8 documents found in 231ms
# 1
Quinteros, Javier
Abstract: This service provides routing information for distributed data centres, in the case where multiple different seismic data centres offer access to data and products using compatible types of services. Examples of the data and product objects are seismic timeseries waveforms, station inventory, or quality parameters from the waveforms. The European Integrated Data Archive (EIDA) is an example of a set of distributed data centres (the EIDA „nodes“). EIDA have offered Arclink and Seedlink services for many years, and now offers FDSN web services, for accessing their holdings. In keeping with the distributed nature of EIDA, these services could run at different nodes or elsewhere; even on computers from normal users. Depending on the type of service, these may only provide information about a reduced subset of all the available waveforms. To be effective, the Routing Service must know the locations of all services integrated into a system and serve this information in order to help the development of smart clients and/or services at a higher level, which can offer the user an integrated view of the entire system (EIDA), hiding the complexity of its internal structure. The service is intended to be open and able to be queried by anyone without the need of credentials or authentication.
# 2
Brunke, Heinz-Peter • Widmer-Schidrig, Rudolf • Korte, Monika
Abstract: For frequencies above 30 mHz the instrument intrinsic noise level of typical fluxgate magnetometers used at geomagnetic observatories usually masks ambient magnetic field variations on magnetically quiet days. Natural field variations referred to as pulsations (Pc-1, Pc-2, Pi-1) fall in this band. Usually their intensity is so small that they rarely surpass the instrumental noise of fluxgate magnetometers. INTERMAGNET has set a minimum quality standard for definitive 1 s data (Turbitt, 2014) which can actually hardly be met by fluxgate magnetometers in use by magnetic observatories. Brunke et al. (2017) propose a method to improve 1Hz observatory data by merging data from the proven and tested fluxgate magnetometers currently in use with induction coil magnetometers into a single data stream. This data publication includes the according MATLAB software package implementing the merging of both data sets. The content of the software package and the functionality of each module is described in the content.txt file that is also included in the zip folder. The resulting data are in line with the INTERMAGNET format for 1 s magnetic data, but surpasses the INTERMAGNET 1 s standard by far. The long term stability of the fluxgate data is not affected. The changes to the fluxgate data remain within the range of the instrument intrinsic noise. In addition to the Matlab software, we provide test datasets of one day length kindly provided by the magnetic observatories Niemegk, Conrad and Eskdalemuir.
# 3
Mills, Steven • Williams, Jack
Abstract: This code (nwrap.ijm) can be used to generate an 'unrolled' circumferential image of a tomographic drill-core scan, such as an X-ray Computed Tomography (CT) scan. The resulting image is analogous to those produced by a DMT CoreScan system®. By comparing such images to geographically references borehole televiewer data, it may be used to reorientate drill-core back into geographic space (Williams et al. submitted). This code should be installed and run as a plugin on ImageJ/Fiji. Full instructions are given in the code and in the Appendix A of Williams et al. (submitted). Examples of unrolled CT scans can be found at Williams et al (2017, http://doi.org/10.5880/ICDP.5052.004).
# 4
Stromeyer, Dietrich • Heidbach, Oliver
Abstract: For the visualization and analysis of the stress field from 4D thermo-hydro-mechanical (THM) numerical model results two main technical steps are necessary. First, one has to derive from the six independent components of the stress tensor scalar and vector values such as the ori-entation and magnitude of the maximum and minimum horizontal stress, stress ratios, differential stress. It is also of great interest to display e.g. the normal and shear stress with respect to an arbitrarily given surface. Second, an appropriate geometry has to be given such as cross sections, profile e.g. for borehole pathways or surfaces on which the model results and further derived values are interpolated. This includes the three field variables temperature, pore pressure and the displacement vector. To facilitate and automate these steps the add-on GeoStress for the professional visualization software Tecplot 360 EX has been programmed. Besides the aforementioned values derived from the stress tensor the tool also allows to calculate the values of Coulomb Failure Stress (CFS), Slip and Dilation tendency (ST and DT) and Fracture Potential (FP). GeoStress also estimates kinematic variables such as horizontal slip, dip slip, rake vector of faults that are implemented as contact surfaces in the geomechanical-numerical model as well as the true vertical depth. Furthermore, the add-on can export surfaces and polylines and map on these all availble stress values. The technical report describes the technical details of the visualization tool, its usage and ex-emplifies its application using the results of a 3D example of a geomechanical-numerical model of the stress field. The numerical solution is achieved with the finite element software Abaqus version 6.11. It also presents a number of special features of Tecplot 360 EX in combination with GeoStress that allow a professional and efficient analysis. The Add-on and a number of example and input files are provided at http://doi.org/10.5880/wsm.2017.001.
# 5
Ziegler, Moritz • Heidbach, Oliver
Abstract: The distribution of data records for the maximum horizontal stress orientation SHmax in the Earth’s crust is sparse and very unequally. In order to analyse the stress pattern and its wavelength or to predict the mean SHmax orientation on a regular grid, statistical interpolation as conducted e.g. by Coblentz and Richardson (1995), Müller et al. (2003), Heidbach and Höhne (2008), Heidbach et al. (2010) or Reiter et al. (2014) is necessary. Based on their work we wrote the Matlab® script Stress2Grid that provides several features to analyse the mean SHmax pattern. The script facilitates and speeds up this analysis and extends the functionality compared to aforementioned publications. The script and a number of example and input files are provided at http://doi.org/10.5880/wsm.2017.002. The script provides two different concepts to calculate the mean SHmax orientation on a regular grid. The first is using a fixed search radius around the grid point and computes the mean SHmax orientation if sufficient data records are within the search radius. The larger the search radius the larger is the filtered wavelength of the stress pattern. The second approach is using variable search radii and determines the search radius for which the variance of the mean SHmax orientation is below a given threshold. This approach delivers mean SHmax orientations with a user-defined degree of reliability. It resolves local stress perturbations and is not available in areas with conflicting information that result in a large variance. Furthermore, the script can also estimate the deviation between plate motion direction and the mean SHmax orientation.
# 6
Meeßen, Christian
Abstract: This code is a python implementation of the p- and s-wave velocity to density conversion approach after Goes et al. (2000). The implementation has been optimised for regular 3D grids using lookup tables instead of Newton iterations. Goes et al. (2000) regard the expansion coefficient as temperature dependent using the relation by Saxena and Shen (1992). In `Conversion.py`, the user can additionally choose between a constant expansion coefficient or a pressure- and temperature dependent coefficient that was derived from Hacker and Abers (2004).For detailed information on the physics behind the approach have a look at the original paper by Goes et al. (2000). Up-to-date contact information are given on the author's github profile https://github.com/cmeessen.
# 7
Isken, Marius • Sudhaus, Henriette • Heimann, Sebastian • Steinberg, Andreas • Daout, Simon • (et. al.)
Abstract: We present a modular open-source software framework - kite (http://pyrocko.org), written in Python and C. The software enables rapid post-processing of space-born InSAR-derived surface displacement maps, swift parametrization and sub-sampling of the displacement measurements. With our package we aim to ease and streamline the optimization of earthquake source parameters from InSAR and GPS data and facilitate their joint optimization with seismological waveforms in combination with the pyrocko toolbox. Through such joint data optimizations from near- and far-field observations the determination of rupture parameters and processes will become more accurate and robust. Moreover, we present an intuitive kinematic deformation modelling sandbox for handling and manipulating various kinds of tectonic and volcanic deformation sources, interacting in elastic homogeneous or layered, full- or half-spaces.
# 8
Heimann, Sebastian • Kriegerowski, Marius • Isken, Marius • Cesca, Simone • Daout, Simon • (et. al.)
Abstract: Pyrocko is an open source seismology toolbox and library, written in the Python programming language. It can be utilized flexibly for a variety of geophysical tasks, like seismological data processing and analysis, calculation of Green's functions and earthquake models' synthetic waveforms and static displacements (InSAR or GPS). Those can be used to characterize extended earthquake ruptures, point sources (moment tensors) and other seismic sources. This publication includes the Pyrocko core, a library providing building blocks for researchers and students wishing to develop their own applications. The Pyrocko framework also ships with application: (1) Snuffler (interactive seismogram browser and workbench), (2) Cake (1D travel-time and ray-path computations), (3) Fomosto (calculate and manage Green’s function databases) and (4) Jackseis (waveform archive data manipulation). Additional applications, as of Grond, Lassie and Kite are individual software publications. See the project page (www.pyrocko.org) for full documentation, tutorials and installation instructions.
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