11 documents found in 383ms
# 1
Mikolaj, Michal
Abstract: This software publication describes the data acquisition, processing and modelling of hydrological, meteorological and gravity time series prepared for the Argentine-German Geodetic Observatory (AGGO) in La Plata, Argentina. The corresponding output data set is available at http://doi.org/10.5880/GFZ.5.4.2018.001 (Mikolaj et al., 2018). Processed hydrological series include soil moisture, temperature, electric conductivity, and groundwater variation. The processed meteorological time series comprise air temperature, humidity, pressure, wind speed, solar short- and long-waver radiation, and precipitation. Modelling scripts include evapotranspiration, combined precipitation, and water content variation in the zone between deepest soil moisture sensor and groundwater. In addition, large-scale hydrological, oceanic as well as atmospheric effect are modelled along with the local hydrological effects. To allow for a comparison of the model outputs to observations, processing script of gravity residuals is provided as well.
# 2
Mikolaj, Michal • Güntner, Andreas • Brunini, Claudio • Wziontek, Hartmut • Gende, Mauricio • (et. al.)
Abstract: The data set contains hydrological, meteorological and gravity time series collected at Argentine-German Geodetic Observatory (AGGO) in La Plata, Argentina. The hydrological series include soil moisture, temperature, electric conductivity, soil parameters, and groundwater variation. The meteorological time series comprise air temperature, humidity, pressure, wind speed, solar short- and long-waver radiation, and precipitation. The observed hydrometeorological parameters are extended by modelled value of evapotranspiration and water content variation in the zone between deepest soil moisture sensor and the groundwater level. Gravity products include large-scale hydrological, oceanic as well as atmospheric effects. These gravity effects are furthermore extended by local hydrological effects and gravity residuals suitable for comparison and evaluation of the model performance. Provided are directly observed values denoted as Level 1 product along with pre-processed series corrected for known issues (Level 2). Level 3 products are model outputs acquired using Level 2 data. The maximal temporal coverage of the data set ranges from May 2016 up to November 2018 with some exceptions for sensors and models set up in May 2017. The data set is organized in a database structure suitable for implementation in a relational database management system. All definitions and data tables are provided in separate text files allowing for traditional use without database installation. Software related to the data acquisition, processing, and modelling can be found in a separate publication describing scripts applied to the data set presented here. The software publication is available at https://doi.org/10.5880/GFZ.5.4.2018.002 (Mikolaj, 2018)
# 3
Heimann, Sebastian • Isken, Marius • Kühn, Daniela • Sudhaus, Henriette • Steinberg, Andreas • (et. al.)
Abstract: Grond is an open source software tool for robust characterization of earthquake sources. Moment tensors and finite fault rupture models can be estimated from a combination of seismic waveforms, waveform attributes and geodetic observations like InSAR and GNSS. It helps you to investigate diverse magmatic, tectonic, and other geophysical processes at all scales. It delivers meaningful model uncertainties through a Bayesian bootstrap-based probabilistic joint inversion scheme. The optimisation explores the full model space and maps model parameter trade-offs with a flexible design of objective functions. Rapid forward modelling is enabled by using pre-computed Green's function databases, handled through the Pyrocko software library. They serve synthetic near-field surface displacements and synthetic seismic waveforms for arbitrary earthquake source models and geometries.
# 4
Ritter, Malte Christian • Santimano, Tasca • Rosenau, Matthias • Leever, Karen • Oncken, Onno
Abstract: This dataset is supplementary to the article of Ritter et al. (2017). In this article, a new experimental device is presented that facilitates precise measurements of boundary forces and surface deformation at high temporal and spatial resolution. This supplementary dataset contains the measurement data from two experiments carried out in this new experimental device: one experiment of an accretionary critical wedge and one of Riedel-type strike-slip deformation. For a detailed description of the set-up and an analysis of the data, please see Ritter et al. (2017). The data available for either experiment are:• A video showing deformation in top view together with the evolution of boundary force. This file is in AVI-format.• A time-series of 2D vector fields describing the surface deformation. These vector fields were obtained from top-view video images of the respective experiment by means of digital image correlation (DIC). Each vector field is contained in a separate file; the files are consecutively numbered. The vector fields are stored in *.mat-files that can be opened using e.g. the software Matlab or the freely available GNU Octave. They take the form of Matlab structure arrays and are compatible to the PIVmat-toolbox by Moisy (2016) that is freely available. The most important fields of the structure are: x and y, that are vectors spanning a coordinate system, and vx and vy, which are arrays containing the actual vector components in x- and y-direction, respectively.• A file containing the measurements of the boundary force applied to drive deformation. This file is also a *.mat-file, containing a structure F with fields force, velocity and position. These fields are vectors describing the force applied by the indenter, the indenter velocity and the indenter position
# 5
Rosenau, Matthias • Corbi, Fabio • Dominguez, Stephane • Rudolf, Michael • Ritter, Malte • (et. al.)
Abstract: This data set contains various data derived from rock and rock analogue testing and analogue models which are presented in Rosenau et al. (2016) to which these data are supplement to..A first group of data contains animations of complementary analogue and numerical models of subduction zone earthquake cycles (A). A second group comprises analogue earthquake data and time series of surface deformation derived from scale models of subduction zone earthquake cycles (B). A third group consist of time series of stick-slip experiments using a ring shear tester (C). Finally, friction data both from rocks and rock analogue materials (D) as well as elasticity data from rock analogues are presented (E).See the Description of data and the List of files in the Data Download section for additional data description.
# 6
Urbani, Stefano • Acocella, Valerio • Rivalta, Eleonora
Abstract: The dataset includes movies of 29 analogue experiments performed to investigate the effects on dike propagation by the following imposed parameters: density ratio between host-rock and magma analogues, rigidity layering and density layering of the host medium, flow rate and topography. The purpose of the experiments is to define a hierarchy of all the parameters considered, by varying systematically each of them, comparing semi-quantitatively the variations on dike geometry and velocity. Experimental setup The experimental set-up consists of a 33 × 58 × 38.5 cm3 Plexiglas box and a peristaltic pump that injects water (magma analogue) into pig-skin gelatin (crustal analogue) alternatively from the bottom (Set 1) and the side of the box (Set 2). The gelatin rheological properties are varied by mixing different concentrations of gelatin powder and NaCl. We refer to “rigidity layering” when the rigidity ratio (i.e. Young’s Modulus) between the upper and lower layer (Eu/El) is < or > 1, and to “density layering” when Eu/El ~ 1, but the two layers show different densities (i.e. the ratio between the density of the upper and lower layer, ρU/ρL). The experiments with topography are prepared by imposing a mold with gently inward dipping flanks (2.4° and 3.7°) on the opposite sides of the box separated by a 8 cm wide horizontal plain on the gelatin surface. This configuration simulates the 2-D along-strike topography of the 2014 Bardarbunga intrusion (Iceland) and allows investigating the role of two opposite slopes on dike propagation. The topography profile dips parallel to the long side of the Plexiglas box (x axis in Figure 1 of Urbani et al. 2018). The flow rate has been changed between 0.079 and 0.435 ml/s. For the details about the model set-up, experimental results and interpretation refer to Urbani et al. (2018). The time-lapse movies show the time evolution of the dike shape, in side and map view, of 29 out of 33 models presented in Urbani et al. (2018). It is recommended to open the films with the VLC media player. The time-lapse of each experiment is indicated in the bottom left corner. A full list of files is given in “Experiments_Summary_2018-012.pdf” in which Set 1 (bottom injection) and Set 2 (lateral injection) experiments are indicated in red and blue color respectively. The same file also provides a summary of the boundary conditions imposed in each experiment. Tu and Tl indicate the thickness of the upper and lower layer respectively.
# 7
De Matteo, Ada • Corti, Giacomo • van Wyk de Vries, Benjamin • Massa, Bruno • Mussetti, Giulio
Abstract: This dataset contains 11 top view photographs of fault pattern in sand surfaces from a series of analogue tectonic experiments run to investigate the interaction between faults and volcanic features in areas characterized by pure extension, such as in rift areas (de-Matteo_2018-004_datasets.zip: Fig 02 – Fig 12). Additionally, a figure with a sketch of the experimental setup is provided (Fig 01), a file describing experimental settings for analogue experiments (Table 1.pdf) and a file with figure captions (Figure captions.pdf). This dataset is supplementary to De Matteo et al. (2018), discussing if and how the presence of a volcanic edifice and/or of an intrusive body (i.e. a magmatic chamber) perturbs the local stress field, influencing the magnitude and the attitude of a fault pattern, in a rift zone. Models had dimensions of 40 x 30 x 5 cm. They were built on a metal table confined by two border walls normal to the extension direction: one of them (fixed wall) was fastened to the table and the other one (mobile wall) was connected to an electrical stepped motor (Fig 01). Models had a common set up consisting of a uniform 3 cm-thick brittle layer, made up of sand settled on a basal ~1.5 cm-thick rubber sheet, made of nitrile rubber, fixed to both walls. The sand was a mixture of dry quartz-sand mixed with K-Feldspar powder (70/30% in weight). The mixture had a grain size <250 µm, an angle of internal friction of ~39°, a cohesion of ~65 Pa and a density of ~1550 kg/m3. In some experiments a small cylindrical pocket of fluid material (1 cm thick and with variable diameter) was introduced in the brittle layer, 1 cm above the surface, to simulate an intrusive body. The fluid material was composed by a different Polydimethylsiloxane (PDMS), with density of ~1100 kg/m3 and viscosity of ~ 700 Pa s (Corti et al., 2005). In some experiments volcanic edifices were introduced, modeled with the sand mixture also used for the brittle layer. The model parameters that have been changed were the presence or not of a volcanic edifice and/or of an intrusive body, the diameters of both the volcano and the intrusive body, the height of the volcano and the depth of the intrusive body. For details of experimental setups see table 1. The stretching of the basal rubber sheet, imposed by using a pure and simple shear deformation apparatus, allowed inducing a progressive, diffuse extension to models. The displacement velocity has been varied from 2 to 10 cm/h since -being purely brittle models- the scaling velocity in not relevant. Experiments were performed at the Laboratorie Magmas et Volcans, Université Blaise Pascal (Clermont-Ferrand, France) and at the Tectonic Modeling Laboratory of the CNR-IGG hosted at the Earth Science Department of the University of Florence (Italy).
# 8
Souloumiac, Pauline • Maillot, Bertrand • Herbert, Justin W. • McBeck, Jessica A. • Cooke, Michele L.
Abstract: The data set includes photos, force measurements, and incremental displacement fields captured in experiment E240 run at the physical modeling laboratory (GEC) at the Université de Cergy-Pontoise. We built the accretionary wedge using a novel sedimentation device [Maillot, 2013] that distributes sand in planar layers and creates homogeneous sandpacks. We include photos of the side of the accretionary wedge in a zipped folder (E240_sideviews). Throughout the experiment, we took a photo every 5 seconds. We include the incremental displacement fields calculated from digital image correlation of sequential photos [Adam et al., 2005; Hoth, 2005] as matlab (.mat) files in a zipped folder (E240_001-062_DIC_MAT), and as .csv files in a zipped folder (E240_001-062_DIC_CSV). The .mat and .csv files are numbered to indicate which sequential photo pairs were used to calculate the displacements. For example, E240_001-062_0001_CSV.csv (and E240_001-062_0001.mat) contain the incremental displacements between photo 001.jpg and 002.jpg. All files are included in a single zip folder (Souloumiac-et-al-2017-supplementary-datasets.zip). The matlab files include the variable arrays x, y, u, v, which are the x and y coordinates (in pixels relative to the upper left corner of the image), and the horizontal (u) and vertical (v) incremental displacement fields (in pixels), respectively. The .csv files contain four columns of data with the x and y coordinates in the first two columns, and the horizontal (u) and vertical (v) displacements in the last two columns. We include force measurements in a text file (E240_force_corrected) with two columns: the first column is the total displacement of the backwall in millimeters at the time that the force measurement was recorded, and the second column is the normal force exerted on the backwall, in Newtons. The force measurements are calculated from measurements of strain gauges mounted on a wall of the sand box (i.e., the backwall) [e.g., Souloumiac et al., 2012].
# 9
van den Ende, Martijn
Abstract: Intergranular pressure solution creep is an important deformation mechanism in the Earth’s crust. The phenomenon has been frequently studied and several analytical models have been proposed that describe its constitutive behavior. These models require assumptions regarding the geometry of the aggregate and the grain size distribution in order to solve for the contact stresses, and often neglect shear tractions. Furthermore, analytical models tend to overestimate experimental compaction rates at low porosities, an observation for which the underlying mechanisms remain to be elucidated. Here we present a conceptually simple, 3D Discrete Element Method (DEM) approach for simulating intergranular pressure solution creep that explicitly models individual grains, relaxing many of the assumptions that are required by analytical models. The DEM model is validated against experiments by direct comparison of macroscopic sample compaction rates. Furthermore, the sensitivity of the overall DEM compaction rate to the grain size and applied stress is tested. The effects of the interparticle friction and of a distributed grain size on macroscopic strain rates are subsequently investigated. Overall, we find that the DEM model is capable of reproducing realistic compaction behavior, and that the strain rates produced by the model are in good agreement with uniaxial compaction experiments. Characteristic features, such as the dependence of the strain rate on grain size and applied stress, as predicted by analytical models, are also observed in the simulations. DEM results show that interparticle friction and a distributed grain size affect the compaction rates by less than half an order of magnitude. The zip-file Van-den-Ende_2017.018.zip contains several folders with raw data from the laboratory experiments, output data from Discrete Element Method simulations, and Python 2.7 script files that read and process these data. All data are stored in ASCII format.
# 10
Darmawan, Herlan • Walter, Thomas • Richter, Nicole • Nikkoo, Mehdi
Abstract: This data publication is a high resolution Digital Elevation Model (DEM) generated for the Merapi summit by combining terrestrial laser scanning (TLS) and unmanned aerial vehicles (UAVs) photogrammetry data acquired in 2014 and 2015, respectively. The structures of the data are further analysed in Darmawan et al. 2017 (http://doi.org/10.1016/j.jvolgeores.2017.11.006). The published datasets consist of combined point clouds with ~65 million data points and a DEM with a resampled resolution of 0.5 m. The DEM data covers the complexity of the Merapi summit with area of 2 km2. The coordinate of the datasets is projected to global coordinates (WGS 1984 UTM Zone 49 South). TLS is a topography mapping technique which exploits the travel time of a laser beam to measure the range between the ground-based scanning instrument and the earth’s surface. TLS provides high accuracy, precision, and resolution for topography mapping, however, it requires different scan position to obtain accurate topography model in a complex topography. The TLS dataset was acquired by using a long-range RIEGL VZ-6000 instrument with a Pulse Repetition Rate (PRR) of 30 kHz. The Merapi data includes an observation range of 0.129 – 4393.75 m, a theta range (vertical) of 73 – 120° with a sampling angle of 0.041°, a phi range (horizontal) of 33° - 233° with a sampling angle of 0.05°, and 12 reflectors for each scan. The used TLS dataset was achieved by combining two scan positions, both realized in September 2014. In order to reduce still eminent shadowing, we conducted additionally a UAV photogrammetry survey. The UAV data allows to fill data gaps and generate a complete 3D point cloud. The UAV photogrammetry was conducted by using DJI Phantom 2 quadcopter drone in October 2015. The drone carried GoPro HERO 3+ camera and a H3-3D gimbal to reduce image shaking. We obtained over 300 images which cover the summit area of Merapi. By applying the Structure from Motion algorithm, we are able to generate a 3D point cloud model of Merapi summit. Further details on this procedure are provided in Darmawan et al. (2017). Structure from Motion is a technique to generate a 3D model based on 2D overlapped images. The algorithm detects and matches the same ground features of 2D images, reconstructs a 3D scene, and calculates a depth map for each camera frame. The algorithm used is implemented in Agisoft Photoscan Professional software. After importing the images in Agisoft, we used the ‘align image’ function with high accuracy setting to generate 3D sparse point cloud and ‘build dense cloud’ function with high quality to generate 3D dense point cloud. The 3D point clouds of TLS and UAV photogrammetry were then georeferenced to our georeferenced 3D point cloud which acquired in 2012. The RMS of TLS and UAV photogrammetry during georeferenced is 0.60 and 0.44 m, respectively, as described in Further details on this procedure are provided in Darmawan et al. (2017). After georeferencing, both 3D point clouds were merged and interpolated to a raster format in the ArcMap software.
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