Search results for "Geophysics"

Cellier aux Moines de Givry, observations sur les bâtiments et leur évolution depuis le Moyen Âge

2012

Inland harbours in Central Europe: Nodes between Northern Europe and the Mediterranean Sea

2019

International audience

European Harbour Data Repository

2018

International audience

Fractal dimension versus density of built-up surfaces in the periphery of Brussels

2007

International audience; This paper aims at showing the usefulness of the fractal dimension for characterizing the spatial structure of the built-up surfaces within the periurban fringe. We first discuss our methodology and expectations in terms of operationality of the fractal dimension theoretically and geometrically. An empirical analysis is then performed on the southern periphery of Brussels (Brabant Wallon). The empirical analysis is divided into two parts: first, the effect of the size and shape of the windows on the fractal measures is empirically evaluated; this leads to a methodological discussion about the importance of the scale of analysis as well as the real sense of fractality…

Deux frères scientifiques de renom : Fernand et Robert de Montessus de Ballore

2011

National audience; Le premier des deux frères, Fernand " Bernard de Montessus de Ballore ", est l'un des précurseurs de la séismologie, selon le terme de l'époque : il a établi par des relevés rigoureux et nombreux que les tremblements de terre étaient en relation avec la géologie et non avec les phases de la lune ou les volcans souterrains comme on le supposait au début du XXe siècle. En 2006, le Laboratoire International Montessus de Ballore est créé entre le CNRS-INSU et l'Université du Chili à Santiago. Le second, Robert " Bernard de Montessus de Ballore ", a œuvré pour les mathématiques : il a reçu un Grand Prix de l'Académie des Sciences en 1906 pour ses travaux dans le domaine des fr…

Single crystal EXAFS at high pressure

2000

Abstract We present a new technique for structure characterization under high pressure conditions. The use of an undulator beam of the third-generation ESRF source of synchrotron radiation has enabled the first single crystal EXAFS experiments at high pressure using a diamond anvil cell as pressure generator. Taking advantage of the linear polarization of X-rays the technique becomes an orientation-selective probe of the local structure of materials. We describe the principle of the technique and some applications.

Geostatistical computing of acoustic maps in the presence of barriers

2009

Acoustic maps are the main diagnostic tools used by authorities for addressing the growing problem of urban acoustic contamination. Geostatistics models phenomena with spatial variation, but restricted to homogeneous prediction regions. The presence of barriers such as buildings introduces discontinuities in prediction areas. In this paper we investigate how to incorporate information of a geographical nature into the process of geostatistical prediction. In addition, we study the use of a Cost-Based distance to quantify the correlation between locations.

Ca-rich carbonates associated with ultrabasic-ultramafic melts. Carbonatite or limestone xenoliths? A case study from the late Miocene Morron de Vill…

2016

The volcanic products of the late Miocene Morron de Villamayor volcano (Calatrava Volcanic Field, central Spain) are known for being one of the few outcrops of leucitites in the entire circum-Mediterranean area. These rocks are important because aragonite of mantle origin has been reported as inclusion in olivine macrocrysts. We use petrographic observations, mineral compositions, as well as oxygen and carbon isotope ratios coupled with experimental petrology to understand the origin of carbonate phase in these olivine-phyric rocks. Groundmass and macrocryst olivines range from δ18OVSMOW of +4.8‰, typical of mantle olivine values, to +7.4‰, indicating contamination by sedimentary carbonate.…

Elastic Geobarometry for Anisotropic Inclusions in Anisotropic Host Minerals: Quartz-in-Zircon

2021

Current models for elastic geobarometry have been developed with the assumption that the host and/or inclusion minerals are elastically isotropic. This assumption has limited applications of elastic thermobarometry to mineral inclusions contained in cubic quasi-isotropic host minerals (e.g., garnet). Here, we report a new elastic model that takes into account the anisotropic elastic properties and relative crystallographic orientation (RCO) of a host-inclusion system where both minerals are noncubic. This anisotropic elastic model can be used for host-inclusion elastic thermobarometric calculations provided that the RCO and elastic properties of both the host and inclusion are known. We the…

Three-Dimensional Simulations of Solar Wind Preconditioning and the 23 July 2012 Interplanetary Coronal Mass Ejection

2020

Predicting the large-scale eruptions from the solar corona and their propagation through interplanetary space remains an outstanding challenge in solar- and helio-physics research. In this article, we describe three dimensional magnetohydrodynamic simulations of the inner heliosphere leading up to and including the extreme interplanetary coronal mass ejection (ICME) of 23 July 2012, developed using the code PLUTO. The simulations are driven using the output of coronal models for Carrington rotations 2125 and 2126 and, given the uncertainties in the initial conditions, are able to reproduce an event of comparable magnitude to the 23 July ICME, with similar velocity and density profiles at 1 …