Rupture Process During the 2015 Illapel,Chile Earthquake: Zigzag-Along-Dip Rupture Episodes     

Ryo Okuwaki  Yuji Yagi  Rafael Aránguiz  Juan González  Gabriel González 《Pure and Applied Geophysics》2016,173(4):1011-1020

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The 16 September 2015 Chile Tsunami from the Post-Tsunami Survey and Numerical Modeling Perspectives     

Rafael Aránguiz  Gabriel González  Juan González  Patricio A. Catalán  Rodrigo Cienfuegos  Yuji Yagi  Ryo Okuwaki  Luisa Urra  Karla Contreras  Ian Del Rio  Camilo Rojas 《Pure and Applied Geophysics》2016,173(2):333-348

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Running safety assessment of trains moving over bridges subjected to moderate earthquakes          下载免费PDF全文

P. A. Montenegro  R. Calçada  N. Vila Pouca  M. Tanabe 《地震工程与结构动力学》2016,45(3):483-504

A study about the running safety of trains moving over bridges subjected to earthquakes is presented. The study focuses on moderate earthquakes with relatively small return periods and high probability of occurrence. The analyses are performed using a nonlinear train‐bridge interaction method proposed by the authors, being the running safety evaluated with safety criteria existent in the literature. The influence on the train running safety of the seismic intensity levels, train running speed, and track quality is evaluated. Because no significant nonlinearity is likely to be exhibited in the columns for moderate levels of seismicity, the analyses are performed in the elastic domain. However, the reduction in the columns stiffness due to cracking is accounted, and a methodology to compute their effective stiffness is proposed. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Hydraulic characterization and hydrological behaviour of a pilot permeable pavement in an urban centre,Brazil   总被引：1，自引：0，他引：1       下载免费PDF全文

Artur Paiva Coutinho  Laurent Lassabatere  Suzana Montenegro  Antônio Celso Dantas Antonino  Rafael Angulo‐Jaramillo  Jaime J. S. P. Cabral 《水文研究》2016,30(23):4242-4254

Considering all the alterations on hydrology and water quality that urbanization process brings, permeable pavement (PP) is an alternative to traditional impermeable asphalt and concrete pavement. The goal of the PP and other low impact development devices is to increase infiltration and reduce peak runoff flows. These structures are barely used in Brazil aiming stormwater management, one of the big hydrological issues in cities throughout the country, with increasing urbanization rates. The main objective of this paper is the hydraulic characterization of a PP and the assessment of its hydrological efficiency from the point of view of the infiltration process. The study focuses on a pilot area in a parking lot in an urban area (Recife, Brazil). Soil elements filling the voids between concrete elements were sampled (particle size density, water contents) and tested with water infiltration experiments at several points of the 3 m × 1.5 m surface pilot area. Beerkan Estimation of Soil Transfer parameters algorithm was applied to the infiltration experiment data to obtain the hydraulic characteristics of the soil composing the PP surface layer, the concrete grid pavers (with internal voids filled with natural soil) permeability being neglected. Results show that the soil hydraulic characteristics vary spatially within the pilot area and that the soil samples have different hydraulic behaviours. The hydraulic characteristics derived from Beerkan Estimation of Soil Transfer parameters analysis were implemented into Hydrus code to simulate runoff, infiltration and water balance over a year. The numerical simulation showed the good potential of the PP for rainfall–runoff management, which demonstrates that PP can be used to retrofit existing parking infrastructure and to promote hydrological behaviour close to natural soils. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Phytoplankton community variations in tropical coastal area affected where submarine groundwater occurs     

Luis Troccoli-Ghinaglia  Jorge A. Herrera-Silveira  Francisco A. Comín  José Rafael Díaz-Ramos 《Continental Shelf Research》2010

The influence of subterranean water discharge on phytoplankton was studied at two localities (Progreso and Dzilam) on the northern coast of the Yucatan Peninsula. Hydrographic and phytoplankton samples were taken monthly between September 1998 and August 1999. High concentration of silicate (>65 μmol L⁻¹) and nitrate (>80 μmol L⁻¹) and low salinity showed the influence of submerged groundwater discharge (SGD) in the area. In Dzilam, hydrological conditions shows low salinity and high concentration of nitrate and silicate favored from the SGD. Meanwhile, high concentrations of ammonium, nitrite, and phosphate at Progreso (>150 000 inhabitants) suggest mixing of SGD and domestic waste waters. Thick-valve pennate diatoms dominated at Dzilam while dinoflagellates dominated in Progreso. Hydrological differences in both study zones suggest that local forcings, and interaction between coastal water masses and SGD plays an important role in hydrological conditions and primary productivity in the coastal zone of Yucatan. The anthropogenic modified SGD in Progreso may affect the nutrient regime and phytoplankton community structure, and may be used as indicator of eutrophication.  相似文献   

POTASSIUM—ARGON AGE OF THE RACO METEORITE (ARGENTINA)     

Rafael R. Gonzlez  Manuel A. Cabrera 《Meteoritics & planetary science》1971,6(3):159-160

The Raco meteorite fell in Raco, a small village in the Province of Tucumán, Argentina, on November 17, 1957. In the Centro de Pesquisas Geocronologicas of the University of Sao Paulo (Brazil), the authors determined its K-Ar age: 4.400±28 m.y.  相似文献   

The Santa Filomena meteorite shower: Trajectory,classification, and opaque phases as indicators of metamorphic conditions     

Amanda Tosi  Maria Elizabeth Zucolotto  Diana Paula Andrade  Othon Cabo Winter  Daniela Cardozo Mourão  Rafael Sfair  Karen Ziegler  Pablo Daniel Perez  Sergio Suarez  Iara Deniz Ornellas  Marcelo Zurita  Julio Cezar Mendes  Alexander Wilhelm Kellner  Wania Wolff 《Meteoritics & planetary science》2023,58(5):621-642

On August 19, 2020, at 13:18—UTC, a meteor event ended as a meteorite shower in Santa Filomena, a city in the Pernambuco State, northeast Brazil. The heliocentric orbital parameters resulting from images by cameras of the weather broadcasting system were semimajor axis a = 2.1 ± 0.1 au, eccentricity e = 0.55 ± 0.03, and inclination i = 0.15^o ± 0.05. The data identified the body as an Apollo object, an Earth-crossing object with a pericenter interior to the Earth's orbit. The chemical, mineralogical, and petrological evaluations, as well as the physical analysis, followed several traditional techniques. The meteorite was identified as a H5-6 S4 W0 ordinary chondrite genomict breccia. The large amount of metal in the meteorite made a metallographic evaluation based on the opaque phases possible. The monocrystalline kamacite crystals suggest a higher petrological type and the distorted Neumann lines imply at least two different shock events. The absence of the plessite phase shows that the meteorite did not reach the highest shock levels S5 and S6. The well-defined polycrystalline taenite is indicative of petrologic types 4 and 5 due to the conserved internal tetrataenite rim at the boundaries. The presence of polycrystalline taenites and the characteristics of the Agrell Effect suggest that the Santa Filomena meteorite did not reheat above 700°C. The absence of martensite confirms reheating temperatures <800°C and a slow cooling rate. The Ni contents and sizes of the zoned taenite particles indicate a slow cooling rate ranging from 1 to 10 K Myr⁻¹.  相似文献   

Characterization of the ecological quality of the coastal Gulf of Lions (NW Mediterranean). A comparative approach based on three biotic indices   总被引：1，自引：0，他引：1  

Labrune C  Amouroux JM  Sarda R  Dutrieux E  Thorin S  Rosenberg R  Grémare A 《Marine pollution bulletin》2006,52(1):34-47

The ecological quality of the Gulf of Lions coast was assessed using three biotic indices (H', AMBI and BQI). The three indices correlated positively. The positive correlation between AMBI and BQI was surprising and was mostly due to the fact that the dominant species Ditrupa arietina featured a low ES50(0.05) but was classified in GI by AMBI. Both H' and BQI were efficient in distinguishing impacted from un-impacted sites but AMBI was not. Differences between H' and BQI were mainly due to the scale used to translate indices in terms of EcoQ. The three indices were able to detect the major changes in macrofauna composition, which occurred in the Bay of Banyuls-sur-Mer during the last 40years. However, the interpretations of such changes in terms of EcoQ differed between indices. These results are discussed relative to the characteristics of the tested indices.  相似文献   

Assessing the extent of induced leakage to an urban aquifer using environmental tracers: an example from Bishkek, capital of Kyrgyzstan, Central Asia   总被引：2，自引：1，他引：1  

Brian L. Morris  W. George Darling  Daren C. Gooddy  Rafael G. Litvak  Ilka Neumann  Ekaterina J. Nemaltseva  Inna Poddubnaia 《Hydrogeology Journal》2006,14(1-2):225-243

A groundwater residence time study of the deep fluvioglacial aquifer supplying Bishkek, capital of Kyrgyzstan, has found evidence of deep infiltration of recent recharge both in the main periurban wellfield and below the city. Commonly-employed hydrochemical markers detected urban influence in the city-centre to depths of 65–100 m, but gave no indication of the important role of induced river/canal bed leakage, either upgradient in the periurban wellfield or within the city. This was revealed by O and H stable isotope measurements, which showed that local rainfall/snowfall play little part in the aquifer water balance. More remarkably, the universal detection of CFCs and SF₆, including in boreholes with 140–220 m deep upper screens, demonstrated that induced leakage of water just a few decades old had penetrated much deeper into the aquifer system than other hydrochemical markers indicated. A two-dimensional flow model set up to test whether such deep pumping-induced leakage could occur below the periurban wellfield confirmed its feasibility. The results imply vertical infiltration rates of 5–10 m/year and demonstrate that in this not-uncommon intergranular aquifer setting, deep boreholes with deep screen settings do not necessarily abstract old water. Hence, there are major implications for urban groundwater management and protection in such settings.

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Resumen Un estudio sobre el tiempo de residencia del agua subterránea, en un acuífero fluvioglacial profundo que abastece a Bishkek, capital de Kyrgyzstan, ha encontrado evidencias de infiltración profunda a partir de recarga reciente, tanto en el campo de pozos de las afueras de la ciudad, como también por debajo de la ciudad. Los indicadores hidroquímicos comúnmente usados, detectaron influencia urbana en el centro de la ciudad hasta profundidades de 65–100 m, pero no dieron indicación del papel importante del goteo inducido en el lecho del canal/río, tanto aguas arriba en el campo de pozos de los suburbios, como también dentro de la ciudad. Esto se reveló mediante mediciones de isótopos estables de O y H, las cuales mostraron que las precipitaciones/nevadas de tipo local, tienen una pequeña contribución en el balance de agua del acuífero. De manera más notoria, la detección universal de CFCs y SF6, incluidos en las rejillas superiores de pozos profundos con 140–220 m de profundidad, demostraron que un goteo inducido de agua, de solo unas pocas décadas de antigüedad, ha penetrado mucho más profundo dentro del sistema acuífero, de lo que los otros marcadores hidroquímicos indicaban. Un modelo bidimensional de flujo, realizado para probar si el goteo inducido—bombeo profundo podía suceder debajo del campo de pozos suburbano, confirmó su factibilidad. Los resultados implican tasas de infiltración vertical de 5 a 10 m/año, y demuestran que los pozos profundos con tramos de rejilla también profundos, no necesariamente extraen aguas antiguas, en estos ambientes acuíferos con porosidad intergranular. Por lo tanto, hay implicaciones importantes para la gestión y protección en zonas urbanas, y para esos ambientes de las aguas subterráneas.

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Résumé Lanalyse du temps de résidence des eaux souterraines dans un aquifère fluvial profond, dorigine glaciaire, qui alimente en eau Bishek, la capitale de Kyrgyzstan a mis en évidence une recharge récente tant dans le captage en eau que sous la ville même. Les traceurs chimiques ont indiqué linfluence urbaine dans le centre de la ville, à une profondeur de 65–100 m, mais ils nont pas mis en évidence le rôle important de lalimentation induite par la couche du fleuve, tant en amont, dans le captage que en aval, dans la ville. Ces effets ont été relevés par des isotopes stables, comme O et h qui ont montré linfluence récente des précipitations dans le bilan hydrique de laquifère. De plus, la détection universelle de CFC et de SF6, y compris dans les forages ayant une profondeur de 140–220 m, montre que lalimentation en eau induite de plusieurs décennies a pénétré à des profondeurs plus grandes que celles indiqués par des traceurs chimiques. Les possibilités dune drainance verticale induite par les pompages dans le puits profonds du captage ont été vérifiées par un modèle bidimensionnel découlement. Les résultats de la modélisation ont conduit à une infiltration verticale de 5–10 m/an et ont démontré aussi que leau extraite par des puits profonds dans un aquifère granulaire nest pas nécessairement dage ancienne. Il sagit donc des implications majeures concernant la gestion et la protection des captages urbaines en eaux souterraines

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Status of the science instruments and their detector plans at the giant magellan telescope     

Gustavo A. Rahmer  Rafael Millan-Gabet 《Astronomische Nachrichten》2023,344(8-9):e20230079

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