Rotational splitting of solar five-minute oscillations of low degree     

Claverie  A.  Isaak  G. R.  McLeod  C. P.  van der Raay  H. B.  Roca Cortes  T. 《Solar physics》1983,82(1-2):233-234

Solar Physics - An analysis of 28 contiguous days of whole disk observations of the solar surface by means of optical resonant scattering in the K 769.9 nm line, taken at the Teide Observatory at...  相似文献   

Petroleum hydrocarbons in the arctic ocean surface water     

Elisabet Fogelqvist  Sören Lagerkvist  Peter Lindroth 《Marine pollution bulletin》1982,13(6):211-213

The concentration of petroleum hydrocarbons in Arctic surface water under the ice north of Svalbard has been determined by fluorescence spectrofluorometry using three different excitation/emission wavelength combinations. With Kuwait crude oil as a reference, the concentration range is 0.1–0.6 μg l^?1 crude oil equivalents with respect to light molecular weight components and 0.05–0.2 μg l^?1 heavy molecular weight components.  相似文献   

Monitoring and Assessing Structural Damage in Historic Buildings     

Julia  Armesto  Pedro  Arias  Javier  Roca  Henrique  Lorenzo 《The Photogrammetric Record》2008,23(121):36-50

  相似文献   

VIRGO: Experiment for helioseismology and solar irradiance monitoring   总被引：1，自引：0，他引：1  

Claus Fröhlich  José Romero  Hansjörg Roth  Christoph Wehrli  Bo N. Andersen  Thierry Appourchaux  Vicente Domingo  Udo Telljohann  Gabrielle Berthomieu  Philippe Delache  Janine Provost  Thierry Toutain  Dominique A. Crommelynck  André Chevalier  Alain Fichot  Werner Däppen  Douglas Gough  Todd Hoeksema  Antonio Jiménez  Maria F. Gómez  José M. Herreros  Teodoro Roca Cortés  Andrew R. Jones  Judit M. Pap  Richard C. Willson 《Solar physics》1995,162(1-2):101-128

The scientific objective of the VIRGO experiment (Variability of solar IRradiance and Gravity Oscillations) is to determine the characteristics of pressure and internal gravity oscillations by observing irradiance and radiance variations, to measure the solar total and spectral irradiance and to quantify their variability over periods of days to the duration of the mission. With these data helioseismological methods can be used to probe the solar interior. Certain characteristics of convection and its interaction with magnetic fields, related to, for example, activity, will be studied from the results of the irradiance monitoring and from the comparison of amplitudes and phases of the oscillations as manifest in brightness from VIRGO, in velocity from GOLF, and in both velocity and continuum intensity from SOI/MDI. The VIRGO experiment contains two different active-cavity radiometers for monitoring the solar constant, two three-channel sunphotometers (SPM) for the measurement of the spectral irradiance at 402, 500 and 862 nm, and a low-resolution imager (LOI) with 12 pixels, for the measurement of the radiance distribution over the solar disk at 500 um. In this paper the scientific objectives of VIRGO are presented, the instruments and the data acquisition and control system are described in detail, and their measured performance is given.died 13 October 1994  相似文献   

Meromixis origin and recent trophic evolution in the Spanish mountain lake La Cruz   总被引：4，自引：0，他引：4  

Ramon Julià  Francesc Burjachs  Maria J. Dasí  Francesc Mezquita  Maria R. Miracle  Josep R. Roca  Guy Seret  Eduardo Vicente 《Aquatic Sciences - Research Across Boundaries》1998,60(4):279-299

  相似文献   

10 Myr evolution of sedimentation rates in a deep marine to non‐marine foreland basin system: Tectonic and sedimentary controls (Eocene,Tremp–Jaca Basin,Southern Pyrenees,NE Spain)     

Andreu Vinyoles  Miguel Lpez‐Blanco  Miguel Garcs  Pau Arbus  Luis Valero  Elisabet Beamud  Beln Oliva‐Urcia  Patricia Cabello 《Basin Research》2021,33(1):447-477

The propagation of the deformation front in foreland systems is typically accompanied by the incorporation of parts of the basin into wedge‐top piggy‐back basins, this process is likely producing considerable changes to sedimentation rates (SR). Here we investigate the spatial‐temporal evolution of SR for the Tremp–Jaca Basin in the Southern Pyrenees during its evolution from a wedge‐top, foreredeep, forebulge configuration to a wedge‐top stage. SR were controlled by a series of tectonic structures that influenced subsidence distribution and modified the sediment dispersal patterns. We compare the decompacted SR calculated from 12 magnetostratigraphic sections located throughout the Tremp–Jaca Basin represent the full range of depositional environment and times. While the derived long‐term SR range between 9.0 and 84.5 cm/kyr, compiled data at the scale of magnetozones (0.1–2.5 Myr) yield SR that range from 3.0 to 170 cm/kyr. From this analysis, three main types of depocenter are recognized: a regional depocenter in the foredeep depozone; depocenters related to both regional subsidence and salt tectonics in the wedge‐top depozone; and a depocenter related to clastic shelf building showing transgressive and regressive trends with graded and non‐graded episodes. From the evolution of SR we distinguish two stages. The Lutetian Stage (from 49.1–41.2 Ma) portrays a compartmentalized basin characterized by variable SR in dominantly underfilled accommodation areas. The markedly different advance of the deformation front between the Central and Western Pyrenees resulted in a complex distribution of the foreland depozones during this stage. The Bartonian–Priabonian Stage (41.2–36.9 Ma) represents the integration of the whole basin into the wedge‐top, showing a generalized reduction of SR in a mostly overfilled relatively uniform basin. The stacking of basement units in the hinterland during the whole period produced unusually high SR in the wedge‐top depozone.  相似文献   

Seismic hazard zonation of Catalonia, Spain, integrating random uncertainties   总被引：2，自引：2，他引：2  

R. Secanell  X. Goula  T. Susagna  J. Fleta  A. Roca 《Journal of Seismology》2004,8(1):25-40

In order to analyse the seismic hazard inCatalonia a new parametric earthquakedataset, in terms of macroseismicintensities, has been used. A newseismotectonic zonation of the area understudy and surrounding regions, which takesinto account the geologic and seismic data,is proposed. From these input data, anestimation of the seismicity of the variousseismotectonic zones has been carried outusing both stationary andnon-stationary models. As seismicity doesnot show important non-stationarities, ahazard analysis, has been carried out withthe parameters from the stationary model. Asensitivity study, using the Montecarlotechnique shows relatively smalluncertainties. For each point of thestudied area the maximum likely feltintensity was also considered. A seismichazard map combining the probabilistic anddeterministic models integratinguncertainties resulting from sensitivityanalysis is proposed.  相似文献   

Acoustic oscillations in the K2III star arcturus     

J. A. Belmonte  A. R. Jones  P. L. Pallé  T. Roca cortés 《Astrophysics and Space Science》1990,169(1-2):77-84

Simultaneous spectrometric and photometric observations have been performed, on the red giant star Arcturus ( Boo), in a search for radial velocity or luminosity variations related to global oscillations of the stellar structure. From a preliminary analysis of the spectrometric data, several frequencies have been discovered in the range from 1 to 50 Hz, the highest amplitude being of 60 ms^–1 at 4.3 Hz. From the analysis of the photometric data, slight evidence of this variation has been found, yielding a value of V/m=48 km s^–1 mag^–1.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.  相似文献   

Analysis of macroseismic and instrumental data for the study of the 19 November 1923 earthquake in the Aran Valley (Central Pyrenees)     

T. Susagna  A. Roca  X. Goula  J. Batlló 《Natural Hazards》1994,10(1-2):7-17

The 19 November 1923 earthquake in the Aran Valley (Central Pyrenees), with observed maximum intensityI _max = VIII (MSK), has been studied through the compiling and reviewing of macroseismic information and collecting and processing early seismograms. Analysis of macroseismic data gives a focal depth ofh = 5 km and an anelastic attenuation coefficient 10^–3 km^–1. Analysis of early instrumental records allows the computation of estimate of magnitude (M _L = 5.6) and seismic moment (M _o = 1.1 × 10¹⁷ N × m) which are consistent with the values ofI _o andh obtained from macroseismic data.  相似文献   

Geoelectrical Classification of Gypsum Rocks     

Ander Guinea  Elisabet Playà  Lluís Rivero  Mahjoub Himi  Ricard Bosch 《Surveys in Geophysics》2010,31(6):557-580

Gypsum rocks are widely exploited in the world as industrial minerals. The purity of the gypsum rocks (percentage in gypsum mineral in the whole rock) is a critical factor to evaluate the potential exploitability of a gypsum deposit. It is considered than purities higher than 80% in gypsum are required to be economically profitable. Gypsum deposits have been studied with geoelectrical methods; a direct relationship between the electrical resistivity values of the gypsum rocks and its lithological composition has been established, with the presence of lutites being the main controlling factor in the geoelectrical response of the deposit. This phenomenon has been quantified in the present study, by means of a combination of theoretical calculations, laboratory measurements and field data acquisition. Direct modelling has been performed; the data have been inverted to obtain the mean electrical resistivity of the models. The laboratory measurements have been obtained from artificial gypsum-clay mixture pills, and the electrical resistivity has been measured using a simple electrical circuit with direct current power supply. Finally, electrical resistivity tomography data have been acquired in different evaporite Tertiary basins located in North East Spain; the selected gypsum deposits have different gypsum compositions. The geoelectrical response of gypsum rocks has been determined by comparing the resistivity values obtained from theoretical models, laboratory tests and field examples. A geoelectrical classification of gypsum rocks defining three types of gypsum rocks has been elaborated: (a) Pure Gypsum Rocks (>75% of gypsum content), (b) Transitional Gypsum Rocks (75–55%), and (c) Lutites and Gypsum-rich Lutites (<55%). From the economic point of view, the Pure Gypsum Rocks, displaying a resistivity value of >800 ohm.m, can be exploited as industrial rocks. The methodology used could be applied in other geoelectrical rock studies, given that this relationship between the resistive particles embedded within a conductive matrix depends on the connectivity of the matrix particles.  相似文献