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11.
High slip rate for a low seismicity along the Palu-Koro active fault in central Sulawesi (Indonesia)
Olivier Bellier Michel Sébrier Thierry Beaudouin Michel Villeneuve Régis Braucher Didier Bourlès Lionel Siame Eka Putranto & Indyo Pratomo 《地学学报》2001,13(6):463-470
In eastern Indonesia, the Central Sulawesi fault system consists of complex left-lateral strike-slip fault zones located within the triple junction area between the Pacific, Indo-Australian and Eurasian plates. Seismicity in Central Sulawesi documents low-magnitude shallow earthquakes related, from NW to SE, to the NNW-trending Palu-Koro (PKF) and WNW-trending Matano fault zones. Study of the active fault traces indicates a northward growing complexity in the PKF segmentation. Left-lateral displacement of 370 ± 10 m of streams incised within fans, whose deposition has been dated at 11 000 ± 2300 years, yields a calculated PKF horizontal slip rate of 35 ± 8 mm yr−1 . This geologically determined long-term slip rate agrees with the far-field strike-slip rate of 32–45 mm yr−1 previously proposed from GPS measurements and confirms that the PKF is a fast slipping fault with a relatively low level of seismicity. 相似文献
12.
Geotectonics - The purpose of this paper is to characterize the configuration of northern Tunisia’s basin during the Cretaceous on the basis of abundant slump folds and frequent... 相似文献
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Vittecoq Benoit Reninger Pierre-Alexandre Bellier Vincent Taïlamé Anne-Lise Nacimento Laureen Gros Emile Violette Sophie 《Hydrogeology Journal》2023,31(5):1331-1352
Montagne Pelée, on the French island of Martinique, eastern Caribbean Sea, has been one of the deadliest volcanoes in the world, with 30,000 victims following the 1902 eruption. Thousands of people still live nearby, and this volcano is a strategic “water tank” for Martinique Island, providing 40% of the island’s water supply. This research aimed to better understand its hydrogeological functioning and the relationship with its complex volcanological evolution, taking advantage of a high-resolution helicopter-borne geophysical survey correlated with hydrogeological data from the boreholes and springs databases. Electromagnetic data, correlated with hydrogeological data, allowed for the identification of unsaturated zones, aquifers, and seawater intrusions, as well as the main geological units. In addition, data synthesised from pumping tests revealed that the older the unconsolidated pyroclastic deposits, the lower their hydraulic conductivity. The structural asymmetry between the northeastern and southwestern volcano flanks impacts its hydrogeological functioning. Consequently, the Montagne Pelée hydrogeological conceptual model is marked by several distinguishable aquifers. The upper perched aquifer within recent lava domes is directly involved in, and impacted by, phreatic eruptions, and it supports low flowrate springs. The remaining effective rainfall infiltrates to depth and recharges the hydrothermal system through vertical fractures. The other aquifers are categorized into three groups: northeastern, southeastern and southwestern flank aquifers. This research is a new step toward a better understanding of the Lesser Antilles volcanoes and more broadly of the central and proximal parts of the andesitic active volcanoes.
相似文献14.
Géométrie et cinématique post-oligocène des failles d'Aix et de la moyenne Durance (Provence,France)
The southern termination of the left-lateral ‘Moyenne Durance’ Fault (FMD) consists in several segments, some being connected to WSW-trending south-verging reverse faults. To the south, the Aix fault is reactivated in a post-Oligocene strike-slip movement showing that these two faults might belong to the same system. This system seems to transfer, in turn, slip to the east-trending, south-verging Trévaresse reverse fault, allowing southward propagation of the Alpine deformation front in western Provence. Fault kinematics analysis shows lateral stress field change between the two faults. Strike-slip stress state is characterized by an average N150°E trending σ1 near the FMD termination, whilst strike-slip and reverse faulting stress states show north-trending to the south. To cite this article: P. Guignard et al., C. R. Geoscience 337 (2005). 相似文献
15.
Amara Masrouhi Olivier Bellier Hemin Koyi 《International Journal of Earth Sciences》2014,103(3):881-900
Detailed geologic mapping, structural analysis, field cross-sections, new dating based on planktonic foraminifera, in addition to gravity signature of Lorbeus diapir, are used to characterize polyphase salt diapirism. This study highlights the role of inherited faulting, which controls and influences the piercement efficiency and the style and geometry of the diapir; and also the localization of evaporite early ascent displaying diapiric growth during extension. Salt was extruded along the graben axis developed within extensional regional early Cretaceous tectonic associated with the North African passive margin evolution. Geologic data highlight reactive diapirism during Albian time (most extreme extension period) and passive diapirism during the late Cretaceous post-rift stage. Northeastern Maghreb salt province gives evidences that contractional deformations are not associated with significant diapirism. During shortening, the initial major graben deforms as complex anticlines where diapirs are squeezed and pinched from their feeding. 相似文献
16.
Accurate chronological records are critical for studying the alluvial fan sequences emplaced during local/global climatic changes but, in general, there are no satisfactory, quantitative dating methods available. In situ -produced 10 Be concentrations have been measured in quartz boulders exposed on Sulawesian late Quaternary fan surfaces. These concentrations suggest that the two fan units evidenced by geomorphic study were emplaced during two distinct major climatic events. The calculated minimum exposure ages imply abandonment ages of 11 kyr and 120 kyr, for the younger and older units, respectively. This study demonstrates that using both the neutron and muon components implicated in the in situ 10 Be production, surficial erosion rates can be estimated and alluvial fans dated. In particular, it shows that in situ 10 Be may be used to date fan emplacement during the last 120 kyr under humid tropical conditions, significantly helping to constrain continental palaeoclimatology. 相似文献
17.
Key features of the IPSL ocean atmosphere model and its sensitivity to atmospheric resolution 总被引：9，自引：8，他引：1
Olivier Marti P. Braconnot J.-L. Dufresne J. Bellier R. Benshila S. Bony P. Brockmann P. Cadule A. Caubel F. Codron N. de Noblet S. Denvil L. Fairhead T. Fichefet M.-A. Foujols P. Friedlingstein H. Goosse J.-Y. Grandpeix E. Guilyardi F. Hourdin A. Idelkadi M. Kageyama G. Krinner C. Lévy G. Madec J. Mignot I. Musat D. Swingedouw C. Talandier 《Climate Dynamics》2010,34(1):1-26
This paper presents the major characteristics of the Institut Pierre Simon Laplace (IPSL) coupled ocean–atmosphere general circulation model. The model components and the coupling methodology are described, as well as the main characteristics of the climatology and interannual variability. The model results of the standard version used for IPCC climate projections, and for intercomparison projects like the Paleoclimate Modeling Intercomparison Project (PMIP 2) are compared to those with a higher resolution in the atmosphere. A focus on the North Atlantic and on the tropics is used to address the impact of the atmosphere resolution on processes and feedbacks. In the North Atlantic, the resolution change leads to an improved representation of the storm-tracks and the North Atlantic oscillation. The better representation of the wind structure increases the northward salt transports, the deep-water formation and the Atlantic meridional overturning circulation. In the tropics, the ocean–atmosphere dynamical coupling, or Bjerknes feedback, improves with the resolution. The amplitude of ENSO (El Niño-Southern oscillation) consequently increases, as the damping processes are left unchanged. 相似文献
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Subsurface electrical imaging of anisotropic formations affected by a slow active reverse fault, Provence, France 总被引：4，自引：0，他引：4
F. Nguyen S. Garambois D. Chardon D. Hermitte O. Bellier D. Jongmans 《Journal of Applied Geophysics》2007,62(4):338-353
In seismic hazard assessment studies, near-surface geophysical prospecting is increasingly used to help in identifying active faults and to constrain seismic deformation parameters (fault offset, recurrence…). In the current study, electrical tomography was used (1) to locate the Trévaresse slow reverse fault (Provence, SE France), the source of the most important seismic event recorded in the 20th century in France and (2) to test electrical tomography's ability to detect faults and tectonic deformation in a complex geological environment. Our study is supported by a detailed geologic and geomorphic field study. In the investigated area, where the geology is made of a succession of folded marl and limestone layers, electrical images are strongly influenced by electrical macro-anisotropy which plays a critical role in this survey, depending on the investigation scale. When resolution (i.e. the smallest target that can be resolved) is larger than the layer thickness (at depth and/or for large electrode spacing), inversion is unable to retrieve the real structure. To successfully interpret these electrical images, in terms of tectonically induced dip variations, we constrain field data interpretation by comparing measured and inverted electrical data with synthetic modelling results and geological data. The synthetic models were hypothetical coarse geological structures determined on the basis of geological/geomorphologic information (e.g. outcropping layers). For shallow depths, when the resolution is smaller or equal to the anisotropy scale, an electrical tomogram yields straightforward interpretation of the subsurface structure. Coupled with numerical modelling, electrical results successfully helped in positioning a trench for fault characterization. 相似文献
20.
Quaternary stress regime change in the Hatay region (SE Turkey) 总被引：1，自引：0，他引：1