Miracle-dz/UniFAR-FTUs huggingface dataset:
Reliability, resilience and vulnerability of a multipurpose storage reservoir / Confiance, résilience et vulnérabilité d'un barrage multi-objectifs

Abstract The behaviour of statistical performance indices, namely, reliability, resilience and vulnerability for a multipurpose storage reservoir is examined. Monte Carlo simulations were carried using data of the Dharoi Reservoir (India) and the inflows to the reservoir were generated by following two approaches: long-memory models and short-memory models. Statistical behaviour of three indices were examined for two cases: (i) municipal and industrial water supply; and (ii) irrigation, thus making a total of six indices for the analysis. To interpret the behaviour of these indices, a probabilistic approach was followed. It was noted that when inflows generated using long-memory models were input in simulation, there were large variations in reliability, resilience and vulnerability among the runs. In contrast, when data from short-memory models were used, the indices were confined to a narrow band. Average values of reliabilities and their variance for both the demands were much higher when the data generated using short-memory models were used. Since natural geophysical hydrological data series display persistence, the results pertaining to long-memory model are closer to reality. It was also shown that the framework of analysis presented can be very useful for multicriteria analysis and interpretation of trade-offs in the reliability space.
Mechanical strength of extended continental lithosphere: Constraints from the Western Rift System, East Africa

Although regional isostasy generally is associated with continental lithospheric compression and foreland basin formation, local isostatic compensation commonly is assumed in models of extensional basin formation. The assumption of negligible lithospheric strength during rifting often is justified on the basis of: (1) high heat flow and temperatures produced by elevating the lithosphere - asthenosphere boundary and (2) fracturing of the crust and lithosphere by normal faults. By modeling the development of rift basins within the Western rift system of East Africa and their associated free air gravity anomalies, we assess the role of basin-producing normal faults in modifying the flexural strength of extended lithosphere. Heat flow and seismicity data from the East African plateau region indicate that the Western rift system located on the western side of the plateau developed in old, cold continental lithosphere. These relatively narrow (40–70 km wide), but deep, basins are bounded along one side by high-angle border faults that penetrate to lower crustal levels, as indicated by seismicity data. Along the length of the Western rift system, depth to pre-rift basement and rift flank topography vary between basins from 1 to 8 km and from 1 to 2 km respectively, with deeper basins generally correlating with higher flanks. Comparison of model predictions with topography and free air gravity profiles reveals that the basin depth and the flank height in the majority of the Western rift basins studied can be explained simply by small heaves (3–10 km) across the border fault and with significant flexural strength of the lithosphere maintained during extension. Where both observed basin depth and flank height could not be reproduced, basins were located adjacent to eruptive volcanic centers active in Miocene-Recent times. In these areas, basin depth, rift flank elevation, and free air gravity anomaly may be modified by magmatic underplating of the crust. Estimates of effective elastic thickness Te obtained from our forward models vary between 17 and 38 km. These Te estimates are consistent with previous values obtained through the wavenumber domain correlation of Bouguer gravity and topography data. We find that the lithosphere beneath East Africa maintains significant flexural strength in extension despite localized, but intense, fracturing of the crust by normal faults that penetrate to lower crustal levels. Therefore the assumption of local isostasy (Te ∼ 0) appears invalid within the youthful Western rift system.
Fractal nature of stratigraphic sequences

Orders of stratigraphic sequences are being used loosely and with widely varying definitions. The orders seem to be subdivisions of convenience rather than an indication of natural structure. It is proposed that, at least at time scales of 103–106 yr, sequences and systems tracts are scale-invariant fractal features in which units bounded by exposure surfaces and units bounded by flooding surfaces are about equally likely. Support for this conceptual model derives from the well-known facts that (1) sediment architecture is largely scale invariant over a wide range of scales in time and space; (2) first-order trends of sea-level movements and sedimentation rates are fractal on all geologically relevant time scales; and (3) detailed studies in carbonates indicate approximately equal abundance of flooding surfaces and demonstrable exposure surfaces among unit boundaries. Finally, traces of prograding shelf edges that step up and step down in response to sea-level changes are demonstrated in this study to have a fractal nature.
Radiocarbon-dated Mytilus edulis and Modiolus modiolus from northern Svalbard: Climatic implications

Eighteen new age determinations on Mytilus edulis shells from northern Svalbard and two new age determinations on Modiolus modiolus shells are presented. Mytilus edulis appeared on the northern coast of Spitsbergen c . 9400 yr BP. Its maximum extension there seems to have been c . 7250 yr BP, which is also indicative of a climatic optimum. The first finding of Modiolus modiolus shells from northern Spitsbergen is reported, and revealed the age of c . 8300 yr BP, which is also indicative of marine climatic optimum conditions. Mytilus lived at the head of Woodfjorden until at least 5300 yr BP, but it is not possible to date its final disappearance from the northern coast. Mytilus has been absent from large parts of the coasts of Svalbard during the entire Holocene, indicating limited influence of warm Atlantic water there. Recent reports of living Mytilus edulis on Bjørnøya indicate a probable new occurrence there, and the question about a further immigration to Spitsbergen should be kept in mind. Such a faunistic change may provide data about a more general climatic warming in this part of the Arctic.
Enzymatic activities in a soil amended with organic wastes at semiarid field conditions

A field experiment to determine changes in soil enzymatic activities responding to various fertilizer applications was carried out at semiarid climatic conditions in central Spain. The field was cultivated with barley, and compost of municipal solid waste at amounts of 20 and 80 Mg ha−1 was added and compared with mineral fertilizer and cow manure (20 Mg ha−1) additions. Enzymatic activities in the soil: urease, phos‐phatase, N‐α‐benzoyl‐L‐argininamide (BAA) hydrolyzing, and casein hydrolyzing activities were determinated at earing (April) and harvest times (end of June). Enzymatic activities were higher at earing than at harvest time, due to favorable environmental conditions. Soils with compost at two application amounts (20 and 80 Mg ha−1) displayed the highest values of urease and BAA hydrolyzing activities, and the urease activity was positively correlated (p ≤ 0.05) with the C and N amount in the soil at earing time. At harvest time, all enzymatic activity values decreased to levels equal to control.
A theory for local evaporation (or heat transfer) from rough and smooth surfaces at ground level

A model proposed earlier (Brutsaert, 1965) for evaporation as a molecular diffusion process into a turbulent atmosphere is extended by joining it with the similarity models for turbulent transfer in the surface sublayer. The assumed mechanisms were suggested by available flow visualization studies near smooth and rough walls; the theoretical result is in good agreement with available experimental evidence. The important dimensionless parameters governing the phenomenon near the surface are the Dalton (or Stanton) number (i.e., mass transfer coefficient), the drag coefficient (u*2/U2), the roughness Reynolds number (u*z0/v) (except for smooth surfaces), and the Schmidt (or Prandtl) number (v/k). The proposed formulation allows the evaluation of the effects of some parameters, such as surface roughness or molecular diffusivity, that were hitherto not well understood. An important practical result is that in contrast to the drag coefficient, the Dalton number is relatively insensitive to changes in roughness length Z0.
Freshening of Subsurface Waters in the Northwest Pacific Subtropical Gyre: Observations and Dynamics

Subsurface salinity anomalies propagating between mid- and low latitudes along isopycnal surfaces have been shown to play an important role in modulating ocean and climate variability. In this study, a sustained freshening and southwestward propagation of subsurface salinity anomalies in the northwest Pacific subtropical gyre and its dynamical mechanism are investigated using observations, numerical outputs, and a predictive model. Analyses of the observations show a pronounced subsurface freshening with salinity decreasing about 0.25 PSU near the 24.5-sigma surface in the northwest Pacific subtropical gyre during 2003-11. This freshening is found to be related to the surface forcing of salinity anomalies in the outcrop zone (25 degrees-35 degrees N, 130 degrees-160 degrees E). A predictive model based on the assumption of salinity conservation along the outcrop isopycnals is derived and used to examine this surface-forcing mechanism. The resemblance between the spatial structures of the subsurface salinity derived from the predictive model and from observations and numerical outputs suggests that subsurface salinity anomalies are ventilated over the outcrop zone. A salinity anomaly with an amplitude of about 0.25 PSU generated by the surface forcing is subducted in the outcrop zone and then propagates southwestward, accompanied by potential vorticity anomalies, to the east of Luzon Strait (similar to 15 degrees N) in roughly one year. When the anomalies reach 15 degrees N, they turn and move gradually eastward toward the central Pacific, associated with an eastward countercurrent on the southern subtropical gyre.
Current structure of the south Indian Ocean

Using recently published atlas data [Olbers et al., 1992] and the Fine Resolution Antarctic Model (FRAM) [Webb et al., 1991], an investigation has been conducted into the structure of the frontal jets centered around the region of the islands of Crozet (46°27'S, 52°0'E) and Kerguelen (48°15'S, 69°10'E) in the south Indian Ocean. Geostrophic current velocities and transports were calculated from the temperature and salinity fields available from the atlas and compared with results from FRAM and previous studies. We have identified the Agulhas Return Front (ARF) and the Subtropical Front (STF), as well as the following fronts of the Antarctic Circumpolar Current (ACC): the Subantarctic Front (SAP), the Polar Front (PF), and the Southern ACC Front (SACCF), from temperature and salinity characteristics and from geostrophic currents. This analysis of model and atlas data indicates that the jets associated with the ARF, STF, and SAF are topograpliically steered into a unique frontal system north of the islands, having some of the largest temperature and salinity gradients anywhere in the world ocean. The frontal jet associated with the ARF is detectable up to 75°E and has associated with it several northward branching jets. The PF bifurcates in the region of the Ob'Lena (Conrad) seamount; subsurface and surface expressions are identified, separated by as much as 8° of latitude immediately west of the Kerguelen Plateau. The surface expression, carrying the bulk of the transport (~65 Sv), is steered through the col in the Kerguelen Plateau at 56°S, 6° south of the latitude normally associated with the PF at this meridian. On crossing the plateau it rejoins the subsurface expression. In the south, passing eastward along the margin of the Antarctic continent and through the Princess Elizabeth Trough, a frontal jet is identified transporting up to 35 Sv, believed to be the SACCF [Orsi et al., 1995], placing the southern extent of the ACC in the region at 67°S. Copyright 1996 by the American Geophysical Union.
Multiplet analysis at Coso geothermal

We have searched the Coso geothermal field (CGF) for microseismicity in seismic doublets, co-located hypocenters that appear to have nearly identical waveforms. Using 1085 high-quality events from 1993 to 1994, we identified numerous doublets, some occurring within minutes of each other. We subdivided hypocentral data into spatial clusters to reduce the computational burden and evaluated multiple cross-correlation pairs, assigning scores to each pair. As an example, one spatial cluster includes 183 events yielding 96 high-correlation (>0.6) paired events. To isolate potential multiplets, equivalence class analysis and cluster analysis routines were used. Among the 96 high-correlation pairs, 24 equivalence classes have been isolated. While most of these are doublets, 8 classes include 3 or more cluster members and one class includes 16 members. Relative locations were calculated using phase shifts between corresponding events. Detailed analysis of hypocenter relocations shows elongate, vertical structure with apparent random temporal variations. The multiplets do not appear to be true repeating events; rather, they are clusters of small, nearly identically oriented ruptures, perhaps representing swarms of fractures activated by fluid-pressure fluctuations. Using the small volumes encompassing each multiplet, we estimate fracture densities measure between 0.02 and 0.4 m−1 and are largest near injection wells.
Structure and evolution of the northern Barents-Kara Sea continental margin from integrated analysis of potential fields, bathymetry and sparse seismic data

SUMMARY The northern Barents–Kara Sea continental margin is a poorly investigated area because of a permanent ice cover hampering seismic exploration. The available geological and geophysical data show that the magma-poor margin developed in response to early Cenozoic breakup and subsequent opening of the Arctic Eurasia Basin. In this study, a series of crustalscale geotransects illustrating the architecture of the continental margin are constructed using sparse seismic reflection profiles and a gravity inversion method incorporating a thermal model of rifting. The continental side of the northern Barents Sea margin is underlain by Palaeozoic–Early Mesozoic deep sedimentary basins separated from the oceanic side by the marginal uplift. A bathymetry analysis complements low-resolution seismic data to predict the sedimentary depocenters beyond the shelf break. These depocenters are associated with troughs, perpendicular to the shelf edge. The depocenter in front of the St. Anna Trough may contain a sedimentary section more than 4 km thick. The gravity correction for the effect of sedimentary cover was added to the inversion. This correction used an exponential density–depth function. The inversion supports a narrow and steep continent–ocean transition (COT; ca. 100 km). The conjugate Lomonosov Ridge margin is modelled using the same technique. Palaeoreconstructions were made to predict the break-up setting. The northern Barents Sea–Lomonosov Ridge rift system can be described as an initially narrow symmetric rift. A transitional zone of extreme thinning is assumed between the oldest spreading magnetic anomaly and the stretched continental crust. The free-air gravity anomaly in the western part ofthemargincanbepredicted bytheupwelling divergentflowmodel implying theexhumation of the lower crust and the continental upper mantle within the COT. It is suggested that an episodeofshearorobliqueextensionbeforebreakupisrequiredtoexplaintheobservednarrow symmetric conjugate margins in the Eurasia Basin.
Background and delayed‐triggered swarms in the central Southern Alps, South Island, New Zealand

Low‐magnitude earthquake swarms (ML ≤ 2.8), consisting of up to 47 events of similar waveforms, have been observed repeatedly in the central Southern Alps, a rapidly uplifting orogen bounded by the transpressive Alpine Fault in the South Island of New Zealand. We compare nine background swarms recorded between November 2008 and April 2010 with five delayed‐triggered swarms that occurred after the MW 7.8 Dusky Sound and the MW 7.1 Darfield (Canterbury) earthquakes. The two types of swarms are similar in terms of the magnitudes, depths, focal mechanisms, and interevent times of the constituent microearthquakes, and appear to both involve the rupture of steeply dipping faults in highly fractured crust in a 10 km × 12 km area in the center of the SAMBA network. The delayed‐triggered swarms occurred at similar epicentral distances (c. 4.5× the rupture length of the mainshocks) to the Dusky Sound and Darfield earthquakes, commenced shortly after the passage of the surface waves, continued for ∼5 and ∼2 days, respectively, and were followed in each case by a ≥2 day long quiescent period, which may suggest clock‐advanced of faults in their failure‐cycle. Triggering thresholds of ≥0.01 MPa proposed elsewhere are similar to the dynamic stress changes computed for the Southern Alps (≥0.09 MPa). However, as 98% of the locatable triggered events occurred several hours after the surface waves had passed, the dynamic stress changes associated with the surface waves themselves are unlikely to have triggered the earthquakes directly. Instead, we suggest that the locations and delays of the triggered swarms are more consistent with triggering by pore pressure diffusion.
RED PALAEOLITHIC PIGMENTS: NATURAL HEMATITE OR HEATED GOETHITE?*

Yellow goethite (α-FeOOH) and red hematite (α-Fe 2 O 3 ) were used as pigments by Palaeolithic painters. When heated, goethite dehydrates and transforms to hematite. Archaeologists wonder whether prehistoric people knew of this property and used it. We present a way to distinguish heated goethite from natural hematite. The methods used are X-ray diffraction and transmission electron microscopy. A double 'signature', namely selective broadening of diffraction reflections and porous nanostructure, is evidenced in heated goethite. Coupled with mineralogical associations, this allows us to establish a procedure to investigate the natural or artificial origin of hematite samples. Applied to the Palaeolithic site of Troubat, it reveals no difference between the Magdalenian and Azilian cultures concerning the heat-treatment of pigments; an area specializing in heat-treating pigments may, nevertheless, have existed inside the cave, which would indicate that heating was deliberate.
On-orbit assessment of the polarization response of COCTS onboard HY-1B satellite

Polarization response could significant affect the accuracy of the radiance measured by the ocean color remote sensors, and it should be corrected before the atmospheric correction processing. For the Chinese Ocean Color and Temperature Scanner (COCTS) onboard the HY-1B satellite which was launched on 11 Apr., 2007, the design goal of the polarization response degree is less than 5% for the scanning angle less than 20°. However, the polarization response coefficients of Hy-1B/COCTS have not yet been completely measured pre-launched, which should be estimated by the on-orbit assessment method. In this paper, we have developed an on-bit assessment method of the polarization response coefficient for satellite ocean color remote sensor. First, the principle of the polarization response of the satellite ocean color sensor is introduced. Then, we provide the on-orbit assessment method of the polarization response for the satellite ocean color sensor. The method has been applied to the Aqua/MODIS to validate its applicability, and the derived polarization response coefficients consist well with the pre-launched measured values. Finally, we apply the method to the HY-1B/COCTS, and the results show that HY-1B/COCTS has large polarization response for the 412nm and 490nm bands with the maximum polarization response degree more than 30%, and the polarization responses at 443nm, 520nm and 565nm are relative small with the degree all less than 15%. The mean values of the polarization response degree are 17.2%, 9.4%, 23.2%, 7.7% and 4.7% for the first five bands of HY-1B/COCTS, respectively.
Elemental composition determined by PIXE analysis of the insoluble aerosol particles in EPICA‐Dome C ice core samples representing the last 27000 years

107 samples from the first 581 m of the EPICA ice core, Dome C, East Antarctica, representing a 27000 year record, were analysed by the PIXE technique. The concentrations of several elements (Na, Mg, Al, Si, S, Cl, K, Ca, Ti, Mn, Fe) were determined in the insoluble particles, collected by filtration from the melted ice samples. The average elemental ratios for Holocene and LGM are in agreement with continental crust values. The element depositional fluxes, evaluated from PIXE concentration data by means of the EPICA ice accumulation rate, are smaller in the Holocene than during Glacial times, confirming the differences in dust loads in the atmosphere during the contrasting climatic conditions. In Holocene, the fraction of the insoluble particle mass (estimated as the sum of the measured element oxides) agrees well with the total dust mass as determined from Coulter Counter measurements, but during the LGM the particle counting shows a larger dust mass.
Fluid flow and mixing in rough-walled fracture intersections

[1] Fracture intersections play a basic role in contaminant transport through fracture networks because they allow different fluids to mix and disperse along the flow paths. We use experimental and numerical methods to understand and improve predictions of these phenomena. Laboratory experiments of mixing between two miscible fluids were performed within an artificial, rough-walled fracture intersection made of textured glass. We also develop a numerical model of mixing based on local application of streamline routing within the irregular aperture distribution of the intersection. This model shows good agreement with the laboratory experiments, both in the amount of average mixing and in the spatial distribution of dye streamlines. The numerical model is used to generalize our results based on aperture statistics, and shows that mixing is significantly affected by how well apertures correlate across the intersection, especially as fractures are closed. We conclude that flow channelization through rough-walled intersecting fractures significantly enhances physical mixing compared to intersecting parallel plates. Relative to transport through parallel plate aperture networks, surface roughness may reduce solute dilution and increase solute dispersion.
Pollen preservation: Experimental wet‐dry cycles in saline and desalinated sediments

Abstract Experimental degradation of pollen by repeated wet‐dry cycles in saline and desalinated sediments show differences in preservation between taxa and between salinity environments. In desalinated sediment, from which the salts were removed artificially, pollen is rapidly degraded, with a significant net loss of pollen after ten wet‐dry cycles. Picea pollen, which remains identifiable even when heavily damaged, suffers greater breakage in desalinated sediments. Artemisia pollen is rapidly rendered unidentifiable by degradation of the sculptural elements in both saline and desalinated sediments. In comparison to desalinated sediments, saline sediments appear to contain less damaged pollen. Growing salt crystals may envelop the pollen grains and stabilize them against mechanical breakage otherwise incurred by flexing of the pollen wall during desiccation. Caution should be exercised when analyzing sediments subject to wet‐dry cycles, and laboratory procedures modified if necessary to avoid desiccation.