Miracle-dz/UniFAR-FTUs huggingface dataset:
An overview of laboratory apparatuses to measure seismic attenuation in reservoir rocks

Intrinsic wave attenuation at seismic frequencies is strongly dependent on rock permeability, fluid properties, and saturation. However, in order to use attenuation as an attribute to extract information on rock/fluid properties from seismic data, experimental studies on attenuation are necessary for a better understanding of physical mechanisms that are dominant at those frequencies. An appropriate laboratory methodology to measure attenuation at seismic frequencies is the forced oscillation method, but technical challenges kept this technique from being widely used. There is a need for the standardization of devices employing this method, and a comparison of existing setups is a step towards it. Here we summarize the apparatuses based on the forced oscillation method that were built in the last 30 years and were used to measure frequency‐dependent attenuation in fluid‐saturated and/or dry reservoir rocks under small strains (10−8–10−5). We list and discuss important technical aspects to be taken into account when working with these devices or in the course of designing a new one. We also present a summary of the attenuation measurements in reservoir rock samples performed with these apparatuses so far.
Tectonic models for accretion of the Central Asian Orogenic Belt

The Central Asian Orogenic Belt (c. 1000–250 Ma) formed by accretion of island arcs, ophiolites, oceanic islands, seamounts, accretionary wedges, oceanic plateaux and microcontinents in a manner comparable with that of circum-Pacific Mesozoic–Cenozoic accretionary orogens. Palaeomagnetic and palaeofloral data indicate that early accretion (Vendian–Ordovician) took place when Baltica and Siberia were separated by a wide ocean. Island arcs and Precambrian microcontinents accreted to the active margins of the two continents or amalgamated in an oceanic setting (as in Kazakhstan) by roll-back and collision, forming a huge accretionary collage. The Palaeo-Asian Ocean closed in the Permian with formation of the Solonker suture. We evaluate contrasting tectonic models for the evolution of the orogenic belt. Current information provides little support for the main tenets of the one- or three-arc Kipchak model; current data suggest that an archipelago-type (Indonesian) model is more viable. Some diagnostic features of ridge–trench interaction are present in the Central Asian orogen (e.g. granites, adakites, boninites, near-trench magmatism, Alaskan-type mafic–ultramafic complexes, high-temperature metamorphic belts that prograde rapidly from low-grade belts, rhyolitic ash-fall tuffs). They offer a promising perspective for future investigations.
Experimental investigation of the thermal dispersivity term and its significance in the heat transport equation for flow in sediments

A review of heat and solute transport in sediments demonstrates that the use of heat as a tracer has not been experimentally evaluated under the same experimental conditions as those used for the evaluation of solute as a tracer. Furthermore, there appears to be disagreement in the earth science literature over the significance of the thermal dispersivity term. To help resolve this disagreement, detailed experimentation with typical groundwater flow velocities (Darcy range, Re < 2.5) was conducted in a specifically designed hydraulic tank containing well‐sorted saturated sand. The experiment enabled, for the first time, the precise monitoring of heat and solute tracer movement from a point source in separate runs under identical solid matrix and steady state flow conditions. Experimental results demonstrate that heat transport with natural groundwater flow velocities can reach a transition zone between conduction and convection (0.5 < Pet < 2.5). The thermal dispersion behavior can be described by using a thermal dispersivity coefficient and the square of the thermal front velocity. We propose an empirical formulation for thermal dispersion with Darcy flow in natural porous media and clarify the disagreement regarding its significance. Finally, it was observed that Darcy velocities independently derived from heat and solute experimentation show a systematic discrepancy of up to 20%, and that experimental thermal dispersion results contain significant scatter.
Humanity from African Naissance to Coming Millennia

information, such as that provided by a reflection in a mirror (Gallup, 1979), which indicates that, like us, chimpanzees have a knowledge of self. These shared behavioral traits were presumably in the repertoire of our common ancestor, which means that we evolved from a species that had the mental capacities required by those traits. Some, but not all, of these capacities are shared with the other two great ape genera, the orangs and gorillas, as well Chiarelli25/07/00+indiceIV/Com2 8-12-2000 17:08 Seite 373
Using internet-based problem-solving activities to enhance students' understanding of 3-dimensional spatial relationships

Abstract Ability to understand 3-dimensional spatial relationships is essential for students' progression in all three disciplines (Geography, Earth and Environmental Sciences) and many students find difficulty in acquiring this ability. This paper presents results for a research project exploring whether or not use of internet-based activities could enhance students' understanding of 3-dimensional spatial relationships: a project funded by the GEES Subject Centre Small-Scale Learning and Teaching Project Fund.
Propagation of impact‐induced shock waves in porous sandstone using mesoscale modeling

Generation and propagation of shock waves by meteorite impact is significantly affected by material properties such as porosity, water content, and strength. The objective of this work was to quantify processes related to the shock‐induced compaction of pore space by numerical modeling, and compare the results with data obtained in the framework of the Multidisciplinary Experimental and Modeling Impact Research Network (MEMIN) impact experiments. We use mesoscale models resolving the collapse of individual pores to validate macroscopic (homogenized) approaches describing the bulk behavior of porous and water‐saturated materials in large‐scale models of crater formation, and to quantify localized shock amplification as a result of pore space crushing. We carried out a suite of numerical models of planar shock wave propagation through a well‐defined area (the “sample”) of porous and/or water‐saturated material. The porous sample is either represented by a homogeneous unit where porosity is treated as a state variable (macroscale model) and water content by an equation of state for mixed material (ANEOS) or by a defined number of individually resolved pores (mesoscale model). We varied porosity and water content and measured thermodynamic parameters such as shock wave velocity and particle velocity on meso‐ and macroscales in separate simulations. The mesoscale models provide additional data on the heterogeneous distribution of peak shock pressures as a consequence of the complex superposition of reflecting rarefaction waves and shock waves originating from the crushing of pores. We quantify the bulk effect of porosity, the reduction in shock pressure, in terms of Hugoniot data as a function of porosity, water content, and strength of a quartzite matrix. We find a good agreement between meso‐, macroscale models and Hugoniot data from shock experiments. We also propose a combination of a porosity compaction model (ε–α model) that was previously only used for porous materials and the ANEOS for water‐saturated quartzite (all pore space is filled with water) to describe the behavior of partially water‐saturated material during shock compression. Localized amplification of shock pressures results from pore collapse and can reach as much as four times the average shock pressure in the porous sample. This may explain the often observed localized high shock pressure phases next to more or less unshocked grains in impactites and meteorites.
Lake Superior Seismic Experiment: Shots and travel times

An extensive and detailed study of the crust and upper mantle in the Lake Superior region was undertaken as part of the International Upper Mantle Project. The shot and station locations and the first-arrival travel times of the 13 participating institutions are presented, together with a description of the experiment. Detailed interpretations of these results will be published individually by the participants at later dates. Several unusual observations have been noted: The velocity in the upper part of the crust exceeds 6.5 km/sec in most of the region, Pn apparent velocities in excess of 9 km/sec were observed at the east end of the lake for a segment of the travel-time curve, and the 1-ton shots were recorded at a range of more than 2500 km.
Temperature—plant pigment—optical relations in a recurrent offshore mesoscale eddy near Point Conception, California

The temperature—plant pigment—optical structure of a mesoscale anticyclonic eddy consistently found in shipboard surveys and satellite-sensed data several hundred kilometers southwest of Point Conception, California, is described on three different time scales (100-day mesoscale, annual, and several-year). The satellite coastal zone color scanner (CZCS) ocean color imagery detected the near-surface chlorophyll structure of the eddy, but in situ optical and plant pigment data suggest that such imagery does not provide a good estimate of the integrated chlorophyll field of the eddy. The temperature and plant pigment boundaries of the eddy, as determined from two-dimensional gradients of advanced very high resolution radiometer (AVHRR) and CZCS imagery, do not coincide spatially. This and in situ temperature, plant pigment, and optical structure provide additional evidence that some eddy systems in the California Current are not isolated vortex systems but rather continuously entrain waters of nonlocal origin laterally into their upper layers. Within the California Current a ratio of AVHRR/CZCS data is useful for separating inshore from oceanic water masses and following their surface entrainment by offshore vortices. The historical 28-year California Cooperative Oceanic Fisheries Investigations data for the Point Conception region of the California Current and remotely sensed data over this region show that the Point Conception eddy is a recurrent feature in the offshore California Current. Moreover, the available data provide evidence that a large number of warm-core mesoscale eddies occur simultaneously in a transition zone between coastal and oceanic regimes, that these features recur at preferred locations within the transition zone, and that this family of eddies should impose a significant offshore boundary condition on the flow of the California Current.
New aeromagnetic data from the western Enderby Basin and consequences for Antarctic‐India break‐up

In order to enhance our understanding of the continental break‐up between East India and Antarctica, a Japanese/German aerogeophysical survey was conducted off eastern Dronning Maud Land and western Enderby Land, Antarctica. The systematic survey with a line spacing of 20 km provides strong constraints on the timing of the initial break‐up of India/Antarctica compared to the conjugate margin south of Sri Lanka. While the continent‐ocean transition is very well marked by pronounced positive and negative magnetic anomalies, no hints on the existence of magnetic spreading anomalies north of this zone has been found in the new data set. Thus, in contrast to most recently published models, the data only support kinematic models, which include a final break‐up of Sri Lanka/India from our investigated area some 90‐118 Ma within the Cretaceous Normal Superchron.
Empirical Issues in Syntax and Semantics 5

Many European languages have two second person pronouns, on e for i formal and one forformal address, such as French tu andvous, respectively. 1 Such pronouns pose an interesting problem for number agreement. A second person formal subject pronoun tr iggers plural agreement on the finite verb regardless of whether the referent is one addressee or m ultiple addressees. Number agreement on non-finite elements, meanwhile, corresponds to semantic number, i.e. cardinality. 2 Thus when used with singular reference, such pronouns trigger mixed a greement. Examples from French and Bulgarian are given in (1) and (2). 3
On the genesis of Rabbit Lake and other unconformity-type uranium deposits in northern Saskatchewan, Canada

A description is given of the geology, mineralogy, and geochemistry of the Rabbit Lake deposit, located in the immediate vicinity of the unconformity between an Aphebian/Archean metamorphosed basement and overlying unmetamorphosed sandstones of the Helikian Athabasca Formation. In the deposit several stages of alteration, mineralization, remobilization, and redeposition, separated by intermittent brecciation, are recognized. The alterations, predominantly chloritization with some tourmalinization, silicification, and dolomitization, are accompanied by introduction of H 2 O, MgO, probably also B, and by leaching of SiO 2 , Na 2 O, K 2 O, CaO, and Sigma Fe 2 O 3 . The deposit is of complex mineralogy and typified by a broad suite of elements including U, Ni, Co, Cu, Pb, Zn, Fe, Mn, As, S, and Se.In the history of the deposit conditions have repeatedly oscillated between oxidizing and reducing, and the temporal relationships between oxidizing, reducing, and mineralizing episodes indicate the importance of redox reactions in shaping the deposit.After comparison with other unconformity-type deposits in the Athabasca Basin, a diagenetic-hydrothermal metallogenetic model is presented. The model invokes percolation of oxidizing diagenetic solutions in the Athabasca Formation, which, being heated under the influence of the geothermal gradient, eventually attained temperatures of around 200 degrees C at the floor of the basin. Reaction of the heated diagenetic solutions with graphitic basement rocks generated methane, which acted as a mobile reductant. Mineralization resulted from interaction of flows of the methane-bearing reducing solutions and the oxidizing diagenetic solutions. The latter have carried the ore constituents to the site of reduction and, hence, of deposition.The ore constituents may have been derived from the Athabasca Formation by leaching during a process of intrastratal weathering and oxidation. Thus, in a broad sense, processes governing the formation of the Saskatchewan unconformity-type deposits may have been similar to those that give rise to sandstone-type roll-front deposits.
Simple discrete-time self-exciting models can describe complex dynamic processes: A case study of COVID-19

Hawkes processes are a form of self-exciting process that has been used in numerous applications, including neuroscience, seismology, and terrorism. While these self-exciting processes have a simple formulation, they can model incredibly complex phenomena. Traditionally Hawkes processes are a continuous-time process, however we enable these models to be applied to a wider range of problems by considering a discrete-time variant of Hawkes processes. We illustrate this through the novel coronavirus disease (COVID-19) as a substantive case study. While alternative models, such as compartmental and growth curve models, have been widely applied to the COVID-19 epidemic, the use of discrete-time Hawkes processes allows us to gain alternative insights. This paper evaluates the capability of discrete-time Hawkes processes by modelling daily mortality counts as distinct phases in the COVID-19 outbreak. We first consider the initial stage of exponential growth and the subsequent decline as preventative measures become effective. We then explore subsequent phases with more recent data. Various countries that have been adversely affected by the epidemic are considered, namely, Brazil, China, France, Germany, India, Italy, Spain, Sweden, the United Kingdom and the United States. These countries are all unique concerning the spread of the virus and their corresponding response measures. However, we find that this simple model is useful in accurately capturing the dynamics of the process, despite hidden interactions that are not directly modelled due to their complexity, and differences both within and between countries. The utility of this model is not confined to the current COVID-19 epidemic, rather this model could explain many other complex phenomena. It is of interest to have simple models that adequately describe these complex processes with unknown dynamics. As models become more complex, a simpler representation of the process can be desirable for the sake of parsimony.
Biostratigrafia a foraminiferi del Cretaceo Superiore della successione di Parco Priore (Calcare di Altamura, Piattaforma Apula, Italia Meridionale)

This study focuses on the biostratigraphic analysis of an Upper Cretaceous 57 m-thick stratigraphic sedimentary succession outcropping in a quarry at Parco Priore, near the city of Altamura in the Murge (Southern Italy). In the studied area the Upper Cretaceous shallow water carbonate successions represent restricted facies deposited in inner shelf settings within the Apulian Platform (sensu D’Argenio, 1974). During the Mesozoic, the Apulian Platform was one of the peri-adriatic platforms (D’Argenio, 1974) localized along the southern margin of the Tethys. These platforms have been often compared to the presentday Bahamas islands for their general shape, size, subsidence rates as well as their inner platform architecture (Bernoulli, 2001). The studied sedimentary succession, belonging to the Calcare di Altamura formation, is mainly characterised by bedded white-reddish bioclastic, often re-crystallised or dolomitised, mudstones/ wackestones. White-grey calcarenitic and calcisiltitic bedded limestones and thin bedded palaeosoil levels are also present. The micropalaeontological assemblage is dominated by benthic foraminifers (Accordiella conica, Cuneolina pavonia, Moncharmontia apenninica, Minouxia conica, Rotorbinella scarsellai, Dicyclina schlumbergeri, Murgeina apula, Cuneolina spp., Pseudolituonella sp., Aeolisaccus kotori, miliolids, textularids) and dasycladacean algae (mainly Thaumatoporella parvovesiculifera). This benthic association allows to refer the Parco Priore succession to the Coniacian‒lower Campanian time interval. Sedimentological, lithological and micropalaeontological characteristics of the studied succession point to a low-energy inner carbonate platform setting with occasional subaerial exposures. [Upper Cretaceous benthic foraminiferal biostratigraphy of Parco Priore (Calcare di Altamura formation, Apulian Platform, southern Italy)]
Planktonic foraminifera from the Lower Cretaceous of Rio Argos sections (southern Spain) and biostratigraphic implications

Abstract The study of planktonic foraminifera from the Lower Cretaceous succession along the Rio Argos (Caravaca, southern Spain) revealed that this group started to diversify much earlier than previously thought. Direct correlation with ammonites shows that, after the first diversification in the early Valanginian, planktonic foraminifera increased remarkably in abundance and number of species at the beginning of the Barremian. More than 10 species occur in the upper Barremian part of the section. The evolutionary appearance of several taxa is shown to have occurred earlier than previously recorded. In particular, the genus Globigerinelloides appeared in the late Valanginian ( G. gottisi ), with G. blowi and G. aptiense first occurring in the early late Barremian, when all Globigerinelloides registered an acme. Hedbergella similis, H. kuznetsovae , and the clavihedbergellids appeared in the early Barremian, followed by a new diversification in the early Aptian. Based on these observations, a new zonation is proposed.
Remote response of the East Asian winter monsoon to tropical forcing related to El Niño-Southern Oscillation

[1] The mechanism of the East Asian winter monsoon variability in response to El Nino−Southern Oscillation (ENSO)-related tropical forcing is investigated using Japanese long-term reanalysis project data, additionally aided by the Japan Meteorological Agency climate data assimilation system. There are at least two different responses, zonally symmetric and asymmetric, of the Asian jet over South Asia to the ENSO-related tropical convective forcing during the Northern Hemisphere winter. The zonally symmetric response, induced by zonally extended anomalous convection from the Philippine Sea through southern India and Sri Lanka, is pronounced at the mature phase of ENSO. The zonally asymmetric response is intimately associated with anomalous convection localized in the vicinity of the Philippine and South China seas, accompanied by an anomalous Walker circulation cell between the Maritime Continent and tropical Indian Ocean. When this asymmetric response is prominent, ENSO-related anomalous convection can give rise to a change in the East Asian winter monsoon system through stationary Rossby wave propagation along the South Asian waveguide. The North Atlantic Oscillation (NAO)-related extratropical forcing is also a crucial factor and contributes not only to the downstream development of subpolar teleconnections across northern Eurasia but also to the reinforcement of the zonally asymmetric pattern of the Asian jet over South Asia, resulting in a significant effect on the East Asian winter monsoon circulation. A combination of the ENSO- and NAO-related forcing plays a vital role in triggering the occurrence of extraordinary anomalous monsoon circulations, such as extremely heavy snowfall in the 2005/2006 winter in Japan.
Dielectric Method for Prediction of Porosity of Saturated Soil

The electromagnetic theory of Maxwell‐Fricke for the electrical conduction through heterogeneous media is extended to develop a theoretical relationship for fluid‐saturated porous media, accounting for the orientation of particles, the porosity and the dielectric constants of the pore fluid, the solid phase and the mixture. Based on this relationship, it is shown that a knowledge of the dielectric constants of saturated soils in the horizontal and vertical directions at high frequencies around 50 MHz provides the necessary data for the evaluation of the porosity for most soils when the dielectric constants of the particle and the solution are known. The method provides a rapid means for laboratory evaluation of the porosity of any saturated soil. It may also be adopted to in situ evaluations of the porosity of any saturated soil.