Miracle-dz/UniFAR-FTUs huggingface dataset:
Understanding a submarine eruption through time series hydrothermal plume sampling of dissolved and particulate constituents: West Mata, 2008–2012

Four cruises between 2008 and 2012 monitored the continuing eruption of West Mata volcano in the NE Lau Basin as it produced plumes of chemically altered water above its summit. Although large enrichments in 3He, CO2, Fe, and Mn were observed in the plumes, the most notable enrichment was that of H2, which reached concentrations as high as 14,843 nM. Strongly enriched H2 concentrations in the water column result from reactions between seawater or magmatic water and extremely hot rocks. In 2008, the observation of elevated H2 concentrations in the water column above West Mata pointed to vigorous ongoing eruptions at the volcano's summit. The eruption was confirmed by visual observations made by the ROV Jason 2 in 2009 and demonstrated that H2 measurements are a vital instrument to detect ongoing volcanic eruptions at the seafloor. Elevated H2 in 2010 showed that the eruption was ongoing, although at a reduced level given a maximum H2 concentration of 4410 nM. In 2012, H2 levels in the water column declined significantly, to a maximum of only 7 nM, consistent with visual observations from the Quest‐4000 ROV that found no evidence of an ongoing volcanic eruption. Methane behaved independently of other measured gases and its concentrations in the hydrothermal plume were very low. We attribute its minimal enrichments to a mixture of mantle carbon reduced to CH4 and biological CH4 from diffuse flow sites. This study demonstrates that ongoing submarine volcanic eruptions are characterized by high dissolved H2 concentrations present in the overlying water column.
Fault-zone guided waves from explosions in the San Andreas fault at Parkfield and Cienega Valley, California

Fault-zone guided waves were successfully excited by near-surface explosions in the San Andreas fault zone both at Parkfield and Cienega Valley, central California. The guided waves were observed on linear, three-component seismic arrays deployed across the fault trace. These waves were not excited by explosions located outside the fault zone. The amplitude spectra of guided waves show a maximum peak at 2 Hz at Parkfield and 3 Hz at Cienega Valley. The guided wave amplitude decays sharply with observation distance from the fault trace. The explosion-excited fault-zone guided waves are similar to those generated by earthquakes at Parkfield but have lower frequencies and travel more slowly. These observations suggest that the fault-zone wave guide has lower seismic velocities as it approaches the surface at Parkfield. We have modeled the waveforms as S waves trapped in a low-velocity wave guide sandwiched between high-velocity wall rocks, resulting in Love-type fault-zone guided waves. While the results are nonunique, the Parkfield data are adequately fit by a shallow wave guide 170 m wide with an S velocity 0.85 km/sec and an apparent Q ∼ 30 to 40. At Cienega Valley, the fault-zone wave guide appears to be about 120 m wide with an S velocity 0.7 km/sec and a Q ∼ 30.
What is Abductive Inference?

Abductive reasoning: constitutes according to Peirce the "first stage" of scientific inquiries (CP 6.469) and of any interpretive processes. "Abduction" is the process of adopting an explanatory hypothesis (CP 5.145) and covers two operations: the selection and the formation of plausible hypotheses. As process of finding premisses, it is the basis of interpretive reconstruction of causes and intentions, as well as of inventive construction of theories.
A New Perspective on the Climate Prediction of Asian Summer Monsoon Precipitation

Abstract A new paradigm for climate (one month and longer) prediction is developed and is applied to the 5-day-averaged Asian summer monsoon (ASM) precipitation. The foundation of the method is to identify climate signals (deterministic components) that constitute the ASM system and predict the temporal fluctuations of the amplitudes (stochastic components) of the individual signals. Climate signals were identified via cyclostationary empirical orthogonal function (CSEOF) analysis of the Xie–Arkin pentad precipitation in this study and include the annual cycle, El Nino/La Nina, and the intraseasonal oscillations of the 40–50-day period band (the Madden–Julian oscillation). Prediction is much facilitated by forecasting the slowly undulating amplitude time series of each climate signal rather than the raw precipitation data directly. The new prediction method results in reasonable forecasts of the pentad precipitation for the test period of 1999–2001. Specifically, the propagation of the intraseasonal oscil.
ISOTOPIC COMPOSITION OF CALCRETE DEPOSITS FROM EUROPE, AFRICA AND INDIA

SUMMARY The four models postulated for the formation of calcrete layers all involve the three-stage process: provision of a carbonate-rich solution, the movement of that solution and the precipitation of solid carbonate, The last step originates from either or both of two main alternatives: loss of C02 out of the solution increasing the pH and consequently the C0:- concentration, or evaporation of the water effecting an increase in the ionic concentration. This paper presents theoretical calculations for the isotopic composition of the carbonate resulting from these two alternative processes. The isotopic composition of calcrete deposits from France, Spain, Italy, Libya, Cyprus, Kenya, Morocco, South Africa and India are compared with the theoretical models. The calcrete samples from Spain, Cyprus and India are probably the result of evaporation processes.
High‐temperature deformation and recrystallization: A variational analysis and its application to olivine aggregates

We develop a framework for a variational analysis of microstructural evolution during inelastic high‐temperature deformation accommodated by dislocation mechanisms and diffusive mass transport. A polycrystalline aggregate is represented by a distribution function characterizing the state of individual grains by three variables, dislocation density, grain size, and elastic strain. The aggregate's free energy comprises elastic energy and energies of lattice distortions due to dislocations and grain boundaries. The work performed by the external loading is consumed by changes in the number of defects and their migration leading to inelastic deformation. The variational approach minimizes the rate of change of free energy with the evolution of the state variables under constraints on the aggregate volume, on a relation between changes in plastic strain and dislocation density, and on the form of the dissipation functionals for defect processes. The constrained minimization results in four basic evolution equations, one each for the evolution in grain size and dislocation density and flow laws for dislocation and diffusion creep. Analytical steady state scaling relations between stress and dislocation density and grain size (piezometers) are derived for quasi‐homogeneous materials characterized by a unique relation between grain size and dislocation density. Our model matches all currently available experimental observations regarding high‐temperature deformation of olivine aggregates with plausible values for the involved micromechanical model parameters. The relation between strain rate and stress for olivine aggregates maintaining a steady state microstructure is distinctly nonlinear in stark contrast to the majority of geodynamical modeling relying on linear relations, i.e., Newtonian behavior.
Thinning and retreat of Glaciar Upsala, and an estimate of annual ablation changes in southern Patagonia

Glaciar Upsala, a freshwater calving glacier in southern Patagonia, has been retreating since 1978, and after a drastic recession of about 700 m a−1 in 1994 the retreat seems to have stopped in 1995. A large ice-thinning rate of 11 m a−1 was obtained between 1990 and 1993, by surveying surface elevations near the terminus of Glaciar Upsala. In 1993–94, the thinning was estimated at about 20 m a−1 near the lateral margin. Some possible causes of the thinning behavior are considered. In the ablation area of Glaciar Perito Moreno, 50 km south of Glaciar Upsala, ablation rates were measured during 110 d in summer 1993–94, and air temperature was continuously recorded throughout 1994. Using a degree-day method with temperature data at the nearest meteorological station, Calafate, annual ablation during the last 30 years was estimated to fluctuate from about 12 ± 2 to 16 ± 2 m a−1 in ice thickness, with a mean of 14 ± 2 m a−1. Thus, the temperature anomaly alone cannot elucidate the thinning of 11 m a−1 at Glaciar Upsala. As a possible mechanism of the ice-thinning, it is suggested that the considerable retreat due to calving may have resulted in reduction of longitudinal compressive stress exerted from bedrock rises and islands near the glacier front, causing a considerable decrease in the emergence flow. Thus, the ice may have thinned at a rate close to the annual ablation rate.
Global distribution of equatorial magnetosonic waves observed by THEMIS

We investigate the wave magnetic field data from three THEMIS spacecraft over the recent 31 months to perform a statistical study of equatorial magnetosonic (MS) wave properties and spatial distribution. The THEMIS spacecraft provide good data coverage in the dominant MS wave region near the equator and at 2≤L≤8. Our global survey shows that strong amplitudes and high occurrence of MS waves are generally observed near the equator, outside the plasmapause, on the dawnside during geomagnetically disturbed periods. In addition, increase of geomagnetic activity shifts the MS wave distribution toward earlier magnetic local time. Strong MS waves generally have RMS wave amplitudes ∼50 pT and an occurrence rate ∼20% on the dawnside outside the plasmapause and could therefore have an important influence on both ring current ion and energetic electron dynamics in the Earth's radiation belts.
Application of Satellite SAR Imagery in Mapping the Active Layer of Arctic Permafrost

A method of mapping the active layer of Arctic permafrost using a combination of conventional synthetic aperture radar (SAR) backscatter and more sophisticated interferometric SAR (INSAR) techniques is proposed. The proposed research is based on the sensitivity of radar backscatter to the freeze and thaw status of the surface soil, and the sensitivity of INSAR techniques to centimeter- to sub-centimeter-level surface differential deformation. The former capability of SAR is investigated for deriving the timing and duration of the thaw period for surface soil of the active layer over permafrost. The latter is investigated for the feasibility of quantitative measurement of frost heaving and thaw settlement of the active layer during the freezing and thawing processes. The resulting knowledge contributes to remote sensing mapping of the active layer dynamics and Arctic land surface hydrology.
Effect of post-fire defoliation on growth of two native grasses in the Caldenal, Argentina

Plant growth in semiarid rangelands may be affect - ed by time grazing is excluded during the post-fire regeneration period. The objective of this field work was to study the effect of post-fire defoliation at different phenological stages (vegetative (early-season defoliation) and internode elongation (late-season defoliation)) on growth of Piptochaetium napostaense and Poa ligu- laris, two very important perennial native grasses in the temperate semi-arid region of central Argentina (Caldenal). In general, the post-fire defoliation treatments did not affect the number of green leaves on tillers of P. napostaense. Early-season post-fire defoliation generally reduced the number of green leaves on tillers of P. ligularis in comparison to those in control plants. Late-season defoliation, however, usually increased the number of green leaves on tillers of P. ligularis. Nevertheless, very few significant (p 0.05) than values on non-defoliated plants, respectively. Immediately after early- and late-season defo- liation treatments, relative growth rates for tiller height and total green length were reduced (p<0.05) on plants of both species with respect to control plants. Our results suggest that a one-year-period without severe defoliations after fire would be at least necessary for not risking the persistence of these perennial grasses in the Calde- nal community.
Oxygen and Asteroids

Hundreds of thousands of asteroids have been discovered in the asteroid belt and in near-Earth space. Oxygen is an abundant element in meteorites and presumably in most asteroids. Spectral reflectance measurements of asteroids in the visible and near-infrared can identify oxygen-bearing minerals such as those found in the olivine, pyroxene, and serpentine groups due to their distinctive absorption features. Interpretation of the mineralogy of asteroids is complicated by the effects of space weathering, which tends to redden and darken the surfaces of asteroids. Asteroids are primarily classified into a number of taxonomic classes and subclasses according to their spectral properties in the visible wavelength region. However, asteroids with similar spectral properties in the visible may have different spectral properties in the near-infrared and, therefore, different interpreted mineralogies. Definite trends in the abundances of different taxonomic classes versus heliocentric distance are apparent. These trends appear to be a function of both composition differences and degree of heating. However, dynamical processes have significantly affected these trends. Close observation of asteroids by spacecraft, such as NEAR-Shoemaker to 433 Eros and Hayabusa to 25143 Itokawa, are currently the best way to discern the mineralogies of individual asteroids.
Laboratory soil piping and internal erosion experiments: evaluation of a soil piping model for low‐compacted soils

Mechanistic models have been proposed for soil piping and internal erosion on well‐compacted levees and dams, but limited research has evaluated these models in less compacted (more erodible) soils typical of hillslopes and streambanks. This study utilized a soil box (50 cm long, 50 cm wide and 20 cm tall) to conduct constant‐head, soil pipe and internal erosion experiments for two soils (clay loam from Dry Creek and sandy loam from Cow Creek streambanks) packed at uniform bulk densities. Initial gravimetric moisture contents prior to packing were 10, 12 and 14% for Dry Creek soil and 8, 12, and 14% for Cow Creek soil. A 1‐cm diameter rod was placed horizontally along the length of the soil bed during packing and carefully removed after packing to create a continuous soil pipe. A constant head was maintained at the inflow end. Flow rates and sediment concentrations were measured from the pipe outlet. Replicate submerged jet erosion tests (JETs) were conducted to derive erodibility parameters for repacked samples at the same moisture contents. Flow rates from the box experiments were used to calibrate the mechanistic model. The influence of the initial moisture content was apparent, with some pipes (8% moisture content) expanding so fast that limited data was collected. The mechanistic model was able to estimate equivalent flow rates to those observed in the experiments, but had difficulty matching observed sediment concentrations when the pipes rapidly expanded. The JETs predicted similar erodibility coefficients compared to the mechanistic model for the more erodible cases but not for the less erodible cases (14% moisture content). Improved models are needed that better define the changing soil pipe cross‐section during supply‐ and transport‐limited internal erosion, especially for piping through lower compacted (more erodible) soils as opposed to more well‐compacted soils resulting from constructing levees and dams. Copyright © 2013 John Wiley & Sons, Ltd.
Mediterranean-style closure of the Paleo-Tethys ocean

The Qiangtang metamorphic belt (QMB) in central Tibet is one of the largest and most recently documented high-pressure (HP) to near-ultrahigh-pressure (near-UHP) belts on Earth. Lu-Hf ages of eclogite- and blueschist-facies rocks within the QMB are 244–223 Ma, indistinguishable from the age of UHP metamorphism in the Qinling-Dabie orogen. Results of a U-Pb detrital zircon study suggest that protoliths of the QMB include upper Paleozoic Qiangtang continental margin strata and sandstones that were derived from a Paleozoic arc terrane that developed within the Paleo-Tethys Ocean to the north. We attribute QMB HP metamorphism to continental collision between the Qiangtang terrane and a Paleo-Tethys arc terrane. This collision, and the coeval South China–North China collision, may have slowed convergence between Laurasia and Gondwana-derived terranes and initiated Mediterranean-style rollback and backarc basin development within much of the remnant Paleo-Tethys Ocean realm.
Seasonal and spatial variability in dissolved organic matter quantity and composition from the Yukon River basin, Alaska

The seasonal and spatial variability of dissolved organic matter (DOM) quantity and chemical composition were investigated in the Yukon River basin of Alaska, United States, and northwestern Canada. Dissolved organic carbon (DOC), chromophoric DOM (CDOM), and dissolved lignin phenols were measured across a range of source waters and the seasonal hydrograph. Strong relationships were determined between CDOM and both DOC and lignin phenols, highlighting the potential for deriving detailed spatial and temporal distributions of DOM composition from CDOM monitoring. Maximum concentrations of measured parameters were observed during the spring flush, when DOM had a remarkably high content of aromatic vascular plant material derived from surface soil and litter layers. A larger portion of riverine DOM was attributed to vascular plant sources than previously believed by utilizing representative vegetation leachates and a soil pore water as end‐members. In combination with recent studies highlighting export of young, labile DOM during the spring flush in northern high‐latitude river systems, our results suggest riverine DOM is less degraded and more labile than previously thought with clear ramifications for its biomineralization or photo‐oxidation in marine environments.
The Post-Colonial Ecology of Siberian Shamanic Revivalism

The Sakha national revival in Sakha (Yakutia), Siberia, aims to recover dying elements of Sakha culture, in order to preserve the Sakha people’s distinctive identity. And yet this revival is itself imbued with assumptions rooted in the European cultures that initiated modernist colonisation. Contemporary Sakha shamanism reflects the tensions within the nationalist revival, in the contrasting tendencies for activists, firstly, to recover what is seen as the old, genuine shamanic practice—and, secondly, to assimilate foreign spiritual techniques. But when these two strands of endeavour are examined with reference to the perceptions of person and environment that formed the basis of pre-Soviet Sakha life, it becomes apparent that they complement each other. Both facilitate the intersection of contrasting knots of relationship, predicated on differing ontologies. Sakha people currently live and work within institutions that have their roots in European modernism. However, older Sakha relationships with a live natural environment have not entirely disappeared. The authors suggest that the persistent presence of an environment imbued with spiritual agency differentiates the Sakha shamanic revival from the European traditions that shape its central motivations. This case reveals the importance of attending to place and environment, in the discussion of post-colonialist identity politics.
The Effect of Three Different Absorption Cross-Sections and their Temperature Dependence on Total Ozone Measured by a Mid-Latitude Brewer Spectrophotometer

Abstract The influence of variations in atmospheric temperature and ozone profiles on the total ozone column (TOC) derived from a Brewer MKII spectrophotometer operating in Thessaloniki, Greece, is investigated using three different sets of ozone absorption cross-sections. The standard Brewer total ozone retrieval algorithm uses the Bass and Paur (1985) cross-sections without accounting for the temperature dependence of the ozone cross-sections which produces a seasonally dependent bias in the measured TOC. The magnitude of this temperature effect depends on the altitude where the bulk of the ozone absorption occurs. Radiosonde measurements for the period 2000 to 2010 combined with climatological ozone profiles were used to calculate the effective temperature of ozone absorption and investigate its effect on the retrieved ozone column. Three different ozone absorption cross-section spectra convolved with the instrument's slit function were used: those of Bass and Paur (hereafter BP), currently used in the standard Brewer retrieval algorithm; those of Brion, Daumont, and Malicet (Malicet et al., 1985; hereafter BDM); and the recently published set by Serdyuchenko et al. (2013 hereafter S13). The temperature dependence of the differential ozone absorption coefficient ranges between 0.09 and 0.13% per degree Celsius for BP, between −0.11 and −0.06% per degree Celsius for BDM, and between 0.018 to 0.022% per degree Celsius for S13, resulting in a seasonal bias in the derived TOC of up to 2%, 1.8%, and 0.4%, respectively. The temperature sensitivity of the differential ozone absorption coefficient for the Brewer spectrophotometer at Thessaloniki for the BP and BDM cross-sections is found to be within the range reported for other Brewer instruments in earlier studies, whereas the seasonal bias in TOC is minimized when using the new S13 cross-sections because of their small temperature dependence.
The SEEK (Sporadic‐E Experiment over Kyushu) Campaign

The SEEK (Sporadic‐E Experiment over Kyushu) campaign was conducted in late August 1996 from the southern region of Kyushu, Japan, to investigate the mechanism for the generation of quasi‐periodic (QP) radar backscatter from field‐aligned irregularities imbedded in nighttime sporadic‐E (Es) layers. SEEK was designed to determine in‐situ small‐scale electrodynamical properties using two sounding rockets and large‐scale dynamics and electrodynamics using ground‐based sensors, which included a transportable radar and other radio and optical instruments deployed in the vicinity of the rocket range. It was observed by this campaign that Es layers existed in a convergent wind shear region, where large electric fields were induced and when active atmospheric gravity waves existed in the mesosphere. However, there was little evidence which positively supported the hypothesis that Es layers were deeply modulated in altitude.
Quantifying Southern Oscillation-Precipitation Relationships

Abstract A series of earlier studies has identified regions of the world in which precipitation appears to have a consistent relationship with the Southern Oscillation (SO). In this paper, the authors attempt to quantify this relationship based on shifts in the statistical distribution of precipitation amounts with emphasis on shifts in the median, which are associated with the warm (low SO index) and cold (high SO index) phases of the SO. This paper is partially an attempt to provide long-range forecasters with some guidance in making seasonal and multiseasonal predictions. Observed SO-related shifts in the median precipitation amounts, expressed as percentiles with respect to “climatological” conditions, can he used as a simple indication of the “typical” SO response for a given region. In general, the authors find that for many of the large areas identified in previous studies, median precipitation amounts shift on the order of 20 percentile points, that is, from the median to either the 30th percentil.