Miracle-dz/UniFAR-FTUs huggingface dataset:
Theoretical expression for an ocean internal soliton synthetic aperture radar image and determination of the soliton characteristic half width

This paper deals with the development of techniques for satellite synthetic aperture radar (SAR) ocean image interpretation. We derived a theoretical model of a radar image for a Korteweg-de Vries type ocean internal soliton and validated the model using ocean internal wave signals taken from ERS-1 SAR and RADARSAT SAR images. The results indicate that the model perfectly simulates ocean internal soliton signatures with double-sign variations of radar backscatter. On the basis of the model, we developed the curve fitting method and the peak-to-peak method for determining the internal soliton characteristic half widths, which then were used to calculate the internal soliton amplitudes. The test results indicate that ocean internal soliton amplitudes derived by the two methods agree with in situ data acquired on the Portuguese Continental Shelf and in the South China Sea with reasonable accuracy. The role that wind fields play in ocean radar remote sensing was also analyzed. Finally, the modulation ratio of ocean internal waves on radar images was quantitatively estimated.
The elemental and biochemical composition of bryophytes from the maritime Antarctic

The elemental and biochemical composition of eight moss species from the maritime Antarctic were determined fornightly (summer) or monthly (winter) from December 1992 to November 1994. Short-duration summer carbohydrate maxima in Calliergon sarmentosum were seen in both years, but no other seasonal patterns were observed. The absence of seasonality in carbon, nitrogen and phosphorus concentrations or their atomic ratios suggest that the mosses were nutrient-sufficient throughout the year, and that nutrient availability was not important in determining moss productivity. Mosses from hydric habitats had lower carbohydrate and higher protein, nitrogen and phosphorus contents than those from drier habitats, possibly as a consequence of higher productivity and continual flushing with nutrients in wet habitats. The results are consistent with the importance of water and the primacy of physical factors in the ecology of Antarctic mosses.
Paleointensity during a chron C26r excursion recorded in west Greenland lava flows

[1] We present Thellier paleointensity data from Vaigat Formation lavas erupted during magnetochron C26r (age ∼60 Ma) in west Greenland. The lavas were emplaced in flow fields, as demonstrated by detailed field observations, the finding of consecutive lavas recording the same paleomagnetic field (intensity and direction), and similar composition suggestive of an identical magma-source. Of particular interest is a ∼140 m thick lava sequence of 31 lavas recording excursional directions that lie ∼60° away from the paleomagnetic pole. Thellier paleointensity determinations of good technical quality demonstrate an average paleofield of 35.0 ± 13.2 μT during the excursion, which is slightly stronger than the average 29.4 ± 14.5 μT stable polarity non-excursional field intensity. Relatively strong excursional field intensity has also been observed in lava sequences in Hawaii, Canary Island, and Japan, suggesting that some geomagnetic excursions represent periods of strong local nondipole fields rather than aborted reversals with significantly weakened dipole field.
Quantification of tropical soil attributes from ETM+/LANDSAT‐7 data

The characterization of physical and chemical soils attributes is a pressing necessity for the agricultural land management optimization in many countries. Currently, soil analyses are performed by chemical treatments in a laboratory, generating environmental and time‐consuming problems. Remote sensing techniques can be faster and cheaper than conventional methods, do not generate chemical residues and are non‐destructive to the samples. The objective of the present work was to determine a remote sensing technique to estimate soil physical and chemical attributes in the regions of Paraguaçu Paulista and Rio Brilhante, in the States of São Paulo and Mato Grosso do Sul, respectively, Brazil, using reflectance data obtained by a sensor located in orbit. Fieldwork was performed to validate orbital data. A total of 110 soil samples were collected representing 43,000 h for the development of spectral models. Landsat‐7 ETM+images were atmospherically corrected and transformed to reflectance. The soil samples observed in the field were located by GPS and evaluated in the orbital image. The method used consists in a detailed investigation of the spectral data, in which the spectral curve, the position of the data in a graphic dispersion, the colour compositions and the pixel cursor values are evaluated. Spectral models were determined to quantify soil attributes. Soil samples from a different area had their attribute contents determined by the models. The attributes studied were sand, silt, clay, pH (CaCl2), organic matter, phosphorus, potassium, calcium, magnesium, aluminium, hydrogen, cation exchange capacity (CEC), sum of cations (SC) base saturation (BS) and aluminium saturation (AS). The results showed weak correlations with some soil attributes, such as SC, K, Ca, Mg, Al and P. High correlations (reaching 0.86) were obtained with sand, clay, silt, OM, CEC and H. On the other hand, validation procedure indicated that the best attributes for quantification were clearly clay (0.61) and sand (0.5). Therefore, there is strong evidence that these attributes can be predicted in similar landscapes, using the multiple‐linear equations developed in this study. This knowledge can be useful in many ways in agriculture, such as soil mapping, determining soil attributes, determining soil information in difficult access regions, and diminishing traditional soil analyses with environmental protection.
Early Identification of Reservoir Compartmentalization by Combining a Range of Conventional and Novel Data Types

Reservoir compartmentalization (vertical and lateral) is often a major uncertainty at the field appraisal stage, impacting important investment decisions. Unfortunately, the most definitive compartmentalization data (dynamic production data) are not usually available so early in field life. This paper illustrates how early indications of compartmentalization can be achieved by integrating various types of conventional and novel data. Using an example of the Ross oilfield, UK Continental Shelf (UKCS), the authors demonstrate how integration of oil compositional data (molecular maturity parameters, gas chromatography [GC] fingerprinting, pressure-volume-temperature [PVT] data) with pressure, well test, and fault seal analysis revealed the presence of several sealing faults, and thus enabled the field to be described in terms of its likely segmentation. Vertical compartmentalization was investigated using a combination of oil geochemistry (maturity, GC fingerprinting), water composition (residual salt analysis), and high-resolution stratigraphy, revealing a continuous shale that has a lateral extent of > 5 km; it divides the reservoir into two main layers. The results of this study helped to decrease uncertainty in field development planning. The key message is that there are many tools available to aid in assessing compartmentalization, but individually they each only give part of the picture. It is therefore importantmore » to use several tools in combination. « less
Sedimentary record of explosive silicic volcanism in a Cretaceous deep‐marine conglomerate succession, northern Antarctic Peninsula

Lower Cretaceous conglomeratic strata exposed on southern Sobral Peninsula were deposited on a deep‐marine apron in the back‐arc Larsen Basin close to its faulted boundary with the Antarctic Peninsula magmatic arc. The succession is dominated by amalgamated beds of clast‐supported conglomerate, which, together with minor intercalated sandstones, consist of varied, but largely basaltic to andesitic, volcanic material and clasts derived from the Palaeozoic–Triassic (meta)sedimentary basement of the arc. Most of the volcanic clasts are thought to have been derived from lithified volcanic successions or older synvolcanic deposits, rather than from sites of coeval eruption. These mixed‐provenance strata enclose a number of intervals, consisting mainly of inverse–normally graded conglomerate and graded–stratified pebbly sandstone, in which the sand fraction is dominated by crystals and vitric grains considered to have been redeposited in the immediate aftermath of explosive silicic arc volcanism. Like syneruption deposits on non‐marine volcaniclastic aprons, these intervals are more sand‐prone than the enclosing strata and appear to show evidence of unusually rapid aggradation. Plagioclase from one such interval has yielded 40Ar/39Ar ages concordant at ≈121 Ma, similar to those obtained from the non‐marine Cerro Negro Formation, deposited within the magmatic arc. It is suggested that the two successions can be viewed as counterparts, both recording a history of mainly basaltic to andesitic volcanism, punctuated by relatively infrequent, explosive silicic eruptions. Whereas the Cerro Negro Formation consists mainly of syneruption deposits, most of the volcaniclastic material delivered to the eruption‐distal, deep‐marine apron appears to have been derived by normal degradation processes. Only rare silicic eruptions were capable of supplying pyroclastic material rapidly enough and in sufficient quantities to produce compositionally distinct syneruption intervals.
When are the Effects of Fiscal Policy Uncertainty Large?

Using a new-Keynesian model with endogenous capital accumulation, I show that uncertainty about fiscal policy can cause large declines in consumption, investment, and output when the zero lower bound (ZLB) binds, but has modest effects when the monetary authority is not constrained by the ZLB. I study uncertainty about the level of government spending and uncertainty about tax rates on consumption, wages, capital income, and investment. In my model, uncertainty about government spending and the wage tax rate has particularly large effects. I show that the effects of fiscal policy uncertainty are largest when the nominal interest rate is on the cusp of the ZLB and also that delaying fiscal policy uncertainty diminishes its effects only if the resolution of uncertainty occurs after ZLB no longer binds.
Thermal Resistivity of Soils

Information on the thermal properties of soils from different disciplines of science and engineering is consolidated to identify low-cost, simple procedures for assessing the variation of the thermal resistivity of soils with changes in moisture content. Three procedures for determining the critical moisture content are presented. The critical moisture content is the moisture content at the knee of the thermal-resistivity-versus-moisture-content curve. The optimum moisture content and plastic limit were found to be physical quantities indicative of the critical moisture content in soils. Also, the upper flex point of the soil-moisture-characteristics curve appears to establish the critical moisture content in soils.
Évaluation de la qualité physico-chimique et du niveau de contamination métallique (Cd, Pb, Zn) des rejets d'eaux usées d'Oran et de Mostaganem (littoral Ouest algérien)

Les zones cotieres sont le lieu d'activites necessitant des eaux de bonne qualite physico-chimique : usages recreatifs, aquaculture et peche. Ces zones sont sous l'influence directe des eaux d'oueds et des eaux usees, par ou transitent les apports des bassins versants, rejets urbains et industriels. Ces rejets entrainent, lorsque le renouvellement des masses d'eau est faible par rapport aux quantites rejetees, des degradations notables de la qualite des eaux et des ecosystemes marins.La presente etude porte sur une evaluation qualitative des eaux d'effluents urbains et industriels de deux poles urbains du littoral oranais (Oran et Mostaganem), dans l'objectif d'evaluer l'etat de la contamination par les metaux lourds (Cd, Pb et Zn), ainsi que l'evaluation de la qualite physico-chimique des eaux marines pour determiner l'impact potentiel de la pollution metallique sur la cote ouest algerienne.La concentration moyenne du cadmium est maximale pour le rejet industriel de Mostaganem (0,88 mg/l – ecart-type : 1,35 mg/l). Pour le zinc, la concentration moyenne la plus elevee (0,92 mg/l – ecart-type : 1,35 mg/l) correspond au rejet urbain de Mostaganem. Le plomb presente des teneurs moyennes assez fortes au niveau des trois rejets etudies : 0,23 mg/l pour le rejet urbain d'Oran (ecart-type : 0,22 mg/l), 0,22 mg/l pour le rejet industriel de Mostaganem (ecart-type : 0,21 mg/l) et 0,19 mg/l pour le rejet urbain de Mostaganem (ecart-type : 0,20 mg/l). Si les concentrations en metaux lourds varient beaucoup d'un prelevement a l'autre, comme le traduisent les ecarts-types, aucune evolution durable ne ressort. Seules les teneurs moyennes du cadmium depassent la limite normative.
Ionosphere gives size of greatest solar flare

On 4 November 2003, the largest solar flare ever recorded saturated the GOES X‐ray detectors; from these a magnitude of X28 (2.8 mW/m2) has been extrapolated (http://sec.noaa.gov/weekly/pdf/prf1471.pdf). However, using the Earth's ionosphere as a giant X‐ray detector, we show the magnitude of this flare is consistent with X45 ± 5 (4.5 ± 0.5 mW/m2), or more than twice that of the two previously recorded largest flares, both about X20. This flare magnitude is determined by using the large observed phase changes recorded at Dunedin, New Zealand, on long VLF radio paths across the Pacific from transmitters in the continental USA and Hawaii. The enhanced X‐ray flux caused a dramatic lowering of the height of the D‐region of the ionosphere, allowing the flare to be measured relative to the GOES observations.
Oligo‐Miocene magnetostratigraphy and rock magnetism of the Xishuigou section, Subei (Gansu Province, western China) and implications for shallow inclinations in central Asia

Magnetostratigraphy of 222 remanent directions together with late Oligocene to early Miocene mammal and charophyte paleontology suggest that 2179 m of the Xishuigou section (Subei, Gansu Province, China) were deposited from ∼26 to ∼19 Ma. Stratigraphic patterns of bulk susceptibility, anisotropy of magnetic susceptibility parameters, and natural and anhysteretic remanent magnetization intensities demonstrate that (1) faulting does not significantly affect the record, (2) sediment deposition was relatively continuous, (3) sediment source changed around 23 Ma, and (4) rapid uplift near Subei occurred at 21 Ma. Subei rotated 27°±5° counterclockwise with respect to the 20 Ma pole from the Eurasian synthetic apparent polar wander path. Folding and rotation of the section took place after 19 Ma. The paleolatitude of Subei is 14° less than at present and 19°±3° less than predicted from the reference pole. Both rock magnetic and paleomagnetic data sets suggest that the unusually low paleolatitude is the result of synsedimentary inclination shallowing, a phenomenon which has likely affected other paleomagnetic data from central Asia.
Estimation of an index flood using data transfer in the UK

Abstract An important part of the statistical procedure for flood frequency analysis in the UK outlined in the Flood Estimation Handbook (FEH) is concerned with estimation of an index flood at an ungauged site. This is carried out through application of a multivariate regression model linking the index flood, defined as the median annual maximum flood, to a set of catchment descriptors. The FEH then emphasises the importance of data transfer from nearby gauged (donor) sites, or from catchments considered to be hydrologically similar but located anywhere in the UK (analogue sites). This paper considers the suggested methods for estimating the index flood at ungauged sites and develops a new and improved data transfer scheme. A study of 728 gauged catchments located in the UK found that the new data transfer method performs better than both using the FEH regression model only and the FEH data transfer method.
Laboratory and seismological observations of lower mantle isotropy

We have carried out seismological and mineral physics investigations to identify the extent and origin of elastic anisotropy in the lower mantle. Based on observations of shear wave splitting, we conclude that the lower mantle is effectively isotropic. This result is surprising since the lower mantle is composed of elastically anisotropic minerals (silicate perovskite, MgO, SiO 2 ) that have been extensively strained by geologic processes. To reconcile the seismic observations, we have measured texture development during deformation and high temperature recrystallization of mantle silicates. We show that these experiments provide a direct explanation for the shear wave splitting measurements: the lower mantle appears isotropic because silicate perovskite maintains an isotropic texture during deformation and recrystallization
The transformation from an estuarine to lacustrine environment in the lower Wairarapa

Abstract The lower Wairarapa valley, which is now a riverine-lacustrine complex, was a large estuary as late as 3500–4000 years B.P. Vegetation at that time was podocarp forest, as it was in the area at the time of European exploration. The most likely explanation of the change in environment is extensive late Holocene alluviation, although retreat from higher post-glacial sea levels, or local tectonic events, cannot be ruled out as contributing factors.
The Nebo-Babel Ni-Cu-PGE Sulfide Deposit (West Musgrave, Australia): Pt. 1. U/Pb Zircon Ages, Whole-Rock and Mineral Chemistry, and O-Sr-Nd Isotope Compositions of the Intrusion, with Constraints on Petrogenesis

The Nebo-Babel intrusion, which hosts a world-class magmatic Ni-Cu-PGE sulfide deposit, is a concentrically zoned, tube-like gabbronorite body. The emplacement of Nebo-Babel at 1068.0 ± 4.3 Ma was part of a major magmatic event, which included the Giles Complex and the Warakurna large igneous province. Field, mineral, chemical, and isotopic data from the Nebo-Babel intrusion indicate that all of the lithostratigraphic units are cogenetic and that the intrusion is the product of three temporally distinct magma pulses. The initial magma pulse, which formed the marginal units of the intrusion, was the most primitive and has assimilated the highest percentage of the country-rock orthogneiss. The subsequent magma pulses, emplaced into the core of the intrusion, were both less primitive and less contaminated. The final and largest magma pulse underwent in situ closed-system crystal fractionation resulting in the observed stratigraphic mineral and whole-rock chemical trends. Emplacement of Nebo-Babel took place at ca. 10- to 12-km depth. Postmagmatic, structural overturning of the intrusion resulted in stratigraphically reversed mineral and chemical trends. All of the Nebo-Babel units can be related by crystal fractionation of parental tholeiitic magma with 8 to 9 wt percent MgO. Mineral δ 18O values are consistent with typical mantle values and preclude large-scale crustal contamination of the parental magma with anything other than material with similar values. Although even the least contaminated intrusive units have negative Nb anomalies and enriched 87Sr/86Sr initial ratios compared to bulk earth at the time, the crustal assimilation must have been significantly less than 10 percent based on mantle-like δ 18O values and 143Nd/144Nd ratios. Trace elements indicate that primitive Nebo-Babel melts equilibrated with spinel facies mantle implying shallow melting beneath a lithosphere less than 80 km thick.
Complexity of the rupture process during the 2009 L’Aquila, Italy, earthquake

SUMMARY In this study, we investigate the rupture history of the 2009 April 6 (Mw 6.1) L’Aquila normal faulting earthquake by using a non-linear inversion of strong motion, GPS and DInSAR data. Both the separate and joint inversion solutions reveal a complex rupture process and a heterogeneous slip distribution. Slip is concentrated in two main asperities: a smaller shallow patch of slip located updip from the hypocentre and a second deeper and larger asperity located southeastwards along-strike direction. The key feature of the source process emerging from our inverted models concerns the rupture history, which is characterized by two distinct stages. The first stage begins with rupture nucleation and with updip propagation at relatively high (∼4.0 km s−1), but still subshear, rupture velocity. The second stage starts nearly 2.0–2.5 s after nucleation and it is characterized by the along-strike rupture propagation. The largest and deeper asperity fails during this stage of the rupture process. The rupture velocity is larger in the updip than in the along-strike direction. The updip and along-strike rupture propagation are separated in time and associated with a Mode II and a Mode III crack, respectively. The comparison between the source models inferred in this study with the Poisson ratio anomalies in the crustal volume containing the fault plane allows the interpretation of the delay in along-strike rupture propagation in terms of a structural control of the rupture history. Our results show that the L’Aquila earthquake featured a very complex rupture, with strong spatial and temporal heterogeneities suggesting a strong frictional and/or structural control of the rupture process.
A comparison between trajectory ensemble and adiabatic parcel modeled cloud properties and evaluation against airborne measurements

A trajectory ensemble model (TEM) and an adiabatic air parcel model have been used to study the sensitivity of cloud droplet number concentration on aerosol chemical composition and vertical wind speed variations in the case of stratocumulus clouds. Cloud droplet number concentrations predicted using the TEM approach, in which trajectories are produced by large eddy simulation, and those derived from an air parcel model fed with a probability density function of measured updraft velocities, are compared to cloud droplet measurements conducted during the Cloud Processing of Regional Air Pollution Advecting Over Land and Sea (CLOPAP) campaign. It was found that much better agreement can be achieved using TEM than with the adiabatic air parcel model. The reason for this is the ripening process decreasing the cloud droplet number concentration in the air parcels having long in-cloud residence time. It was also found that the sensitivity of cloud droplet number concentration to aerosol properties is much smaller with TEM than expected from the adiabatic air parcel model simulations. As current parameterizations used to estimate cloud droplet number concentration in many large-scale models are based on adiabatic air parcel models, it is possible that the aerosol indirect effect for stratocumulus and stratus clouds with low vertical wind speeds is overestimated unless the sink resulting from ripening is taken into account.
Palynology of Amphidium Schimp. (Amphidiaceae M. Stech): can spore morphology circumscribe the genus?

Amphidium Schimp. is characterized by cushion-forming erect primary stems, linear-lanceolate leaves, and gymnostome capsules. The phylogenetic position of Amphidium is uncertain, with the genus having been variously included in Zygodontaceae Schimp. , Rhabdoweisiaceae Limpr. , Orthotrichaceae Arn. and Amphidiaceae M. Stech. A palynological investigation was performed of the three species of the genus that occur in the Americas: Amphidium lapponicum (Hedw.) Schimp. , Amphidium mougeotii (Bruch & Schimp.) Schimp. , and Amphidium tortuosum (Hornsch.) Cufod. Spores were observed and measured for greatest diameter under light microscopy both before and after acetolysis. Non-acetolyzed spores were observed under scanning electron microscopy to assess surface ornamentation of the sporoderm. All spores observed were smaller than 20 μm and heteropolar, with surface ornamentation reflecting a combination of different elements, such as gemmae, rugulae and perforations. The palynological characteristics observed here suggest that the genus Amphidium, and thus its contained species, be placed in their own family.