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Interplay between tectonics and surface processes in the evolution of mountain ranges: Insights from landscape dynamics, uplift, and active deformation of Talesh Mountains (NW Iranian Plateau margin)
No full textISSN:0169-555xISSN:1872-695XISSN:1872-695
Stream laws in analog tectonic-landscape models
No full textISSN:2196-632XISSN:2196-6311ISSN:2196-631
Le rôle du manteau asthénosphérique dans le développement de la topographie des système Atlas-Meseta (Maroc).
No full textThe interplay between uplift, which is mostly controlled by tectonics or deep-seated mechanisms and the efficiency of surface processes, which is primarly set by climate, modulates the growth and the decay of topography across diverse temporal and spatial scales. In active orogens, tectonic and climatic forcings are the dominant processes in controlling the landscape evolution and the creation of topographic relief, as largely demonstrated by numerical and quantitative investigations. Conversely, in tectonically quiescent settings, a few field-based studies have documented that the main control on topography is exerted by bedrock erodibility and to a minor extent by climate. Regions that experienced an increase in uplift rates (i.e., topographic rejuvenation) are in disequilibrium and are characterized by the coexistence of a transient landscape that is still recording the previous boundary conditions and a steep topography that has already adjusted to the new uplift rates. Consequently, the landscape of the renjuvineted regions contains at the same time information on present and past uplift (and erosion) conditions and hence represents a first-order geomorphological archive. To explore the landscape dynamics of a rejuvenated topography, we investigated the Atlas-Meseta system of Morocco, which represents a large-scale orographic system characterized by active orogens and quiescent domains. Particularly, it includes the High and the Middle Atlas, which represent active orogens, and the Anti-Atlas and the Western and Estern Meseta, which are tectonically incactive domains. The entire Atlas system has undergone a Cenozoic phase of topographic resurgence as testified by geological, geomorphological and volcanological contraints. However, the low amount of crustal shortening and the presence of an anomalous thinning of the lithosphere beneath suggest an important contribution of deep-seated processes in generating and supporting the topography of this orographic system.Here I combine a quantitative analysis of regional and basin-scale topography, stream profiles analysis (knickpoints characterization, longitudinal profiles and -plot) and landscape modelling, with denudation rates inferred from 10Be concentrations from bedrocks and watersheds in the quiescent Anti-Atlas and Western Meseta. The results of this study allow deciphering and quantifing the erosional dynamics that control the topographic relief production and the landscape uplift history for shorter and longer time scales. This approach further provides the possibility to dechiper, quantify, and differentiate the deep-seated, large wavelength signal, from the shallower contributions (i.e., tectonics and possibly magma injection) in the Atlas-Meseta system.L'interaction entre le soulèvement, principalement contrôlé par la tectonique ou les mécanismes profonds liés à la dynamique du manteau, et l'efficacité des processus de surface, principalement déterminée par le climat, module la croissance et la décroissance de la topographie à diverses échelles temporelles et spatiales. Dans les orogènes actifs, les forçages tectoniques et climatiques sont les processus dominants dans le contrôle de l'évolution du paysage et de la création du relief topographique, comme le démontrent largement les études numériques et quantitatives. A l'inverse, dans les contextes tectoniquement calmes, quelques études de terrain ont montré que le contrôle principal de la topographie est exercé par l'érodabilité du substratum rocheux et, dans une moindre mesure, par le climat. Les régions qui ont connu une augmentation des taux de soulèvement (c'est-à-dire un rajeunissement topographique) sont en déséquilibre et sont caractérisées par la coexistence d'un paysage transitoire qui conserve encore les conditions aux limites précédentes et d'une topographie abrupte qui s'est déjà adaptée aux nouveaux taux de soulèvement. Par conséquent, le paysage des régions rajeunies contient en même temps des informations sur les conditions de soulèvement (et d'érosion) présentes et passées et représente donc une archive géomorphologique de premier ordre. Pour explorer la dynamique du paysage d'une topographie rajeunie, nous avons étudié le système Atlas-Meseta du Maroc, qui représente un système orographique à grande échelle caractérisé par des orogènes actifs et des domaines quiescents. En particulier, il comprend le Haut et le Moyen Atlas, qui représentent des orogènes actifs, et l'Anti-Atlas et la Meseta occidentale et orientale, qui sont des domaines tectoniquement inactifs. L'ensemble du système Atlas a subi une phase cénozoïque de résurgence topographique comme en témoignent les contraintes géologiques, géomorphologiques et volcanologiques. Cependant, la faible quantité de raccourcissement crustal et la présence d'un amincissement anormal de la lithosphère sous-jacente suggèrent une contribution importante des processus profonds dans la génération et le soutien de la topographie de ce système orographique.Ici, nous combinons une analyse quantitative de la topographie régionale et à l'échelle du bassin, une analyse des profils de rivières (caractérisation des knickpoints, profils longitudinaux et -plot) et une modélisation du paysage, avec les taux de dénudation déduits des concentrations en nucléide cosmogénique 10Be produit in situ dans les roches du substratum rocheux et les sédiments modernes transportés dans les bassins versants de l'Anti-Atlas et de la Meseta occidentale. Les résultats de cette étude permettent de déchiffrer et de quantifier la dynamique érosive qui contrôle la production du relief topographique et l'histoire du soulèvement du paysage pour des échelles de temps courtes et longues. Cette approche offre en outre la possibilité de déchiffrer, de quantifier et de différencier le signal profond de grande longueur d'onde des contributions moins profondes (c'est-à-dire la tectonique et éventuellement l'injection de magma) dans le système Atlas-Meseta
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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