body. Viscous deformation in the vein was initially accommodated by quartz basal 〈 a 〉 slip. Under the prevailing deformation conditions, however, dislocation glide- and possibly creep-accommodated deformation of quartz was inefficient, and this resulted in localized strain hardening. In response to the (1) hardening, (2) progressive and cyclic increase of the fluid pressure, and (3) increasing competence contrast between the vein and the weakly foliated host phyllonite, vein quartz crystals began to deform by brittle processes along specific, suitably oriented lattice planes, creating microgouges along microfractures. Nucleated new grains rapidly sealed these fractures as fluids penetrated the actively deforming system. The grains grew initially by solution precipitation and later by grain boundary migration. We suggest that the different initial orientation of the vein crystals led to strain accommodation by different mechanisms in the individual crystals, generating remarkably different microstructures. Crystals suitably oriented for basal slip, for example, accommodated strain mainly viscously and experienced only minor fracturing. Instead, crystals misoriented for basal slip hardened and deformed predominantly by domainal fracturing. This study indicates the importance of considering shear zones as dynamic systems wherein the activated deformation mechanisms may vary through time in response to the complex temporal and spatial evolution of the shear zone, often in a cyclic fashion.

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: 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: Using ordered weight averaging (OWA) for multicriteria soil fertility evaluation by GIS (case study: southeast Iran) Marzieh Mokarram and Majid Hojati Solid Earth Discuss., doi:10.5194/se-2016-112,2016 Manuscript under review for SE (discussion: open, 0 comments) The aim of this study is to take the advantage of the incorporation of fuzzy into GIS-based soil fertility analysis by OWA in west Shiraz, Fars province, Iran. The results show that with decreasing risk (no trade-off), almost all of the parts of the study area were not suitable for soil fertility. While increasing risk, more area was suitable in terms of soil fertility in the study area.

Description: Quantitative experimental monitoring of molecular diffusion in clay with positron emission tomography Johannes Kulenkampff, Abdelhamid Zakhnini, Marion Gründig, and Johanna Lippmann-Pipke Solid Earth, 7, 1207-1215, doi:10.5194/se-7-1207-2016, 2016 Clay is the prominent barrier material in the geosphere, but diffusion of dissolved species is possible. Diffusion parameters are commonly determined on small samples, disregarding heterogeneity. With positron emission tomography (PET), we monitored heterogeneous transport patterns on larger samples. From the time dependence of the spatial tracer distribution, we derived reliable anisotropic diffusion coefficients, and found indications of preferential transport zones.

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: 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: 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: Determining the variation of soil properties in the Batumi Delta Bülent Turgut and Merve Ateş Solid Earth Discuss., doi:10.5194/se-2016-101,2016 Manuscript under review for SE (discussion: open, 0 comments) The aim of this study was to determine certain basic properties of soils in the Batumi delta, to determine the relationships of studied properties, and to identify differences with regards to these properties between different sampling sites in the delta that were selected based on the delta morphology. In this context, a total of 125 soil samples were collected from five different sampling sites, and the clay, silt and sand content of the samples were determined along with their mean weight diameter (MWD) values, aggregate stability (AS) values, amount of water retained under −33 kPa (FC) and −1500 kPa (WP) pressure and organic matter (OM) content. Correlation analysis indicated that clay content and OM were positively correlated with MWD, and OM was positively correlated with AS. However, the sand content was found to be negatively correlated with MWD. In addition, clay, silt and OM content were positive correlated with FC and WP. Variance analysis results determined statistically significant differences between the sampling sites with respect to all of the evaluated properties. The active delta section of the study area was characterized by high sand content, while the lower delta plain was characterized by high OM and AS values, and the upper delta plain was characterized by high WMD values, high FC and WP moisture content levels and high clay and silt content. In conclusion, it was demonstrated that the examined properties were significantly affected by the different morphological positions and usages of these different areas. These results may help with the management of agricultural lands in the Batumi delta, which has never been studied before.

Description: Differences and influencing factors related to underground water carbon uptake by karsts in the Houzhai Basin, southwestern China Junyi Zhang, Zihao Bian, Minghong Dai, Lachun Wang, Chunfen Zeng, and Weici Su Solid Earth, 7, 1259-1268, doi:10.5194/se-7-1259-2016, 2016 Carbon sink in karstic areas is very important at a global scale. Consequently, accurate determination of the carbon sink of karst ecosystems has become a core issue in research. We used flow and carbon ion concentration data from three stations with different environmental background conditions in the Houzhai Basin, southwestern China, to analyse the differences in carbon uptake between stations and to determine their impact factors. The results show that carbon sink discharge was mainly controlled by the flow at each site. Preliminary analysis indicated that the rapid increase in flow only had a partial dilution effect on the ion concentrations due to the high speed and stability of chemical carbonate weathering. The Land-Use and Cover-Change (LUCC) type had important effects on the bicarbonate ion concentrations; under stable run-off conditions, the influence of flow variation on the ion concentration was lower than the effects of chemical carbonate weathering on bicarbonate ion concentrations under different environmental conditions (a comparison of Laoheitan and Liugu stations showed a difference of 150 %). However, if run-off increased significantly, the impact of run-off variation on bicarbonate ions was greater than the effects of chemical carbonate weathering caused under different environmental conditions. This work provides a reference for the calculation of the karst geological carbon sink.

Description: Measuring and crust-correcting finite-frequency travel time residuals – application to southwestern Scandinavia Solid Earth, 6, 1117-1130, 2015 Author(s): M. L. Kolstrup and V. Maupin We present a data-processing routine to compute relative finite-frequency travel time residuals using a combination of the Iterative Cross-Correlation and Stack (ICCS) algorithm and the Multi-Channel Cross-Correlation method (MCCC). The routine has been tailored for robust measurement of P- and S-wave travel times in several frequency bands and for avoiding cycle-skipping problems at the shortest periods. We also investigate the adequacy of ray theory to calculate crustal corrections for finite-frequency regional tomography in normal continental settings with non-thinned crust. We find that ray theory is valid for both P and S waves at all relevant frequencies as long as the crust does not contain low-velocity layers associated with sediments at the surface. Reverberations in the sediments perturb the arrival times of the S waves and the long-period P waves significantly, and need to be accounted for in crustal corrections. The data-processing routine and crustal corrections are illustrated using data from a~network in southwestern Scandinavia.

Description: The hydrothermal power of oceanic lithosphere Solid Earth, 6, 1131-1155, 2015 Author(s): C. J. Grose and J. C. Afonso We have estimated the power of ventilated hydrothermal heat transport, and its spatial distribution, using a set of recently developed plate models which highlight the effects of axial hydrothermal circulation and thermal insulation by oceanic crust. Testing lithospheric cooling models with these two effects, we estimate that global advective heat transport is about 6.6 TW, significantly lower than most previous estimates, and that the fraction of that extracted by vigorous circulation on the ridge axes ( 〈 1 My old) is about 50 % of the total, significantly higher than previous estimates. These new estimates originate from the thermally insulating properties of oceanic crust in relation to the mantle. Since the crust is relatively insulating, the effective properties of the lithosphere are "crust dominated" near ridge axes (a thermal blanketing effect yielding lower heat flow) and gradually approach mantle values over time. Thus, cooling models with crustal insulation predict low heat flow over young seafloor, implying that the difference of modeled and measured heat flow is due to the heat transport properties of the lithosphere, in addition to ventilated hydrothermal circulation as generally accepted. These estimates may bear on important problems in the physics and chemistry of the Earth because the magnitude of ventilated hydrothermal power affects chemical exchanges between the oceans and the lithosphere, thereby affecting both thermal and chemical budgets in the oceanic crust and lithosphere, the subduction factory, and the convective mantle.

Description: Analysis of soil moisture condition under different land uses in the arid region of Horqin sandy land, northern China Solid Earth, 6, 1157-1167, 2015 Author(s): C. Y. Niu, A. Musa, and Y. Liu Land use plays an important role in controlling spatial and temporal variations of soil moisture by influencing infiltration rates, runoff and evapotranspiration, which is important to crop growth and vegetation restoration in semiarid environments, such as Horqin sandy land in north China. However, few studies have been conducted comparing differences of dynamics of soil water conditions and the responses of soil to infiltration under different land use types in semiarid area. Five different land use types were selected to analyze soil moisture variations in relation to land use patterns during the growing season of 2 years. Results showed that soil moisture condition was affected by different land uses in semi-arid sandy soils. The higher soil moisture content among different land uses was exhibited by the grassland, followed by cropland, poplar land, inter-dunes and shrub land. The temporal variations of soil moisture in different land uses were not always consistent with the rainfall due to the dry sequence. Moreover, soil water at the surface, in the root zone and at the deep soil layer indicated statistical differences for different types of land cover. Meanwhile, temporal variations of soil moisture profile changed with precipitation. However, in the deep soil layer, there was a clear lag in response to precipitation. In addition, seasonal variations of profile soil moisture were classified into two types: increasing and waving types. And the stable soil water layer was at 80–120 cm. Furthermore, the infiltration depth exhibited a positive correlation with precipitation under all land uses. This study provided an insight into the implications for land and agricultural water management in this area.

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: 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: 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: 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.