Source time function clustering reveals patterns in earthquake dynamics

We cluster a global data base of 3529 M > 5.5 earthquakes in 1995-2018 based on a dynamic time warping dissimilarity of their source time functions (STFs). The clustering exhibits different degrees of STF shape complexity and suggests an association between STF complexity and earthquake source parameters. Thrust events are in large proportion with simple STF shapes and at all depths. In contrast, earthquakes with complex STF shapes tend to be located at shallow depth in complicated tectonic regions with preferentially strike slip mechanism and relatively longer duration. With 2D dynamic modeling of earthquake ruptures on heterogeneous pre-stress and linear slip-weakening friction, we find a systematic variation of the simulated STF complexity with frictional properties. Comparison between the observed and synthetic clustering distributions provides useful constraints on elements of the frictional properties. In particular, the characteristic slip-weakening distance could be constrained to be generally short (< 0.1 m) and depth dependent

SCOPED: Seismic COmputational Platform for Empowering Discovery [Year 2]

This poster was presented at the NSF CSSI annual PI meeting in Houston, September 26-27, 2023. This summarizes the Year 2 efforts of the SCOPED project.The NSF funding awards are OAC-CSSI 2104052 [UAF/Tape], OAC-CSSI 2103621 [MINES/Bozdag], OAC-CSSI 2103701 [UW/Denolle], OAC-CSSI 2103741 [Columbia/Waldhauser], OAC-CSSI 2103494 [TACC/Wang]

Sobre la información de amplitud transmitida por el campo sísmico ambiental

The use of the ambient seismic field (ASF) to extract Earth’s response has received significant attention in the last several years. Multiple studies demonstrate the utility of the ASF for estimating high-resolution velocity models in various locations. In this paper, we discuss the amplitude information carried by the ASF. Amplitude information includes both amplification effects due to elastic structure, such as low velocity sedimentary basins, and attenuation effects in the crust and upper mantle or even in buildings. As has been suggested by other authors, amplitude measurements may be biased due to nonuniformities in ambient field excitation; however, we find very similar and stable results for different time intervals for both amplification and attenuation, suggesting that this bias may not be as large as feared. We conclude that valuable amplitude information can be recovered from the ASF through careful processing. Amplitude measurements may be particularly valuable due to the enhanced sensitivity of attenuation to fluids and/or temperature fluctuations. 2011 Acade´mie des sciences. Published by Elsevier Masson SAS. All rights reserve

Urbanisme et participation

Si l’urbanisme est l’un des domaines privilégiés pour la mise en œuvre des processus participatifs, comme l’enquête publique ou le débat public, il n’a qu’assez peu évolué pour améliorer ces processus dont les insuffisances sont pourtant identifiées depuis longtemps par la doctrine. Assez indifférent, le législateur semble même véhiculer une image plutôt péjorative des mécanismes participatifs, les présentant comme un obstacle à l’efficacité économique et normative. Parallèlement, certains acteurs, élus et administrés vont pleinement s’approprier les outils de la participation et tenter de les faire évoluer.While participatory processes, such as a public enquiry or a public debate, are a major concern in town and country planning issues, there has been little progress in improving these processes, of which the deficiencies have, however, long been recognised. Somewhat disinterested, the legislator even seems to convey a rather pejorative view of participatory mechanisms, suggesting that they present an obstacle to economic and regulatory efficiency. At the same time, certain actors, both elected officials and citizens, are making full use of the participatory mechanisms and are trying to improve them

Chronique de jurisprudence constitutionnelle française 2016

Désormais traditionnelle dans cette revue, cette chronique de jurisprudence constitutionnelle n’a pas vocation à être exhaustive et cherche davantage à livrer au lecteur une analyse contextualisée des décisions qui ont retenu l’attention des auteurs. Il nous a semblé à première vue que le Conseil constitutionnelle avait réservé une jurisprudence de premier choix aux droits économiques et sociaux protégés par la Constitution, constat qui, à l’issue de notre analyse, est finalement apparu beaucoup moins évident. Les droits civils et politiques ne sont toutefois pas en reste puisque la jurisprudence du Conseil dans ce domaine a été, comme à l’accoutumée, abondante et elle s’est avérée globalement protectrice, bien que là encore elle ne soit pas exempte de certaines critiques.Now traditional in this journal, this chronicle of constitutional case law does not intend to provide an exhaustive list of all the decisions taken by the Constitutional Council over the course of the year but aims to give a critical and contextualised analysis of some of the most important decisions, in our view, for 2016. At first, we felt that the constitutional case law had concentrated on the economic and social rights protected by the Constitution, but then our analysis showed that this was not strictly true. As in the past, the constitutional case law concerning civil and political rights is abundant and generally protective, even if some decisions can be criticised

Seismology in the cloud: guidance for the individual researcher

The commercial cloud offers on-demand computational resources that could be revolutionary for the seismological community, especially as seismic datasets continue to grow. However, there are few educational examples for cloud use that target individual seismological researchers. Here, we present a reproducible earthquake detection and association workflow that runs on Microsoft Azure. The Python-based workflow runs on continuous time-series data using both template matching and machine learning. We provide tutorials for constructing cloud resources (both storage and computing) through a desktop portal and deploying the code both locally and remotely on the cloud resources. We report on scaling of compute times and costs to show that CPU-only processing is generally inexpensive, and is faster and simpler than using GPUs. When the workflow is applied to one year of continuous data from a mid-ocean ridge, the resulting earthquake catalogs suggest that template matching and machine learning are complementary methods whose relative performance is dependent on site-specific tectonic characteristics. Overall, we find that the commercial cloud presents a steep learning curve but is cost-effective. This report is intended as an informative starting point for any researcher considering migrating their own processing to the commercial cloud

Chronique de jurisprudence constitutionnelle française janvier 2007-mars 2008 1

International audienc

Chronique de jurisprudence constitutionnelle française 2008

International audienc

Chronique de jurisprudence constitutionnelle française 2008

La période courant du mois d’avril 2008 au mois de janvier 2009 n’aura pas été la plus mémorable du point de vue de l’histoire de la jurisprudence constitutionnelle. Face aux lois qui ont frontalement touché les droits fondamentaux l’année dernière, cette année s’est révélée beaucoup plus calme ; une année de transition donc, toutefois marquée par une révision importante de la Constitution. Le 21 juillet 2008, le Congrès adoptait en effet la 24e réforme de la Constitution de 1958, afin de tir..