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61.
Rosa María Mateos Inmaculada García-Moreno Paola Reichenbach Gerardo Herrera Roberto Sarro Joan Rius Raúl Aguiló Federica Fiorucci 《Landslides》2016,13(4):751-763
The Tramuntana range, in the northwestern sector of the island of Mallorca (Balearic Islands, Spain), is frequently affected by rockfalls which have caused significant damage, mainly along the road network. In this work, we present the procedure we have applied to calibrate and validate rockfall modelling in this region, using 103 cases of the available detailed rockfall inventory (630 rockfall events collected since the eighteenth century). We have exploited STONE (Guzzetti et al. 2002), a GIS-based rockfall simulation software which computes 2D and 3D rockfall trajectories starting from a DTM and maps of the dynamic rolling friction coefficient and of the normal and tangential energy restitution coefficients. The appropriate identification of these parameters determines the accuracy of the simulation. To calibrate them, we have selected 40 rockfalls along the range which include a wide variety of outcropping lithologies. Coefficients values have been changed in numerous attempts in order to select those where the extent and shape of the simulation matched the field mapping. Best results were summarized with the average statistical values for each parameter and for each geotechnical unit, determining that mode values represent more precisely the data. Initially, for the validation stage, 10 well-known rockfalls exploited in the calibration phase have been selected. Confidence tests have been applied to their modelling results taking into account not only the success but also the mistakes. The best accuracy is obtained when the rockfall has a preferential trajectory and worse results when the rockfall follows two or more trajectories. Additionally, the greater the rockfall runout length, the less precise the simulation is. We have further validated the calibrated parameters along the Ma-road (111 km), the main transportation corridor in the range, using 63 rockfall events that occurred during the past 18 years along the road. Of the rockfalls where source areas were properly identified, 81.5 % are well represented by STONE modelling, as the travel paths and the depositional areas are successfully ascertained. Results of the analysis have been used by the Road Maintenance Service of Mallorca to assess hazard and risk posed by rockfall at regional scale to design the road management plan. 相似文献
62.
Model for the Processing and Estimation of Dual Frequency Echo Sounder Observations in Detailed Bathymetries 总被引：1，自引：0，他引：1
Raúl Pereda García Felipe Piña García Julio Manuel De Luis Ruiz Raúl Husillos Rodríguez 《Marine Geodesy》2016,39(3-4):305-320
The dataset acquired by an echo sounder generally comprises outliers and erroneous measurements which must be automatically processed. The main aim of this research is the development and validation of an algorithm which permits detecting outliers, estimating their real value from data acquired with a multifrequency echo sounder, and verifying the measure according to the desired accuracy. The process considers the nature of the seabed and improves the density and number of lectures without globally compromising the precision, but enhancing it in areas with anomalous measurements. Twenty-nine percent of this type of measurements, which would have been otherwise rejected, have been estimated. 相似文献
63.
— We have tested to which extent commonly used dynamic rupture parameters can be resolved for a realistic earthquake scenario from all available observations. For this purpose we have generated three dynamic models of the Landers earthquake using a single, vertical, planar fault with heterogeneity in either the initial stress, the yield stress, or the slip-weakening distance. Although the dynamic parameters for these models are inherently different, all the simulations are in agreement with strong motion, GPS, InSAR, and field data for the event. The rupture propagation and slip distributions obtained for each model are similar, showing that the solution of the dynamic problem is non-unique. In other words, it is not always possible to separate strength drop and the slip-weakening distance using rupture modeling, in agreement with the conclusions by GUATTERI and SPUDICH (2000). 相似文献
64.
Sonia Pérez-Plaza Fernando Fernández-Palacín Manuel Berrocoso Raúl Páez Belén Rosado 《Mathematical Geosciences》2018,50(6):659-677
This paper demonstrates the usefulness of approaching the dynamic study of the precise positioning of a network of permanent global positioning system (GPS) stations through functional data analysis. The displacement data for each GPS station, obtained from observations of the global navigation satellite system, are a discrete sample of the positioning curve. The aim of this paper is to reconstruct the original functions in order to use them as functional data. In the method presented in this paper, the geodetic series are obtained first by processing the GPS data with respect to a reference station. Second, for each station, a cleaning process is applied to eliminate the values considered as outliers, and the missing values are imputed by using a Kalman filter. Finally, the original functions are reconstructed by using smoothing techniques and by evaluating several bases of functions. Moreover, these functions are treated with statistical techniques for functional data. This procedure is applied to the permanent stations of the south of the Iberian peninsula and the north of Africa (SPINA) network. The topocentric series: east, north and up are analysed. In the analysis of the positioning curves, there is observed a synchronized behaviour of the functions in those periods of time with important seismic activity. This behaviour also appears in the analysis of the second principal component of the East and up dimensions. Furthermore, the first two principal components of the East coordinate enable us to make a classification of the stations in the SPINA network. The classification made is consistent with the previous knowledge of the tectonic plates in the studied area. 相似文献
65.
Joaquín Torres-Sospedra Joan Avariento David Rambla Raúl Montoliu Sven Casteleyn Mauri Benedito-Bordonau 《International journal of geographical information science》2015,29(11):1955-1968
A Smart City relies on six key factors: Smart Governance, Smart People, Smart Economy, Smart Environment, Smart Living and Smart Mobility. This paper focuses on Smart Mobility by improving one of its key components: positioning. We developed and deployed a novel indoor positioning system (IPS) that is combined with an outdoor positioning system to support seamless indoor and outdoor navigation and wayfinding. The positioning system is implemented as a service in our broader cartography-based smart university platform, called SmartUJI, which centralizes access to a diverse collection of campus information and provides basic and complex services for the Universitat Jaume I (Spain), which serves as surrogate of a small city. Using our IPS and based on the SmartUJI services, we developed, deployed and evaluated two end-user mobile applications: the SmartUJI APP that allows users to obtain map-based information about the different facilities of the campus, and the SmartUJI AR that allows users to interact with the campus through an augmented reality interface. Students, university staff and visitors who tested the applications reported their usefulness in locating university facilities and generally improving spatial orientation. 相似文献
66.
Ana Julia Abascal Sonia Castanedo Vicente Fernández Raúl Medina 《Ocean Dynamics》2012,62(7):1073-1089
In this work, the benefits of high-frequency (HF) radar ocean observation technology for backtracking drifting objects are analysed. The HF radar performance is evaluated by comparison of trajectories between drifter buoys versus numerical simulations using a Lagrangian trajectory model. High-resolution currents measured by a coastal HF radar network combined with atmospheric fields provided by numerical models are used to backtrack the trajectory of two dataset of surface-drifting buoys: group I (with drogue) and group II (without drogue). A methodology based on optimization methods is applied to estimate the uncertainty in the trajectory simulations and to optimize the search area of the backtracked positions. The results show that, to backtrack the trajectory of the buoys in group II, both currents and wind fields were required. However, wind fields could be practically discarded when simulating the trajectories of group I. In this case, the optimal backtracked trajectories were obtained using only HF radar currents as forcing. Based on the radar availability data, two periods ranging between 8 and 10?h were selected to backtrack the buoy trajectories. The root mean squared error (RMSE) was found to be 1.01?km for group I and 0.82?km for group II. Taking into account these values, a search area was calculated using circles of RMSE radii, obtaining 3.2 and 2.11?km2 for groups I and II, respectively. These results show the positive contribution of HF radar currents for backtracking drifting objects and demonstrate that these data combined with atmospheric models are of value to perform backtracking analysis of drifting objects. 相似文献
67.
Kyu-Dong Oh Young Woon Kang Kee Suk Ra Hong Suh Park 《Astrophysics and Space Science》2000,271(3):303-320
Two colour (B and V) photoelectric observations of EB-type eclipsing binary GO Cyg were carried out for 15 nights during October and December
1996. Three new times of minimum lights have been derived. With these and previously published times of minimum lights, a
continuous period increase of dP/dt = 1.51 × 10-7 d yr-1 was estimated from the quadratic light element. B and V light curves have been analyzed by the method of the Wilson and Devinney Differential Correction. GO Cyg is confirmed to
belong to the group of near contact systems based on light curve analysis and its absolute dimensions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
68.
Ana J. Abascal Sonia Castanedo Paula Núñez Adam Mellor Annika Clements Beatriz Pérez Mar Cárdenas Helios Chiri Raúl Medina 《Marine pollution bulletin》2017,114(1):302-314
This paper presents a high-resolution operational forecast system for providing support to oil spill response in Belfast Lough. The system comprises an operational oceanographic module coupled to an oil spill forecast module that is integrated in a user-friendly web application. The oceanographic module is based on Delft3D model which uses daily boundary conditions and meteorological forcing obtained from COPERNICUS and from the UK Meteorological Office. Downscaled currents and meteorological forecasts are used to provide short-term oil spill fate and trajectory predictions at local scales. Both components of the system are calibrated and validated with observational data, including ADCP data, sea level, temperature and salinity measurements and drifting buoys released in the study area. The transport model is calibrated using a novel methodology to obtain the model coefficients that optimize the numerical simulations. The results obtained show the good performance of the system and its capability for oil spill forecast. 相似文献
69.
Seismic hazard in Buenos Aires,Argentina: A preliminary study on the effects of long‐distance earthquakes on tall buildings 
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下载免费PDF全文 The 2015 Illapel earthquake produced self‐evacuation of tall buildings in the city of Buenos Aires, Argentina, located 1280 km away from the epicenter. The ground motions in Buenos Aires due to the main event (Mw 8.3) and its aftershocks were registered by a new seismometer. The data collected allowed to estimate the maximum story drift ratios and top floor accelerations for tall buildings in Buenos Aires. The similarities between the response spectra and the Fourier amplitude spectra for the mainshock and its aftershocks show the influence that the dynamic properties of the 300‐m soil deposit have on the large acceleration amplification produced in these groups of buildings. 相似文献
70.
Low‐P melting of metapelitic rocks and the role of H2O: Insights from phase equilibria modelling 下载免费PDF全文
下载免费PDF全文 Alfonso M. Sola Pavlina Hasalová Roberto F. Weinberg Néstor O. Suzaño Raúl A. Becchio Fernando D. Hongn Nilson Botelho 《Journal of Metamorphic Geology》2017,35(9):1131-1159
Water‐fluxed melting has long been thought to have a minor influence on the thermal and chemical structure of the crust. We report here on amphibolite facies metasedimentary rocks from the 490–450 Ma Famatinian Orogen, in northwest Argentina, that have undergone water‐fluxed incongruent biotite melting at relatively low temperature, which have produced and lost a significant volume of melt. The protoliths consist of the turbiditic Puncoviscana Formation (Neoproterozoic to Early Cambrian). The field area exhibits a condensed metamorphic field gradient, from greenschist to amphibolite facies suprasolidus conditions, recording a low pressure almost isobaric path, reaching peak conditions estimated at 700°C at 4 kbar. Thermodynamic modelling in the MnNCKFMASHTO system is applied to investigate melting at such low pressure as a function of water content. Calculations using a typical turbidite composition show how small amounts of added free H2O may increase significantly the melt fraction with little or no change in either the melt or residual phase compositions. They indicate negligible difference in normative An–Ab–Or proportions and ferromagnesian contents between melts derived by dehydration and water‐fluxed melts. The same is true for the content of H2O dissolved in melts, which remains constant and the melt produced is granitic whether or not aqueous fluids are present. Thus, neither the residue nor the melt composition are indicators of the presence of aqueous fluids during anatexis. Recognizing the impact of small additions of H2O to an anatectic terrane may therefore be difficult. The most significant change related to water‐fluxing is the relative proportions of minerals and melt fraction, rather than the actual mineral assemblage. The modal proportion of feldspar decreased while those of cordierite and biotite increased in the residual assemblages, as <5 mol.% of free H2O was added. The impact of this addition is to more than double the proportion of water‐undersaturated melt to 25–30 mol.%. We have also developed a simple way to estimate how much melt a residual rock has lost, if the compositional trends of the protoliths are known. In summary, we find that even though the addition of small amounts of free H2O impacts significantly on rock fertility, there is little obvious record in the field. The combined application of careful petrological investigation and thermodynamic modelling is the key to identify the influence of aqueous fluids, and exploit systems that became open not only to fluid influx but also to the extraction of melt. 相似文献