26 research outputs found
The Belgian Macroseismic Database : creation, validation, and its implications for engineering seismology
No full textFor the average citizen in Belgium, earthquakes are perceived as distant events, unlikely to ever affect their daily lives or warrant concern. This perception is supported by the relative absence of significant seismic activity in Belgium over the past 30 years. Such inactivity is not unusual, as Belgian intraplate seismicity is characterized by low to moderate diffuse seismicity with long periods of inactivity. Occasionally, however, large(r) earthquakes have occurred and are likely to occur again, causing damage throughout vast regions in Belgium. Since 1985, Belgium’s instrumental seismic network has been significantly expanded which improved the detection accuracy and earthquake coverage across the country. Due to Belgium’s low to moderate seismicity, however, the number of recorded earthquakes remains limited and unrepresentative of the long-term seismic activity. To achieve a more comprehensive assessment of the seismic hazard, an additional source of information on the impact of earthquakes is required. This gap can be addressed using macroseismic intensity data. Macroseismic intensity is the classification of the severity of ground shaking at a specific location. It is based only on the observed shaking effects on people and its surroundings. Since the start of the 20th century, the Royal Observatory of Belgium (ROB) has collected an extensive amount of macroseismic data on felt events, offering a rich database which summarizes the impact of seismic events on Belgium. Up until now, however, this wealth of information was not readily available, no comprehensive compilation of collected macroseismic data was provided and information on it was limited and scattered throughout various research papers and projects. Consequently, the main objectives of this PhD research are to facilitate and promote the use of Belgian macroseismic data in future applications towards seismic hazard assessments and real-time impact monitoring. This was accomplished through: 1)The publication of the Belgian Traditional Macroseismic (BTM) database, a comprehensive compilation of 20th-century macroseismic data including 23,950 intensity data points (IDPs) for 80 felt events (Neefs et al. 2024a, 2024b). 2)The publication of the Belgian Online Macroseismic (BOM) database, providing a first compilation of online collected macroseismic intensity data since 2002, with 1,220 IDPs for 39 felt events. 3)Illustrating the potential of Belgian macroseismic data, through an evaluation of the predictions provided by the most recent Belgian seismic hazard model with observed intensities, and through an evaluation of the performance of various Intensity Prediction Equations (IPEs) on the observed intensity attenuation rate. The macroseismic survey methodologies that provided the data incorporated in the BTM and BOM databases are described in detail in this dissertation: from small-scale improvised surveys to the systematic mass-distribution of communal questionnaires and the online volunteer-based “Did You Feel It?” inquiries which, in practice, have replaced traditional macroseismic surveys in Belgium. These various macroseismic methodologies and sources are subjected to a critical review of their quality, illustrating the considerable extent of their associated uncertainties. To ensure the continuation of the collection of both traditional and online macroseismic surveys and to reduce their uncertainties in the future, new survey methodologies are suggested. Both databases combined provide a detailed summary of the impact of 125 years of seismic activity on Belgium. The maximum intensity registered is intensity 7 on the European Macroseismic Scale (EMS-98), with widespread damage in the affected localities where this intensity was observed. The earthquakes with the largest impact on Belgium in this time span are the ML = 5.6 Zulzeke-Nukerke 1938 earthquake, the ML = 5.1 Liège 1983 earthquake and the recurring shallow, small to moderate and triggered earthquakes in the Hainaut coal basin throughout most of the 20th century. The information in the BTM and BOM databases allow evaluating possible limitations on the current seismic hazard assessment of Belgium. This evaluation indicates that the predicted values align with the macroseismic observations, providing a validation of the Belgian seismic hazard map. However, as only limited data on local site effects from seismic station locations and their unconstrained share in amplification effects was used, large-scale site effects mapping is needed to extrapolate these finding throughout Belgium. Finally, the performances of various selected IPEs are compared with observed intensity attenuation rates. This evaluation illustrates that earthquake source depths are the main variable that determines IPE performances. Several IPEs are suggested to model the attenuation rates of Belgian earthquakes: the IPE by Camelbeeck et al. (2022) is best fit for shallow earthquakes, with focal depths lower than 10 km, even outside the Hainaut coal basin for which this IPE was developed. For deep(er) earthquakes, with focal depths equal to or greater than 10 km, the “chi-square regression” model by Stromeyer and Grünthal (2009) and the “French stable continental region” by Bakun and Scotti (2006) provide the best attenuation rates.(FSA - Sciences de l'ingénieur) -- UCL, 202
La prévision de l'œuvre
No full textEingespannt in ein Projekt, in die Zwänge der Verwirklichung, sowie in einen vagen schöpferischen Appell, öffnen sich die Wege zum Werk hin : fast immer schwierig, voiler Chaos, aber stets unter dem Zeichen dichterischer inventio. Indem der Autor Virtualitàt und Verschriftlichung des Werks (Signatur der Moderne) verbindet mit dem graphischen Raum der Arbeitshandschriften, auf welchem sich schöpfe-rische Projektion niederschlägt, hait er uns an zum Nachdenken ûber den Zusammenhang zwischen genetischem Werdegang des Werks und gelungener ästhetischer Virtualität.Este artigo interroga-se a proposito dos aspectos mais mobeis e flutuantes da critica genética, procurando as fronteiras nas quais se implica ou se encontra implicada. Um dos obstãculos importantes que deve enfrentar esta crftica é o carãter unico de cada exemplo, a partir do quai pode e devecomo a critica textual construir os paradigmas e uma poética. É preciso sublinhar o papel inventivo e piloto dos pre-textos mais ricos. A margem de invençâo é ampla jã que os papeis funcionais do texto final inspiram so excepcionalmente o método de exploração genética. Tem âreas em que a critica genética se desenvolve cômoda e operativa, como na autotextualidade e na intertextualidade. Contudo como o mostra um exemplo tomado em Madame Bovary -, a crîtica genética deve, para preservar o seu rigor, pararse nos limites da critica textual, sem entrar em interpretaçôes globais -em particular hermenéuticas -que são alheias, até contraditorias, à sua natureza.Caught between a project, the constraints of carrying it out and an obscure creative injunction, the roads leading towards the work open up, often with difficulty and chaotically, but always with on the horizon the creation still to come. Relating modern theories of the «virtuality » of the work and of writing with the projective space of working manuscripts, the author offers for consideration the interplay of the genetic trajectories of the work and the aesthetic virtuality finally realised.Presi fra un progetto, le leggi della sua realizzazione e un imperativo creatore confu i sentieri che conducono all'opera si aprono spesso in maniera difficile e castica ma sempre all'orizzonte dell' invenzione futura. mettendo in rapporto le teorie moderne sulla «virtualité » dell'opera e la sua scrittura con gli spazi di progettazione che sono i dossiers genetici, l'autore invita a considerare come si relazzionano i percorsi genetici e la sua virtualité estetica già conquistata.Pris entre un projet, les contraintes de la réalisation et une injonction créatrice confuse, les chemins vers l'œuvre s'ouvrent, souvent difficilement, chaotiquement, mais toujours dans l'horizon de l'invention à venir. Mettant en relation les propos modernes sur la «virtualité » de l'œuvre et sur l'écriture avec l'espace de projection que sont les dossiers de travail, l'auteur invite à considérer comment jouent ensemble les parcours génétiques de l'œuvre et la virtualité esthétique conquise.Encuadrados por un proyecto, por las exigencias de la realizaciôn y por un impulso creador confuso, los caminos que conducen a la obra se abren, a menudo dificilmente, caoticamente, pero siempre en el hori-zonte de la futura invencion. Relacionando los conceptos mas modernos sobre la «virtualidad » de la obra y la escritura, con el espacio de proyeccion que son los dossieres de trabajo, el autor propone una reflexion acerca de la interaction de los recorridos genéticos de la obra y la virtualidad estética conquistada.Neefs Jacques. La prévision de l'œuvre. In: Genesis (Manuscrits-Recherche-Invention), numéro 6, 1994. Enjeux critiques. pp. 107-116
Macroseismic intensity data points for shallow 20th century earthquakes in the Hainaut coal area and the 1983 Liège earthquake (Belgium)
No full text<p>This dataset contains macroseismic data points and source parameters for 28 shallow 20th-century earthquakes in the Hainaut area, as well as for the 1983-11-08 Liège earthquake, all in Belgium. For each earthquake, there is 1 CSV-file containing minimum and maximum evaluated macroseismic intensity, latitude, longitude, commune name, epicentral distance and azimuth. The source parameters (origin time, epicentral coordinates, hypocentral depth, magnitude, maximum intensity, macroseismic radius and number of observations) are listed in a XLSX file. The ID_EARTH column in this file corresponds to the first part of the CSV filenames.<br>The most significant difference with respect to the original dataset is an update of the coordinates of several Belgian localities that are used to locate the IDPs, resulting mainly in insignificant changes (<1 km difference for 96% of the IDPs used here), but a few outliers up to a difference of 22 km occur as well. This can result in significantly higher or lower epicentral distances for a few IDPs. Other adjustments to the data include the addition of intensity 1 values (not felt) and the removal, addition or modification of some IDPs (>20 IDPs in total). For the 1983 Liège earthquake (ID_EARTH=651), more significant changes were made to the IDP dataset as part of a major update of the ROB traditional macroseismic database, such as the addition of 297 new IDPs (~90% not felt), the modification of intensity values of 19 IDPs and the removal of 3 IDPs that were previously assigned to the wrong municipality.</p>
Testing the applicability of ground motion prediction equations for the Hainaut region (Belgium) using intensity data
No full textIn regions where strong earthquakes occurred before the deployment of dense seismic and accelerometric networks, intensity datasets can help select appropriate ground motion prediction equations (GMPEs) for seismic hazard studies. This is the case for the Hainaut seismic zone, which was one of the most seismically active zones in and around Belgium during the twentieth century. A recent reassessment of the intensity dataset of the area showed that intensities in this region attenuate much faster with distance than in other parts of northwestern Europe. Unfortunately, this characteristic has not yet been taken into account in current hazard maps for Belgium and northern France. Based on this dataset, we evaluate the goodness of fit of published GMPEs with intensities in Hainaut by means of a ground-motion-to-intensity conversion equation (GMICE) and according to different metrics (Likelihood, Log-likelihood and Euclidean-based Distance Ranking) published in literature. We also introduce a new measure to specifically evaluate the distance trend. Our results show that none of the tested GMPEs convincingly fits the intensity dataset, in particular the fast attenuation with distance. Nevertheless, applying the few GMPEs that show a reasonable fit in seismic hazard computations, we observe a decrease of the influence of the Hainaut seismicity on hazard maps for Belgium and northern France. This result is compatible with the earthquake intensity observations for the last 350 years in this part of Europe
Jeu et contraintes dans la création contemporaine
No full textL objet de ce travail est l écriture sous contrainte dans la littérature, et plus spécialement dans les lettres françaises du XX-ème siècle. Ce principe riche d une tradition séculaire, se définit comme un ensemble de règles formelles que l écrivain superpose aux règles normatives et applique consciemment et systématiquement pour construire des oeuvres littéraires. La contrainte est déclinée sous de multiples aspects - du procédé rhétorique au concept artistique et dans diverses disciplines et cultures. Ceci permet de l envisager comme une notion fondamentale de l esthétique formaliste et en analyser différentes approches et interprétations. Elle s attache aussi à y déterminer le statut du texte, de l auteur et du lecteur, sans oublier la place et le rôle que ce genre peut avoir dans la création contemporaine. L écriture sous contrainte se présente, par-delà le passionnant jeu verbal, comme une source d inspiration intarissable, mais aussi et surtout comme un instrument de contestation et de subversion, un moyen de libération autant que de quête spirituelleThe dissertation is devoted to 'writing under restrictions' in fiction in general and in the French literature of the 20th century in particular. This mode of writing dates back several centuries and is defined as a number of specific formal rules, or restrictions, that an author adds to the existing linguistic and cultural norms, and deliberately and systematically follows in his/her writing of a work of fiction. These restrictions are analysed in a number of aspects from specific rhetorical devices to global artistic concepts, and within the context of various disciplines and cultures, which allows to treat these limitations as a formalist aesthetics in its own right. The dissertation studies various approaches to interpretation of restricted writing, defining the status of the text, the author and the reader, as well as the place and the role that is given to this kind of literature in the contemporary creation. Restricted writing, as it appears, is both a source of inspiration and a word game, moreover, it also turns out to be an instrument of dissent and subversion, a tool for liberation and a way of spiritual questST DENIS-BU PARIS8 (930662101) / SudocSudocFranceF
Le Traité de la Volonté d'Honoré de Balzac
No full textDans sa thèse, l'auteur propose un point de vue sur l'œuvre de Balzac qui s'attache à des aspects philosophiques jusqu'ici relativement inaperçus. La lecture méthodique des auteurs mentionnés par Balzac dans La Comédie humaine et la lecture des ouvrages de l'époque sur les sujets relevés dans les brouillons de jeunesse, fait ressortir un intérêt unique et obsédant pour l'actus, la volonté, ce qui permet d'identifier la lecture de jeunesse comme les brouillons du Traité de la Volonté. La volonté, le génie, l'Absolu, tel était le résultat de la superposition des lectures de jeunesse de Balzac. Dans ses recherches sur la volonté, Balzac conduit un parallèle avec les philosophes allemands, notamment avec Schopenhauer, qui, comme Balzac, s'intéressait, pour le même but, au magnétisme animal et aux écrivains mystiques. Ces recherches ont conduit Balzac à l'idée de comparer l'animalité et l'humanité, ce qui a abouti au grand projet de La Comédie humaine, qui devient la description de l'enfer de l'humanité, séparée de la connaissance absolue et la recherche de la voie vers l'Absolu.In her thesis, the author suggests making a change of the point of view on the work of Balzac and discovering the new aspects which up to here are spent unnoticed. The methodical reading of authors, mentioned by Balzac in The Human Comedy and the reading of the works of period on the subjects noted in youth drafts, highlights only and obsessing interest : the actus, the will, what allows to identify the youth reading as draft of the Treaty of the Will. The will, the genius, the Absolute, such was the result of the superimposing of the youth reading of Balzac. In his researches on the will, Balzac goes in parallel with the German philosophers, in particular with Schopenhauer, who, as Balzac, was interested, for the same purpose, in the animal magnetism and in the mystic writers. These researches brought Balzac at the idea of comparing the bestiality and the humanity, what ended in the great project of The Human Comedy, which becomes the description of the humanity as an Hell, separated from the absolute knowledge and the research for way towards the Absolute.ST DENIS-BU PARIS8 (930662101) / SudocSudocFranceF
The Belgian traditional macroseismic (BTM) database of the twentieth century
No full textMacroseismic intensity data have been gathered continuously in Belgium since the start of the twentieth century. In this study, we review the applied survey practices used over the previous century: from small-scale ad-hoc improvised surveys to the mass distribution of collective questionnaire versions sent to local authorities. The variety of survey methodologies causes a high degree of heterogeneity within the resulting macroseismic data, increasing the uncertainty in macroseismic applications that rely on homogeneous data. We thoroughly re-evaluated the original source material and intensity scale conversions in order to create the Belgian Traditional Macroseismic (BTM) database, a comprehensive compilation of 20th-century macroseismic data in which all sources are properly referenced. The BTM database currently consists of 23,950 intensity data points (IDPs) on the European Macroseismic Scale for 80 felt earthquakes, ranging from 2.4 to 5.8 on the local magnitude (ML) scale. Each IDP is provided with a source type and each earthquake is attributed a data quality parameter that indicates the level of uncertainty associated with its IDP source quality. The publication of the BTM database facilitates the use of Belgian macroseismic data for a variety of seismological purposes and allows us to summarize the overall seismic impact on Belgium for the duration of a century. Like in many other parts of the world, traditional procedures have practically been discontinued in Belgium in favour of an online enquiry. However, the potential for high-quality data following a traditional survey methodology is still large and we strongly recommend its continuation
The damaging 1932 Uden Earthquake in the Netherlands – revision of cross‑border macroseismic data and its impact on source parameters
No full textA re-assessment of the macroseismic intensity data was conducted for the second-largest instrumentally recorded event in the Netherlands: the 20 November 1932 Uden earthquake. This event was felt across the Netherlands, Belgium and Germany. Intensity values on the EMS98 scale were assigned based on original data (reports/enquiries/letters), manually for the Netherlands and automatically for Belgium, with existing German data added for completeness. The updated dataset was used to calculate macroseismic location and magnitude using the Bakun and Wentworth (1997, 1999) algorithm. To capture epistemic uncertainty, four newly calibrated intensity attenuation relations were applied and their results averaged. The results using only intensity data from the Netherlands provided stable solutions within the region of maximum observed intensity ( Imax = VII). However, including Belgian and German data shifted the source location outside this region and becomes less reliable, likely due to differences in data collection methods and local/regional site effects. Comparison of confidence levels from the BW method with bootstrap modelling showed that almost all bootstrap results fall within the 50% confidence region. A more realistic estimate for the location uncertainty was derived from the bootstrap analysis. The revised source parameters are 51.63°N and 5.61°E ± 7.3 km for the source location and ML = 5.1 ± 0.3 ( MS 4.9 ± 0.3) for the magnitude
Crise de l’œuvre, crise des genres : le roman épistolaire au tournant des Lumières
No full textThe epistolary novel shares, at the turn of the Enlightenment, the crisis which invests the work and opens the literary genres caused by the erosion of notions of totality and normative relevance, crisis which is expressed in the poetics of ruins inaugurated by Diderot and the aesthetics of the fragment, theorized by Friedrich Schlegel and the Jena school. From that time, the work is no longer seen as something accomplished and immutable, but as
the result of a review process theoretically infinite, a state among others, whose publication would be the result of a combination of circumstances, an "accident" rather than the precise will of an author. Far from representing the last act which completes it, the work identifies itself more and more will all stages of revision contributing to its transformation. It is a matter of modern concept affirming the problematic nature of the work: the illegitimacy of its origin,
its impossible completion. The incompleteness is one of the keywords of modernity, the "open form" being felt as a guarantee against the untruth threatening the myth of totality. The fragmentary choice is the turntable around which the epistolary novel rotates at the turn of the Enlightenment. A choice which cannot in any case be limited to a simple technicality, but which reproduces a mental attitude, a new thinking approach. A revolution, according to Michel Foucault, for whom "the last years of the eighteenth century were broken by
a discontinuity similar to that which broke in the early seventeenth century, the Renaissance thought; [.] knowledge residing in a new space
Le concept d'aventure dans la prose narrative française du vingtième siècle
No full textThrough adventure, literature's topos par excellence, Robert Louis Stevenson, Marcel Schwob, Pierre Mac Orlan and Blaise Cendrars demonstrate the urgency, in an age of rationalism and historical positivism, of restoring imagination as a cognitive tool with fundamental social and political functions in the construction of any human community. As an apologist of the romance, Stevenson excavates the common ground between novel and romance, between history and literature, namely the art of narrative. For Stevenson, narrative constitutes the point of view from which to consider the representation of reality. While the novel and history tend to approach reality as content, the romance points to its principle of creation. The shift in point of view from reality to representation and from content to principle allows a new conception of subjectivity and another relation to knowledge to emerge. Following Stevenson, French authors writing in the context of World War I and its aftermath take up epistemological and ontological questions pertaining to the imagination and extend them beyond literary debate, to society at large.Ph.D.Includes bibliographical references (p. 497-520)
