The hot, warm and cold gas in Arp 227 – an evolving poor group     

R. Rampazzo  P. Alexander  C. Carignan  M. S. Clemens  H. Cullen  O. Garrido  M. Marcelin  K. Sheth  G. Trinchieri 《Monthly notices of the Royal Astronomical Society》2006,368(2):851-863

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Asteroseismology of the β Cephei star ν Eridani – I. Photometric observations and pulsational frequency analysis     

G. Handler  R. R. Shobbrook †  M. Jerzykiewicz  K. Krisciunas  T. Tshenye  E. Rodríguez  V. Costa  A.-Y. Zhou  R. Medupe  W. M. Phorah  R. Garrido  P. J. Amado  M. Paparó  D. Zsuffa  L. Ramokgali  R. Crowe  N. Purves  R. Avila  R. Knight  E. Brassfield  P. M. Kilmartin  P. L. Cottrell 《Monthly notices of the Royal Astronomical Society》2004,347(2):454-462

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Rock Glaciers in the Patagonian Andes: An Inventory for the Monte San Lorenzo (Cerro Cochrane) Massif, 47° S          下载免费PDF全文

Daniel Falaschi  Takeo Tadono  Mariano Masiokas 《Geografiska Annaler: Series A, Physical Geography》2015,97(4):769-777

Although rock glaciers in the Central and Desert Andes of Argentina and Chile have been previously studied in detail, much less attention has been paid to the occurrence of these permafrost forms in Patagonia. Recently, however, the establishment of the Argentinean Glacier Inventory program, which intends to inventory and monitor all ice masses along the Argentinean Andes, has started a large amount of new geocryological research. The project is designed to provide reliable and worldwide comparable results, supported by well established technical procedures and background information. Presented here is the first rock glacier inventory of the Monte San Lorenzo (Cerro Cochrane) region in the southern Patagonian Andes. A total of 130 intact (9.86 km²) and 47 fossil (1.45 km²) landforms were inventoried using two 2.5 m resolution ALOS Panchromatic Remote‐sensing Instruments for Stereo Mapping images. Since the Argentinean federal initiative described above legally protects all rock glaciers in the country as water reserves, and due to the little scientific knowledge concerning rock glaciers in the vast majority of the Patagonian Andes, this inventory provides an important basis for political decision‐making and opens further geocryological research avenues for the Patagonian region in general.  相似文献   

Redox state of iron during high-pressure serpentinite dehydration   总被引：1，自引：1，他引：0  

Baptiste Debret  Nathalie Bolfan-Casanova  José Alberto Padrón-Navarta  Fatima Martin-Hernandez  Muriel Andreani  Carlos J. Garrido  Vicente López Sánchez-Vizcaíno  María Teresa Gómez-Pugnaire  Manuel Muñoz  Nicolas Trcera 《Contributions to Mineralogy and Petrology》2015,169(4):1-18

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Platinum-group elements, S, Se and Cu in highly depleted abyssal peridotites from the Mid-Atlantic Ocean Ridge (ODP Hole 1274A): Influence of hydrothermal and magmatic processes   总被引：1，自引：0，他引：1  

Claudio Marchesi  Carlos J. Garrido  Jason Harvey  José María González-Jiménez  Károly Hidas  Jean-Pierre Lorand  Fernando Gervilla 《Contributions to Mineralogy and Petrology》2013,166(5):1521-1538

Highly depleted harzburgites and dunites were recovered from ODP Hole 1274A, near the intersection between the Mid-Atlantic Ocean Ridge and the 15°20′N Fracture Zone. In addition to high degrees of partial melting, these peridotites underwent multiple episodes of melt–rock reaction and intense serpentinization and seawater alteration close to the seafloor. Low concentrations of Se, Cu and platinum-group elements (PGE) in harzburgites drilled at around 35–85 m below seafloor are consistent with the consumption of mantle sulfides after high degrees (>15–20 %) of partial melting and redistribution of chalcophile and siderophile elements into PGE-rich residual microphases. Higher concentrations of Cu, Se, Ru, Rh and Pd in harzburgites from the uppermost and lowest cores testify to late reaction with a sulfide melt. Dunites were formed by percolation of silica- and sulfur-undersaturated melts into low-Se harzburgites. Platinum-group and chalcophile elements were not mobilized during dunite formation and mostly preserve the signature of precursor harzburgites, except for higher Ru and lower Pt contents caused by precipitation and removal of platinum-group minerals. During serpentinization at low temperature (<250 °C) and reducing conditions, mantle sulfides experienced desulfurization to S-poor sulfides (mainly heazlewoodite) and awaruite. Contrary to Se and Cu, sulfur does not record the magmatic evolution of peridotites but was mostly added in hydrothermal sulfides and sulfate from seawater. Platinum-group elements were unaffected by post-magmatic low-temperature processes, except Pt and Pd that may have been slightly remobilized during oxidative seawater alteration.  相似文献   

Late Holocene palaeoenvironments of the Nutria Mansa 1 archaeological site,Argentina     

Mariano Bonomo  Alejandro Fabián Zucol  Beatriz Gutiérrez Téllez  Andrea Coradeghini  María Susana Vigna 《Journal of Paleolimnology》2009,41(2):273-296

This paper presents results of interdisciplinary palaeoenvironmental research carried out on a sediment sequence from the Nutria Mansa 1 archaeological site. This late Holocene site is located in the Pampean plains, Argentina. Siliceous microfossils were recorded (i.e. phytoliths, diatoms, chrysophytes, sponges) and micro-charcoal was analyzed. In addition, fauna identified at the site were correlated with regional palaeoclimatic evidence. Based on the microfossil associations, we concluded that the human occupations occurred beside a fluvial and brackish-freshwater lacustrine setting. Grass communities were located on its margins that developed under a warm temperate climate with evidence for dryness and marked seasonality in part of the record. Although some stratigraphic and faunal evidence indicates a possible temperature increase, these fluctuations were not sufficient to extirpate mammals of arid and cold environments.  相似文献   

A unified framework for earthquake risk assessment of transportation networks and gross regional product     

Federico Carturan  Mariano Angelo Zanini  Carlo Pellegrino  Claudio Modena 《Bulletin of Earthquake Engineering》2014,12(2):795-806

Natural threats like earthquakes, hurricanes or tsunamis have had serious impacts on communities. In the past, major earthquakes in the United States like Loma Prieta 1989, Northridge 1994, or recent events in Italy like L’Aquila 2009 or Emilia 2012 emphasized the importance of preparedness and awareness to reduce social impacts. In addition to that, earthquake damaged businesses dramatically reduced the gross regional product. Generating scenario earthquakes in a proper way is important to suitably assess the risk in bridge networks and social losses in terms of gross regional product reduction. Seismic hazard is traditionally assessed by means of probabilistic seismic hazard analysis (PSHA). Although PSHA well represents the hazard at a specific location it is not suitable for spatially distributed systems. Scenario earthquakes can overcome this problem; they represent the actual distribution of ground shaking for a spatially distributed system while being hazard consistent. In this work a methodology to generate scenario earthquakes has been proposed using a novel approach with the aim of being the basic step for investigating possible earthquake consequences in seismic areas and contributing to reduce losses.  相似文献   

HVSR estimation of site effects in Melilla (Spain) and the damage pattern from the 01/25/2016 Mw 6.3 Alborán Sea earthquake     

L&#;pez Casado  Carlos  Garrido  Jes&#;s  Delgado  Jos&#;  Pel&#;ez  Jos&#; Antonio  Henares  Jes&#;s 《Natural Hazards》2017,93(1):153-167

The January 25, 2016, Mw 6.3 Alborán Sea earthquake shook the autonomous city of Melilla (Spain) with a macro-seismic intensity of VI (EMS-98). In spite of this low intensity, significant non-structural damages were reported, whose cost was estimated in more than 13 million euros. The damages were concentrated in the modernist district, which is considered the most important and valuable part of the city. This scenario is not new in Melilla, since historical and instrumental seismicity studies based on intensities felt in Melilla have revealed that earthquakes with intensities of V–VI have a return period of approximately 25 years. However, seismic microzonation studies have not been carried out so far. In this paper, we present a seismic microzonation study based on seismic noise measurements and the foreshock, mainshock and aftershock records of the January 25, 2016, earthquake. The seismic signals were processed using the horizontal-to-vertical spectral ratio (HVSR) technique. The frequency amplification results were correlated with geological formations, and after that they were correlated with the distribution of damages. The lagoon and the recent alluvial deposits show the maximum number of damaged buildings and maximum frequency amplifications of 2–8 between 2 and 7 Hz. In the coastal deposits, some amplification in the same frequency range has been observed, but other formations show a minimum number of damaged buildings and a flat spectral response ratio. Two important factors in this damage pattern are the high vulnerability of ornamental facades characteristics (non-structural elements) of the modern architecture buildings and their location on the lagoon and the recent alluvial deposits where maximum site amplification is reached.

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Speciation and Kinetics of Trihalomethane Formation in Drinking Water in Mexico     

Sofía E. Garrido  M. Guadalupe Fonseca 《Ground Water Monitoring & Remediation》2010,30(1):79-86

Water chlorination continues to be one of the most common water disinfection processes, especially in developing countries. When natural organic matter (NOM) is present, the process produces disinfection by-products (DBPs), some of them being trihalomethanes (THMs). This study determined the presence, speciation, and kinetics of THMs formation in the water supply for the northern area of the city of Toluca, Mexico. The results show that the concentrations of THMs are below the maximum allowable limits of 200 μg/L in accordance with NOM-127-SSA1-1994. Regarding THMs speciation, the presence of chloroform was more frequently observed in domestic water; furthermore, in one sample in which bromoform was present, it dominated over the chlorine species. Regarding the kinetics of THMs formation, a maximum concentration of THMs (THMs_Max) of 13.02 μg/L was obtained, and the time required to reach 50% THMs_Max ( t ₅₀) was 39.45 min.  相似文献   

Rangeland hydrology and erosion model (RHEM) enhancements for applications on disturbed rangelands   总被引：2，自引：0，他引：2       下载免费PDF全文

Osama Z. Al‐Hamdan  Mariano Hernandez  Frederick B. Pierson  Mark A. Nearing  C. Jason Williams  Jeffrey J. Stone  Jan Boll  Mark A. Weltz 《水文研究》2015,29(3):445-457

The rangeland hydrology and erosion model (RHEM) is a new process‐based model developed by the USDA Agricultural Research Service. RHEM was initially developed for functionally intact rangelands where concentrated flow erosion is minimal and most soil loss occurs by rain splash and sheet flow erosion processes. Disturbance such as fire or woody plant encroachment can amplify overland flow erosion by increasing the likelihood of concentrated flow formation. In this study, we enhanced RHEM applications on disturbed rangelands by using a new approach for the prediction and parameterization of concentrated flow erosion. The new approach was conceptualized based on observations and results of experimental studies on rangelands disturbed by fire and/or by tree encroachment. The sediment detachment rate for concentrated flow was calculated using soil erodibility and hydraulic (flow width and stream power) parameters. Concentrated flow width was calculated based on flow discharge and slope using an equation developed specifically for disturbed rangelands. Soil detachment was assumed to begin with concentrated flow initiation. A dynamic erodibility concept was applied where concentrated flow erodibility was set to decrease exponentially during a run‐off event because of declining sediment availability. Erodibility was estimated using an empirical parameterization equation as a function of vegetation cover and surface soil texture. A dynamic partial differential sediment continuity equation was used to model the total detachment rate of concentrated flow and rain splash and sheet flow. The enhanced version of the model was evaluated against rainfall simulation data for three different sites that exhibit some degree of disturbance by fire and/or by tree encroachment. The coefficient of determination (R²) and Nash–Sutcliffe efficiency were 0.78 and 0.71, respectively, which indicates the capability of the model using the new approach for predicting soil loss on disturbed rangeland. By using the new concentrated flow modelling approach, the model was enhanced to be a practical tool that utilizes readily available vegetation and soil data for quantifying erosion and assessing erosion risk following rangeland disturbance. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献