Standardization of Seismic Tomographic Models and Earthquake Focal Mechanisms Datasets Based on Web Technologies, Visualization with Keyhole Markup Language

We present two projects in seismology that have been ported to web technologies, which provide results in Keyhole Markup Language (KML) visualization layers. These use the Google Earth geo-browser as the flexible platform that can substitute specialized graphical tools to perform qualitative visual data analyses and comparisons. The Network of Research Infrastructures for European Seismology (NERIES) Tomographic Earth Model Repository contains datasets from over 20 models from the literature. A hierarchical structure of folders that represent the sets of depths for each model is implemented in KML, and this immediately results into an intuitive interface for users to navigate freely and to compare tomographic plots. The KML layer for the European-Mediterranean Regional Centroid-Moment Tensor Catalog displays the focal mechanism solutions or moderate magnitude Earthquakes from 1997 to the present. Our aim in both projects was to also propose standard representations of scientific datasets. Here, the general semantic approach of XML has an important impact that must be further explored, although we find the KML syntax to be more shifted towards detailed visualization aspects. We have thus used, and propose the use of, Javascript Object Notation (JSON), another semantic notation that stems from the web-development community that provides a compact, general-purpose, data-exchange format

OMBRA: OBSERVING MONTELLO BROAD ACTIVITY DEPLOYMENT OF A TEMPORARY SEISMIC NETWORK TO STUDY THE DEFORMATION PROCESS ACROSS MONTELLO FAULT (EASTERN ALPS)

Istituto Nazionale di GeofisicaPublishedope

Imaging lateral heterogeneity in the northern Apennines from time reversal of reflected surface waves

Prominent arrivals in the coda of seismograms from the wider Alpine area can be associated with lateral reflections of Love waves at the northern Apennines mountain chain (Italy), where structural heterogeneity causes an abrupt contrast in phase velocity. We discuss an approach to image lateral heterogeneity from reflected surface waves using intermediate-period, three-component coda waveforms as sources for an adjoint wavefield that propagates the reflections backward in time. We numerically compute three-dimensional sensitivity kernels for the dependence of coda waveforms on P-velocity, S-velocity and density, based upon correlations between the adjoint and the regular forward wavefields. We consider synthetic coda waveforms for a simplified model of the northern Apennines, as well as real coda observations from five moderate magnitude earthquakes (MW 4.6-5.6) in the southern Alps. Wave propagation is simulated based upon the spectral-element method, for which a three-dimensional regional earth model is used in the case of real data. Single event sensitivity kernels and their stacks provide clear images of the reflectivity associated with the northern Apennines in kernels for density and S- wave speed. The kernels show that surface-wave reflections occur near the axial zone of the mountain chain. Apart from the Apennines, the approach is able to unravel other smaller reflectivity patches from the coda waveforms, located for example at the Ivrea zone in the southern Alps. Our coda misfit kernels can be integrated in a gradient- based waveform tomography, where they could enhance the sharpness of the model at lateral heterogeneities.In press3.3. Geodinamica e struttura dell'interno della TerraJCR Journalreserve

Standardization of Seismic Tomographic Models and Earthquake Focal Mechanisms Datasets Based on Web Technologies, Visualization with Keyhole Markup Language

We present two projects in seismology that have been ported to web technologies, which provide results in Keyhole Markup Language (KML) visualization layers. These use the Google Earth geo-browser as the flexible platform that can substitute specialized graphical tools to perform qualitative visual data analyses and comparisons. The Network of Research Infrastructures for European Seismology (NERIES) Tomographic Earth Model Repository contains datasets from over 20 models from the literature. A hierarchical structure of folders that represent the sets of depths for each model is implemented in KML, and this immediately results into an intuitive interface for users to navigate freely and to compare tomographic plots. The KML layer for the European-Mediterranean Regional Centroid-Moment Tensor Catalog displays the focal mechanism solutions or moderate magnitude Earthquakes from 1997 to the present. Our aim in both projects was to also propose standard representations of scientific datasets. Here, the general semantic approach of XML has an important impact that must be further explored, although we find the KML syntax to be more shifted towards detailed visualization aspects. We have thus used, and propose the use of, Javascript Object Notation (JSON), another semantic notation that stems from the web-development community that provides a compact, general-purpose, data-exchange format.Published47-563.1. Fisica dei terremotiJCR Journalope

Imaging lateral heterogeneity in the northern Apennines from time reversal of reflected surface waves

Prominent arrivals in the coda of seismograms from the wider Alpine area can be associated with lateral reflections of Love waves at the northern Apennines mountain chain (Italy), where structural heterogeneity causes an abrupt contrast in phase velocity. We discuss an approach to image lateral heterogeneity from reflected surface waves using intermediate-period, three-component coda waveforms as sources for an adjoint wavefield that propagates the reflections backward in time. We numerically compute three-dimensional sensitivity kernels for the dependence of coda waveforms on P-velocity, S-velocity and density, based upon correlations between the adjoint and the regular forward wavefields. We consider synthetic coda waveforms for a simplified model of the northern Apennines, as well as real coda observations from five moderate magnitude earthquakes (MW 4.6-5.6) in the southern Alps. Wave propagation is simulated based upon the spectral-element method, for which a three-dimensional regional earth model is used in the case of real data. Single event sensitivity kernels and their stacks provide clear images of the reflectivity associated with the northern Apennines in kernels for density and S- wave speed. The kernels show that surface-wave reflections occur near the axial zone of the mountain chain. Apart from the Apennines, the approach is able to unravel other smaller reflectivity patches from the coda waveforms, located for example at the Ivrea zone in the southern Alps. Our coda misfit kernels can be integrated in a gradient- based waveform tomography, where they could enhance the sharpness of the model at lateral heterogeneities