Miracle-dz/UniFAR-FTUs huggingface dataset:
A volcanotectonic survey of Ascraeus Mons, Mars

[1] Ascraeus Mons is one of the largest volcanoes on Mars. It is replete with well-preserved features that can be used to understand its volcanotectonic evolution. Previous studies of this volcano focused on specific features, and were limited by the quality and coverage of contemporary data. Our objective is to review and enhance the existing developmental model for Ascraeus by considering all endogenic surface features on the volcano. We surveyed the volcano's caldera complex, flank terraces, pit structures, sinuous rilles, arcuate grabens, and small vents. We report the spatial and temporal distributions of these features, appraise their proposed formation mechanisms in light of our mapping results, and propose a detailed geological history for Ascraeus Mons. An initial shield-building phase was followed by the formation of a summit caldera complex and small parasitic cones, while compression due to flexure of the supporting basement led to extensive terracing of the shield flanks. An eruptive hiatus followed, ending with the construction of expansive rift aprons to the northeast and southwest. Against later, extensive flank resurfacing in the late Amazonian, continued flexure formed arcuate grabens concentric to the edifice. Localized eruption and surface flow of a fluid agent (lava and/or water) from within the volcano then produced a population of rilles on the lower flanks. Finally, in a change of flank tectonic regime from compression to extension, pit crater chains and troughs developed on the main shield and rift aprons, eventually coalescing to form large embayments at the northeast and southwest base of the volcano.
Haze Days in North China and the associated atmospheric circulations based on daily visibility data from 1960 to 2012

Haze is a severe hazard that greatly influences traffic and daily life with great economic losses and threats to human health. To enhance understanding of the haze occurrences, this study examined the haze variations over North China and their associated atmospheric circulations for the period of 1960–2012 using daily visibility data. Results indicate that the haze events over this region primarily occur in boreal winter of year and mainly in the morning of day. The results of the analysis of the long‐term variations indicate that the annual haze days were relatively few in the 1960s but increased steeply in the 1970s and have remained stable to the present. Some differences are obvious among seasons. A stably increasing trend is discernable in summer and autumn, relatively low in the 1960s and the 1990s–2000s and relatively high in the 1970s–1980s in spring and winter. Haze variations in urban regions are quite similar to haze variations in rural regions but with more haze days in urban regions because of the high aerosol emissions. Further analyses indicate that the occurrences of severe haze events in boreal winter generally correlate with the weakened northerly winds and the development of inversion anomalies in the lower troposphere, the weakened East Asian trough in the midtroposphere, and the northward East Asian jet in the high troposphere. All of these factors provide a favorable atmospheric background for the maintenance and development of haze events in this region.
Product‐error‐driven generator of probable rainfall conditioned on WSR‐88D precipitation estimates

The existence of large errors in precipitation products delivered by the network of Weather Surveillance Radar, 1988 Doppler (WSR‐88D) radars is broadly recognized. However, their quantitative characteristics remain poorly understood. Recently, the authors developed a functional‐statistical model that quantifies the relation between radar rainfall and the corresponding true rainfall in a way that is applicable to the probabilistic quantitative precipitation estimation planned for future use by the U.S. National Weather Service. The model consists of a deterministic distortion function and a random uncertainty factor, both conditioned on given radar rainfall values. It also accounts for the spatiotemporal correlations in the random uncertainty factor. The model components were estimated on the basis of a 6‐year‐long data sample that considers the effects of seasons, range from radar, and time scales. In this study, the authors present two different applications of the aforementioned uncertainty model: (1) the estimation of rainfall probability maps and (2) the generation of radar rainfall ensembles. In the former, maps of the rainfall exceedance probability for any threshold are produced, given a radar rainfall map. We also present the analytical derivation of the exceedance probability maps at coarser spatial scales. In the latter, the users can generate ensembles of probable true rainfall fields that are consistent with the observed radar rainfall and its error structure. Simulation of the random component is based on the Cholesky decomposition method. Finally, the authors discuss possible uses of these applications in hydrology and hydroclimatology.
Dissolved organic carbon distribution and origin in the Nordic Seas: Exchanges with the Arctic Ocean and the North Atlantic

[1] Dissolved organic carbon (DOC) and in situ fluorescence were measured along with hydrographic parameters in the Greenland, Iceland, and Norwegian Seas (Nordic Seas). Surface ( 1000 m) were relatively high (∼50 μM DOC) compared with other ocean basins indicating active vertical transport of DOC in this region on decadal timescales. Based on existing vertical transport estimates and 15 μM of semilabile DOC we calculated an annual vertical net DOC export of 3.5 Tg C yr−1 in the Greenland Sea and about 36 Tg C yr−1 for the entire Arctic Mediterranean Sea (AMS) including the Greenland-Scotland Ridge overflow. It appears that physical processes play a determining role for the distribution of DOC in the AMS.
VELOCITY AND CONCENTRATION DISTRIBUTIONS OF SEDIMENT‐LADEN OPEN CHANNEL FLOW 1

ABSTRACT: A mathematical model to predict both velocity and concentration distributions for sediment‐laden open channel flow is developed. Velocity profiles are derived by theoretical analysis and numerical method. Logarithmic law and semi‐empirical wake function concept are not adopted. An empirical equation for the ratio of sediment exchange and fluid diffusion coefficients is considered to solve the diffusion equation for suspended‐sediment concentration profiles. Four sets of experimental data from previous researchers are compared to numerical calculation. In the engineering applications, velocity and concentration profiles of sediment‐laden flow can be predicted simultaneously by the present model with the measured velocity and sediment‐concentration at reference level.
Evaluation of uneven water resource and relation between anthropogenic water withdrawal and ecosystem degradation in Changjiang and Yellow River basins

The diverse hydro‐climate between northern and southern China causes serious complications related to increasing food demand, declining water availability, and increasing flood risk in Changjiang and Yellow River basins. The huge projects of Three Gorges Dam (TGD) for diminishing flood and South‐to‐North Water Transfer Project (SNWTP) for driving water from Changjiang to Yellow and Hai Rivers to compensate for an imbalance of environmental resources will not necessarily solve all of the problems that they were originally intended to address. A sophisticated eco‐hydrological model is required to evaluate the optimum amount of transferred water associated with these projects, together with socio‐economic and environmental consequences. For this purpose, the process‐based National Integrated Catchment‐based Eco‐hydrology (NICE) model was modified to couple with complex sub‐systems in irrigation, stream junction, reservoir operation, and water transfer, to develop coupled human and natural systems and evaluate cause and effect of uneven water resources. The model clarified the impact of irrigation on eco‐hydrological processes and predicted hydrologic change after TGD and SNWTP to estimate whether dilemmas between water stress, crop productivity, and ecosystem degradation would diminish. The result also showed the missing role of surface water – groundwater interactions and lateral subsurface flow, usually not considered important by assuming stationarity in previous researches of continental scales. A heterogeneous pattern of Time‐Integrated Normalized Difference Vegetation Index gradient in agricultural fields helped to estimate uneven crop yield and its relation to water availability. This integrated approach will have some roles not only to re‐consider this complex process from the view point of hydrologic and biogeochemical cycles, but also to clarify how the substantial pressures of complicated problems can be overcome by effective trans‐boundary solutions. Copyright © 2013 John Wiley & Sons, Ltd.
El sinrift de la dorsal de Huincul, Cuenca Neuquina: evolucióny control sobre la estratigrafía y estructura del área

The synrift of the Huincul High, Neuquen Basin: Evolution and control on the stratigraphy and structure of the area. The Huincul High constitutes an outstanding E-W morpho-structural feature that splits the Neuquen Basin into two, it spans for more than 250 km from the Andean orogenic front, eastwards to the General Roca area. It is composed by a trend of E-W oriented, strongly asymmetric and south verging anticlines with a vertical throw exceeding 1.5 km. The evolution of the Huincul High began with the development of a series of NW oriented half-grabens, typically with the downthrown block to the north; this tendency shifts in the eastern end to more WNW-ENE oriented half grabens. They are normally 10 to 20 km long in strike direction with a 1.5 to 5 km thick infill of Upper Triassic to Lower Toarcian deposits. The morphology previous to the first marine transgressions during Early Jurassic times was of a series of half-grabens whose relief had been partly leveled by the volcanic and clastic deposits of the Precuyano; besides prominent basement highs and volcanic edifices controlled the distri- bution of the Jurassic marine sediments. The influence of the rift subsidence is well documented until Early Toarcian times; afterwards the area went through a period of relative tectonic quiescence accompanied by the progradation of the depositio- nal systems from the south regardless of the underlying structural features. The development of a compressive system span- ning from the Upper Jurassic to the Upper Cretaceous gave the Huincul High its present day configuration.
ACCURACY AND CONSISTENCY OF WATER‐CURRENT MIETERS 1

ABSTRACT: The measurement of discharge in natural streams requires hydrographers to use accurate meters that have consistent performance among meters of the same model. This paper presents the results of an investigation into the accuracy and consistency of four models of current meters‐Price Type‐AA, Price Pygmy, Marsh McBirney 2000, and Swoffer 2100. Test results for six meters of each model are presented. Variation of meter performance within a model is used as an indicator of consistency, and percent velocity error that is computed from a measured reference velocity is used as an indicator of meter accuracy. Velocities measured by each meter are also compared to the manufacturer's published or advertised accuracy limits. The investigation found the Price models to be more accurate and consistent than the other models. The Price models met their respective accuracy limits over the range of test velocities better than the other models. The Marsh McBirney model usually measured within its accuracy specification. The Swoffer meters did not meet the stringent Swoffer accuracy limits for all the velocities tested. The Swoffer model had accuracies similar to the Price Type‐AA model when individual meter rating equations were computed and used. Every model tested had meters that did not meet manufacturer accuracy limits. Because current meters are not consistently accurate within a model, hydrographers should periodically check meters against a velocity standard.
A new blowup criterion of strong solutions to the two‐dimensional equations of compressible nematic liquid crystal flows

In this paper, we concern the Cauchy problem of two‐dimensional (2D) compressible nematic liquid crystal flows with vacuum as far‐field density. Under a geometric condition for the initial orientation field, we establish a blowup criterion in terms of the integrability of the density for strong solutions to the compressible nematic liquid crystal flows. This criterion generalizes previous results of compressible nematic liquid crystal flows with vacuum, which concludes the initial boundary problem and Cauchy problem.
Graphite as a lubricating agent in fault zones: An insight from low‐ to high‐velocity friction experiments on a mixed graphite‐quartz gouge

Graphite is a very low friction material, often enriched within fault zones due to mechanical or chemical processes. The effects of weak minerals on the strength of faults have been examined by friction experiments on bimineralic mixtures. However, previous experiments were conducted with limited shear strains, even though applied shear strains and textural developments had already been signaled as significant factors in the weakening of faults. We therefore conducted large‐displacement, low‐ to high‐velocity friction experiments with graphite‐quartz gouges, to determine how much graphite is needed to reduce frictional strength, and to examine how textures contribute to the strength reduction of a mature fault at various slip rates. We found that the coefficients of friction of the gouges decrease nonlinearly with increasing graphite fraction for any given shear strain and slip rate, decreasing first with 5–20 vol% graphite, then reaching similar frictional levels to pure graphite with 30–50 vol% graphite. The nonlinear weakening trends can be fitted by sigmoidal curves. The weakening with 10–30 vol% graphite is associated with zones of slip‐localization and the development of a graphite‐lubricated penetrative slip surface(s). With increasing shear strain, the relationship between strength and graphite fraction evolves abruptly from an early gentle curve to a sigmoidal curve, and the frictional strength drops significantly even with small amounts of graphite (~10 vol%). Our results highlight the importance of shear strain and textural developments on weak faults, not only with respect to graphite, but also other fault lubricants such as the phyllosilicates.
Agricultural Intensification and Rural Sustainable Livelihoods: a 'Think Piece'

This paper examines agricultural intensification as a strategy for achieving sustainable livelihoods, comparing evidence from a number of areas that have undergone such a process in particular, the introduction of Green Revolution methods. Noting the variable impact the Green Revolution has had on different regions, crops and individuals, it reviews the explanations for these differences provided in the literature. The paper outlines the key conceptual questions surrounding intensification, setting them within the context of the broader environment and population debate. Citing evidence from Africa and Asia that challenges the simplistic assumption that population growth and environmental degradation necessarily go hand in hand, it demonstrates the complexity of the processes at work and discusses the importance of institutional factors, such as land tenure, in determining whether intensification is sustainable in the longer term.
Astronomical markings at three sites on Fajada Butte.

A seven-year study of prehistoric Pueblo sites of the Chaco culture has revealed that these people possessed a sophisticated astronomy. Evidence of this prehistoric astronomy consists of multiple light markings on petroglyphs and of several alignments of major structures. This paper presents the results of a recent study of 13 markings at three sites on Fajada Butte in Chaco Canyon, New Mexico; these results are presented in the context of earlier research in this area. Each marking is a distinctive pattern of shadow and light that appears on a petroglyph at a key point in the solar or lunar cycle, i.e., at an extreme or midposition of these cycles, including the meridian passage of the sun at solar noon. [Note: times quoted throughout this chapter are in apparent solar time, in which noon occurs each day when the sun is due south on the meridian. The basic astronomical concepts used here are explained in Aveni (1980) and Krupp (1977). ] Many of the markings simultaneously record two key points in different cycles, such as noon and solstice or noon and equinox. A minimum of 17 key points are indicated by the markings at these three sites.
Temporal controls on dissolved organic matter and lignin biogeochemistry in a pristine tropical river

[1] Dissolved organic carbon (DOC), lignin biomarkers, and the optical properties of dissolved organic matter (DOM) were measured in the Epulu River (northeast Democratic Republic of Congo) with the aim of investigating temporal controls on the quantity and chemical composition of DOM in a tropical rainforest river. Three different periods defined by stages of the hydrologic regime of the region, (1) post dry flushing period, (2) intermediary period, and (3) start of the dry period/post flush, were sampled. Temporal variability in DOM quantity and quality was observed with highest DOC, lignin concentration (Σ8) and carbon-normalized (Λ8) values during the flushing period attributed to greater surface runoff and leaching of organic-rich horizons, with lowest values in the dry period/post flush once source materials were well leached. Chromophoric DOM (CDOM) was strongly correlated to DOC and Σ8 (r2 = 0.85 and 0.83, respectively; p < 0.001), and CDOM quality measurements (SUVA254, spectral slope ratio and fluorescence index) were strongly correlated to Λ8 values (r2 = 0.77, 0.69, and 0.75, respectively; p < 0.001), demonstrating the ability to derive DOC and lignin export and to track DOM quality in tropical riverine systems from simple optical measurements. This study demonstrates similar effects in the variability of DOM quantity and quality due to changing hydrologic inputs for a tropical river as has been previously reported for temperate and northern high-latitude rivers. Therefore, flushing periods in tropical rivers warrant further study, as they are critical toward understanding ecosystem biogeochemistry as maximal export of freshly leached plant material occurs during this time period.
Pain behavior and phenotype in a modified anterior lumbar disc puncture mouse model

Abstract Background An experimental study was performed to improve the anterior approach model of intervertebral disc degeneration (IVDD). Objective The aims of this study were to investigate the anterior approach model of IVDD for the cause of death, phenotypes, and underlying mechanisms of low back pain in mice. Method In this study, we conducted an anterior puncture procedure on a cohort of 300 C57BL/6J mice that were 8 weeks old. Our investigation focused on exploring the causes of death in the study population (n = 300) and assessing the time‐course changes in various parameters, including radiographical, histological, immunofluorescence, and immunohistochemistry analyses (n = 10). Additionally, we conducted behavioral assessments on a subset of the animals (n = 30). Results Transverse vertebral artery rupture is a major factor in surgical death. Radiographical analyses showed that the hydration of the nucleus pulposus began to decrease at 2 weeks after puncture and obviously disappeared over 4 weeks. 3D‐CT showed that disc height was significantly decreased at 4 weeks. Osteophyte at the anterior vertebral rims was observed at 2 weeks after the puncture. As the time course increased, histological analyses showed progressive disruption of the destruction of the extracellular matrix and increased secretion of inflammatory cytokines and apoptosis. Behavioral signs of low back pain were increased between the puncture and sham groups at 4 weeks. Conclusion The improvement of anterior intervertebral disc approach model in mice will be useful to investigate underlying mechanisms and potential therapeutic strategies for behavior and phenotypes. Furthermore, the application of vibrational pre‐treatment can be used to increase the sensitivity of axial back pain in the model, thereby providing researchers with a reliable method for measuring this critical phenotype.
Assessing aeolian beach‐surface dynamics using a remote sensing approach

A remote sensing technique for assessing beach surface moisture was used to provide insight into beach‐surface evolution during an aeolian event. An experiment was carried out on 21 October 2007 at Greenwich Dunes, Prince Edward Island National Park, Canada, during which cameras were mounted on a mast on the foredune crest at a height of about 14 m above the beach. Maps of beach surface moisture were created based on a calibrated relationship between surface brightness from the photographs and surface moisture content measured in situ at points spaced every 2.5 m along a transect using a Delta‐T moisture probe. A time sequence of maps of surface moisture content captured beach surface evolution through the transport event at a spatial and temporal resolution that would be difficult to achieve with other sampling techniques such as impedance probes. Erosion of the foreshore and berm crest resulted in an increase in surface moisture content in these areas as the wetter underlying sediments were exposed. Flow expansion downwind of the berm crest led to sand deposition and a consequent decrease in surface moisture content. Remote sensing systems such as the one presented here allow observations of the combined evolution of beach surface moisture, shoreline position, and fetch distances during short‐term experiments and hence provide a comprehensive rendering of sediment erosion and transport processes. Copyright © 2012 John Wiley & Sons, Ltd.
EVIDENCE FOR RECENT NEAR-CATASTROPHIC COLLISION ON LARGE CHONDRITIC METE-

Northwest Africa (NWA) 869 represents one of the largest meteorite finds from the Saharan desert. It consists of thousands of fusion-crusted individuals from less than one gram up to more than 20 kilograms with an estimated total weight on the order of 7 metric tons. This meteorite was initially classified as an L4-6 fragmental breccia, but was recently reclassified as an L3-6 chondrite breccia [1]. Noble gas measurements revealed that NWA 869 contains solar gases [2] and hence is a regolith breccia. Since the abundance of regolith breccias among L-chondrites is only ~3% [3], NWA 869 represent a rather unique and large sample of the lithified regolith of the L-chondrite parent body. In this paper, we present concentrations of noble gases and cosmogenic radionuclides on bulk samples and separated lithologies. With this information we determine the irradiation history (transit time, shield-ing depths) of the meteoroid during transit from par-ent body to Earth and the irradiation history of its breccia components on the parent asteroid prior to lithification. In addition, we used