Miracle-dz/UniFAR-FTUs huggingface dataset:
A new, improved and fully automatic method for teleseismic depth estimation of moderate earthquakes (4.5 < M < 5.5): application to the Guerrero subduction zone (Mexico)

S U M M A R Y The depth of an earthquake is difficult to estimate because of the trade-off between depth and origin time estimations, and because it can be biased by lateral Earth heterogeneities. To face this challenge, we have developed a new, blind and fully automatic teleseismic depth analysis. The results of this new method do not depend on epistemic uncertainties due to depth-phase picking and identification. The method consists of a modification of the cepstral analysis from Letort et al. and Bonner et al., which aims to detect surface reflected (pP, sP) waves in a signal at teleseismic distances (30◦–90◦) through the study of the spectral holes in the shape of the signal spectrum. The ability of our automatic method to improve depth estimations is shown by relocation of the recent moderate seismicity of the Guerrero subduction area (Mexico). We have therefore estimated the depth of 152 events using teleseismic data from the IRIS stations and arrays. One advantage of this method is that it can be applied for single stations (from IRIS) as well as for classical arrays. In the Guerrero area, our new cepstral analysis efficiently clusters event locations and provides an improved view of the geometry of the subduction. Moreover, we have also validated our method through relocation of the same events using the new International Seismological Centre (ISC)-locator algorithm, as well as comparing our cepstral depths with the available Harvard–Centroid Moment Tensor (CMT) solutions and the three available ground thrust (GT5) events (where lateral localization is assumed to be well constrained with uncertainty <5 km) for this area. These comparisons indicate an overestimation of focal depths in the ISC catalogue for deeper parts of the subduction, and they show a systematic bias between the estimated cepstral depths and the ISC-locator depths. Using information from the CMT catalogue relating to the predominant focal mechanism for this area, this bias can be explained as a misidentification of sP phases by pP phases, which shows the greater interest for the use of this new automatic cepstral analysis, as it is less sensitive to phase identification.
Arsenic hazard in shallow Cambodian groundwaters

Abstract Our recent discovery of hazardous concentrations of arsenic in shallow sedimentary aquifers in Cambodia raises the spectre of future deleterious health impacts on a population that, particularly in non-urban areas, extensively use untreated groundwater as a source of drinking water and, in some instances, as irrigation water. We present here small-scale hazard maps for arsenic in shallow Cambodian groundwaters based on >1000 groundwater samples analysed in the Manchester Analytical Geochemistry Unit and elsewhere. Key indicators for hazardous concentrations of arsenic in Cambodian groundwaters include: (1) well depths greater than 16 m; (2) Holocene host sediments; and (3) proximity to major modem channels of the Mekong (and its distributary the Bassac). However, high-arsenic well waters are also commonly found in wells not exhibiting these key characteristics, notably in some shallower Holocene wells, and in wells drilled into older Quaternary and Neogene sediments. It is emphasized that the maps and tables presented are most useful for identifying current regional trends in groundwater arsenic hazard and that their use for predicting arsenic concentrations in individual wells, for example for the purposes of well switching, is not recommended, particularly because of the lack of sufficient data (especially at depths >80 m) and because, as in Bangladesh and West Bengal, there is considerable heterogeneity of groundwater arsenic concentrations on a scale of metres to hundreds of metres. We have insufficient data at this time to determine unequivocally whether or not arsenic concentrations are increasing in shallow Cambodian groundwaters as a result of groundwater-abstraction activities.
Performance of lucerne-grass pastures on Wakanui silt loam

Abstract Lucerne-grass pastures were established by overdrilling ‘Grasslands Ariki’ ryegrass and ‘Grasslands Apanui’ cocksfoot into Medicago sativa Link ‘Wairau’, a “hay” type lucerne, and M. glutinosa M. Bieb. ‘College Glutinosa’, a “grazing” type lucerne. Where pastures were grazed at the early-flowering stage of lucerne growth in warm season, yield of both grasses in cool season of the first year from over-drilling was similar, contributing 11–12% to annual total dry herbage production. Ryegrass did not persist beyond summer of the second year of measurement, or cocksfoot beyond summer of the third year. The yield of legume was higher from M. sativa than from M. glutinosa in the third year. In the second and third years, grazing at more frequent intervals than the early-flowering stage of lucerne growth substantially reduced lucerne yield and only slightly increased grass yield. Where grazing management aimed for maximum yield of lucerne in warm season, the inclusion of perennial grasses gave no sustai.
Neoproterozoic sedimentation on the northeast margin of Laurentia and the opening of Iapetus

Abstract Very thick shallow water sedimentary sequences were deposited in Neoproterozoic time along the future margins of Laurentia. On the eastern margin these include the Eleonore Bay and Hecla Hoek sequences of Greenland and Svalbard; these are described and their geotectonic context briefly reviewed. They present both geotectonic and geodynamic problems: why did subsidence continue for some 300 Ma prior to the opening of Iapetus, and how could 15–20 km of sediment be accommodated in an ensialic environment? Prolonged slow stretching appears to have affected the eastern margin of Laurentia while the western (Cordilleran) margin progressed through the rift-drift transition as the Pacific opened. It is proposed that expansion of the Pacific was associated with both the convergence of Proto-Gondwanan continental terranes during the Pan-African orogeny (the extended SWEAT hypothesis) and also the maintenance of very slow extension rates on the future Iapetus margin. The strain-hardening effect of slow stretching may have been inhibited by a continuous basin-fill of juvenile heat-producing Grenville detritus. The onset of subduction in the Pacific freed up this margin; major rifting took place between East Greenland and possibly the Tornquist margin of Baltica in Vendian time, followed by the opening of northern Iapetus.
Sea-level curve for Pennsylvanian eustatic marine transgressive-regressive depositional cycles along midcontinent outcrop belt, North America

At least 55 cycles of marine inundation and withdrawal are recognized in the mid-Desmoinesian to mid-Virgilian Midcontinent outcrop sequence in North America. They range from widespread major cycles (classic cyclothems) with deep-water facies extending across the northern shelf, through intermediate cycles persisting as marine horizons across the shelf, to minor cycles developed on the lower shelf or as parts of major cycles. Biostratigraphic differentiation of the cycles should establish interbasinal correlation on a scale fine enough to allow evaluation of differential tectonics and sedimentation. Sequential groupings of cycles are more irregular than proposed megacyclothems or mesothems, but they may be obscured by the distinctness of the major cyclothems. Estimates of cycle periods range from about 40 to 120 x 10/sup 3/ yr for the minor cycles up to about 235 to 400 x 10/sup 3/ yr for the major cyclothems. The range for all cycles corresponds well to the range of periods of Earth's orbital parameters that constitute the Milankovitch insolation theory for the Pleistocene ice ages, and it further supports Gondwanan glacial control for the Pennsylvanian cycles. Even though the dominant period of the major Pennsylvanian cyclothems is up to four times longer than the dominant 100,000-yr period inmore » the Pleistocene, the shapes of both curves display rapid marine transgression (rapid melting of ice caps) and slow interrupted regression (slow buildup of ice caps), which suggest similar linkages between the climatic effects of the orbital parameters and ice-cap formation and melting, at the two different scales, widely separated in time. 28 references, 3 figures. « less
Tools to Improve the Process of Engineering Design: An Analysis of Team Configuration and Project Support

The purpose of this research was to determine how team design and project management (planning and tracking) affected planning and design performance and the people involved in the process. A laboratory study was conducted to evaluate three factors: team design (individuals versus groups of three), project support (no project support versus manual project support versus automated project support), and the engineering design life-cycle, which includes conceptual design, preliminary design, and detailed design. There were six observations per treatment, involving a total of 72 undergraduate engineering students. The impact of these factors were evaluated for planning time, design cycle time, cost effectiveness, cost variance, schedule variance, mental workload, and job satisfaction. For treatments that called for groups, group process was evaluated in addition to group workload. The results showed groups took 61% more time to plan their projects compared to individuals (p<0.01). Planning time was 31% longer for participants with manual support compared to those with automated project support (p<0.01). Schedule variance (p<0.01) and cost variance (p<0.001) decreased 24% and 23%, respectively, over time during the design process. The design cycle time was 17% longer for participants without project support compared to those with automated project support (p<0.05). During design, groups and individuals allocated their time differently (p<0.05). Mental workload, measured with the NASA Task Load Index (TLX), showed workload increased 16% over time (p<0.001). In addition, the combination of design phase and project tracking support affected the TLX (p<0.01). Job satisfaction was 5% lower at the end of the design project compared to the beginning of design (p<0.05). From the analysis on group process, the type of project support affected the group process during planning. Groups with manual support interacted 83% more than those with automated support (effective behaviors: p<0.01; ineffective behaviors: p<0.05). During design, the roles individuals played within the group affected how much they contributed to the group’s process (effective behaviors: p<0.0001; ineffective behaviors: p<0.01). There were several practical implications that can be drawn from this study. In the decision to use teams versus groups, there was evidence that groups were able to attend to more of the design requirements than individuals, which resulted in the design of systems with higher reliability. However the tradeoff of using groups were in the labor cost and in longer planning and status report meetings. Therefore the organization’s goals need to be carefully considered before selecting the team design. For project support, there were clear benefits to automating the planning process. Automation resulted in better Gantt chart and planning sessions that were completed more quickly compared to those with manual support. Furthermore, systems designed with automated support resulted in lower design costs compared to systems designed without project support.
The effect of wind speed and bed slope on sand transport

This paper reports on a wind tunnel study of the effects of bed slope and wind speed on aeolian mass transport. The use of a sloping wind tunnel has enabled estimation of the friction angle α to be about 40° for saltating particles in the range 170–540 μm. A formula relating dimensionless mass transport to friction speed and bed slope is proposed, and mass transport data for five uniform sand samples and one non‐uniform sand sample are shown to fit the equation well. In particular, the relationship reveals an overshoot in mass transport slightly above threshold collisions, a feature also evident when previous experimental data is re‐examined. As the number of mid‐air collisions between the saltating particles increases greatly with wind speed, the overshoot may occur as a result of increasing energy losses resulting from the collisions. Finally, it is demonstrated that data for saltating snow shows a similar overshoot in the dimensionless transport rate.
Comportamiento de los indicadores biológicos del suelo en unidades lecheras

Para evaluar el comportamiento de los indicadores biologicos del suelo se seleccionaron seis unidades de produccion vacuna, ubicadas en el municipio San Jose de las Lajas, en la provincia Mayabeque. Se tuvieron en cuenta las siguientes condiciones: tipo de suelo, pastizales y sistemas de manejo. Se estudiaron diferentes indicadores de la actividad de la microflora (respiracion basal e inducida por diferentes sustratos y actividad celulolitica), la macro y mesofauna. La actividad de la biomasa microbiana presento pocas diferencias entre las unidades. Las magnitudes de la respiracion basal en los suelos fue alta (0.85-1.18 mg CO2. g suelo-1). Todos los suelos respondieron a la adicion de carbono, nitrogeno y fosforo. Desde el punto de vista de la calidad microbiologica, los de las unidades cuatro y cinco presentaron las mejores condiciones. En los diferentes agroecosistemas de pastizales se encontraron poblaciones de mesofauna. No se pudo predecir la dinamica poblacional de estos grupos en los meses de muestreo. Se determino el menor numero de acaros y chollebolos con respecto a otros insectos. En la macrofauna del suelo hubo diferencias (P < 0.001) en cuanto al numero de individuos y la biomasa entre los dos estratos estudiados en todas las unidades, excepto en la uno y cuatro. Las unidades tres, cuatro y cinco mostraron valores superiores, entre 2.5 y 2.33 individuos m-2. Sin embargo, la uno (14 de Valle del Peru) y dos (Genetico 4), que presentaron menores poblaciones, tuvieron valores de biomasa superiores. Las lombrices, las larvas de coleopteros y las hormigas constituyeron los grupos principales en los ecosistemas estudiados. Los suelos no presentan signos de degradacion microbiologica y estuvieron presentes los demas grupos edaficos del suelo (meso y macrofauna). Se concluye que los indicadores biologicos en todas las unidades estudiadas son apropiados. Se recomienda continuar esta investigacion a largo plazo y realizar nuevos
Seismic reflectivity anomalies in sediments at the eastern flank of the Juan de Fuca Ridge: Evidence for fluid migration?

A high-resolution seismic survey was carried out in the vicinity of Ocean Drilling Program (ODP) Leg 168 drill sites at the eastern flank of the Juan de Fuca Ridge. Three seismic systems with different source frequencies up to 4000 Hz were used simultaneously along each seismic line. The data sets were combined to provide the best possible resolution at any given depth level. An integrated interpretation of narrow zones of low reflection amplitudes is presented, which are related to basement highs but are independent of seafloor topography. The effect is most pronounced above a buried basement ridge in the vicinity of ODP Sites 1030 and 1031, where higher porosity values are present. Higher porosities can reduce seismic impedance contrasts and may therefore cause the observed low reflection amplitudes. In addition, Biot-Stoll's [Biot, 1956a, b; Stoll, 1989] model suggests that attenuation coefficients are porosity dependent and reflection amplitudes are further decreased at higher seismic frequencies when porosity increases. Since zones of higher porosities are potential pathways for fluids, they may be associated with hydrothermally driven fluid discharge, which was previously predicted above the buried basement ridge. It is therefore proposed that the observed seismic amplitude reduction in the vicinity of ODP Sites 1030 and 1031 indicates zones of upward fluid migration.
The nature of Martian fluids based on mobile element studies in salt‐assemblages from Martian meteorites

The S, Cl, and Br abundances determined in salt assemblages in Nakhla and Lafayette olivine fracture fillings and in gas-rich impact-melt (GRIM) glasses from Shergotty and EET79001 Lithologies A & B using EMPA/EDS/APS X-ray Microprobe techniques are compared with the S and Cl abundances determined by Gooding and coworkers in similar samples using quadrupole mass-spectrometric techniques. All the analytical methods yield relatively high Cl and low SO{sub 3} abundances in Nakhla indicating a SO{sub 3}/Cl ratio of {approx}0.2. The same ratio in Lafayette secondary salts seems to be {approx}2. In the case of GRIM glasses from Shergotty and EET79001 Lith A & Lith B, the SO{sub 3} abundance is found to be high whereas the Cl abundance is low yielding a SO{sub 3}/Cl ratio of {approx}5--300 (large errors are associated with these ratios because of low Cl signals). The salts found in Nakhla fracturefillings are inferred to have formed from Cl-rich fluids (high pH) near nakhlite source region on Mars, whereas the secondary minerals found in shergottite GRIM glasses seem to be associated with SO{sub 3}-rich fluids (low pH) near shergottite source region on Mars. The Cl-rich fluids seem to have infiltrated into the nakhlite source region {approx}600 Ma ago,more » whereas the SO{sub 3}-rich fluids likely percolated into the shergottite source region at {approx}180 Ma (or less) suggesting the possible existence of two types of fluid sources on Mars. « less
Tangibilidade e intangibilidade na determinação do desempenho superior e persistente de firmas brasileiras

Preconiza a RBV que os recursos e competencias sao distribuidos de forma heterogenea entre as firmas de determinada industria, sendo, portanto, a principal causa da variacao observada no desempenho das empresas. Quando esses recursos sao raros, valorosos e dificeis de serem imitados e a firma dispoe de uma estrutura organizacional adequada para explora-los, eles tem o potencial de promover o desempenho superior e persistente da empresa. Utilizando o modelo adaptado de Villalonga (2004), a presente pesquisa foi realizada com o objetivo inicial de avaliar se o desempenho superior e persistente das firmas tem alguma relacao com a intangibilidade dos recursos das mesmas. No momento seguinte, verificou-se se o desempenho superior e persistente das empresas foi influenciado pela variacao da tangibilidade de seus recursos. O desempenho da firma foi medido pelo lucro especifico da firma (LEF), calculado pela diferenca entre o retorno sobre o ativo (ROA) da firma e o valor medio do ROA do setor da economia do qual a empresa faz parte. Desempenho superior indicou que a firma apresentou LEF acima da media do setor e desempenho persistente indicou que o desempenho superior permaneceu no longo prazo. A intangibilidade dos recursos foi medida pelo Q de Tobin e a tangibilidade pela variacao do PL. A amostra foi constituida por empresas brasileiras de capital aberto com acoes listadas na Bovespa e com informacoes disponiveis na base de dados da Consultoria Economatica®. As tecnicas estatisticas utilizadas foram regressoes multivariadas usando o metodo de Minimos Quadrados Ordinarios (MQO), analises de painel estatico com estimativas por efeitos fixos (EF) e efeitos aleatorios (EA) e painel dinâmico com estimativas pelo Metodo dos Momentos Generalizados (GMM). Os principais resultados encontrados sugerem que, para a realidade brasileira, a intangibilidade dos recursos e um fator que contribui para o desempenho acima da media das firmas. No entanto, essa influencia e perceptivel de forma positiva e significativa em poucos setores da economia. Mesmo contribuindo para o desempenho superior, a intangibilidade dos ativos nao se revelou como vantagem competitiva sustentavel, pois foi constatado que esses recursos nao contribuem para a persistencia do desempenho superior das firmas, divergindo assim de resultados obtidos em outros estudos. Existem evidencias estatisticas de que a variacao dos recursos tangiveis tem importância para explicar o desempenho acima da media das firmas brasileiras. No entanto, percebe-se uma influencia bastante variavel entre os setores da economia. Alem de contribuir para o desempenho superior, a tangibilidade dos recursos pode ser considerada como uma fonte de vantagem competitiva sustentavel, pois contribuiu de forma significativa para a sustentabilidade do desempenho superior das firmas de diversos setores da economia.
Some dinoflagellate cysts from the Kimmeridge Clay Formation in North Yorkshire and Dorset, UK

SUMMARY Four new dinoflagellate cyst species are described; Circulodinium copei sp. nov., Rhynchodiniopsis martonense sp. nov. and Trichodinium piaseckii sp. nov. are from the Kimmeridge Clay Formation of North Yorkshire (Kimmeridgian, Pectinatites pectinatus Zone), and Senoniasphaera clavelli sp. nov. is from the Kimmeridge Clay Formation (Kimmeridgian, Aulacostephanous autissiodorensis Zone) in Dorset, England. These taxa have potential for use as stratigraphic markers and have also been recorded from equivalent sediments in the North Sea, Mid-Norway and Barents Sea areas.
Upper Famennian and Lower Tournaisian sections of the Moravian Karst (Moravo‐Silesian Zone, Czech Republic): a proposed key area for correlation of the conodont and foraminiferal zonations

Foraminiferal and conodont faunas at the Devonian–Carboniferous (D–C) boundary in the southern part of the Moravian Karst (Czech Republic) were studied in different facies of the basin slope. The joint presence of foraminifers and conodonts in calciturbidites along with a positive δ13C excursion of the Hangenberg anoxic event enabled the high‐resolution calibration of the late Famennian–early Tournaisian interval (Upper expansa–crenulata conodont zones). The conodont stratigraphic and biofacies succession reveals a strong correlation with other European areas. The Siphonodella sulcata morphotype (close to Group 1 sensu Kaiser and Corradini and “nov. gen. nov. sp. 1” sensu Tragelehn) enters prior to the Hangenberg Event, which resembles Upper and Uppermost Famennian conodont successions from Franconia, Bavaria and Morocco. The diversification of the early siphonodellids takes place after the Hangenberg Event and after the protognathodid radiation. In terms of foraminiferal biostratigraphy, the D–C boundary interval is characterized by the first appearance datum (FAD) of Tournayellina pseudobeata close below the D–C boundary followed by a sequence of Tournaisian bioevents, where apart from the last appearance datums (LADs) of quasiendothyrs, the FADs of the Neoseptaglomospiranella species and chernyshinellids play an important role in a similar manner as in Eastern Europe. The correlation of these bioevents elsewhere is often hindered by glacioeustatically‐driven unconformities and widespread occurrences of unfavourable facies for plurilocular foraminifers (Malevka beds and Bisphaera beds). Copyright © 2013 John Wiley & Sons, Ltd.