Miracle-dz/UniFAR-FTUs huggingface dataset:
Using the historical atmospheric lead-deposition record as a chronological marker in sediment deposits in Europe

Atmospheric deposition of large-scale lead pollution has occurred for at least 3000 years in Europe. Metal production and smelting were the main sources until the twentieth century when emissions from vehicles using alkyl-leaded petrol became dominant. Analyses of lake-sediment and peat deposits in Sweden and other regions in Europe, as well as ice cores from Greenland, suggest synchronous temporal changes in past pollution deposition. Characteristic features in the atmospheric pollution fallout were caused by: the peak in lead pro duction during the Roman period; the marked Mediaeval increase in mining and metal production; the rapidly increasing use of cars and leaded gasoline after the second world war along with increased industrial emissions until around 1970, which was followed by a major improvement due to environmental legislation. For northern Europe at least, these characteristic changes can be used to determine, with reasonable accuracy, at which levels ad 0, ad 1000–1200 and ad 1970 are situated in lake-sediment deposits. To identify these levels, stable lead isotope analyses (206Pb/207Pb ratios) have proven to be very useful besides concentration determinations. Particularly useful are the isotope analyses in areas, such as Sweden, where the differences in 206Pb/207Pb ratios are large between the natural catchment lead and the pollution lead.
Using a Gridded Global Dataset to Characterize Regional Hydroclimate in Central Chile

AbstractCentral Chile is facing dramatic projections of climate change, with a consensus for declining precipitation, negatively affecting hydropower generation and irrigated agriculture. Rising from sea level to 6000 m within a distance of 200 km, precipitation characterization is difficult because of a lack of long-term observations, especially at higher elevations. For understanding current mean and extreme conditions and recent hydroclimatological change, as well as to provide a baseline for downscaling climate model projections, a temporally and spatially complete dataset of daily meteorology is essential. The authors use a gridded global daily meteorological dataset at 0.25° resolution for the period 1948–2008, adjusted by monthly precipitation observations interpolated to the same grid using a cokriging method with elevation as a covariate. For validation, daily statistics of the adjusted gridded precipitation are compared to station observations. For further validation, a hydrology model is driven.
Two competing pathways of aerosol effects on cloud and precipitation formation

Aerosols may influence cloud formation through two pathways: One is the effect on cloud microphysics by forming smaller and more numerous cloud droplets reducing precipitation and consequently enhancing cloud lifetime. The second is referred to as the aerosol dynamic‐hydrological effect in which the aerosol direct, semi‐direct, and indirect effects can modulate atmospheric radiation, which perturbs atmospheric circulation, leading to redistributions of clouds and precipitation. Here this study examines climate sensitivities using a general circulation model coupled with an aerosol transport‐radiation model. The model is run first with prescribed meteorology in order to isolate the cloud microphysical effect. It is run in a separate experiment with internally generated meteorology that includes dynamic‐hydrological effect as the aerosols modify clouds and interact with the radiation. We find in some regions that the dynamic‐hydrological effect in the free model runs counteracts the microphysical effects seen in the prescribed runs.
Thermal-infrared remote sensing and Kirchhoff's law: 2. Field measurements

Laboratory and field measurements of the spectral, directional emissivity of surfaces were compared to emissivities calculated from directional hemispherical reflectances to establish the apparent validity of Kirchhoff's law under terrestrial field conditions. The laboratory measurements confirmed results of an earlier experiment that showed that rocks and coarse particulate surfaces follow Kirchhoff's law in the 8 to 14 μm atmospheric window, whereas very fine particulates may not. However, laboratory measurements of samples heated from below are not an adequate simulation of field conditions. Nonetheless, field measurements demonstrated similar results for materials heated by the Sun. Apparent deviations from Kirchhoff's law of more than 0.04 were measured for fine-particulate (quartz) surfaces, dependent on the intensity of downwelling radiance from atmospheric water vapor and clouds. Examples of natural surfaces that may deviate from Kirchhoff's law include wind-blown dust deposits, fresh snow, frosts, and fine volcanic ash in the vicinity of explosive volcanism. Apparent deviations from Kirchhoff's law are caused by steep thermal gradients in the infrared skin depth. A new technique probed this vertical temperature structure, with a sensitivity of 0.2°C, revealing details of a 2°C temperature difference within the infrared-emitting region (the top ∼150 μm) of a fine-particulate surface.
Comparison of directly measured CCN with CCN modeled from the number-size distribution in the marine boundary layer during ACE 1 at Cape Grim, Tasmania

Cloud condensation nucleus concentration (CCN) was measured directly at a supersaturation of 0.5% with a thermal gradient diffusion cloud chamber at Cape Grim, Tasmania, during the First Aerosol Characterization Experiment (ACE 1) field study in November and December of 1995. Number-size distributions N(Dp) from 3 to 800 nm diameter and the hygroscopic properties of the aerosol in the 30 to 300 nm diameter range (which contains most of the CCN active at 0.5%) were measured concurrently at the same location. This data set provides a basis to compare measured and modeled CCN concentrations. A critical particle diameter that would form cloud droplets at 0.5% supersaturation was derived from the hygroscopic growth data including consideration of the hydration of the size distribution measurement. This empirically derived diameter incorporates the effects of soluble and insoluble mass as well as an effective van't Hoff factor and surface tension as described by Kohler theory for heterogeneous nucleation of cloud droplets. The size distributions were integrated for diameters greater than the critical value and compared to the directly measured CCN concentrations. The modeled CCN concentration was 95 cm−3 during baseline sector periods and 128 cm−3 overall. This was about 20% greater than the directly measured CCN concentration and well correlated (R2 = 0.7) with measured CCN. Two thirds of the CCN at 0.5% supersaturation derive from an accumulation mode (80 nm 200 nm) and the Aitken mode (Dp < 80 nm). The data include air masses from continental, anthropogenic, and biomass burning sources as well as the more dominant marine source.
Archaean felsic volcanism in the northeastern Yilgarn Block, Western Australia

Felsic volcanic rocks in the northeastern Yilgarn Block form two major groups with distinctive petrochemical characteristics and tectonic settings. Discrete calc‐alkaline volcanic centres composed predominantly of andesite were formed during the development of a major volcano‐sedimentary basin and were erupted contemporaneously with tholeiitic basalt. Parental calc‐alkaline melts were derived by shallow, hydrous partial melting of LIL‐enriched mantle; Y‐ and HREE‐depleted, Sr‐enriched dacitic volcanic rocks and dacite to rhyolite undepleted in Y and HREE and depleted in Sr associated with andesite in some of the volcanic centres were derived from an intermediate parent by crystal fractionation involving variable proportions of the modal minerals. Calc‐alkaline volcanism is believed to have been triggered by “hot spot’ activity rather than subduction. Rhyolite enriched in Zr, Nb, Y and HREE was deposited in a linear trough in a tectonic zone which disrupted the western margin of the volcano‐sedimentary bas.
Age and correlation of the Nimrod Group and other precambrian rock units in the central Transantarctic Mountains, Antarctica

Abstract Potassium-argon dates determined on hornblendes from amphibolites in the regionally metamorphosed gneisses and schists of the Nimrod Group at the head of the Nimrod Glacier range in age from 500 to 1,050 m.y. The younger dates agree with previously determined K—Ar ages on micas and probably indicate reheating of the metamorphic terrane during emplacement of the Granite Harbour Intrusives in the Ordovician. Precambrian ages clustered between 1,000 and 1,050 m.y. probably date the end of the regional metamorphism that is termed Nimrod Orogeny and is the earliest event known to have affected the Transantarctic Mountains. An event at about the same time has been recognised on the continental margin of east Antarctica between 90° E and 130° E and in western Queen Maud Land. Elsewhere it has been overprinted with loss of radiogenic argon and strontium by later events, especially the 450–520 m.y. Ross Orogeny. Late Precambrian orogenic activity, lasting between 620 and 680 m.y. , may also b recorded in t.
The Causes of City-Suburban Political Polarization? A Canadian Case Study

Recent research conducted in both the United States and Canada has found that residents of inner cities and suburbs are diverging in their voting behavior and political attitudes. The mechanisms producing such a divergence, however, have remained unclear. After identifying a set of distinct hypotheses for why one might expect residents of inner cities and suburbs to differ in their political views, this article draws on a survey undertaken by the author in one electoral district in the Toronto region to empirically test the relative contribution of each of the hypothesized mechanisms in explaining the geography of party preferences. This study suggests there is no single explanation for the city-suburban cleavage, and that the mechanisms producing it are complex. Spatial segregation (based on individual attributes such as race, ethnicity, and class) is clearly important; however neighborhood self-selection, local experience, and, to a lesser extent, mode of consumption all have significant independent effects. Particularly important is the self-selection of supporters of political parties on the left into the inner city, stemming either from a search for a “sense of community” or the desire to link their lifestyle choices to their political convictions, whereas supporters of parties farther to the right are more likely to choose postwar suburban neighborhoods out of a preference for private space. In contrast, there is little evidence that housing tenure or the sharing of political information between neighbors are factors independently producing city-suburban political differences within the study district.
Soil-Water Characteristic Curves of Stabilized Expansive Soils

The engineering properties of expansive soils are conventionally improved through the use of additives such as fly ash, lime, and chemical additives. Such soils are often referred to as stabilized or modified or treated expansive soils. The soil-water characteristic curves (SWCC) of two expansive soils from Texas were measured both in natural and stabilized conditions using the pressure plate apparatus in the suction range of 0-1,000 kPa. The SWCC results are used to interpret the expansive soil behavior due to stabilizer treatment. In addition, relationships were developed between the basic soil and stabilizer properties such as water content, dry density, liquid limit, plastic limit, and stabilizer dosages and the model constants of the SWCC formulation of Fredlund and Xing via multiple linear regression analysis. The analysis showed that higher coefficients of correlations can be achieved by using six independent soil properties. The comparisons between the predicted and measured volumetric water contents are within ±20% for ash-treated expansive soils, and within ±15% for combined ash- and fiber-treated expansive soils. The research data and interpretation analysis presented here can be extended to understand volume change behaviors of other stabilized expansive soils using the SWCC test data.
The Effect of Various Soil Hydraulic Property Estimates on Soil Moisture Simulations

Models of water movement in unsaturated soils require accurate representations of the soil moisture retention and hydraulic conductivity curves; however, commonly used laboratory methods and pedotransfer functions (PTFs) are rarely verified against field conditions. In this study, we investigated the effects of using soil hydraulic property information obtained from different measurement and estimation techniques on one‐dimensional model predictions of soil moisture content. Pairs of time domain reflectometry waveguides and tensiometers were installed at two depths in the side of a soil pit face to obtain in situ measurements. Undisturbed soil samples were taken near the instruments and subjected to particle size analysis, multistep outflow (MSO), and falling‐head permeability tests to obtain estimates of the soil moisture retention curves. Three scaling methods were then applied to improve the fit of the various estimates to the field data. We found that soil hydraulic property estimates obtained from inverse methods lead to the best simulations of soil moisture dynamics, and that laboratory MSO tests or commonly used PTFs perform poorly. These laboratory and PTF estimates can be dramatically improved, however, by simply constraining the range of possible moisture contents to the minimum and maximum measured in the field. It appears that this method of scaling PTF results can be used to obtain soil hydraulic property inputs of sufficient accuracy for plot‐scale modeling efforts without requiring expensive laboratory or in situ tests.
Strong evidence for non‐similar earthquake source scaling in central Italy

The scaling of earthquakes of the Central Apennines (Italy) is investigated using broadband seismograms from the Colfiorito sequence (4 ≤ MW ≤ 6). Our results are not consistent with self‐similar scaling, and can be described by the following relationship: M0 ∝ fc−(3 + ɛ), where ɛ = 1.7 ± 0.3. We speculate that dynamic fault lubrication by fluid pressurization may be responsible for such extreme behavior, and use our results for the calibration of a weak‐motion‐based predictive relationship for the ground motion (MW ≤ 4.1) up to MW ∼ 6 for this region.
A mantle plume model for the equatorial highlands of Venus

The Equatorial Highlands of Venus consist of four main structures, Atla, Beta, Ovda, and Thetis regiones. Each has a circular to oval-shaped planform and rises 4–5 km above the mean planetary radius. These highlands are associated with long-wavelength geoid highs, with amplitudes ranging from 35 m at Ovda to 120 m at Atla. They also contain topographic valleys, interpreted as extensional rift zones, and Beta is known to contain shield volcanoes. These characteristics are all consistent with the Equatorial Highlands being formed by mantle plumes. An alternative model, in which Ovda and Thetis are interpreted as spreading centers analogous to terrestrial mid-ocean ridges, fails to explain most of the observed geoid anomalies and topography in these regions. Some smaller highlands, such as Bell Regio, Eistla Regio, and the Hathor/Innini/Ushas region, may also be plume related, but most coronae are unlikely to be the direct result of plume activity. We have modeled plumes using a cylindrical, axisymmetric finite element code and a depth-dependent, Newtonian rheology. We compare our model results with profiles of geoid and topography across Atla, Beta, Ovda, and Thetis; our best model fits are for Beta and Atla. Assuming whole mantle convection and that Earth and Venus have similar mantle heat flows, Venus must lack an Earth-like low-viscosity zone in its upper mantle in order satisfy the observed geoid and topography for these features. This conclusion is consistent with the long-wavelength admittance spectrum of Venus and with the observed differences in the slopes of the geoid spectra for the two planets. One explanation for the different viscosity structures of the two planets could be that the mantle of Venus is drier than Earth's mantle.
Large-scale imaging of high-latitude convection with Super Dual Auroral Radar Network HF radar observations

The HF radars of the Super Dual Auroral Radar Network (SuperDARN) provide measurements of the E × B drift of ionospheric plasma over extended regions of the high-latitude ionosphere. With the recent augmentation of the northern hemisphere component to six radars, a sizable fraction of the entire convection zone (approximately one-third) can be imaged nearly instantaneously (∼2 min). To date, the two-dimensional convection velocity has been mapped by combining line-of-sight velocity measurements obtained from pairs of radars within common-volume areas. We describe a new method of deriving large-scale convection maps based on all the available velocity data. The measurements are used to determine a solution for the distribution of electrostatic potential, Φ, expressed as a series expansion in spherical harmonics. The addition of data from a statistical model constrains the solution in regions of no data coverage. For low-order expansions the results provide a gross characterization of the global convection. We discuss the processing of the radar velocity data, the factors that condition the fitting, and the reliability of the results. We present examples of imaging that demonstrate the response of the global convection to variations in the interplanetary magnetic field (IMF). In the case of a sudden polarity change from northward to southward IMF, the convection is seen to reconfigure globally on very short (<6 min) timescales.
Horizontal Response of Piles in Layered Soils

An inexpensive and realistic procedure is developed for estimating the lateral dynamic stiffness and damping of flexible piles embedded in arbitrarily layered soil deposits. Starting point is the determination of the pile deflection profile for a static force at the top using any reasonable method—beam‐on‐Winkler foundation, finite elements, well‐instrumented pile load tests in the field, etc. Material as well as radiation damping due to waves emanating at different depths from the pile‐soil interface are rationally taken into account; the overall equivalent damping at the top of the pile is then obtained as a function of frequency by means of a suitable energy relationship. The method is applied to study the dynamic behavior of three different piles embedded in two idealized and one actual layered soil deposit; the results of the method, obtained by hand computations, compare favorably with the results of three dimensional dynamic finite element analyses.
Vulnerability Assessment at Village Level Due to Tides, Surges and Wave Setup

An assessment of cyclone risk and vulnerability at the village level has evolved, which is an important component of the information system for local level development action plans for preparedness and mitigation. Here, a case study for the Nellore district along the east coast of India is considered. Using maximum probable surges along the coast, total water level (TWL) due to the combined effect of surge, tide, and wind wave is computed for the most vulnerable coastal villages of the Nellore district due to any tropical cyclones. The computations suggest that the TWL along the Nellore coast varies from 2 m in the south to 4 m in the north.
Dynamics of the Gulf Stream/deep western boundary current crossover. Part II: Low-frequency internal oscillations

Abstract A low-frequency oscillation in the Gulf Stream/deep western boundary current (DWBC) system is identified and its influences on several important aspects of the basin-scale circulation are investigated. An eddy-resolving regional primitive equation model is used to demonstrate that feedbacks between the Gulf Stream, with its associated northern and southern recirculation gyres, and the upper core of the DWBC can lead to self-sustaining large amplitude internal oscillations of roughly decadal frequency. The oscillator cycle is described as follows: The upper core of the DWBC is entrained under the Gulf Stream through interaction with the eddy-driven northern and southern recirculation gyres, as described in Part I of this study. Once entrained, the low potential vorticity DWBC water stabilizes the Gulf Stream and suppresses the eddy fluxes that maintained the interior recirculation gyres. This causes the upper DWBC to switch to a southward path along the western boundary, thus removing the source o.
Low‐temperature oxidation in MORB of titanomagnetite to titanomaghemite: A gradual process with implications for marine magnetic anomaly amplitudes

Mid-ocean ridge basalt (MORB) samples, varying in age from Recent to Jurassic, were selected for electron microscopic and rock magnetic studies. Our observations indicate that the degree of oxidation of titanomagnetite in MORB increases only gradually with sample age. The titanomagnetite in recent MORB ( 100 ka). Both electron microscopic observations and rock magnetic data support the notion that low-temperature oxidation of titanomagnetite to titanomaghemite in MORB is a gradual process. Moreover, the rate of maghemitization is controlled by many factors on both macroscopic and microscopic scales, including regional oceanic crustal structures, lithological features, grain size, and surrounding matrices. Pillow lavas and the tops of massive flows tend to have higher degrees of oxidation than the interiors of massive flows, owing to higher porosity and permeability of the former. In contrast, interstitial glass can protect fine titanomagnetite grains from alteration. The natural remanent magnetization (NRM) intensity of MORB varies as a function of age, magnetic granulometry, concentration of magnetic materials, and the degree of alteration. Fine-grained MORB samples typically have higher NRM intensity. The NRM intensity appears to decrease substantially with increasing degree of maghemitization and, hence, with age. The envelope of the smoothed magnetic anomaly amplitudes resembles the change in NRM intensity for MORB samples of the last 30 million years, but the underlying assumption that the highest degree of maghemitization observed in the samples of a given age is entirely responsible for these intensity changes is not supported. Maghemitization of the micrometer-sized and larger grains is probably only partly responsible, whereas a significant contribution to NRM intensities is inferred from those submicrometer-sized titanomagnetite grains that remained protected from oxidation by the surrounding matrix of interstitial glass.
Cathodoluminescence of calcite decomposed from dolomite in high–temperature skarn

Purple – cathodoluminescent calcite associated with periclase and survival dolomite has been found from the skarn minerals in the Kanehira mine located in the eastern part of Hiroshima Prefecture. Paragenesis of these minerals suggests that the decomposition of dolomite at 700 – 750 °C under dry condition during skarnitization could promote the production of characteristic calcite. Cathodoluminescence (CL) spectroscopy of the calcite reveals its blue emissions related to defect centers possibly derived from its origin, also similar CL features in the dolomite. Spectral deconvolution of the CL in the calcite and dolomite clari ﬁ ed two emission components at 2.67 and 3.30 eV, of which former corresponds to structural defect by thermally – in ﬂ uenced stress and the latter to intrinsic defect comparable to ‘ back ground blue ’ previously reported in calcite. The facts imply that the calcite with purple CL might leave the defects in its structure during thermal decomposition of dolomite at relatively high – temperature skarnization.