Miracle-dz/UniFAR-FTUs huggingface dataset:
Isotope characterisation of ground ice in northern Canada

This paper reviews isotopic research on the characterisation and identification of various types of ground ice throughout the Canadian Arctic, including buried glacier ice, massive segregated ice, segregated ice lenses and offshore ice‐rich permafrost, as well as ice related to other cold‐region phenomena such as ice wedges, icings (aufeis), frost blisters and pingos. The formational age of ground ice bodies ranges from recent (seasonal ice in the active layer) to tens of thousands of years, when the region experienced widespread continental‐scale glaciation. Modern ice lenses generally have 18O/16O ratios of ‐18 to ‐22‰, while modern ice wedges usually range from ‐22 to ‐25‰. δ18O values as high as ‐14‰ are representative of the Hypsithermal period (4000 to 8000 years BP), while glacial‐age ice has been measured with 18O/16O ratios as low as ‐36‰. Buried glacier ice often preserves climatic variations from the time of snow deposition. Other massive ground ice bodies contain isotopic signatures (18O and 2H) that indicate variable fractionation of the isotopes during freezing of the source water at stationary freezing fronts in either open or closed systems. Placing the ice bodies into a time frame can be accomplished either through age dating of the enclosing sediments and encased organics, or by direct dating of the ice utilising tritium (3H) for relatively young ice and radiocarbon (14C) analysis of contained gas bubbles for older ice. Copyright © 2011 John Wiley & Sons, Ltd.
Simulation of South Asian aerosols for regional climate studies

[1] Extensive intercomparison of columnar and near-surface aerosols, simulated over the South Asian domain using the aerosol module included in the regional climate model (RegCM4) of the Abdus Salam International Centre for Theoretical Physics (ICTP) have been carried out using ground-based network of Sun/sky Aerosol Robotic Network (AERONET) radiometers, satellite sensors such as Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR), and ground-based black carbon (BC) measurements made at Aerosol Radiative Forcing over India (ARFI) network stations. In general, RegCM4 simulations reproduced the spatial and seasonal characteristics of aerosol optical depth over South Asia reasonably well, particularly over west Asia, where mineral dust is a major contributor to the total aerosol loading. In contrast, RegCM4 simulations drastically underestimated the BC mass concentrations over most of the stations, by a factor of 2 to 5, with a large spatial variability. Seasonally, the discrepancy between the measured and simulated BC tended to be higher during winter and periods when the atmospheric boundary layer is convectively stable (such as nighttime and early mornings), while during summer season and during periods when the boundary layer is convectively unstable (daytime) the discrepancies were much lower, with the noontime values agreeing very closely with the observations. A detailed analysis revealed that the model does not reproduce the nocturnal high in BC, observed at most of the Indian sites especially during winter, because of the excessive vertical transport of aerosols under stable boundary layer conditions. As far as the vertical distribution was concerned, the simulated vertical profiles of BC agreed well with airborne measurements during daytime. This comprehensive validation exercise reveals the strengths and weaknesses of the model in simulating the spatial and temporal heterogeneities of the aerosol fields over South Asia.
The Great Mortgaging: Housing Finance, Crises, and Business Cycles

This paper unveils a new resource for macroeconomic research: a long-run dataset covering disaggregated bank credit for 17 advanced economies since 1870. The new data show that the share of mortgages on banks’ balance sheets doubled in the course of the 20th century, driven by a sharp rise of mortgage lending to households. Household debt to asset ratios have risen substantially in many countries. Financial stability risks have been increasingly linked to real estate lending booms which are typically followed by deeper recessions and slower recoveries. Housing finance has come to play a central role in the modern macroeconomy.
New Pressure–Void Ratio Relationship for Structured Soils in the Virgin Compression Range

AbstractThe pressure–void ratio relationship of many structured soils in the virgin compression range is highly nonlinear. The initial part of the compression curve is characterized by the breakdown of structures, whereas the behavior in the postdestructuration range is influenced by soil mineralogy. A robust pressure–void ratio relationship should include parameters that account for the distinct mechanisms that control the behavior in the destructuration and postdestructuration ranges. A new pressure–void ratio relationship based on a modified secant compression index is proposed. It is shown that the variation of the proposed secant compression index with a logarithm of pressure can be approximated by a hyperbolic form with two parameters. The new relationship has been verified in a wide range of naturally structured soils. Parametric studies conducted show that one parameter controls the compression behavior within the stress range where the destructuration is dominant, and the other parameter controls.
Experimental studies in Precambrian paleontology: Structural and chemical changes in blue-green algae during simulated fossilization in synthetic chert

Experimental data concerning the effects of diagenesis and fossilization on soft-bodied microorganisms (particularly algae preserved in siliceous sediments) have been obtained through systematic monitoring of morphological and organic chemical changes in filamentous blue-green algae ( Lyngbya majuscula , Oscillatoriaceae) during simulated fossilization in synthetic chert. With increasing time and temperature, there were tendencies toward reddening, darkening, and fragmentation of algal filaments, reduction in the size of algal cells and sheaths, destruction of micellar order in sheaths (with consequent loss of bire-fringent character), coalescence of trichomes, and destruction of intracellular components with preferential preservation of sheaths and cell walls. In addition, some algal filaments were damaged by growth of quartz spherulites, producing artifactual morphologies that appear to have natural counterparts in Precambrian fossiliferous cherts. Original algal hydrocarbons, and particularly normal alkanes, were relatively stable, but several previously absent hydrocarbons were produced through decomposition of other organic compounds. Isoprenoid compounds, chlorins, and probably porphyrins were derived from the degradation of algal chlorophyll. The δC 13 PDB value of algal carbon was unaffected in most experiments but decreased by 3‰ under extreme time and temperature conditions. Results of this study suggest trends in the morphological degradation of naturally silicified algae, demonstrate that certain morphologies are artifacts of the silicification process, and suggest possible explanations of observed organic chemical trends in recent and ancient sediments.
Mechanical and hydraulic behaviour of a soft inorganic clay treated with lime

A comprehensive series of laboratory tests was conducted on an inorganic clayey sediment in order to predict the mechanical behaviour of dredged sediments used in reclamation projects. The soil used was a Louiseville clay, which was mixed with various quantities of lime (010%) and had a varied water content (122650%). Tests were carried out with special large cells and standard oedometers to look at both the compressibility and the hydraulic conductivity. Once pozzolanic reactions are begun, for a given curing time, a linear relationship between preconsolidation pressure and lime concentration is observed. Compressibility results indicate that it is possible to define a separate compression curve for each lime concentration and curing time. Adding lime will influence the hydraulic conductivity both by flocculation and by the formation of secondary minerals. If only flocculation occurs, an increase in hydraulic conductivity follows. If enough lime is added, the resulting secondary minerals will create ma.
Character and origin of variably deformed granitoids in central southern Sweden: implications from geochemistry and Nd isotopes

We present major and trace element data for eighteen 1.71–1.66 Ga granitoid samples, and Sm–Nd whole‐rock isotope data for eleven of these samples, in a transect across the border between the Transscandinavian Igneous Belt (TIB) and the Eastern Segment in central southern Sweden. The geochemistry of the granitoids varies from alkalic to alkali‐calcic and peraluminous in the east to predominantly calc‐alkaline and metaluminous in the west. Rocks in the west also have lower SiO2 contents. Trace element signatures favour formation in an active continental margin setting. Nd isotope data are completely overlapping along the transect and initial εNd values are mildly depleted in the range +0.3 to +2.6. The combined data suggest that the magmas were derived mainly from juvenile, pre‐existing crust, increasingly mafic and less alkaline towards the west. Copyright © 2011 John Wiley & Sons, Ltd.
Thermal analysis of the southern Powder River Basin, Wyoming

Temperature and geologic data from over 3000 oil and gas wells within a 180 km × 30 km area that transect across the southern Powder River Basin in Wyoming, U.S.A. , were used to determine the present thermal regime of the basin. Three‐dimensional temperature fields within the transect, based on corrected bottomhole temperatures (BHTs) and other geologic information, were assessed using: (1) A laterally constant temperature gradient model in conjunction with an L1 norm inversion method, and (2) a laterally variable temperature gradient model in conjunction with a stochastic inversion technique. The mean geothermal gradient in the transect is 29°C/km, but important lateral variations in the geothermal gradient exist. The average heat flow for the southern Powder River Basin is 52mW/m2 with systematic variations between 40mW/m2 and 60mW/m2 along the transect. Extremely high local heat flow (values up to 225mW/m2) in the vicinity of the Teapot Dome and the Salt Creek Anticline and low heat flow of 25mW/m2 occ.
Determination of soil sorptivity and hydraulic conductivity from the disk infiltrometer

A simple two-term infiltration equation was used to determine soil sorptivity and hydraulic conductivity from cumulative infiltration data from the disk infiltrometer. Parameters of the equation were obtained by fitting the equation to cumulative infiltration data. The parameters of the first and second terms in the equation were related to soil sorptivity and hydraulic conductivity, respectively. By using the two-term infiltration equation, sorptivity and hydraulic conductivity were estimated for various soils, radii and tensions of the disk infiltrometer, and initial infiltration conditions. Sorptivity and hydraulic conductivity values calculated using the method and simulated cumulative infiltration data resulted in excellent agreement with the theoretical results. The relative error of estimation of sorptivity and hydraulic conductivity was within 5% for most cases. The method can be used to determine the soil hydraulic properties from infiltrometer infiltration for a wide range of soils, having a retention function of the type of either van Genuchten, Russo, or Zhang and van Genuchten.
Evaluation of the temporal relationship between daily min/max air and land surface temperature

Daily minimum and maximum air temperature (min/max Ta) exhibits a strong linear correlation with remotely sensed land surface temperature (LST). However, LST-based predictions of min/max Ta exhibit a strong seasonal pattern in their errors. This study examines the temporal trends in min/max Ta and LST, and shows that the strongest correlation exhibited by any of these variables is a temporal autocorrelation that is periodic in nature. This study analyses the temporal relationship between min/max Ta and LST, and shows that this results in a temporal trend in the errors of LST-based min/max Ta predictions that can primarily be explained by a phase shift between the seasonal oscillations of min/max Ta and LST. After removing the elevation and periodic temporal trend from the min/max Ta and LST measurements, a weak linear correlation was exhibited between min Ta and LST and a moderate linear correlation was exhibited between max Ta and LST. Fitting models to the detrended min/max Ta and LST measurements resulted in an LST-based model of min/max Ta that no longer exhibited seasonal variability in the model errors, and had a lower mean absolute error (MAE) than either a model based only on the elevation and temporal trends or one based on the elevation and LST trends alone. Thus, the results of this study show that in creating relationships between LST and air temperature, it is important to address the phase shift between the annual oscillations of these variables. This study shows that removing the annual oscillation using a Fourier model of the temporal trend improves the LST-based min/max Ta prediction by 0.6°C to 0.8°C.
The tommotiid Kelanella and associated fauna from the early Cambrian of southern Montagne Noire (France): implications for camenellan phylogeny

A carbonate bed of the Pardailhan Formation, early Cambrian, southern Montagne Noire (southern France), provided microfossils such as Hyolithellus sp. , Torellella cf. mutila and Torellella sp. along with numerous disarticulated pieces of composite skeletons such as valves of the brachiopod Eoobolus priscus and of the bradoriid Monceretia erisylvia, and chancelloriid sclerites (Chancelloria sp.). The assemblage also furnished a rich set of sclerites from the tommotiid Kelanella altaica. Five morphological variations of the latter have been identified. The presence of concentric ribs formed by distal inflation of selected shell laminae in Kelanella supports its assignment to the camenellans. More particularly, the presence of transverse structures within the internal cavity (septa) of Kelanella suggests a close relationship with the Lapworthellidae. However, the latter differ from Kelanella by the continuous morphological variation along their scleritome which is also composed of simple conical elements with uniform ornamentation. Several forms of Kelanella are similar to mitral and sellate sclerites of Camenella, whereas some other forms are comparable to Kennardia. The new material suggests that Kelanella occupies a transitional position between Lapworthellidae and the grouping of Tommotiidae and Kennardiidae. Such a phylogenetic position also implies that the number of sclerite morphotypes tends to decrease within the camenellan scleritome during evolution.
Pumped-Storage Solution towards Energy Efficiency and Sustainability: Portugal Contribution and Real Case Studies

This paper aims at presenting different pumped-storage solutions for improving the energy efficiency and economic sustainability of water systems. The assessment of pumped-storage solutions, either using fresh water or sea-water, is seen as a viable option to solve problems of energy production, as well as in the integration of intermittent renewable energies, providing system flexibility due to energy loads’ fluctuation, as long as the storage of energy from intermittent sources. Pumped-storage is one of the best and most efficient options in terms of renewable resources as an integrated solution allowing the improvement of the energy system elasticity and the global system efficiency. Two real case studies are presented: a fresh water system installed in a river dams—the Alqueva system, in Portugal—and a sea-water system in an arid region of the Cape Verde Islands in Africa. These cases demonstrate the benefits associated to pumped-storage solutions, depending on the storage volume capacity, operational rules and energy tariffs.
The UCLA-University of Utah epidemiologic survey of autism: genealogical analysis of familial aggregation.

To assess familial aggregation of autism, 86 autistic subjects were linked to the Utah Genealogical Database. Kinship coefficients were estimated for all possible pairs of autistic subjects and then averaged. Fifty replicate sets of matched control subjects (86 members in each set) were drawn randomly from the database, and the average kinship coefficient was computed for all possible pairs of individuals in each set. The average kinship coefficient for the autistic subjects was approximately 1/1,000, while the average kinship coefficients for the 50 control groups ranged from 4/100,000 to 1.6. /10,000. These results indicate a strong tendency for autism to cluster in families. When kinship was analyzed by specific degrees of relationship, it was shown that the familial aggregation of autism is confined exclusively to sib pairs and does not extend to more remote degrees of relationship. This finding indicates that a single-gene model is unlikely to account for most cases of autism.
Decadal Spinup of the South Pacific Subtropical Gyre

Abstract An increase in the circulation of the South Pacific Ocean subtropical gyre, extending from the sea surface to middepth, is observed over 12 years. Datasets used to quantify the decadal gyre spinup include satellite altimetric height, the World Ocean Circulation Experiment (WOCE) hydrographic and float survey of the South Pacific, a repeated hydrographic transect along 170°W, and profiling float data from the global Argo array. The signal in sea surface height is a 12-cm increase between 1993 and 2004, on large spatial scale centered at about 40°S, 170°W. The subsurface datasets show that this signal is predominantly due to density variations in the water column, that is, to deepening of isopycnal surfaces, extending to depths of at least 1800 m. The maximum increase in dynamic height is collocated with the deep center of the subtropical gyre, and the signal represents an increase in the total counterclockwise geostrophic circulation of the gyre, by at least 20% at 1000 m. A comparison of WOCE and.
Common millennial-scale variability of Antarctic and Southern Ocean temperatures during the past 5000 years reconstructed from the EPICA Dome C ice core

Measurements of the two water stable isotopes (dD and d18O) along EPICA (European Project for Ice Coring in Antarctica) Dome C ice core are combined with simple isotopic modelling (distillation models) to reconstruct the variability of both the site temperature (East Antarctica) and the moisture source temperature (nowadays probably the subantarctic Indian Ocean). We discuss the difference between the reconstructed site and source temperature pro” les with respect to the initial isotopic data. We show that (i) the early-Holocene optimum appears” rst in Antarctica and 800 years later in the Southern Ocean, and (ii) during the last 5000 years, the site and source temperatures co-vary at the centennial timescale. An 833-year periodicity is observed only on deuterium and site temperature and therefore probably of local origin.
Global monitoring of plankton blooms using MERIS MCI

The MERIS maximum chlorophyll index (MCI), measuring the radiance peak at 709 nm in water‐leaving radiance, indicates the presence of a high surface concentration of chlorophyll a against a scattering background. The index is high in ‘red tide’ conditions (intense, visible, surface, plankton blooms) and is raised when aquatic vegetation is present. A bloom search based on the MCI has resulted in the detection of a variety of events in Canadian, Antarctic and other waters round the world, as well as detection of extensive areas of pelagic vegetation (Sargassum spp.), previously unreported in the scientific literature. Since 1 June 2006, global MCI composite images, at a spatial resolution of 5 km, are being produced daily from all MERIS (daylight) passes of reduced resolution (RR) data. The global composites significantly increase the area now being searched for events, although the reduced spatial resolution may cause smaller events to be missed. This paper describes the composites and gives examples of plankton bloom events that they have detected. It also shows how the composites are affected by the South Atlantic anomaly (SAA), where cosmic rays impact the detectors of the MERIS instrument.
Anisotropic P‐wave attenuation measured from a multi‐azimuth surface seismic reflection survey

A system of aligned vertical fractures produces azimuthal variations in stacking velocity and amplitude variation with offset, characteristics often reported in seismic reflection data for hydrocarbon exploration. Studies of associated attenuation anisotropy have been mostly theoretical, laboratory or vertical seismic profiling based. We used an 11 common‐midpoint‐long portion of each of four marine surface‐seismic reflection profiles, intersecting each other at 45° within circa 100 m of a common location, to measure the azimuthal variation of effective attenuation, Q−1eff and stacking velocity, in a shallow interval, about 100 m thick, in which consistently orientated vertical fracturing was expected due to an underlying salt diapirism. We found qualitative and quantitative consistency between the azimuthal variation in the attenuation and stacking velocity, and published amplitude variation with offset results. The 135° azimuth line showed the least apparent attenuation (1000 Q−1eff= 16 ± 7) and the fastest stacking velocity, hence we infer it to be closest to the fracture trend: the orthogonal 45° line showed the most apparent attenuation (1000Q−1eff= 52 ± 15) and slowest stacking velocity. The variation of Q−1eff with azimuth φ is well fitted by 1000Q−1eff= 34 − 18cos[2(φ+40°)] giving a fracture direction of 140 ± 23° (±1SD, derived from ‘bootstrapping’ fits to all 114 combinations of individual common‐midpoint/azimuth measurements), compared to 134 ± 47° from published amplitude variation with offset data. The effects of short‐window spectral estimation and choices of spectral ratio bandwidth and offset ranges used in attenuation analysis, individually give uncertainties of up to ±13° in fracture direction. This magnitude of azimuthal variation can be produced by credible crack geometries (e.g., dry cracks, radius 6.5 m, aspect ratio 3 × 10−5, crack density 0.2) but we do not claim these to be the actual properties of the interval studied, because of the lack of well control (and its consequences for the choice of theoretical model and host rock physical properties) and the small number of azimuths available here.