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31.
In recent decades, the space geodesy has been applied to the areas such as transportation, infrastructure planning, navigation, etc. Among them, the precise positioning at the Global Navigation Satellite System (GNSS) stations yields better view in the understanding of the crustal deformation that requires global-scale measurements. There have been numerous studies examining the data process of continuous GNSS observations in the field of earth monitoring. More recently, GNSS stations established for continuously operating reference station networks have been beneficial resources in the tectonic plate-monitoring studies in lieu of campaign-type observations. However, this requires that the Continuously Operating Reference Station (CORS) should be established on stable structures acting like foundations and requires investigation of the long-term repeatability time series. This study aims to introduce recently established national CORS network, named CORS-TR, covering the entire Turkey and Northern Cyprus, and to explain the process of the long-term data obtained from the network on the characteristics of the tectonic plate movement within the area. The results of the CORS-TR data process present a great potential of using continuously operating reference stations not only in real-time kinematic applications of conventional geodesy studies but also in detecting and monitoring the crustal deformations of those that are crucial in earthquake-prone areas like Turkey. Since the findings are computed from the results of the all permanent stations of CORS-TR network, this study also examines the GNSS observation quality of the network for the given time interval. One of the major conclusions of the data process conducted in the study displays that the CORS-TR stations established on the carefully selected large and low-rise existing building had been more stable than the stations on the ground which have been subjected to soil settlement since the construction.  相似文献   
32.
Geothermal exploration is typically limited to high-grade hydrothermal reservoirs that are usually found in the western United States, yet large areas with subsurface temperatures above 150°C at economic drilling depths can be found east of the Rocky Mountains. The object of this paper is to present new heat flow data and to evaluate the geothermal potential of Texas and adjacent areas. The new data show that, west of the Ouachita Thrust Belt, the heat flow values are lower than east of the fault zone. Basement heat flow values for the Palo Duro and Fort Worth Basins are below 50 mW/m2 while, in the frontal zone of the belt, they can exceed 60 mW/m2. Further east, along the Balcones fault system the heat flow is in general higher than 55 mW/m2. The eastern most heat flow sites are in Louisiana and they show very high heat flow (over 80 mW/m2), which is associated with the apparently highly radioactive basement of the Sabine uplift. The geothermal resource in this area is large and diverse, and can be divided in high grade (temperature above 150°C) convective systems, conductive based enhanced geothermal systems and geothermal/geopressured systems. One of the most attractive areas east of the cordillera extends from eastern Texas across Louisiana and Arkansas to western Mississippi. Here temperatures reach exploitation range at depths below 4 km, and tapping such a resource from shut in hydrocarbon fields is relatively easy. The initial costs of the development can be greatly reduced if existing hydrocarbon infrastructure is used, and therefore using shut-in hydrocarbon fields for geothermal purposes should not be neglected.  相似文献   
33.
The goal of this paper is to present especially the source and the type of liquefaction-related failures of those buildings which satisfied the structural codes of buildings and practices but experienced settlement, tilting and overturning in Adapazari during the Turkey earthquake of August 17, 1999. In this context, the Adapazari region is first evaluated in terms of geological setting, tectonics, seismicity and liquefaction susceptibility based on in situ and laboratory test data. In addition, the number of stories, types of buildings and their related failures have been mapped accordingly. Furthermore, laboratory model tests are conducted to enforce and/or confirm the type of building's failures with particular reference to their geometrical shape and the number of stories assuming that the models representing buildings satisfy the structural codes of buildings and practices.  相似文献   
34.
Resume. Situés dans la partie la plus distale du bassin molassique suisse et dans le prolongement sud du fossé rhénan, les dép?ts conglomératiques appartenant au groupe stratigraphique des Gompholithes & Conglomérats ont fait l’objet d’une étude sédimentologique et paléontologique détaillée. La multitude des affleurements réalisés lors des travaux de construction de l’autoroute Transjurane dans la région de Porrentruy (Jura), permet d’appréhender ces paléoenvironnements rupéliens (Oligocène inférieur). Les études sédimentologiques et paléontologiques révèlent l’existence d’environnements c?tiers avec des falaises de calcaires mésozo?ques entaillées par des canyons où se trouvent des rivières au régime torrentiel. Ces rivières qui érodent les couches du Mésozo?que créent des galets qui sont déposés sous la forme de deltas marins progradant vers le nord. A l’abri des exutoires des canyons se développent quelques environnements lacustres. Ces dép?ts conglomératiques sont fortement liés à l’activité tectonique rupélienne. La distension rhénane et l’activité de la faille transformante située entre le fossé rhénan et le bassin de la Bresse subdivisent les différents blocs mésozo?ques en horsts et grabens, permettant ainsi l’érosion des sédiments dans les parties hautes (horst) et leur transport dans les zones basses (graben). La découverte de rares galets de roches endogènes et effusives dans les dép?ts conglomératiques montre un transport du socle des Vosges vers le sud dans la région de Porrentruy par l’intermédiaire sans doute d’une dérive littorale. Bien que la surrection des Vosges et de la Forêt-Noire et leur mise à l’érosion soient connues dès la base du Miocène, la présence de ces galets atteste l’existence de failles dès le début du Rupélien qui mettent à l’érosion le socle du massif des Vosges.
Located in the distal part of the Swiss Molasse Basin and in the southern extension of the Rhine Graben, the conglomeratic deposits belonging to the Gompholithes & Conglomérats stratigraphic group have been the object of detailed sedimentological and paleontological studies. The great number of outcrops that came into sight during the building works of the Transjurane highway in the vicinity of Porrentruy (Swiss Jura) lead to a better understanding of Rupelian paleoenvironments (Early Oligocene). The sedimentological and paleontological studies reveal the existence of coastal environments with Mesozoic limestone cliffs notched by canyons with torrential rivers. Those rivers eroding the Mesozoic series create pebbles deposits forming marine deltas prograding towards North. In protected areas, some lacustrine environments can develop. These conglomeratic deposits are strongly bound to the Rupelian tectonic activity. The rhenish distension and the activity of the transform faults located between the Rhine Graben and the Bresse basin divide the Mesozoic blocks in horst and graben structures, thus allowing the erosion of sediments in higher regions (horst) and their transport in lower zones (graben). The discovery of rare pebbles made of endogene and effusive rocks in those conglomeratic deposits shows a transport coming from the Vosges massifs towards south to the Porrentruy region, probably with the support of a littoral drift. Although the surrection of the Vosges and Schwarzwald massifs (and the beginning of their erosion) is normally attributed to the base of the Miocene, the presence of those pebbles attests the existence of faults putting the basement of the Vosges massif to erosion since the base of Rupelian.
Manuscrit re?u le 4 février 2003 Révision acceptée le 30 mars 2005  相似文献   
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Potassium-rich volcanic rocks in the Isparta area (SW Turkey) consist mainly of older (Pliocene) volcanic rock suites (e.g., lamprophyre, basaltic trachyandesite, trachyandesite, trachyte) and younger (Quaternary) caldera forming lava dome/flows (e.g., tephriphonolite, trachyte) and pyroclastics (ash/pumice fall deposits and ignimbritic flows). The magnetic susceptibility (K) was performed for both groups. The magnetic susceptibility value of the less evolved rocks characterized by SiO2 < 57 wt% (e.g., basaltic trachyandesite, tephriphonolite, lamprophyric rocks) and having mostly mafic phenocrysts such as pyroxene, amphibole, and biotite-phlogopite is over 10 (10−3 [SI]). Fine to medium-grained and subhedral to anhedral opaque minerals are scattered especially in the matrix phase of the less evolved volcanic rocks. However, the K value of the more evolved rocks (e.g., trachyte and trachyandesites) with SiO2 over 57 wt% vary between 0.1 and 28, but most of them below 10. SI values are negatively correlated with SiO2, Na2O, but positively correlated with Fe2O3, CaO, MnO, P2O5 and MgO contents, suggesting inverse variation of SI with fractionation of potassic magma. That is to say that less evolved volcanic rocks have relatively higher magnetic susceptibility values in the volcanic suite. Fine to medium-grained and subhedral to anhedral Fe-Ti oxides are scattered mainly in the matrix phase of the less evolved volcanics, presumably cause the pronounced relatively higher magnetic susceptibility.  相似文献   
38.
CONT08 was a 15 days campaign of continuous Very Long Baseline Interferometry (VLBI) sessions during the second half of August 2008 carried out by the International VLBI Service for Geodesy and Astrometry (IVS). In this study, VLBI estimates of troposphere zenith total delays (ZTD) and gradients during CONT08 were compared with those derived from observations with the Global Positioning System (GPS), Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS), and water vapor radiometers (WVR) co-located with the VLBI radio telescopes. Similar geophysical models were used for the analysis of the space geodetic data, whereas the parameterization for the least-squares adjustment of the space geodetic techniques was optimized for each technique. In addition to space geodetic techniques and WVR, ZTD and gradients from numerical weather models (NWM) were used from the European Centre for Medium-Range Weather Forecasts (ECMWF) (all sites), the Japan Meteorological Agency (JMA) and Cloud Resolving Storm Simulator (CReSS) (Tsukuba), and the High Resolution Limited Area Model (HIRLAM) (European sites). Biases, standard deviations, and correlation coefficients were computed between the troposphere estimates of the various techniques for all eleven CONT08 co-located sites. ZTD from space geodetic techniques generally agree at the sub-centimetre level during CONT08, and??as expected??the best agreement is found for intra-technique comparisons: between the Vienna VLBI Software and the combined IVS solutions as well as between the Center for Orbit Determination (CODE) solution and an IGS PPP time series; both intra-technique comparisons are with standard deviations of about 3?C6?mm. The best inter space geodetic technique agreement of ZTD during CONT08 is found between the combined IVS and the IGS solutions with a mean standard deviation of about 6?mm over all sites, whereas the agreement with numerical weather models is between 6 and 20?mm. The standard deviations are generally larger at low latitude sites because of higher humidity, and the latter is also the reason why the standard deviations are larger at northern hemisphere stations during CONT08 in comparison to CONT02 which was observed in October 2002. The assessment of the troposphere gradients from the different techniques is not as clear because of different time intervals, different estimation properties, or different observables. However, the best inter-technique agreement is found between the IVS combined gradients and the GPS solutions with standard deviations between 0.2 and 0.7?mm.  相似文献   
39.
A Draconid meteor shower outburst was observed from on board two scientific aircraft deployed above Northern Europe on 8th October 2011. The activity profile was measured using a set of photographic and video cameras. The main peak of the activity occurred around 20:15 ± 0:0.5 UT which is consistent with the model prediction as well as with the IMO network visual observations. The corrected hourly rates reached a value of almost 350. The brighter meteors peaked about 15–20 min earlier than the dimmer ones. This difference can be explained by different directions of the ejection of the meteoroids from the parent comet. One of the instruments was even able to detect meteors connected with the material ejected from the parent comet before 1900 and thus confirmed the prediction of the model, although it was based on uncertain pre-1900 cometary data. Another small peak of the activity, which was caused by material ejected during the 1926 perihelion passage of the parent comet, was detected around 21:10 UT. The mass distribution index determined using the narrow field-of-view video camera was 2.0 ± 0.1. This work shows that the observation of meteor outbursts can constrain the orbital elements, outgassing activity and existence of jets at the surface of a comet.  相似文献   
40.
The space segment of the European Global Navigation Satellite System (GNSS) Galileo consists of In-Orbit Validation (IOV) and Full Operational Capability (FOC) spacecraft. The first pair of FOC satellites was launched into an incorrect, highly eccentric orbital plane with a lower than nominal inclination angle. All Galileo satellites are equipped with satellite laser ranging (SLR) retroreflectors which allow, for example, for the assessment of the orbit quality or for the SLR–GNSS co-location in space. The number of SLR observations to Galileo satellites has been continuously increasing thanks to a series of intensive campaigns devoted to SLR tracking of GNSS satellites initiated by the International Laser Ranging Service. This paper assesses systematic effects and quality of Galileo orbits using SLR data with a main focus on Galileo satellites launched into incorrect orbits. We compare the SLR observations with respect to microwave-based Galileo orbits generated by the Center for Orbit Determination in Europe (CODE) in the framework of the International GNSS Service Multi-GNSS Experiment for the period 2014.0–2016.5. We analyze the SLR signature effect, which is characterized by the dependency of SLR residuals with respect to various incidence angles of laser beams for stations equipped with single-photon and multi-photon detectors. Surprisingly, the CODE orbit quality of satellites in the incorrect orbital planes is not worse than that of nominal FOC and IOV orbits. The RMS of SLR residuals is even lower by 5.0 and 1.5 mm for satellites in the incorrect orbital planes than for FOC and IOV satellites, respectively. The mean SLR offsets equal \(-44.9, -35.0\), and \(-22.4\) mm for IOV, FOC, and satellites in the incorrect orbital plane. Finally, we found that the empirical orbit models, which were originally designed for precise orbit determination of GNSS satellites in circular orbits, provide fully appropriate results also for highly eccentric orbits with variable linear and angular velocities.  相似文献   
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