Miracle-dz/UniFAR-FTUs huggingface dataset:
Seasat‐derived gravity over the Musicians Seamounts

The two-dimensional gravity field over the Musicians seamount province in the Pacific Ocean has been derived from Seasat altimetry. Geoid maps were produced by fitting a minimum curvature surface to the sea surface height measurements. As a check on the quality of this interpolation method, we also gridded the data using weighted grid point averages. Fourier transforms of both the geoid and geoid gradient were used to determine the gravity field. We have compared gravity maps produced these different ways in order to identify the problems involved in pushing Seasat data to the limits of its spatial resolution and accuracy. Our minimum-curvature interpolation scheme was determined to be the more accurate and cost effective mapping method, while gravity obtained by transforming the geoid produced more reliable gravity maps. The bathymetry of this area was used to predict the gravity field by filtering the bathymetry under the assumption that it is regionally compensated by a thin elastic plate. Gravity fields predicted for a variety of effective elastic thicknesses were compared to the Seasat-derived gravity, particularly in areas with good track coverage. The derived gravity tends to favor a thin plate with an effective elastic thickness of ∼5 km, though the east-west ridges in the south display a smaller signal more consistent with Airy compensation. This variation may be indicative of early fracturing of the lithosphere in the south, or it may be a manifestation of the age difference and early thermal structure across the Murray fracture zone, which separates the seamount province into northern and southern sections. Neighboring seamounts with different flexural signatures, particularly in the south, may indicate that volcanism occurred in the same location over an extended period of time.
Acoustic Emissions as a Tool for Hydraulic Fracture Location: Experience at the Fenton Hill Hot Dry Rock Site

Microearthquakes with magnitudes between -6 and -2 have been observed in three successive massive injections of water at the hot dry rock geothermal energy development project's demonstration site at Fenton Hill, NM. The injections were part of a program to increase the heat transfer area of hydraulic fractures and to decrease the flow-through impedance between wells in the energy extraction system under construction. The microearthquakes were used in mapping the location of the extended hydraulic fractures. The large shear- to compressional-wave-amplitude ratio observed in the signals suggests that the microearthquakes result from shear failure, probably on preexisting planes of weakness that intersect or make up the main hydraulic system. Failure resulting from increased pore pressure is a likely cause for the microearthquakes. Knowledge of the failure criterion for the reservoir rocks permits calculation of the pore pressure increases necessary for failure. At Fenton Hill, it appears that pressures 2 Pa (0.00029 psi) above hydrostatic are necessary. For this hypothesis of microearthquake occurrence to hold, the effective reservoir permeability must be four orders of magnitude above that for the bulk rock, as would be the case if there were permeable joints or fractures in the reservoir before hydraulic stimulation.
Soil geographic data bases

AS an element of the National Cooperative Soil Survey, the Soil Conservation Service has established soil geographic data bases to improve the storage, manipulation, and retrieval of soil map information. People involved in agriculture, agribusiness, forestry, environmental protection, and land use planning and management often have difficulty locating and interpreting soil data. Frequently, these data are not in a form that permits easy analysis, particularly if the data must be analyzed together with other resource information. Soil and other natural resource data are unique in that spatial distribution and variability on the landscape are important components. Soil data often must be integrated with other spatial data. SCS has established three soil geographic data bases representing different scales of soil mapping. Each data base links digitized soil map unit delineations with computerized data for each map unit, giving the proportionate extent of the component soils and their properties. With these computerized data bases, users will be able to store, retrieve, analyze, and display soil data efficiently. They will also be able to integrate the data with other spatially referenced resource and demographic data in geographic information systems. The three data bases The three soil geographic data bases include the Soil Survey …
Seasonal Characteristics of Spherical Aerosol Distribution in Eastern Asia: Integrated Analysis Using Ground/Space-Based Lidars and a Chemical Transport Model

Seasonal characteristics of spherical aerosol distributions in eastern Asia were investigated between July 2006 and December 2008 using data from ground-based and space-borne lidar observations and the Community Multi-scale Air Quality Modeling System (CMAQ) chemical transport model simulation. The seasonal variation of spherical aerosol optical thickness (AOT) observed at four ground lidar stations surrounding the East China Sea (Beijing, Guangzhou, Seoul, and Hedo/Okinawa) was generally consistent with CMAQ simulation results. Detailed analyses confirmed clear regional differences in aerosol compositions. Analyses of aerosol vertical profiles revealed that the spherical aerosol variation is greatest in Beijing, with scale height varying between 720 m and 2100 m. The analyses also revealed that the seasonal variation patterns of spherical AOT are classifiable into ‘summer peak’ and ‘summer trough’ types. Northern sites (Beijing and Seoul) are of the summer peak type; southern sites (Guangzhou and Okinawa) show the summer trough pattern. Our analyses demonstrated that the Asian summer-winter monsoon system plays a major role in regulating such seasonal variation. The CMAQ simulated variation of spherical aerosols is well correlated to the synoptic scale monsoon variation.
Cross-Border Regions and Territorial Restructuring in Central Europe

As the world's `first postmodern political form', Europe provides an excellent laboratory for exploring how border regions offer new spaces of/for governance, cultural interaction, and economic development. With the backdrop of dynamic transboundary regionalization in Europe, this article has two goals: the first is to provide a critical review of some recent literature on territorial restructuring whose spatial ambit curiously omits transboundary space. Second, the article follows in the tradition of recent literature on regionalism in geography by exploring competing visions of the scales which are appropriate for organizing particular political and economic activities, in order to call for more engagement with transboundary regionalism.A case-study from Saxony (Germany) shows that the functional utilitarianism — and resulting short half life — of some European transboundary regions is a factor inhibiting the emergence of coherent regions.This notwithstanding, evidence also suggests that cross-border cooperation is becoming a key tool as localities and other territories strive to become `global'. The tangled map of current regional initiatives within the European Union (EU) reflects the temporal emergence and disappearance of cross-border regions in response to changing political priorities and shifting macro-institutional funding sources. The article shows that transboundary regions play an important role in territorial restructuring in Central Europe, but not necessarily in the way EU regional policy intends.
Possible Sprigginid Worm and a New Trace Fossil from the Nama Group, South West Africa

Two new fossils, a possible sprigginid worm and a new trace fossil, were discovered in loose shale slabs from the Upper Clastic Member of the Kuibis Formation on a farm, Buchholzbrunn 99, in the Bethanie district, South West Africa. The discovery of a sprigginid worm seems to strengthen the relationship between the faunas of the Nama Group and of the Ediacara in Australia. A new trace fossil, Buchholzbrunnichnus kroneri , provides evidence that mollusc-like organisms inhabited the Precambrian Kuibis (Nama) sea.
Field‐aligned currents' scale analysis performed with the Swarm constellation

We present a statistical study of the temporal‐ and spatial‐scale characteristics of different field‐aligned current (FAC) types derived with the Swarm satellite formation. We divide FACs into two classes: small‐scale, up to some 10 km, which are carried predominantly by kinetic Alfvén waves, and large‐scale FACs with sizes of more than 150 km. For determining temporal variability we consider measurements at the same point, the orbital crossovers near the poles, but at different times. From correlation analysis we obtain a persistent period of small‐scale FACs of order 10 s, while large‐scale FACs can be regarded stationary for more than 60 s. For the first time we investigate the longitudinal scales. Large‐scale FACs are different on dayside and nightside. On the nightside the longitudinal extension is on average 4 times the latitudinal width, while on the dayside, particularly in the cusp region, latitudinal and longitudinal scales are comparable.
Evaluation of source gas lifetimes from stratospheric observations

Simultaneous in situ measurements of the long-lived trace species N2O, CH4, 12, CFC-113, CFC-11, CCl4, CH3CCl3, H-1211, and SF6 were made in the lower stratosphere and upper troposphere on board the NASA ER-2 high-altitude aircraft during the 1994 campaign Airborne Southern Hemisphere Ozone Experiment/ Measurements for Assessing the Effects of Stratospheric Aircraft. The observed extratropical tracer abundances exhibit compact mutual correlations that show little interhemispheric difference or seasonal variability except at higher altitudes in southern hemisphere spring. The environmental impact of the measured source gases depends, among other factors, on the rate at which they release ozone-depleting chemicals in the stratosphere, that is, on their stratospheric lifetimes. We calculate the mean age of the air from the SF6 measurements and show how stratospheric lifetimes of the other species may be derived semiempirically from their observed gradients with respect to mean age at the extratropical tropopause. We also derive independent stratospheric lifetimes using the CFC-11 lifetime and the slopes of the tracer's correlations with CFC-11. In both cases, we correct for the influence of tropospheric growth on stratospheric tracer gradients using the observed mean age of the air, time series of observed tropospheric abundances, and model-derived estimates of the width of the stratospheric age spectrum. Lifetime results from the two methods are consistent with each other. Our best estimates for stratospheric lifetimes are 122±24 years for N2O, 93±18 years for CH4, 87±17 years for CFC-12, 100±32 years for CFC-113, 32±6 years for CCl4, 34±7 years for CH3CCl3, and 24±6 years for H-1211. Most of these estimates are significantly smaller than currently recommended lifetimes, which are based largely on photochemical model calculations. Because the derived stratospheric lifetimes are identical to atmospheric lifetimes for most of the species considered, the shorter lifetimes would imply a faster recovery of the ozone layer following the phaseout of industrial halocarbons than currently predicted.
Analytical Dissolved Oxygen Model for Sinusoidally Varying BOD

An analytical solution is developed for biochemical oxygen demand (BOD) and dissolved oxygen concentration (DO) in a river for the case when BOD loading concentration and DO loading concentration each vary sinusoidally. The analytical solution is for the quasi-steady-state (periodic) case as the initial condition is ignored, but the boundary conditions are satisfied. Thus, the analytical solution is applicable from the BOD and DO loading locations to the concentration front. This distance is calculated by making use of the memory length concept. The solution is developed by breaking the BOD and DO equations into three subproblems, which are solved separately, then combined by applying the superposition principle. The solution is tested against published solutions from the literature, which include an integral equation, a perturbation solution, and a numerical solution. The analytical solution is easy to apply and extends the cases with which engineers can compare their numerical models. The results sugges.
Models for an ecosystem approach to fisheries

This report reviews the methods available for assessing the impacts of interactions between species and fisheries and their implications for marine fisheries management. A brief description of the various modelling approaches currently in existence is provided, highlighting in particular features of these models which have general relevance to the field of the ecosystem approach to fisheries (EAF). The report concentrates on the currently available models representative of general types such as bionergetic models, predator-prey models and minimally realistic models. Short descriptions are given of model parameters, assumptions and data requirements. Some of the advantages, disadvantages and limitations of each of the approaches in addressing questions pertaining to EAF are discussed. The report concludes with some recommendations for moving forward in the development of multi-species and ecosystem models and for the prudent use of the currently available models as tools for provision of scientific information on fisheries in an ecosystem context. Plagányi, É. E. Models for an ecosystem approach to fisheries. FAO Fisheries Technical Paper. No. 477. Rome, FAO. 2007. 108p.
Particle-Scale Insight into Deformation Noncoaxiality of Granular Materials

AbstractThis paper explores the mechanism of deformation noncoaxiality from the particle scale. A multiscale investigation has been carried out with the particle-scale information obtained from discrete element simulation on granular materials. The specimens were prepared anisotropically and sheared in various loading directions. The deformation noncoaxiality, i.e., noncoincidence between the principal stress direction and the principal strain increment direction, was observed. The directional statistical theory has been used to study the anisotropies in material fabric and particle interactions, and to characterize them in terms of direction tensors. Based on the stress-force-fabric relationship, the stress direction was determined from these direction tensors. In monotonic loading, it was observed that the force anisotropy is always coaxial with the loading direction, i.e., the strain increment direction, while the fabric anisotropy only gradually approaches the loading direction. This noncoincidence be.
Retrieval of chlorophyll content and LAI of crops using hyperspectral techniques: application to PROBA/CHRIS data

Hyperspectral/multiangular data allow the retrieval of important vegetation properties at canopy level, such as the Leaf Area Index (LAI) and Leaf Chlorophyll Content. Current methods are based on the relationship between biophysical properties and retrievals from those spectral bands (from the complete hyperspectral/multiangular information) where specific absorption features are present within the considered spectral range. Furthermore, new sensors such as PROBA/CHRIS provide continuous hyperspectral reflectance measurements that can be considered as a continuous function of wavelength. The mathematical analysis of these continuous functions allows a new way of exploiting the relationships between spectral reflectance and biophysical variables by more powerful and stable mathematical tools, in particular for the retrieval of LAI and chlorophyll content. Within the overall context of the European Space Agency (ESA) Spectra Barrax Campaign (SPARC) experiment, an extensive field study was carried out in La Mancha, Spain, simultaneously to the overflight of airborne imaging spectrometers (AHS, HyMAP, ROSIS) and the overpass of CHRIS‐PROBA and MERIS sensors. During the SPARC‐2003 and SPARC‐2004 campaigns, numerous ground measurements were made in the Barrax study area (covering LAI, fCover, leaf chlorophyll a+b, leaf water content and leaf biomass), together with other complementary data, and a total of 17 CHRIS‐PROBA images were acquired. Representative points have been selected from a total of nine different crops, and also retrieved from the CHRIS‐PROBA images acquired within the days of the field campaign. About 250 reflectance spectra from five different observation angles have been analysed. Hyperspectral reflectance spectra have been adjusted by means of third‐degree polynomial functions between 500 nm and 750 nm, and correlations observed between LAI values and the coefficients of these polynomials yielded LAI as a result of the mathematical fitting. On the other hand, the area under the spectral reflectance curves has been calculated in the interval from 600 nm to 700 nm, the region of the red spectral interval where strong absorption features for chlorophyll have been observed, though areas under the curves are also strongly correlated to the chlorophyll content of the crops. Furthermore, a linear relationship between these areas and the chlorophyll content is proposed in this work. This relationship allows the retrieval of leaf chlorophyll by satellite data, based on the spectral information. Both of the proposed methods are almost independent of the observation angles employed. The high number of in situ measurements acquired simultaneously to satellite overpasses, and the broad available range of data, have allowed validation of both methods, with a large number of data and in a statistically consistent manner.
Elastic stress and deformation near a finite spherical magma body: Resolution of the point source paradox

Approximate solutions are obtained for the stress and displacement fields due to a pressurized spherical cavity in an elastic half-space. The solutions take the form of series expansions in powers of e = a/d, where a is the cavity radius and d is the depth. The leading-order term in the expression for the surface uplift, which arises at O(e3), recovers the well-known result of Mogi for the response to a point dilatation. The first higher-order correction accounts for a cavity of finite size and thus offers the possibility of fitting leveling data for not only the depth but also the radius and pressure increment. However, this correction is of O(e6) and, consequently, is weak. The result provides a formal explanation for the success of the point dilatation model in representing uplift data even when it is known independently that e is not small. The higher-order correction causes the surface uplift to fall off more rapidly in the radial direction, implying that a fit of the point source solution tends to underestimate the depth d. In contrast to the surface displacement, the stress field near the cavity is affected profoundly by the proximity of the free surface. Three higher-order corrections to the stress field are obtained, which result in a uniformly valid approximation to O(e5). The hoop stress at the cavity exhibits a tensile maximum at the circle of tangency with a cone with its apex at the free surface. This result appears to be consistent with the locus of fractures radiating outward from the magma body inferred by seismic methods in Long Valley, California.
Influence of pore‐pressure on the event‐size distribution of induced earthquakes

During an Enhanced Geothermal System (EGS) experiment, fluid is injected at high pressure into crystalline rock, to enhance its permeability and thus create a reservoir from which geothermal heat can be extracted. The fracturing of the basement caused by these high pore‐pressures is associated with microseismicity. However, the relationship between the magnitudes of these induced seismic events and the applied fluid injection rates, and thus pore‐pressure, is unknown. Here we show how pore‐pressure can be linked to the seismic frequency–magnitude distribution, described by its slope, theb‐value. We evaluate the dataset of an EGS in Basel, Switzerland and compare the observed event‐size distribution with the outcome of a minimalistic model of pore‐pressure evolution that relates event‐sizes to the differential stressσD. We observe that the decrease of b‐values with increasing distance of the injection point is likely caused by a decrease in pore‐pressure. This leads to an increase of the probability of a large magnitude event with distance and time.
On the feasibility of magma fracture within volcanic conduits: Constraints from earthquake data and empirical modelling of magma viscosity

In the last decade several studies have indicated that magma within volcanic conduits can undergo repeated failure and healing, thus, providing a realistic source mechanism for the peculiar sequences of low‐frequency earthquakes that often announce eruptions. Although geological observations, laboratory experiments, and numerical modelling support such a hypothesis, the links between geophysical observations and the proposed models remain qualitative. This study focuses on providing constraints to the relationship between the occurrence of repeating earthquakes and magma fracture at andesite volcanoes. Empirical modelling of viscosity is incorporated into the fundamental physics of magma fracture in order to assess whether and where the conditions for brittle failure are met within volcanic conduits. A case study from the 1995‐ongoing eruption of Soufrière Hills Volcano, Montserrat, is presented. The locations of earthquakes from a pre‐eruptive low‐frequency seismic swarm illuminate a relatively compact source volume at depths of 100–300 meters below sea level. Viscosity modelling confirms that the Soufrière Hills magma could rupture at those depths.
Energy Partitioning and Evapotranspiration over a Rice Paddy in Southern Brazil

AbstractDuring approximately 80% of its growing season, lowland flooded irrigated rice ecosystems in southern Brazil are kept within a 5–10-cm water layer. These anaerobic conditions have an influence on the partitioning of the energy and water balance components. Furthermore, this cropping system differs substantially from any other upland nonirrigated or irrigated crop ecosystems. In this study, daily, seasonal, and annual dynamics of the energy and water balance components were analyzed over a paddy rice farm in a subtropical location in southern Brazil using eddy covariance measurements. In this region, rice is grown once a year in low wetlands while the ground is kept fallow during the remaining of the year. Results show that the energy budget residual corresponded to up to 20% of the net radiation during the rice-growing season and around 10% for the remainder of the year (fallow). The energy and water balance analysis also showed that because of the high water table in the region, soil was near sat.