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181.
Parameters of the distant galaxy clusters of 3C295 (z=0.46) and Cl 0024+1654 (z=0.39) are compared with the predictions made using galaxies of the local clusters Coma (z=0.023) and DC 0329–52 (z=0.057) taking theK-effect into account. The distributions of colour and morphological type, and the amplitudesF +/F of the 0 4000 discontinuity are examined and no evidence for evolution of the galaxies and the clusters can be seen.  相似文献   
182.
A detailed analysis of bathymetry and magnetic data of Visakhapatnam-Paradip shelf, east coast of India revealed three major structural lineaments over the shelf/slope of the area. Models derived from the anomalies associated with the trends indicate that trend A represents horst and graben type continental basement while trend B is due to a series of dyke intrusions. Trend C off Chilka lake forms the northward extension of 85°E lineation from deep sea Bengal Fan. A two stage evolution of the eastern continental margin of India has been inferred from the study of this part of the margin, viz., the rift stage evidenced by dyke intrusions of reverse polarity located within the inner part of the shelf and post-rift stage characterized by vertical tectonics in the form of a horst and graben type continental basement. The hotspot related aseismic 85°E ridge further complicated the tectonics of this part of the area.  相似文献   
183.
The vegetational history of the penultimate glacial period, Marine Isotope Stage (MIS) 6 (c. 185–135 ka), has remained relatively unexplored. Here we present a new record from the Ioannina basin, north‐west Greece, which constitutes the highest‐resolution terrestrial pollen record for this interval produced to date. It shows that the vegetation history of MIS 6 in this region can be divided into two parts: an early period (185–155 ka) with pronounced oscillations in tree population extent, and a later period (155–135 ka) with much smaller tree populations and subdued oscillations. This pattern is analogous to the MIS 3/MIS 2 division during the last glacial in the same sequence, although the early part of MIS 6 had larger Pinus populations and fewer temperate trees relative to the equivalent interval in MIS 3. This implies cooler and wetter conditions, which is somewhat counterintuitive given the high summer insolation during MIS 6e, but is in line with other palaeoclimatic evidence from the Mediterranean. Comparison with North Atlantic records suggests that despite the absence of pronounced iceberg discharges during MIS 6, North Atlantic millennial‐scale variability had a significant downstream impact on tree populations in north‐west Greece. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
184.
Coastal topography is the principal variable that affects the movement of the tsunami wave on land. Therefore, land surface elevation data are critical to a tsunami model for computing extent of inundation. Elevation data from India's remote sensing satellite CARTOSAT-1 are available for the entire Indian coastline, while elevation data collected using Airborne Laser Terrain Mapper (ALTM) are only available for selected sections of the coastline. This study was carried out to evaluate the suitability of CARTOSAT-1 and ALTM elevation data sets in the tsunami inundation modeling. Two areas of the coastal Tamil Nadu that were severely affected during the December 2004 tsunami and surveyed extensively for mapping the extent of inundation were selected as the study areas. Elevation data sets from ALTM, CARTOSAT-1 and field measurement collected using Real-time Kinematic GPS (RTK-GPS) were compared for these areas. The accuracy of ALTM and CARTOSAT-1 data, the significance of interpolation methods and data used on model outputs were studied. The analysis clearly revealed that the elevation accuracy of CARTOSAT-1 data (+/?2m) was much lower than ALTM data (+/?0.6m). However, it was found that despite the differing elevation accuracy, both ALTM and CARTOSAT-1 can be used to produce tsunami inundation maps for open coasts with an accuracy of 185 m (2 grid cells) at 75% and 50% confidence level, respectively.  相似文献   
185.
186.
The author reminisces upon a career of almost 40 years as a practising surveyor photogrammetrist, both as a Royal Engineer officer and as a director of a commercial survey organisation. The reminiscences include service with the Survey of India, war time operations in the Middle East and South East Asia Command, and commercial surveys of all types in developing countries. Professional service with international surveying and photogrammetric organisations is also mentioned, with particular reference to the fraternal aspects of international photogrammetry.  相似文献   
187.
The southeastern Arabian Sea (SEAS), located in the Indian Ocean warm pool, is a key-region of the regional climate system. It is suspected to play an important role in the dynamics of the Asian summer monsoon system. The present study reports the salient features derived from a newly harvested observational dataset consisting of repeated fortnightly XBT transects in the SEAS over the period 2002–2008. The fortnightly resolution of such a multi-year record duration is unprecedented in this part of the world ocean and provides a unique opportunity to examine the observed variability of the near-surface thermal structure over a wide spectrum, from intra-seasonal to interannual timescales. We find that most of the variability is trapped in the thermocline, taking the form of upwelling and downwelling motions of the thermal stratification. The seasonal variations are consistent with past studies and confirm the role of the monsoonal wind forcing through linear baroclinic waves (coastally-trapped Kelvin and planetary Rossby waves). Sub-seasonal variability takes the form of anomalous events lasting a few weeks to a few months and occurs at two preferred timescales: in the 30–110 day band, within the frequency domain of the Madden–Julian oscillation and in the 120–180 day band. While this sub-seasonal variability appears fairly barotropic in the offshore region, the sign of the anomaly in the upper thermocline is opposite to that in its lower part on many occasions along the coast. Our dataset also reveals relatively large interannual temperature variations of about 1 °C from 50 to 200 m depth that reflect a considerable year-to-year variability of the magnitude of both upwelling and downwelling events. This study clearly demonstrates the necessity for sustained long-term temperature measurements in the SEAS.  相似文献   
188.
189.
The Proterozoic Eastern Ghats Mobile Belt along the east coast of India shares a thrusted lower contact with the surrounding cratons. The thrust, known as the Terrane Boundary shear zone, is associated with two large lateral ramps resulting in a curved outline on the northwestern corner of the mobile belt. The Eastern Ghats Mobile Belt is divided into two lithotectonic units, the Lathore Group and the Turekela Group, based on their lithological assemblages and deformational history. On the basis of published data from a Deep Seismic Sounding (DSS) profile of the Eastern Ghats crust, the Terrane Boundary Shear Zone is considered to be listric in nature and acts as the sole thrust between craton and mobile belt. The Lathore and Turekela Groups are nappes. With this structural configuration the NW part is described as a fold thrust belt. However, the thrusting postdates folding and granulite metamorphism that occurred in the Eastern Ghats, as in the Caledonide type of fold thrust belt of NW Scotland. The Terrane Boundary Shear Zone is interpreted to be contiguous with the Rayner-Napier boundary of the Enderby Land in a Gondwana assembly.  相似文献   
190.
This study of fluvial terraces of the River Rhine and tributaries aims to search for indications of Pleistocene tectonic activity. The study area includes the northern Upper Rhine Graben (URG), the Mainz Basin and the adjacent Rhenish Massif with the Middle Rhine Valley. High rates of Quaternary surface processes, large amount of human modifications, relatively slow tectonic deformation and presently low intra-plate seismic activity characterize this area. Therefore, the records of relatively slow tectonic deformation are less well preserved and thus difficult to detect. This study uses the relative position of fluvial terraces to determine the more local effects of fault movements on the terraces and to evaluate their displacement rates and patterns. The research is based on a review of previous terrace studies and new terrace mapping from the eastern Mainz Basin and the bordering URG using topographic map interpretations and field observations. This newly mapped sequence of terrace surfaces can be correlated to other terraces in the vicinity on the basis of relative height levels. Terrace correlation between the western Mainz Basin and Middle Rhine Valley relies on a single chronostratigraphic unit (Mosbach sands) and additional relative height correlations. This is the first study to present a continuous correlation of terraces from the western margin of the URG to the Rhenish Massif and enables the study of the transition from the subsiding graben to the uplifted Rhenish Massif. By means of a longitudinal profile, which ranges from the URG to the Rhenish Massif, the influence of individual fault movements on the terrace levels and the large-scale regional uplift is demonstrated. It is evident from the profile that the uplift of Early to Middle Pleistocene terraces increases northwards, towards the Rhenish Massif. The uplift was diachronic, with a significant pulse occurring first in the northern URG (Lower Pleistocene) and later in the Rhenish Massif (Middle Pleistocene). The largest vertical displacements are recorded for the boundary fault separating the Mainz Basin and the Rhenish Massif (Hunsrück–Taunus Boundary Fault) and for faults bounding the northeastern Mainz Basin. The motions and displacement rates calculated for individual faults indicate deformation rates in the order of 0.01–0.08 mm/year. At this stage, the calculation of displacement rates depends mostly on a single dated stratigraphic unit. Additional dating of terrace deposits is urgently needed to better constrain the temporal development of the terrace sequence and the impact of tectonic movements.  相似文献   
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