13 documents found in 399ms
# 1
van Dongen, Renee • Scherler, Dirk • Wittmann, Hella • von Blanckenburg, Friedhelm
Abstract: Concentrations of in-situ-produced cosmogenic 10Be in river sediment are widely used to estimate catchment-average denudation rates. Typically, the 10Be concentrations are measured in the sand fraction of river sediment. However, the grain size of bedload sediment in most bedrock rivers covers a much wider range. Where 10Be concentrations depend on grain size, denudation rate estimates based on the sand fraction alone are potentially biased. To date, knowledge about catchment attributes that may induce grain-size-dependent 10Be concentrations is incomplete or has only been investigated in modelling studies. Here we present an empirical study on the occurrence of grain-size-dependent 10Be concentrations and the potential controls of hillslope angle, precipitation, lithology, and abrasion. We first conducted a study focusing on the sole effect of precipitation in four granitic catchments located on a climate gradient in the Chilean Coastal Cordillera. We found that observed grain size dependencies of 10Be concentrations in the most-arid and most-humid catchments could be explained by the effect of precipitation on both the scouring depth of erosion processes and the depth of the mixed soil layer. Analysis of a global dataset of published 10Be concentrations in different grain sizes (n=73 catchments) – comprising catchments with contrasting hillslope angles, climate, lithology, and catchment size – revealed a similar pattern. Lower 10Be concentrations in coarse grains (defined as “negative grain size dependency”) emerge frequently in catchments which likely have thin soil and where deep-seated erosion processes (e.g. landslides) excavate grains over a larger depth interval. These catchments include steep (> 25°) and humid catchments (> 2000mm yr-1). Furthermore, we found that an additional cause of negative grain size dependencies may emerge in large catchments with weak lithologies and long sediment travel distances (> 2300–7000 m, depending on lithology) where abrasion may lead to a grain size distribution that is not representative for the entire catchment. The results of this study can be used to evaluate whether catchment-average denudation rates are likely to be biased in particular catchments. Samples from the Chilean Coastal Cordillera were processed in the Helmholtz Laboratory for the Geochemistry of the Earth Surface (HELGES). 10Be/9Be ratios were measured at the University of Cologne and normalized to the KN01-6-2 and KN01-5-3 standards. Denudation rates were calculated using a time-independent scaling scheme according to Lal (1991) and Stone (2002) (St scaling scheme) and the SLHL production rate of 4.01 at g-1 yr-1 as reported by Phillips et al. (2016) The global compilation exists of studies that measured 10Be concentrations in different grain sizes from the same sample location. We only included river basins of <5000 km2 which measured 10Be concentrations in at least one sand-sized fraction <2 mm and at least one coarser fraction >2 mm. Catchment parameters have been recalculated using a 90-m SRTM DEM. The data are presented in Excel and csv tables. Table S1 describes the characteristics of the samples catchments, Table S2 includes the grain size dependent 10Be-concentrations measured during this study and Table 3 the global compilation of grain size dependent 10Be-concentrations. All samples of this study (the Chilean Coastal Cordillera) are assigned with International Geo Sample Numbers (IGSN). The IGSN links are included in Table S2 and in the Related References Section on the DOI Landing Page. The data are described in detail in the data description file and in van Dongen et al. (2018) to which they are supplementary material to.
# 2
Albert, Francisca
Abstract: This data set includes movies and images of sandbox experiments aiming at understainding the process of subduction erosion at active plate margins (Albert, 2013). Four experiments are documented by means of movies showing the evolution of a strong wedge (sand-sugar mix, “Reference experiment.avi”), a weak wedge (sand only, “F1 experiment.avi”) and two successive phases of a wedge that undergoes subduction erosion by subducting topographic highs (first stage without subducting topography= “HL.1 experiment.avi” and second stage with subducting topography = “HL.2 experiment.avi”). Images of preliminary tests and experiments not considered in Albert (2013) are given in “Appendix A2.2.pdf” (small box experiments) and “Appendix A3.3.pdf” (experiments varying friction and slope).
# 3
Reiter, Karsten • Kukowski, Nina • Ratschbacher, Lothar • Rosenau, Matthias
Abstract: This data publication includes animations and figures of eight scaled analogue models that are used to investigate the evolution of a curved mountain belt akin to the Pamir and Hindu Kush orogenic system and adjacent Tadjik basin. Crustal deformation is simulated by means of indentation of two basement blocks into a sedimentary sequence and the formation of a curved fold-and-thrust belt.The experimental set-up has two adjacent rigid indenters representing the basement blocks moving in parallel with a velocity difference (Figure 1). The slow indenter moves with a relative velocity ranging from 40 to 80% of that of the fast one. A layer of quartz sand in front of the indenters, 1 by 1 meter in size and 1.5 cm thick, represents the sedimentary basin infill. A basal detachment layer is made up of low-friction glass beads or viscous silicone oil representing weak shale or evaporates layers, respectively. The surface evolution by means of topography and strain distribution is derived from 3-D particle image velocimetry (PIV). This allows visualizing and analysing the development of the model surface during the complete model run at high spatio-temporal resolution. All details about the model set-up, modelling results and interpretation can be found in Reiter et al. (2011).The here provided additional material includes time-lapse movies showing the topographic evolution of the eight models. These visualizations are oblique views played back at 60-fold velocity for the “glass beads experiments” (gb40 to gb80) and 3600-fold velocity for the “silicone experiments” (si60, si-gb60).In addition to the experiment movies we provide a set of figures. The figures include surface views as well as cross-sections through the finite models highlighting the link between topography and internal structure of the simulated curved fold-and-thrust belts. Additionally, attribute maps of distinct morphometric measures (curvature, slope) and deformation parameters (uplift, horizontal translation) for the experiments with glass beads detachments are given. Finally, the movie “Experimenting.avi” shows in time-lapse the whole workflow of setting up, conducting and documenting an experiment, which originally required three days (for experiment si-gb60).An overview on the parameters used in the experimental series of the movie sequences is given in the explanatory file (Explanations_Reiter-et-al-2016.pdf). A full list of files is given in “list-of-files-Reiter-et-al-2016.pdf”.
# 4
Rudolf, Michael • Boutelier, David • Rosenau, Matthias • Schreurs, Guido • Oncken, Onno
Abstract: The datasets that are presented here have been obtained to provide a rheological benchmark of silicones used in various analog modeling laboratories. The data contains rheological measurements of several polydimethylsiloxanes (PDMS) and filled silicone oils. The samples of eight different silicone oils originate from seven laboratories. Each sample was analyzed using rotational controlled shear rate tests (CSR), temperature sweep test, and dynamical oscillation tests (amplitude and frequency sweeps). Detailed information on the analysis and interpretation of the data is found in Rudolf, et al. (2016).The data is provided as comma-separated files in *.csv format. Each file contains multiple measurements, each starting with own data series information that is followed by the actual measurement in the form of a table including the individual units of measure. Furthermore the results from ReSpect (Takeh & Shanbhag, 2013) for the discrete Maxwell relaxation spectra are provided. All files can be opened using a text-editor, MS Excel, or equivalent software.More information about the datasets is available in the file Explanations_Rudolf-et-al-2016.pdf, an overview on the available files in the List_of_Files_Rudolf-et-al-2016 (in .pdf and .xlsx format). All information and overview files are also included in Rudolf-et-al-2016_datasets.zip.
# 5
Klinkmüller, Matthias • Schreurs, Guido • Rosenau, Matthias
Abstract: This dataset provides compaction data from axial testing on natural and artificial granular materials used for experimental simulation by the analogue geodynamic modelling community (21 sands and glass beads). The material samples have been collected community-wide and analysed at GFZ Potsdam in the framework of the GeoMod2008 conference benchmark initiative. The context of data collection, details of the material samples and measuring techniques as well as interpretation and discussion of results can be found in Klinkmüller et al. (2016) to which this dataset is supplement material.
The data presented here are derived by uniaxial, confined compression testing using the Axial Tester at GFZ Potsdam’s analogue laboratory for tectonic modelling . Each sample has been carefully prepared by the same person and measured consistently following the same protocol. Preparation included sieving at 250 ml/min from 30 cm height into the container (jar). Up to 2000 kPa of uniaxial compression has been applied in 50 cycles. Laboratory conditions were air conditioned during all the measurements (Temperature: 23°C, Humidity: 45%).The resulting stress curve data are presented at 20 Hz frequency and the Unit of N. From the stress curves the compaction data have been derived. These correspond to the normalized sample height (normalized to the initial height) of the sample at the beginning of each cycle and are characterized by an exponential decrease over the 50 cycles. From that the following compaction parameters are derived: total compaction (shortening after 50 cycles Ct=eps50), the compaction during the first cycle (eps1) as well as the compaction index (Ci = eps1/eps50). Compaction data are finally visualized in the compactionDataPlot file.Each material sample has a relation to three files: stress curve data (txt format, 50 files per sample), compaction data (in xls and txt format), compaction plot (pdf format), examples of which are shown below. An overview of all files of the data set is given in the table CompactionDataOverview.xls.
# 6
Klinkmüller, Matthias • Kemnitz, Helga • Schreurs, Guido • Rosenau, Matthias
Abstract: This dataset provides images from scanning electron microscope (SEM) photography of natural and artificial granular materials used for experimental simulation by the analogue geodynamic modelling community (21 sands and glass beads). The material samples have been collected community-wide and analysed at GFZ Potsdam in the framework of the GeoMod2008 conference benchmark initiative. The context of data collection, details of the material samples and measuring techniques as well as interpretation and discussion of results can be found in Klinkmüller et al. (2016) to which this dataset is supplement material.
The data presented here are derived by using the scanning electron microscope facility at GFZ Potsdam. The selected grains were mounted on aluminium stubs supplied with conductive carbon tabs and gold-palladium coated. The study was performed using a ZEISS DSM 692 (in 2008) and (in 2009) a ZEISS ULTRA 55 Plus Schottky-type field emission scanning electron microscope (FESEM) at acceleration voltages from 7 to 20 kV. In both cases, we used the secondary (SE) electron signals providing the best spatial resolution of the sample morphology.The resulting SEM images are presented. From each sample several magnifications are provided ranging from overview (50x-100x) to particle portraits (100x-500x) and, for glass beads, to surface landscapes (500x-10.000x).
An overview of all files of the data set is given in the table SEMDataOverview.
# 7
Klinkmüller, Matthias • Schreurs, Guido • Rosenau, Matthias
Abstract: This dataset provides friction data from ring shear test (RST) on natural and artificial granular materials used for experimental simulation by the analogue geodynamic modelling community (21 sands and glass beads). The material samples have been collected community-wide and analysed at GFZ Potsdam in the framework of the GeoMod2008 conference benchmark initiative. The context of data collection, details of the material samples and measuring techniques as well as interpretation and discussion of results can be found in Klinkmüller et al. (2016) to which this dataset is supplement material.
The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994) at GFZ Potsdam’s analogue laboratory for tectonic modelling. Each sample has been carefully prepared by the same person and measured consistently following the same protocol. Preparation included sieving at 250 ml/min from 30 cm height into the shear cell. Measurements have been done at normal loads (normal stress) of 430, 860, 1290, 1720, and 2150 Pa and shear velocity of 3 mm/min typical of experimental conditions. Laboratory conditions were air conditioned during all the measurements (Temperature: 23°C, Humidity: 45%). The measurements presented here correspond to internal friction, shearing inside the material. Data for so-called basal or wall friction, i.e. shearing against a fixed plate, are available on request.The resulting shear stress curves are presented at 5 Hz frequency and the Unit of Pa. From the shear stress curves the friction data, i.e. peak, dynamic and reactivation friction, have been picked manually and are presented as data pairs (normal stress & respective shear strength). Matlab-based regression analysis of these friction data by means of (a) multilinear regression of all data pairs and (b) mutual regression of two data pairs constrains the material shear failure envelope characterized by friction coefficient (slope of regression line) and cohesion (y-axis intercept of regression line). The results are presented by friction plots.
Each material sample corresponds to three files: shear stress curves (xls/txt format), friction data (txt format), friction plots (pdf format), examples of which are shown below. An overview of all files of the data set is given in the table RSTDataOverview.
Cited reference: Schulze, D. (1994), Entwicklung und Anwendung eines neuartigen Ringschergerätes. Aufbereitungstechnik 35 (10), 524-535.
# 8
Pittore, Massimiliano • Ozturk, Ugur • Moldobekov, Bolot • Saponaro, Annamaria
Abstract: The EMCA landslide catalog of Central Asia covers mostly western and northern Kyrgyzstan as well as Tajikistan's Region of Republican Subordination. The catalog is a summary (point locations) of the documented landslides between 1954 and 2009, which are collected by the Central Asian Institute for Applied Geosciences through geological surveys (field campaigns) on single sites close to urban areas in order to mitigate landslide risk. The catalog is presented in identical .csv and NetCDF (.nc) formats. Both the formats include the point locations of the landslides (variables: latitude [WGS 84], longitude [WGS 84]), and the dates of about 5% of the landslides (variable: date). The remaining %95 of the data is undated and marked as NaT (dating not possible). These documented landslides mostly happened on soft and semi-hard rock layers within the areas made of Mesozoic-Cenozoic formations: these formation are represented mainly by layers of clays, argillites, siltstones, sandstones, marls, limestone, gypsum and conglomerates, which are mostly covered by Quaternary loess deposits (Kalmetieva et al., 2009, p.75). The EMCA landslide catalog is far from being a complete datasets for the entire region, since majority of the area is inaccessible or hard to reach due to mountainous relief, which in turn decreases the chance of collecting information about ancient as well as modern landslides through field campaigns.
# 9
Ritter, Malte Christian • Leever, Karen • Rosenau, Matthias • Oncken, Onno
Abstract: The dataset presented here contains the results of mechanical testing of two granular materials (quartz sand and glass micro beads) that are commonly used in analogue tectonic experiments. The data were acquired using a ring-shear tester RST-01.pc [Schulze, 1994]. Tests were performed at different normal loads ranging from 125 Pa to 4000 Pa and with eight to ten repetitions per normal load and material. The parameters measured are: rotation velocity, shear stress, normal load and sample dilation, all as a function of time. A detailed analysis and interpretation of the data can be found in the main article of [Ritter et al., 2016].The data were measured in the ring-shear tester RST-01.pc [Schulze, 1994, see below] at GFZ Potsdam’s analogue laboratory for tectonic modelling. All samples have been prepared and measured by the same person. Preparation was by sifting from a constant height of 30 cm into the shear cell. Tests were performed at different normal loads ranging from 125 Pa to 4000 Pa and with eight to ten repetitions per normal load and material. For normal loads below 500 Pa, the samples were pre-loaded by shortly increasing the normal load to 500 Pa and then resetting it to the desired value prior to the onset of deformation. This pre-loading was carried out for technical reasons. Preliminary tests at a normal load of 300 Pa have shown that this does not affect the strength.The data are presented as shear curves in tab-separated text files. The file names consist of (in this order) material, normal load and a running number. Each file contains one shear curve and consists of a header describing the individual measurements followed by a table with one column per parameter (read more in the dataset description pdf).References:Schulze, D. (1994) Entwicklung und Anwendung eines neuartigen Ringschergerätes, Aufbereitungstechnik, 35(10), 524–535.
# 10
Dietze, Michael
Abstract: Environmental seismoloy is a scientific field that studies the seismic signals, emitted by Earth surface processes. This R package eseis provides all relevant functions to read/write seismic data files, prepare, analyse and visualise seismic data, and generate reports of the processing history. eseis contains a growing set of function to handle the complete workflow of environmental seismology, i.e., the scientific field that studies the seismic signals that are emitted by Earth surface processes. The package supports reading the two most common seismic data formats, general functions for preparational and analytical signal processing aswell as specified functions for handling signals generated by Earth surface processes. Finally, graphical plot functions are provided, too. The software package contains 51 functions and two example data sets (eseis-supplementary_material.zip). It makes use of a series of dependency packages described in the DESCRIPTION file of the package.
spinning wheel Loading next page