Miracle-dz/UniFAR-FTUs huggingface dataset:
Rb–Sr and Sm–Nd isotopic studies of mafic igneous rocks from the Ryoke plutono‐metamorphic belt in the Setouchi area, Southwest Japan: implications for the genesis and thermal history

Abstract Rb–Sr and Sm–Nd isochron ages were determined for whole rocks and mineral separates of hornblende‐gabbros and related metadiabases and quartz‐diorite from Shodoshima, Awashima and Kajishima islands in the Ryoke plutono‐metamorphic belt of the Setouchi area, Southwest Japan. The Rb–Sr and Sm–Nd whole‐rock‐mineral isochron ages for six samples range from 75 to 110 Ma and 200–220 Ma, respectively. The former ages are comparable with the Rb–Sr whole‐rock isochron ages reported from neighboring Ryoke granitic rocks and are thus due to thermal metamorphism caused by the granitic intrusions. On the contrary, the older ages suggest the time of formation of the gabbroic and related rocks. The initial 87Sr/86Sr and 143Nd/144Nd ratios of the gabbroic rocks (0.7070–0.7078 and 0.51217–0.51231 at 210 Ma, respectively) are comparable with those of neighboring late Cretaceous granites and lower crustal granulite xenoliths from Cenozoic andesites in this region. Because the gabbroic rocks are considered to be fragments of the lower crustal materials interlayered in the granulitic lower crust, their isotopic signature has been inherited from an enriched mantle source or, less likely, acquired through interaction with the lower crustal materials. The Sr and Nd isotopic and petrologic evidence leads to a plausible conclusion that the gabbroic rocks have formed as cumulates from hydrous mafic magmas of light rare earth element‐rich (Sm/Nd < 0.233) and enriched isotopic (ɛSr > 0 and ɛNd < 0) signature, which possibly generated around 220–200 Ma by partial melting of an upper mantle. We further conclude that they are fragments of refractory material from the lower crust caught up as xenoblocks by granitic magmas, the latter having been generated by partial melting of granulitic lower crustal material around 100 Ma.
Velocity/interface model building in a thrust belt by tomographic inversion of global offset seismic data

Between September and November 1999, two test seismic lines were recorded in the southern Apennine region of southern Italy using the global offset technique, which involves the acquisition of a wide offset range using two simultaneously active seismic spreads. One consisted of a symmetrical spread moving along the line, with geophone arrays every 30 m and a maximum offset of 3.6 km. The other one consisted of fixed geophone arrays every 90 m with a maximum offset of 18 km. This experimental acquisition project was carried out as part of the enhanced seismic in thrust belt (ESIT) research project, funded by the European Union, Enterprise Oil and Eni‐Agip. An iterative and interactive tomographic inversion of refraction/reflection arrivals was carried out on the data from line ESIT700 to produce a velocity/interface model in depth, which used all the available offsets. The tomographic models allowed the reconstruction of layer interface geometries and interval velocities for the target carbonate platform (Apula) and the overburden sequence. The value of this technique is highlighted by the fact that the standard approach, based on near‐vertical reflection seismic and a conventional processing flow, produced poor seismic images in both stack and migrated sections.
Dispersion and radial depth of investigation of borehole modes

Sonic techniques in geophysical prospecting involve elastic wave velocity measurements that are performed by placing acoustic transmitters and receivers in a fluid‐filled borehole. The signals recorded at the receivers are processed to obtain compressional‐ and shear‐wave velocities in the surrounding formation. These velocities are generally used in seismic surveys for the time‐to‐depth conversion and other formation parameters, such as porosity and lithology. Depending upon the type of transmitter used (e.g. monopole or dipole) and as a result of eccentering, it is possible to excite axisymmetric (n= 0), flexural (n= 1) and quadrupole (n= 2) families of modes propagating along the borehole. We present a study of various propagating and leaky modes that includes their dispersion and attenuation characteristics caused by radiation into the surrounding formation. A knowledge of propagation characteristics of borehole modes helps in a proper selection of transmitter bandwidth for suppressing unwanted modes that create problems in the inversion for the compressional‐ and shear‐wave velocities from the dispersive arrivals. It also helps in the design of a transmitter for a preferential excitation of a given mode in order to reduce interference with drill‐collar or drilling noise for sonic measurements‐while‐drilling. Computational results for the axisymmetric family of modes in a fast formation with a shear‐wave velocity of 2032 m/s show the existence of Stoneley, pseudo‐Rayleigh and anharmonic cut‐off modes. In a slow formation with a shear‐wave velocity of 508 m/s, we find the existence of the Stoneley mode and the first leaky compressional mode which cuts in at approximately the same normalized frequency ωa/VS= 2.5 (a is the borehole radius) as that of the fast formation. The corresponding modes among the flexural family include the lowest‐order flexural and anharmonic cut‐off modes. For both the fast and slow formations, the first anharmonic mode cuts in at a normalized frequency ωa/VS= 1.5 approximately. Cut‐off frequencies of anharmonic modes are inversely proportional to the borehole radius in the absence of any tool. The borehole quadrupole mode can also be used for estimating formation shear slownesses. The radial depth of investigation with a quadrupole mode is marginally less than that of a flexural mode because of its higher frequency of excitation.
The Bordeaux VLBI Image Database

As part of its contribution to the International VLBI Service for Geodesy and As- trometry (IVS) and to the maintenance and im- provement of the current International Celes- tial Reference Frame (ICRF), the VLBI group in Bordeaux produces VLBI images of extra- galactic radio sources on a regular basis. These images are used to derive structure correction maps and structure indices along with visibility maps and values of source compactness which allow one to characterize the astrometric suit- ability of the ICRF sources. All such prod- ucts are available on-line through the Bordeaux VLBI Image Database (BVID). The BVID in- cludes more than 1500 VLBI images at 2.3 and 8.4 GHz for over 700 different sources, as well as 7500 structure correction maps and vis- ibility maps. This dataset is constantly ex- panding as new VLBI experiments are pro- cessed. The Bordeaux VLBI Image Database is accessible through the following web address: http://www.obs. u-bordeaux1.fr/BVID/.
Using satellite imagery to validate snow distribution simulated by a hydrological model in large northern basins

Owing to the scarcity of hydro‐climatic data in high latitudes, most hydrological models are validated using only discharge data from the basin outlets. In view of the important contribution of snowmelt to northern river flows, there is a need to evaluate model performance in terms of the ability to simulate the seasonal pattern of change in the basin snow cover. The paucity of ground observations renders satellite information a suitable alternative. The moderate resolution imaging spectroradiometer (MODIS) global snow‐cover product provided by the National Snow and Ice Data Center (NSIDC) offers one such tool to validate simulated snow coverage in rugged sub‐arctic and boreal terrain. This study examines the usefulness of applying MODIS data to validate the hydrological simulation for two test basins: the Liard (275 000 km2) and the Athabasca (133 000 km2) Basins in Canada. Changing extent of snow cover simulated by the Semi‐distributed Land Use‐based Runoff Processes (SLURP) macro‐hydrologic model was compared with MODIS imagery at four bi‐weekly intervals in 2000 and 2001. The simulated patterns of seasonal snow‐cover change are consistent with the remotely sensed information, with melt beginning from the lower elevations in the east where less snow was accumulated, to the higher elevations in the west bearing more snow. The overall results show the need and the usefulness of MODIS as a tool for validating snow distribution simulated by the hydrological model in large northern basins. Copyright © 2008 John Wiley & Sons, Ltd.
Detecting network communities: a new systematic and efficient algorithm

An efficient and relatively fast algorithm for the detection of communities in complex networks is introduced. The method exploits spectral properties of the graph Laplacian matrix combined with hierarchical clustering techniques, and includes a procedure for maximizing the ‘modularity’ of the output. Its performance is compared with that of other existing methods, as applied to different well-known instances of complex networks with a community structure, both computer generated and from the real world. Our results are, in all the cases tested, at least as good as the best ones obtained with any other methods, and faster in most of the cases than methods providing similar quality results. This converts the algorithm into a valuable computational tool for detecting and analysing communities and modular structures in complex networks.
Transport of conservative chemical through an unsaturated two‐dimensional Miller‐similar medium with steady state flow

Numerical simulation of water flow in a two-dimensional, macroscopically homogeneous, Miller-similar medium showed the existence of a network of flow channels with two complementary states separated by a critical point [Roth, 1995]. The consequences of this for solute transport are explored by numerical simulations using particle tracking. It is found that many experimentally observed features of transport through soil are reproduced qualitatively by these simulations. Analyzing the results reveals that in the corresponding effective medium the travel distance for the transition to convection-dispersion and the effective dispersivity depend on the water flux. In particular, the effective longitudinal dispersivity, which is often assumed to be a material constant of the porous structure, is found to vary by more than an order of magnitude with a minimum near the critical point. The simulations further demonstrate that the local structure of the velocity field and the subscale hydrodynamic dispersion are of minor importance for the field-averaged transport process.
The sensitivity of microbial processes in Icelandic soils to increasing temperatures

The sensitivity of microbial processes in Icelandic soils to increasing temperatures R. Guicharnaud, O. Arnalds, and G. I. Paton Agricultural University of Iceland, Department of Land Resources, Iceland Agricultural University of Iceland, Department of Environmental Sciences, Iceland Institute of Biological and Environmental Sciences, Cruickshank Building, University of Aberdeen, St. Machar Drive, Aberdeen AB24 3UU, UK Received: 26 May 2009 – Accepted: 4 June 2009 – Published: 9 July 2009 Correspondence to: R. Guicharnaud (rannveig@lbhi.is) Published by Copernicus Publications on behalf of the European Geosciences Union.
USE OF THE OSMOTIC TENSIOMETER TO MEASURE NEGATIVE PORE WATER PRESSURE

The osmotic tensiometer was developed to provide a method of direct measurement of tension in the pore water of soils. A study was undertaken at the University of Saskatchewan to investigate the instrument's operational characteristics and its applicability to practical engineering problems. The study covered long-term stability, response time to changes in pore water pressure, and response to changes in ambient temperature. It was found that the internal prestress pressure tended to diminish with time, probably due to leakage of the confined solute through the semipermeable membrane. However, it was possible to individually calibrate each instrument to correct for this effect. Second, the pressure response of the osmotic tensiometers indicated that a transient flow process was occurring; the equilibration time of the device was primarily a function of the configuration and materials of the unit and the compressibility of the solution in the chamber. Third, it was found that changes in ambient temperature considerably affected the internal reference pressures. These results indicate that osmotic tensiometers may be useful to measure negative pore water pressures, providing that the temperature is controlled and the pore water pressure is constant. This may restrict their usefulness to research applications. (Author)
Improvement of Water Area Classification During a Flood Using RADARSAT SAR Imagery and Terrain Informations In Mountainous Area

The brightness values of Synthetic Aperture Radar (SAR) imagery are largely influenced by the local terrain relief. In water areas such as oceans and rivers with relatively flat areas, SAR imagery has lower backscattered signals than other surfaces. Although SAR imagery with its own energy sources is very applicable to flood monitoring due to its sensitivity to the water area, several distortions caused by local terrain relief must be carefully considered before actual classification process. Since backscattering coefficients of shadow area are very similar to those of the water area, it is essential to remove the radiometric distortion caused by local relief especially in mountainous areas. In this study we tested four different cases of local terrain relief compensation processes based on the preprocessing of input SAR imagery and local surface information such as elevation and slopes for accurate water extent. The case when the input RADARSAT SAR imagery is classified with the local slope information is best in terms of flood area estimation, even in small streams and watershed of different elevation categories. Consequently in mountainous areas the combination of SAR imagery and slope information is the best combination in the estimation of inundated areas during the flood.
The response to deforestation and desertification in a model of West African monsoons

Since Charney proposed his theory on the dynamics of deserts and droughts in the Sahel [Charney, 1975], there has been significant scientific interest in the interaction between vegetation and climate in this region. The essence of this interaction is that the atmospheric circulation, and therefore rainfall, over this region may be sensitive to changes in vegetation cover near the desert border. Here we describe simulations of the West African monsoons with a simple zonally‐symmetric model. The results suggest that the potential impact of human induced change of land cover on regional climate depends critically on the location of the change in vegetation cover. That is, desertification along the border with the Sahara (e.g., in Chad, Niger, Mali and Mauritania) leaves a relatively minor impact on monsoon circulation and regional rainfall; deforestation along the southern coast of West Africa (e.g., in Nigeria, Ghana and Ivory Coast) may result in complete collapse of monsoon circulation, and a significant reduction of regional rainfall.
Global ice cloud observations: radiative properties and statistics from moderate-resolution imaging spectroradiometer measurements

Global Ice Cloud Observations: Radiative Properties and Statistics from Moderateresolution Imaging Spectroradiometer Measurements. (August 2007) Kerry Glynne Meyer, B.S., Texas A&M University; M.S., Texas A&M University Chair of Advisory Committee: Dr. Ping Yang Ice clouds occur quite frequently, yet so much about these clouds is unknown. In recent years, numerous investigations and field campaigns have been focused on the study of ice clouds, all with the ultimate goal of gaining a better understanding of microphysical and optical properties, as well as determining the radiative impact. Perhaps one of the most recognized instruments used for such research is the Moderateresolution Imaging Spectroradiometer (MODIS), carried aboard the NASA EOS satellites Terra and Aqua. The present research aims to support ongoing efforts in the field of ice cloud research by use of observations obtained from Terra and Aqua MODIS. First, a technique is developed to infer ice cloud optical depth from the MODIS cirrus reflectance parameter. This technique is based on a previous method developed by Meyer et al. (2004). The applicability of the algorithm is demonstrated with retrievals from level-2 and -3 MODIS data. The technique is also evaluated with the operational MODIS cloud retrieval product and a method based on airborne ice cloud observations. From this technique, an archive of daily optical depth retrievals is constructed. Using simple statistics, the global spatial and temporal distributions of ice clouds are determined.
Decadal Variability of Sea Ice Drift in the Weddell Sea for the Period from 1979 to 2006

The knowledge and understanding of sea ice drift variability is essential for an assessment of, e.g., varying ice production rates, deformation processes, ice export and also stratification changes in the ocean. The goal of this study is the determination of the decadal variability of sea ice motion in the Weddell Sea and its relation to atmospheric forcing. Yearly and monthly mean drift vector fields for every 10-year period are computed from observations from 1979-2006 and from simulations with the Finite Element Sea ice-Ocean Model (FESOM) for 1948-2008. Ice motion patterns are analysed with respect to the long-term mean in order to identify decadal changes in the typical drift patterns. Observed motion vector fields for Antarctic sea ice are provided by the National Snow and Ice Data Center (NSIDC). The vector fields are created from a combination of satellite data from the 37 GHz and 85 GHz channels of the Scanning Multichannel Microwave Radiometer (SMMR, 1978-1987) and the Special Sensor Microwave/Imager (SSM/I, 1987-2006) as well as from the Advanced Very High Resolution Radiometer (AVHRR, 1981-2000). The gridded data sets have a spatial resolution of 25 km and are available for a temporal resolution of one day. Data from the NCEP/NCAR reanalysis have been used to force the model simulations and are also used to identify the driving forces for ice drift variability.
Palaeogeographical influence on Late Eocene biosiliceous sponge‐rich sedimentation, southern Western Australia

Late Eocene nearshore shallow‐marine environments within the Bremer and western Eucla Basins of southern Western Australia were characterized by the thick deposition of spongolite and spiculite deposits. Epibenthic sponge communities dominated estuaries and topographically complex basin margin embayments‐archipelagos, while cool‐water carbonates with up to 10% sponges accumulated in open‐shelf environments. The transition from a biosiliceous to calcareous epibenthos was related to the degree of palaeogeographical ‘protection’. Within basement‐protected embayments there was an offshore gradation from shoreface spongolite and pure spiculite to a muddy spiculite facies towards central embayment areas. Calcareous fossils are rare throughout embayment facies, but rapidly increase in more open outer archipelago areas. This depositional relationship occurred along 2000 km of the Late Eocene southern Australian coastline. Palaeogeographical protection from strong currents acted in concert with: (1) a planar, low‐gradient inland topography with sluggish run‐off, supplying fine‐grained sediment, nutrients, and abundant dissolved silica; and (2) a microtidal setting, weak to moderate swells and opposing wind and Coriolis surface current forcing, which inhibited water exchange between embayments‐estuaries and the open shelf. This situation led to an embayment water chemistry that encouraged prolific sponge growth. Calcareous spiculites record the mixing front between these embayment waters and normal open‐shelf waters supporting cool‐water carbonates.
Learning structural conjunction of image content by sparse graphical model

In this paper we present a novel method on learning structural conjunction of image content by sparse graphical model. We first use matrix-variate distributions to formulate two statistical structure models and establish the connection between them. The connection leads us to sparse Gaussian graphical models in which sparse regression technique such as lasso is used for concentration matrix estimation as well as structure learning. Our proposed theoretical framework and structure selection methods provide an approach for exploiting structural conjunction of data. We apply this approach to construction of underlying structural correlation between image content, and demonstrate the effectiveness by solving image jigsaw problem.
Reply to comment by L. Cathles and W. Fjeldskaar on 'The inference of mantle viscosity from an inversion of the Fennoscandian relaxation spectrum'

The analysis of Mitrovica & Peltier (1993; henceforth ‘MP’) involved inferences of mantle viscosity based on Bayesian inversions of the Fennoscandian relaxation spectrum (henceforth ‘FRS’). The inversions yielded constraints on the average viscosity within a set of radial regions resolved by the data, and quantified various trade-offs associated with the inference. The MP study also used forward calculations to predict the relaxation spectrum for a set of nine viscosity models. The inversion-derived constraints were then used to determine the cause of any misfit between these predictions and the observational constraints on the FRS. One of the models chosen in this exercise, labelled LVZ, was characterized by the elastic structure of the seismic model PREM (Dziewonski & Anderson 1981), an elastic lithosphere of thickness 70 km, and a 90 km thick sublithospheric region of low (2 x 1019 Pa s) viscosity overlying an isoviscous, 10” Pas, mantle. The x2 misfit between the observed FRS and the spectrum computed using the LVZ model (- 295) was significantly in excess of the 99 per cent confidence limit (- 74). The comment by Cathles & Fjeldskaar ( 1996; henceforth ‘CF) is directed toward results associated with the LVZ model only. In particular, CF argue that: (1) the LVZ model is a ‘miscalculation’ of their preferred model for the region, which they label ‘FC‘; and (2) their own calculation of the relaxation spectrum using the LVZ model differs from the MP prediction-they are able to reproduce the MP results only by altering the thickness of the low-viscosity zone to 55 km. We consider both of these points in turn.
Deep structure of the Anglo–Brabant massif revealed by seismic profiling

Abstract Deep seismic reflection profiles over the Anglo–Brabant massif in the southern North Sea reveal reflection patterns throughout the crust that are distinctive and which differ significantly from those observed beneath adjacent areas with Mesozoic basins. Comparisons with reflection profiles from other platform areas suggest that the reflection patterns indicate large-scale structural features associated with compressional tectonics. If so, they may represent thrust structures associated with continental accretion of preferred Caledonian age.