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31.
Myriam Cuylaerts Lieven Naudts Robbert Casier Andrey V. Khabuev Oleg V. Belousov Eugene E. Kononov Oleg Khlystov Marc De Batist 《Geo-Marine Letters》2012,32(5-6):383-394
New high-resolution multibeam bathymetry data recorded in 2009 in the deepest lake in the World, Lake Baikal, Siberia, enabled a better understanding of the morphology of ten known lake-bed structures—the Bolshoy, Malenki, Malyutka and Stari mud volcanoes in the South Baikal Basin, the K1–4 structures in the Selenga delta, and the Novosibirsk and St. Petersburg structures in the Central Baikal Basin—and also the discovery of 29 new lake-bed structures. These new structures are the S1, Tolstiy, mTSG and S2 in the South Baikal Basin, the P1–P4, P6–P19 and K5–K8 in the Selenga delta accommodation zone, and the C1, C3 and C4 edifices in the Central Baikal Basin. In all, 39 positive relief structures were identified and their large-scale distribution mapped. Based on their typical shape, the observation of high-reflectivity areas on side-scan sonar data records, and evidence of feeder channels on subsurface data, these structures can be classified as mud volcanoes. This has already been confirmed in other publications for the Bolshoy, Malenki and K2 structures, by the recovery of mud breccias in sediment cores. Most structures occur on or near faults and have orientations parallel with the major faults and main stress orientations in the basins, suggesting a strong structural control on the formation of the mud volcanoes. Their slopes are generally steeper than 5°, consistent with interpretation as mud cones formed by high-viscosity, stiff mud plugs. Only few structures appear to be characterised by a crater, in which case this apparent crater seems to be formed by the coalescence of several single cones, leaving a depression in the centre. Some structures have a moat, which has probably an erosional origin. Furthermore, three depressions have been found, named P5, P20 and C2, which are suggested to be pockmarks. 相似文献
32.
Sonja Schuh Roberto Silvotti Ronny Lutz Björn Loeptien Elizabeth M. Green Roy H. Østensen Silvio Leccia Seung-Lee Kim Gilles Fontaine Stéphane Charpinet Myriam Francœur Suzanna Randall Cristina Rodríguez-López Valerie van Grootel Andrew P. Odell Margit Paparó Zsófia Bognár Péter Pápics Thorsten Nagel Benjamin Beeck Markus Hundertmark Thorsten Stahn Stefan Dreizler Frederic V. Hessman Massimo Dall’Ora Dario Mancini Fausto Cortecchia Serena Benatti Riccardo Claudi Rimvydas Janulis 《Astrophysics and Space Science》2010,329(1-2):231-242
In 2007, a companion with planetary mass was found around the pulsating subdwarf B star V391 Pegasi with the timing method, indicating that a previously undiscovered population of substellar companions to apparently single subdwarf B stars might exist. Following this serendipitous discovery, the EXOTIME (http://www.na.astro.it/~silvotti/exotime/) monitoring program has been set up to follow the pulsations of a number of selected rapidly pulsating subdwarf B stars on time scales of several years with two immediate observational goals:
- determine $\dot{P}$ of the pulsational periods P
- search for signatures of substellar companions in O–C residuals due to periodic light travel time variations, which would be tracking the central star’s companion-induced wobble around the centre of mass
33.
Travis G. Gerwing Diana J. Hamilton Myriam A. Barbeau Katy Haralampides Gordon Yamazaki 《Estuaries and Coasts》2017,40(3):717-725
The spillway gates of the Petitcodiac Causeway, a hydraulic structure ~35 km upstream of the mouth of the Petitcodiac River in New Brunswick, Canada, were permanently opened in April 2010. The short-term effect opening the spillway gates had on downstream intertidal mudflats of the upper Bay of Fundy was investigated. Specifically, a multivariate before-after-control-impact design was used to determine if opening the spillway gates affected the invertebrate community (crustaceans, polychaetes, and molluscs), abiotic sediment conditions (sediment water content, mean particle size, penetrability, and depth of the apparent redox potential discontinuity), or resource availability (sediment chlorophyll a concentration and organic matter content) of five intertidal mudflats (two impacted sites, three reference sites) spanning Chignecto Bay, the northern arm of the upper Bay of Fundy, up to 5 months post-opening. No biologically or statistically meaningful differences were detected between impacted and reference sites for any of the measured variables. This suggests that opening the causeway did not have a quantifiable impact on these intertidal mudflats, at least within half a year of the opening. This is likely a result of the macrotidal nature of the Bay of Fundy that overwhelmed any immediate changes to hydrodynamics that occurred after the opening of the causeway gates. 相似文献
34.
Seismic Microzonation: A Comparison between Geotechnical and Seismological Approaches in Pointe-à-Pitre (French West Indies) 总被引：1，自引：0，他引：1
Benoit LeBrun Anne-Marie Duval Pierre-Yves Bard Olivier Monge Myriam Bour Sylvain Vidal Hubert Fabriol 《Bulletin of Earthquake Engineering》2004,2(1):27-50
Pointe-à-Pitre, the main city of Guadeloupe in the French West Indies, has on several occasions been partially destroyed by
major historical earthquakes. Moreover, a post-seismic assessment of the damage from the 1985 Montserrat earthquake indicates
that the town is prone to site effects. Consequently, from 1996 to 1998, BRGM conducted a seismic microzonation study based
on geotechnical and geological data. At the same time, three seismological studies were being conducted – two based on earthquake
recordings using a time-series analysis and the classical spectral ratio (CSR) method (CETE/LCPC and BRGM), and the third
based on noise measurement at 400 points using the horizontal-to-vertical noise ratio (HVNR) method (CETE/LCPC). The objective
of this paper is not to carry out a new microzonation study by taking into account all the results, but rather to show in
what respects the results of these different methods are in agreement or not. A comparison of the results of the seismological
studies with the geotechnical microzonation shows that they are in fairly good agreement, albeit with some discrepancies.
The results indicate that the seismological methods and the geotechnical data are highly complementary and should be used
together in compiling seismic transfer-function microzonation maps.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
35.
Myriam Schmutz Yves Albouy Roger Guérin Olivier Maquaire Jacques Vassal Jean-Jacques Schott Marc Descloîtres 《Surveys in Geophysics》2000,21(4):371-390
In order to evaluate the risk of an earthflow to evolve abruptly into torrential surge, knowledge of its internal structure is necessary. This study deals with the internal structure of the Super Sauze earthflow developed in black marls in the southern French Alps. Difficulties in this study area are a rough topography, surface heterogeneities and a large thickness variability of the earthflow mass. These conditions hamper the application of geotechnical methods as a preferred investigation mean. Moreover, they pose problems to geophysical investigations and their interpretation.This paper shows the advantage offered by the joint inversion of Time Domain ElectroMagne-tism data (TDEM) and data obtained from Direct Current soundings (DC). The results of the joint inversions are checked using geotechnical data. The internal structure of the earthflow interpreted on the basis of joint inversion data is comparable to that obtained from geotechnical results. Moreover, contrary to separate electrical and TDEM inversions, a satisfactory joint inversion model can be derived without supplying additional a priori information. 相似文献
36.
Acta Geotechnica - In practice, prior to treating a soil with lime, the optimum lime content required for the cation exchange and for providing sufficient Ca2+ and high pH for pozzolanic reaction... 相似文献
37.
Acta Geotechnica - This study aims at investigating the lime treatment effect on the changes in microstructure and water retention property of compacted saline soil, with consideration of the... 相似文献
38.
Stéphanie Gallino Myriam Bulloz Emmanuel Naffrechoux Marc Dzikowski Dominique Gasquet 《Applied Geochemistry》2008
Sulphurous thermal springs account for a few percent of all thermal springs. As each degree of oxidation of elemental S corresponds to a different S species, sulphurous spring waters may contain a variety of S species. Total S content is one of the parameters measured when analysis is carried out for issuing a spa’s operating licence. Under French law these parameters must be stable over time. The two spas in Aix-les-Bains are fed by a number of natural springs and boreholes, whose waters have total reduced S concentrations of between 30 and 800 mg L−1. To ensure compliance with the requirements of the spas’ operating licences, particularly in terms of total reduced S content, official analysis of the waters is carried out every month at random dates and times. Monthly analyses have revealed seasonal variations in the S content of some of Aix-les-Bains’ springs; therefore, more frequent monitoring was carried out in order to investigate the extent and causes of these fluctuations. As well as seasonal variations, this monitoring has revealed daily and hourly fluctuations that appear to be related to extraction rates. For some of the springs and boreholes, S concentrations were correlated with extraction rates; for others, an increase in extraction rate led to a reduction in total S content. Concentrations of sulphide ions (one of the species included in the total sulphur analyses) were monitored at the same time as the total S content. Variations in sulphide ion concentrations and in sulphide concentration/total S ratios did not appear to be linked to variations in flow rate. These tests show that random monthly testing is not suitable for monitoring the stability of S contents, as this parameter can only be considered stable in terms of its yearly mean value. 相似文献
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40.
Clment Suavet Pierre Rochette Myriam Kars Jrme Gattacceca Luigi Folco Ralph P. Harvey 《Polar Science》2009,3(2):100-109
Micrometeorites have been recovered from traps located at the summit of nunataks in the Transantarctic Mountains (TAM), Antarctica. They constitute the TAM micrometeorite collection. Micrometeorites accumulated by direct infall for hundreds of thousands of years. This long collection duration is confirmed by the wide range of weathering by dissolution of olivine in the stony micrometeorites from the TAM collection. A statistical study of the size distribution and frequency by type of this collection, and comparison with other Antarctic micrometeorite collections (the South Pole Water Well collection and the Walcott Névé collection), suggest that the TAM collection is essentially unbiased. Thanks to the very long exposure of the traps, large diameter (>1000 μm) micrometeorites are present in sufficiently large numbers to allow a statistically meaningful estimate of their size distribution in this size range for the first time. We found that the slope of the size distribution remains constant in the 100–1600 μm size range. Therefore, the size distribution of micrometeorites in this size range is controlled by a single process. 相似文献