Global Positioning System measurements of strain accumulation and slip transfer through the restraining bend along the Dead Sea fault system in Lebanon   总被引：1，自引：0，他引：1  

Francisco Gomez  Gebran Karam  Mohamad Khawlie  Simon McClusky  Philippe Vernant  Robert Reilinger  Rani Jaafar  Charles Tabet  Kamal Khair  Muawia Barazangi 《Geophysical Journal International》2007,168(3):1021-1028

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Synchronicity in Climate and Vegetation Transitions Between Europe and North America During the Holocene     

K. Gajewski  André E. Viau  Michael Sawada  David E. Atkinson  Philippe Fines 《Climatic change》2006,78(2-4):341-361

Interpreting the postglacial climate history of the European continent using pollen data has proven difficult due in part to human modification of the landscape. Separating climate from human-caused changes in the vegetation requires a strategy for determining times of change across the entire region. We quantified transitions in the vegetation across Europe during the past 12,000 years using a mixture model approach on two datasets: radiocarbon dates from pollen diagrams and zone boundaries from selected reference sites. Major transitions in the vegetation, as recorded in pollen diagrams, appear synchronous across the continent. These transitions were also synchronous with those identified in North America pollen diagrams and major environmental changes recorded in North Atlantic marine records and Greenland ice cores. This synchronicity suggests that the major vegetation transitions in Europe during the Holocene and late glacial were primarily caused by large-scale atmospheric circulation change. These climate changes may have caused some of the cultural, political and migration changes in European societies during the Holocene.  相似文献   

Soil surface characteristics influence on infiltration in black marls: application to the Super‐Sauze earthflow (southern Alps,France)     

Jean‐Philippe Malet  Anne‐Veronique Auzet  Olivier Maquaire  Bruno Ambroise  Luc Descroix  Michel Esteves  Jean‐Pierre Vandervaere  Emmanuel Truchet 《地球表面变化过程与地形》2003,28(5):547-564

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On the Origin of Near-Surface Streaks in the Neutrally-Stratified Planetary Boundary Layer     

Philippe Drobinski  Ralph C. Foster 《Boundary-Layer Meteorology》2003,108(2):247-256

The dynamics of near-surface streak formation in the neutrallystratified, rotating planetary boundary layer areinvestigated. The purpose of this note is to compare large-eddysimulation results to theoretical predictions suggesting thatstreaks are associated with non-normal mode optimal perturbations.Streaks are regions near the surface of alternating high and lowspeed fluid organized into nearly linear bands, with horizontalspacing of several hundred metres, oriented up to 30° relativeto the geostrophic wind, that evolve through a continuous cycle ofgeneration, growth, decay and reformation. We find that the earlystages of streak formation and growth are consistent with thelinear theory.  相似文献   

Comparative geochemistry of cadmium, rhenium, uranium, and molybdenum in continental margin sediments     

BjØrn Sundby  Philippe Martinez  Charles Gobeil 《Geochimica et cosmochimica acta》2004,68(11):2485-2493

The concentrations of authigenic phases of Cd, Re, U, and Mo increase with depth in four 45-cm-long sediment box cores collected along the axis of the Laurentian Trough, Gulf of St. Lawrence. Average authigenic accumulation rates, estimated from element inventories, are similar to rates in other continental margin environments. Strong regional variations in sediment accumulation rate and sulfide concentration have little influence on the accumulation rates of Cd and Re. This suggests that slow precipitation kinetics controls the accumulation of Cd and Re in these sediments. The accumulation rate of authigenic U is more variable; it may be tied to the kinetics of microbially mediated U reduction and be controlled by the availability of reactive organic matter. Authigenic Mo is distinguished by a sharp subsurface concentration minimum, above which Mo cycles with manganese. Mo released to pore water upon reduction of Mn oxides diffuses downward and enriches the subsurface sediment. Mo accumulates most rapidly in the sediment with the highest sulfide content. Slow conversion of molybdate to thiomolybdate may explain the much slower Mo accumulation rate in the less sulfidic sediments. A component of authigenic Mo accumulates with pyrite in an approximately constant Mo:Fe ratio. The accumulation rate of pyrite and associated Mo is insensitive to AVS abundance. Pyrite formation may be limited by the reactivity of iron oxide minerals.  相似文献   

From rifting to spreading in the eastern Gulf of Aden: a geophysical survey of a young oceanic basin from margin to margin   总被引：1，自引：0，他引：1  

Sylvie Leroy  Pascal Gente  Marc Fournier  Elia d'Acremont  Philippe Patriat  Marie-Odile Beslier  Nicolas Bellahsen  Marcia Maia  Angelina Blais  Julie Perrot  Ali Al-Kathiri  Serge Merkouriev  Jean-Marc Fleury  Pierre-Yves Ruellan  Claude Lepvrier  Philippe Huchon 《地学学报》2004,16(4):185-192

A geophysical survey in the eastern Gulf of Aden, between the Alula–Fartak (52°E) and the Socotra (55°E) transform faults, was carried out during the Encens–Sheba cruise. The conjugate margins of the Gulf are steep, narrow and asymmetric. Asymmetry of the rifting process is highlighted by the conjugate margins (horst and graben in the north and deep basin in the south). Two transfer fault zones separate the margins into three segments, whereas the present‐day Sheba Ridge is divided into two segments by a transform discontinuity. Therefore segmentation of the Sheba Ridge and that of the conjugate margins did coincide during the early stages of oceanic spreading. Extensive magma production is evidenced in the central part of the western segment. Anomaly 5d was identified in the northern and southern parts of the oceanic basin, thus confirming that seafloor spreading in this part of Gulf of Aden started at least 17.6 Ma ago.  相似文献   

Response to the comment by R. H. Byrne on “Solubility of platinum in aqueous solutions at 25°c and pHs 4 to 10 under oxidizing conditions” (2001) Geochim. Cosmochim. Acta65, 4453-4466     

Mohamed Azaroual  Bruno Romand  Philippe Freyssinet 《Geochimica et cosmochimica acta》2003,67(13):2511-2513

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Experimental evidence of non-linear resonance effects between retrograde precession and the tilt-over mode within a spheroid     

J. Noir  P. Cardin  D. Jault  J.-P. Masson 《Geophysical Journal International》2003,154(2):407-416

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Discovery of a double impact crater in Libya: the astrobleme of Arkenu     

Philippe Paillou  Ake Rosenqvist  Jean-Marie Malezieux  Bruno Reynard  Tom Farr  Essam Heggy 《Comptes Rendus Geoscience》2003,335(15):1059-1069

Using orbital imaging radar, we detected a double circular structure, located in the southeastern part of the Libyan Desert, which is partially hidden under sandy sediments. Fieldwork confirmed it to be an unknown double impact crater, each crater having a diameter of about 10 km, younger than 140 Ma. Sampling on the site enabled the observation of quantities of shatter cone structures and impact breccias containing planar fractures. To cite this article: P. Paillou et al., C. R. Geoscience 335 (2003).  相似文献   

On the variation of pulsar periods in close binary systems     

Philippe Jetzer  Marcus Strässle  Norbert Straumann 《New Astronomy》1998,3(8):1540-630

X-ray pulsars, which form together with a main sequence star or a giant a close binary system, show strong variations in their pulse period. Epochs of spin-up and spin-down interchange on timescales of some tens up to some thousand days.

We study this phenomenon in the framework of the disk-fed model by Ghosh and Lamb, which we generalize by allowing for an inclination angle χ between the magnetic dipole moment μ and the rotation axis. Moreover, we take into account the relatively small magnetic field induced by currents in the magnetosphere flowing along the dipole field lines. This component, which we calculate numerically, leads to a torque perpendicular to the rotation axis and induces a precession of it. Due to this additional degree of freedom, the calculated pulse period history is much smoother than in the classical Ghosh and Lamb model. Within this extended model we compute, as an example, the pulse period history of Cen X-3 using the observed X-ray flux as a measure for the mass accretion rate. Qualitative accordance with the measured pulse period data (see e.g. Nelson et al., 1997 [ApJ, 488, L117]) is found to be good.  相似文献