Wind Transport of Radionuclide- Bearing Dust, Peña Blanca, Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Velarde, R.; Goodell, P. C.; Gill, T. E.; Arimoto, R.

2007-05-01

This investigation evaluates radionuclide fractionation during wind erosion of high-grade uranium ore storage piles at Peña Blanca (50km north of Chihuahua City), Chihuahua, Mexico. The aridity of the local environment promotes dust resuspension by high winds. Although active operations ceased in 1983, the Peña Blanca mining district is one of Mexico`s most important uranium ore reserves. The study site contains piles of high grade ore, left loose on the surface, and separated by the specific deposits from which they were derived (Margaritas, Nopal I, and Puerto I). Similar locations do not exist in the United States, since uranium mining sites in the USA have been reclaimed. The Peña Blanca site serves as an analog for the Yucca Mountain project. Dust deposition is collected at Peña Blanca with BSNE sediment catchers (Fryrear, 1986) and marble dust traps (Reheis, 1999). These devices capture windblown sediment; subsequently, the sample data will help quantify potentially radioactive short term field sediment loss from the repository surface and determine sediment flux. Aerosols and surface materials will be analyzed and radioactivity levels established utilizing techniques such as gamma spectroscopy. As a result, we will be able to estimate how much radionuclide contaminated dust is being transported or attached geochemically to fine grain soils or minerals (e.g., clays or iron oxides). The high-grade uranium-bearing material is at secular equilibrium, thus the entire decay series is present. Of resulting interest is not only the aeolian transport of uranium, but also of the other daughter products. These studies will improve our understanding of geochemical cycling of radionuclides with respect to sources, transport, and deposition. The results may also have important implications for the geosciences and homeland security, and potential applications to public health. Funding for this project is provided in part via a NSF grant to Arimoto.

The Marine Ecology of the Laguna San Rafael (Southern Chile): Ice Scour and Opportunism

NASA Astrophysics Data System (ADS)

Davenport, John

1995-07-01

Surveys of the intertidal fauna and flora, the plankton, fish, birds and marine mammals of the Laguna San Rafael were carried out by a Raleigh International Expedition in January-February 1993. The Laguna is dominated by the effects of scouring, low temperature and low salinity produced by the calving, tide-water San Rafael glacier that discharges into the Laguna. The fauna and flora are simple and largely limited to a small sector of the Laguna, relatively unaffected by ice. There is a predominance of herbivorous fish, ducks, geese and swans, feeding mainly on macroalgae. Penguins, cormorants, sea lions and porpoises make up the top predators. The strandline is influenced by very heavy rainfall and supports a fauna of freshwater and terrestrial molluscs and earthworms, fed upon by birds and frogs. Large numbers of mussels are present in the north-eastern sector of the Laguna, but many are found in poor condition, high on the shore. It is suggested that poor condition and mortality are caused by large calving waves that dislodge mussels. Such waves are caused by occasional loss of massive quantities of ice from the glacier.

LAGUNA DESIGN STUDY, Underground infrastructures and engineering

NASA Astrophysics Data System (ADS)

Nuijten, Guido Alexander

2011-07-01

The European Commission has awarded the LAGUNA project a grant of 1.7 million euro for a Design Study from the seventh framework program of research and technology development (FP7-INFRASTRUCTURES - 2007-1) in 2008. The purpose of this two year work is to study the feasibility of the considered experiments and prepare a conceptual design of the required underground infrastructure. It is due to deliver a report that allows the funding agencies to decide on the realization of the experiment and to select the site and the technology. The result of this work is the first step towards fulfilling the goals of LAGUNA. The work will continue with EU funding to study the possibilities more thoroughly. The LAGUNA project is included in the future plans prepared by European funding organizations. (Astroparticle physics in Europe). It is recommended that a new large European infrastructure is put forward, as a future international multi-purpose facility for improved studies on proton decay and low-energy neutrinos from astrophysical origin. The three detection techniques being studied for such large detectors in Europe, Water-Cherenkov (like MEMPHYS), liquid scintillator (like LENA) and liquid argon (like GLACIER), are evaluated in the context of a common design study which should also address the underground infrastructure and the possibility of an eventual detection of future accelerator neutrino beams. The design study is also to take into account worldwide efforts and converge, on a time scale of 2010, to a common proposal.

Lichenometry in the Cordillera Blanca, Peru: “Little Ice Age” moraine chronology

NASA Astrophysics Data System (ADS)

Solomina, Olga; Jomelli, Vincent; Kaser, Georg; Ames, Alcides; Berger, Bernhard; Pouyaud, Bernard

2007-10-01

This paper is a comparison and compilation of lichenometric and geomorphic studies performed by two independent teams in the Cordillera Blanca, Peru, in 1996 and 2002 on 66 "Little Ice Age" moraines of 14 glaciers. Using eleven new control points, we recalibrated the initial rapid growth phase of the previously established Rhizocarpon subgenus Rhizocarpon growth curve. This curve was then used to estimate the age of "Little Ice Age" moraines. The time of deposition of the most prominent and numerous terminal and lateral moraines on the Pacific-facing side of the Cordillera Blanca (between AD 1590 and AD 1720) corresponds to the coldest and wettest phase in the tropical Andes as revealed by ice-core data. Less prominent advances occurred between AD 1780 and 1880.

How many populations set foot through the Patagonian door? Genetic composition of the current population of Bahía Blanca (Argentina) based on data from 19 Alu polymorphisms.

PubMed

Resano, M; Esteban, E; González-Pérez, E; Vía, M; Athanasiadis, G; Avena, S; Goicoechea, A; Bartomioli, M; Fernández, V; Cabrera, A; Dejean, C; Carnese, F; Moral, P

2007-01-01

The city of Bahía Blanca occupies a strategic place in Argentina south of the Pampean region in the north-east corner of the Patagonia. Since 1828, this city has been the historical and political border between Amerindian lands in the south, and the lands of European colonists. Nowadays, Bahía Blanca is an urban population mainly composed by descendents of immigrants from Spain and other European countries with apparently low admixture with Amerindians. In view of the unexpectedly high Amerindian admixture levels (about 46.7%) suggested by mtDNA data, and protein markers (19.5%), we analyzed a set of 19 Alu polymorphisms (18 autosomal, 1 of Chromosome Y) in a well-documented genealogical sample from Bahía Blanca. The genotyped sample was made up of 119 unrelated healthy individuals whose birth place and grandparent origins were fully documented. According to available genealogical records, the total sample has been subdivided into two groups: Bahía Blanca Original (64 individuals with all 4 gandparents born in Argentina) and Bahía Blanca Mix (55 individuals with one to three grandparents born out of Argentina). Allele frequencies and gene diversity values in Bahía Blanca fit well into the European ranges. Population relationships have been tested for 8 Alu markers, whose variation has been described in several Amerindian and European samples. Reynolds genetic distances underline the significant genetic similarity of Bahía Blanca to Europeans (mean distance 0.044) and their differentiation from Amerindians (0.146). Interestingly enough, when the general sample is divided, Bahía Blanca Original appears slightly closer to Amerindians (0.127) in contrast to Bahía Blanca Mix (0.161). Furthermore, the genetic relationships depicted through a principal components analysis emphasize the relative similarity of Bahía Blanca Original to Amerindians. A thorough knowledge of the sample origins has allowed us to make a subtle distinction of the genetic composition of

'Laguna Hollow'Undisturbed

NASA Technical Reports Server (NTRS)

2004-01-01

This image shows the patch of soil at the bottom of the shallow depression dubbed 'Laguna Hollow' where the Mars Exploration Rover Spirit will soon begin trenching. Scientists are intrigued by the clustering of small pebbles and the crack-like fine lines, which indicate a coherent surface that expands and contracts. A number of processes can cause materials to expand and contract, including cycles of heating and cooling; freezing and thawing; and rising and falling of salty liquids within a substance. This false-color image was created using the blue, green and infrared filters of the rover's panoramic camera. Scientists chose this particular combination of filters to enhance the heterogeneity of the martian soil.

Redhead duck behavior on lower Laguna Madre and adjacent ponds of southern Texas

USGS Publications Warehouse

Mitchell, C.A.; Custer, T.W.; Zwank, P.J.

1992-01-01

Behavior of redheads (Aythya americana) during winter was studied on the hypersaline lower Laguna Madre and adjacent freshwater to brackish water ponds of southern Texas. On Laguna Madre, feeding (46%) and sleeping (37%) were the most common behaviors. Redheads fed more during early morning (64%) than during the rest of the day (40%); feeding activity was negatively correlated with temperature. Redheads fed more often by dipping (58%) than by tipping (25%), diving (16%), or gleaning (0.1%). Water depth was least where they fed by dipping (16 cm), greatest where diving (75 cm), and intermediate where tipping (26 cm). Feeding sequences averaged 5.3 s for dipping, 8.1 s for tipping, and 19.2 s for diving. Redheads usually were present on freshwater to brackish water ponds adjacent to Laguna Madre only during daylight hours, and use of those areas declined as winter progressed. Sleeping (75%) was the most frequent behavior at ponds, followed by preening (10%), swimming (10%), and feeding (0.4%). Because redheads fed almost exclusively on shoalgrass while dipping and tipping in shallow water and shoalgrass meadows have declined in the lower Laguna Madre, proper management of the remaining shoalgrass habitat is necessary to ensure that this area remains the major wintering area for redheads.

Evolución de estrellas enanas blancas en el contexto de una constante de gravitación G variable en el tiempo

NASA Astrophysics Data System (ADS)

Benvenuto, O. G.; Althaus, L. G.; Torres, D. F.

En este trabajo se estudia por primera vez de manera autoconsistente la evolución de las estrellas enanas blancas en el caso de una constante de gravitación G variable en el tiempo. Teniendo en cuenta que: 1) las enanas blancas son en general estrellas muy viejas y 2) su fuente de energía es básicamente de origen térmico y gravitacional, estos objetos son en principio muy adecuados para analizar distintas teorías de gravitación. Los cálculos que aquí presentamos fueron realizados utilizando nuestro código de evolución estelar, el cual calcula la evolución de estrellas enanas blancas por medio del esquema iterativo de Henyey. Dicho código, basado en una descripción física muy detallada, ha sido modificado para tener en cuenta la variación del valor de G. Encontramos que un G variable (decreciente en el tiempo) modifica fuertemente la evolución de las enanas blancas, conduciendo a un rápido enfriamiento de la estrella. Nuestros resultados son comparados con recientes datos observacionales sobre la función de luminosidad de las enanas blancas.

Predictive optimal control of sewer networks using CORAL tool: application to Riera Blanca catchment in Barcelona.

PubMed

Puig, V; Cembrano, G; Romera, J; Quevedo, J; Aznar, B; Ramón, G; Cabot, J

2009-01-01

This paper deals with the global control of the Riera Blanca catchment in the Barcelona sewer network using a predictive optimal control approach. This catchment has been modelled using a conceptual modelling approach based on decomposing the catchments in subcatchments and representing them as virtual tanks. This conceptual modelling approach allows real-time model calibration and control of the sewer network. The global control problem of the Riera Blanca catchment is solved using a optimal/predictive control algorithm. To implement the predictive optimal control of the Riera Blanca catchment, a software tool named CORAL is used. The on-line control is simulated by interfacing CORAL with a high fidelity simulator of sewer networks (MOUSE). CORAL interchanges readings from the limnimeters and gate commands with MOUSE as if it was connected with the real SCADA system. Finally, the global control results obtained using the predictive optimal control are presented and compared against the results obtained using current local control system. The results obtained using the global control are very satisfactory compared to those obtained using the local control.

[Aquatic insects and water quality in Peñas Blancas watershed and reservoir].

PubMed

Mora, Meyer Guevara

2011-06-01

The aquatic insects have been used to evaluate water quality of aquatic environments. The population of aquatic insects and the water quality of the area were characterized according to the natural and human alterations present in the study site. During the monthly-survey, pH, DO, temperature, water level, DBO, PO4 and NO3 were measured. Biological indexes (abundance, species richness and the BMWP-CR) were used to evaluate the water quality. No relation between environmental and aquatic insects was detected. Temporal and spatial differences attributed to the flow events (temporal) and the presence of Peñas Blancas reservoir (spatial). In the future, the investigations in Peñas Blancas watershed need to be focused on determining the real influence of the flows, sediment release and the possible water quality degradation because of agriculture activities.

Characterization of Two Microbial Isolates from Andean Lakes in Bolivia

NASA Technical Reports Server (NTRS)

Demergasso, C.; Blamey, J.; Escudero, L.; Chong, G.; Casamayor, E. O.; Cabrol, N. A.; Grin, E. A.; Hock, A.; Kiss, A.; Borics, G.

2004-01-01

We are currently investigating the biological population present in the highest and least explored perennial lakes on earth in the Bolivian and Chilean Andes, including several volcanic crater lakes of more than 6000 m elevation, in combination of microbiological and molecular biological methods. Our samples were collected in saline lakes of the Laguna Blanca Laguna Verde area in the Bolivian Altiplano and in the Licancabur volcano crater (27 deg. 47 min S/67 deg. 47 min. W) in the ongoing project studying high altitude lakes. The main goal of the project is to look for analogies with Martian paleolakes. These Bolivian lakes can be described as Andean lakes following the classification of Chong. We have attempted to isolate pure cultures and phylogenetically characterize prokaryotes that grew under laboratory conditions. Sediment samples taken from the Licancabur crater lake (LC), Laguna Verde (LV), and Laguna Blanca (LB) were analyzed and cultured using enriched liquid media under both aerobic and anaerobic conditions. All cultures were incubated at room temperature (15 to 20 C) and under light exposure. For the reported isolates, 36 hours incubation were necessary for reaching optimal optical densities to consider them viable cultures. Ten serial dilutions starting from 1% inoculum were required to obtain a suitable enriched cell culture to transfer into solid media. Cultures on solid medium were necessary to verify the formation of colonies in order to isolate pure cultures. Different solid media were prepared using several combinations of both trace minerals and carbohydrates sources in order to fit their nutrient requirements. The microorganisms formed individual colonies on solid media enriched with tryptone, yeast extract and sodium chloride. Cells morphology was studied by optical and electronic microscopy. Rodshape morphologies were observed in most cases. Total bacterial genomic DNA was isolated from 50 ml late-exponential phase culture by using the CTAB

The Downstream Fate of Glacial Runoff and Groundwater in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

McKenzie, J. M.; Gordon, R.; Chavez, D.; Maharaj, L.; Baraer, M.; Mark, B. G.; Lautz, L. K.

2013-12-01

Rapid glacier recession in the Cordillera Blanca, Peru, is raising concerns about current and future water resources for the inhabitants of the Rio Santa watershed. Glacier meltwater buffers stream discharge throughout the range, reducing the variability of annual runoff and maintaining stream flows during the dry season. Groundwater is also an important component of dry season runoff as it can contribute as much as 50-70% to outflow in some Rio Santa tributaries. A better understanding of groundwater dynamics in high elevation watersheds is needed, including quantification of recharge, subsurface processes, and available storage. We present the results from recent groundwater studies in the Cordillera Blanca where numerous investigative techniques have been used, including ground penetrating radar, hydraulic conductivity measurements, tracer tests, and hydrochemical mixing models. Our research focuses primarily on the low-relief pampa valley floors across which glacial-melt derived rivers flow. Across the Cordillera, these valley systems cover approximately 65 km2 and are comprised of unconsolidated glacial, talus, and lacustrine deposits and wetlands. The valleys commonly have buried, permeable, talus aquifers that are overlain by relatively impermeable, glaciolacustrine deposits. Glaciofluvial outwash deposits also act as aquifers (hydraulic conductivity of 10-4 m/s). The travel time of water stored in these systems is generally less than 3-4 years and the maximum observed dry season groundwater velocity is 60 cm/day. While groundwater represents an important component of dry season water resources source of water in the Cordillera Blanca, it is also potentially vulnerable to climate change including changes in the precipitation regime and decrease in glacially derived recharge.

Flying High With Civil Air Patrol: The Sierra Blanca Civil Air Patrol Squadron.

ERIC Educational Resources Information Center

Carnicom, Gene E.

The Sierra Blanca Civil Air Patrol (CAP) Cadet Squadron from Mescalero, New Mexico, is a program funded by the tribe and the state of New Mexico for Mescalero Apache youth. The national CAP Cadet Program promotes moral leadership, aerospace education, leadership, and physical fitness; Mescalero cadets have learned self-confidence and leadership…

77 FR 49455 - Proclaiming Certain Lands as an Addition to and Becoming a Part of the Laguna Reservation for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-16

... Laguna, New Mexico. FOR FURTHER INFORMATION CONTACT: Ben Burshia, Bureau of Indian Affairs, Division of... membership. Pueblo of Laguna Indian Reservation Cibola County, New Mexico Those certain parcels of land known..., NEW MEXICO, DECEMBER 1999'', certified on December 2, 1999, by Garry P. Hugg, New Mexico Professional...

Proglacial Groundwater Flux and Storage in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Chavez, D.; McKenzie, J. M.; Baraer, M.; Mark, B. G.

2012-12-01

As tropical glaciers continue to rapidly retreat in the Cordillera Blanca, Peru, dry-season water resources are becoming more dependent on groundwater baseflow. Therefore, understanding the flux and storage of proglacial groundwater is necessary to forecast how groundwater storage can offset decreasing water resources. Recent studies of the Rio Santa Watershed, which drains the western slopes of the Cordillera Blanca, have identified that groundwater is the largest contributor to outflow from many watersheds during the dry season and that the flux of groundwater is temporarily available (< 4years). These groundwater estimates are based on chemical mass balance models that use hydrochemical and isotopic results primarily from surface water samples and stream discharge measurements. Although effective, this approach is limited by the absence of data from proglacial aquifers. In July, 2012, we installed six groundwater monitoring wells to a maximum depth of 6 m in two proglacial valleys in the Cordillera Blanca. For each well, water samples were collected for hydrochemical and isotopic analysis, slug-tests were conducted to measure hydraulic conductivity, and water levels were continuously monitored using pressure transducers. In both valleys we observed an upper layer of clay to silt sized glaciolacustrine material at each drill site. This layer was typically less than 5 m in thickness and had a low hydraulic conductivity (< 10-7 m/s). Underlying the clay layer were water bearing units of course material (either well-sorted sand/gravel or talus deposits) with an average hydraulic conductivity of 10-5 m/s. Additionally numerous discontinuous sand lenses and localized glaciofluvial gravel deposits were observed within the clay layer. The glaciolacustrine deposits behave as confining units that were capable of generating localized artesian conditions in the coarse grain units. The occurrence of the clay units adjacent to the main stream channels suggests that the

A large eruption convulsed in prehistoric times an extensive area of Catamarca, Southern Central Andes, NW Argentina

NASA Astrophysics Data System (ADS)

Fernandez-Turiel, Jose-Luis; Ratto, Norma; Perez-Torrado, Francisco-Jose; Rodriguez-Gonzalez, Alejandro; Rejas, Marta; Lobo, Agustin

2016-04-01

Geomorphological, stratigraphical, mineralogical and chemical characteristics of many recent 30-160 cm ash deposits occurring at the Bolsón de Fiambalá in Catamarca, NW Argentina, allow their correlation. This lithostratigraphic unit is named Fiambalá Ash and it is uncovered or covered by colluvial deposits and present-day aeolian deposits, reworked products of the primary fall deposits. The grain size of these ash deposits is gritty rather than silty. They are nearly unique among regional ashes in containing hornblende phenocrysts. In addition, they are made up of glass (subangular blocky shards), feldspars, biotite, and quartz; magnetite, ilmenite, apatite and titanite are scarce. The glass is rhyolitic (˜75 to 79 % m/m SiO2; ˜3 to 4 % m/m Na2O; ˜3 to 5 % m/m K2O; 1 to 2 % m/m CaO; normalized to 100 %). On the other hand, in northern margins of Fiambalá basin, extensive remnants of fines-poor pumiceous debris flows and hyperconcentrated sandflow deposits as thick as 10 m are exposed on the walls of the river gorges, where the base is usually covered, e.g., Chuquisaca River. There is no significant unconformity or intercalation of other materials, thus suggesting rapid emplacement after a single eruptive event. A preliminary age of Fiambalá Ash based on archaeological studies bracket it between 1400-1270 and 1270-980 cal a BP (OxCal 4.2.4, SHCal13, 2 sigma). The geographical distribution, the geomorphological features observed in satellite images and the information on the main trends of the stratigraphy, the abundance of hornblende and biotite in the younger proximal ash fall deposits, ignimbrites and lava-domes of the Nevado Tres Cruces complex, favours this edifice as the strongest candidate to be the source of the Upper Holocene pyroclastic deposits found in the Fiambalá basin. The archaeological records seem to evidence the abrupt environmental and societal changes associated with this major eruption. Significant areas of Catamarca were likely

Implementacion de modulos constructivistas que atiendan "misconceptions" y lagunas conceptuales en temas de la fisica en estudiantes universitarios

NASA Astrophysics Data System (ADS)

Santacruz Sarmiento, Neida M.

Este estudio se enfoco en los "misconception" y lagunas conceptuales en temas fundamentales de Fisica como son Equilibrio Termodinamico y Estatica de fluidos. En primer lugar se trabajo con la identificacion de "misconceptions" y lagunas conceptuales y se analizo en detalle la forma en que los estudiantes construyen sus propias teorias de fenomenos relacionados con los temas. Debido a la complejidad en la que los estudiantes asimilan los conceptos fisicos, se utilizo el metodo de investigacion mixto de tipo secuencial explicativo en dos etapas, una cuantitativa y otra cualitativa. La primera etapa comprendio cuatro fases: (1) Aplicacion de una prueba diagnostica para identificar el conocimiento previo y lagunas conceptuales. (2) Identificacion de "misconceptions" y lagunas del concepto a partir del conocimiento previo. (3) Implementacion de la intervencion por medio de modulos en el topico de Equilibrio Termodinamico y Estatica de Fluidos. (4) Y la realizacion de la pos prueba para analizar el impacto y la efectividad de la intervencion constructivista. En la segunda etapa se utilizo el metodo de investigacion cualitativo, por medio de una entrevista semiestructurada que partio de la elaboracion de un mapa conceptual y se finalizo con un analisis de datos conjuntamente. El desarrollo de este estudio permitio encontrar "misconceptions" y lagunas conceptuales a partir del conocimiento previo de los estudiantes participantes en los temas trabajados, que fueron atendidos en el desarrollo de las distintas actividades inquisitivas que se presentaron en el modulo constructivista. Se encontro marcadas diferencias entre la pre y pos prueba en los temas, esto se debio al requerimiento de habilidades abstractas para el tema de Estatica de Fluidos y al desarrollo intuitivo para el tema de Equilibrio Termodinamico, teniendo mejores respuestas en el segundo. Los participantes demostraron una marcada evolucion y/o cambio en sus estructuras de pensamiento, las pruebas estadisticas

Alkaline precipitation in Bahia Blanca, Argentina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piccolo, M.C.; Perillo, G.M.E.; Varela, P.

1988-02-01

The spatial, meteorological, and seasonal factors associated with precipitation pH in Bahia Blanca and its surroundings are presented. From April 1984 to April 1985, 85 rain events were studied from 12 sites that represent significant land-use sectors of the city. Mean pH for all sites ranged from 6.5 to 7.2. The area is characterized by alkaline precipitation since most stations reported maximum values in excess of 7.6. The highest values of pH were observed under the influence of continental air masses, which have traveled over the pampas soil, thus introducing large amounts of alkaline cations. The lowest pH values weremore » obtained during the winter season when marine advection introduces high concentrations of spray. Stations located close to the estuary and the industrial park present the larger effect of sea spray but also of the incidence of an incipient atmospheric contamination.« less

Empirical downscaling of atmospheric key variables above a tropical glacier surface (Cordillera Blanca, Peru)

NASA Astrophysics Data System (ADS)

Hofer, M.; Kaser, G.; Mölg, T.; Juen, I.; Wagnon, P.

2009-04-01

Glaciers in the outer tropical Cordillera Blanca (Peru, South America) are of major socio-economic importance, since glacier runoff represents the primary water source during the dry season, when little or no rainfall occurs. Due to their location at high elevations, the glaciers moreover provide important information about climate change in the tropical troposphere, where measurements are sparse. This study targets the local reconstruction of air temperature, specific humidity and wind speed above the surface of an outer tropical glacier from NCEP/NCAR reanalysis data as large scale predictors. Since a farther scope is to provide input data for process based glacier mass balance modelling, the reconstruction pursues a high temporal resolution. Hence an empirical downscaling scheme is developed, based on a few years' time series of hourly observations from automatic weather stations, located at the glacier Artesonraju and nearby moraines (Northern Cordillera Blanca). Principal component and multiple regression analyses are applied to define the appropriate spatial downscaling domain, suitable predictor variables, and the statistical transfer functions. The model performance is verified using an independent data set. The best predictors are lower tropospheric air temperature and specific humidity, at reanalysis model grid points that represent the Bolivian Altiplano, located in the South of the Cordillera Blanca. The developed downscaling model explaines a considerable portion (more than 60%) of the diurnal variance of air temperature and specific humidity at the moraine stations, and air temperature above the glacier surface. Specific humidity above the glacier surface, however, can be reconstructed well in the seasonal, but not in the required diurnal time resolution. Wind speed can only be poorly determined by the large scale predictors (r² lower than 0.3) at both sites. We assume a complex local interaction between valley and glacier wind system to be the main

Integrating Multiple Geophysical Methods to Quantify Alpine Groundwater- Surface Water Interactions: Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Glas, R. L.; Lautz, L.; McKenzie, J. M.; Baker, E. A.; Somers, L. D.; Aubry-Wake, C.; Wigmore, O.; Mark, B. G.; Moucha, R.

2016-12-01

Groundwater- surface water interactions in alpine catchments are often poorly understood as groundwater and hydrologic data are difficult to acquire in these remote areas. The Cordillera Blanca of Peru is a region where dry-season water supply is increasingly stressed due to the accelerated melting of glaciers throughout the range, affecting millions of people country-wide. The alpine valleys of the Cordillera Blanca have shown potential for significant groundwater storage and discharge to valley streams, which could buffer the dry-season variability of streamflow throughout the watershed as glaciers continue to recede. Known as pampas, the clay-rich, low-relief valley bottoms are interfingered with talus deposits, providing a likely pathway for groundwater recharged at the valley edges to be stored and slowly released to the stream throughout the year by springs. Multiple geophysical methods were used to determine areas of groundwater recharge and discharge as well as aquifer geometry of the pampa system. Seismic refraction tomography, vertical electrical sounding (VES), electrical resistivity tomography (ERT), and horizontal-to-vertical spectral ratio (HVSR) seismic methods were used to determine the physical properties of the unconsolidated valley sediments, the depth to saturation, and the depth to bedrock for a representative section of the Quilcayhuanca Valley in the Cordillera Blanca. Depth to saturation and lithological boundaries were constrained by comparing geophysical results to continuous records of water levels and sediment core logs from a network of seven piezometers installed to depths of up to 6 m. Preliminary results show an average depth to bedrock for the study area of 25 m, which varies spatially along with water table depths across the valley. The conceptual model of groundwater flow and storage derived from these geophysical data will be used to inform future groundwater flow models of the area, allowing for the prediction of groundwater

Vascular plants and a brief history of the Kiowa and Rita Blanca National Grasslands

Treesearch

Donald L. Hazlett; Michael H. Schiebout; Paulette L. Ford

2009-01-01

Administered by the USDA Forest Service, the Kiowa and Rita Blanca National Grasslands occupy 230,000 acres of public land extending from northeastern New Mexico into the panhandles of Oklahoma and Texas. A mosaic of topographic features including canyons, plateaus, rolling grasslands and outcrops supports a diverse flora. Eight hundred twenty six (826) species of...

Winter distributions of North American Plovers in the Laguna Madre regions of Tamaulipas, Mexico and Texas, USA

USGS Publications Warehouse

Mabee, Todd J.; Plissner, Jonathan H.; Haig, Susan M.; Goossen, J.P.

2001-01-01

To determine the distribution and abundance of wintering plovers in the Laguna Madre of Texas and Tamaulipas, surveys were conducted in December 1997 and February 1998, along a 160 km stretch of barrier islands in Mexico and- 40 km of shoreline on South Padre Island, Texas. Altogether, 5,673 individuals, representing six plover species, were recorded during the surveys. Black-bellied Plovers Pluvialis squatarola were the most numerous (3 ,013 individuals) representing 53% of the total number of plovers observed. Numbers of Piping Charadriusm elodu, Snowy C . alexandrinus, Semipalmated C. semipalmatus and Wilson's Plovers C. wilsonia were 739, 1,345, 561, and 13 birds, respectively. Most individuals (97%) of all species except Wilson's Plovers were observed on bayside flats of the barrier islands. Similar numbers of Piping Plovers were recorded at South Padre Island, Texas, and in the Laguna Madre de Tamaulipas. Over 85% of the individuals of each of the other species were found in the more extensively surveyed Mexico portion of Laguna Madre. In Tamaulipas, most plover species were observed more often on algal flats than any other substrate. These results provide evidence of the value of these systems as wintering areas for plover species and indicate the need for more extensive survey efforts to determine temporal and spatial variation in the distribution of these species within the Laguna ecosystem.

Ceratopetalum (Cunoniaceae) fruits of Australasian affinity from the early Eocene Laguna del Hunco flora, Patagonia, Argentina

PubMed Central

Hermsen, Elizabeth J

2017-01-01

Abstract Background and Aims Radially symmetrical, five-winged fossil fruits from the highly diverse early Eocene Laguna del Hunco flora of Chubut Province, Patagonia, Argentina, are named, described and illustrated. The main goals are to assess the affinities of the fossils and to place them in an evolutionary, palaeoecological and biogeographic context. Methods Specimens of fossil fruits were collected from the Tufolitas Laguna del Hunco. They were prepared, photographed and compared with similar extant and fossil fruits using published literature. Their structure was also evaluated by comparing them with that of modern Ceratopetalum (Cunoniaceae) fruits through examination of herbarium specimens. Key Results The Laguna del Hunco fossil fruits share the diagnostic features that characterize modern and fossil Ceratopetalum (symmetry, number of fruit wings, presence of a conspicuous floral nectary and overall venation pattern). The pattern of the minor wing (sepal) veins observed in the Patagonian fossil fruits is different from that of modern and previously described fossil Ceratopetalum fruits; therefore, a new fossil species is recognized. An apomorphy (absence of petals) suggests that the fossils belong within crown-group Ceratopetalum. Conclusions The Patagonian fossil fruits are the oldest known record for Ceratopetalum. Because the affinities, provenance and age of the fossils are so well established, this new Ceratopetalum fossil species is an excellent candidate for use as a calibration point in divergence dating studies of the family Cunoniaceae. It represents the only record of Ceratopetalum outside Australasia, and further corroborates the biogeographic connection between the Laguna del Hunco flora and ancient and modern floras of the Australasian region. PMID:28110267

Mantle to Surface Fluid Transfer Above a Flat Slab Subduction Zone: Isotopic Evidence from Hot Springs in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Newell, D. L.; Jessup, M. J.; Hilton, D. R.; Shaw, C. A.; Hughes, C. A.

2015-12-01

Thermal springs in the Cordillera Blanca, Peru, provide geochemical evidence for deeply circulated hydrothermal fluids that carry significant mantle-derived helium. The Cordillera Blanca is a ~200 km-long NNW-SSE trending mountain range in the Peruvian Andes located above an amagmatic flat-slab subduction segment. The west side of the range is bounded by the Cordillera Blanca detachment that preserves a progression of top to the west ductile shear to brittle normal faulting since ~5 Ma. We report aqueous and stable isotope geochemical results from fluid and gas samples collected in 2013 and 2015 from 13 hot springs emanating from the Cordillera Blanca detachment and associated hanging wall faults. Most springs are vigorously bubbling (degassing), and range in temperature, pH, and conductivity from 17-89 °C, 5.95-8.87, and 0.17-21.5 mS, respectively. The hottest springs issue directly from the northern segment of the detachment. Geochemically, springs are CO2-rich, alkaline-chloride to alkaline-carbonate waters, with elevated trace metal contents including Fe, Cu, As, Zn, Sb, and Tl. Notably, As contents are ≤11 ppm, indicating that thermal waters may be adversely impacting local water quality. Water δ18O and δD, trends in elemental chemistry, and cation geothermometry collectively demonstrate mixing of hot (200-260 °C) saline fluid with cold meteoric recharge along the fault. Helium isotope ratios (3He/4He) for dissolved gases in the hot springs range from 0.62 to 1.98 RC/RA, indicating the presence of ~25% mantle-derived helium, assuming mixing of an asthenospheric end-member with the crustal helium reservoir. CO2/3He and carbon stable isotope ratios indicate a carbon source derived from mixing of crustal sources with minor mantle carbon. Overall, the volatile signature overlaps with orogen-wide datasets where crustal overprinting has modified mantle contributions at active arc volcanoes. Given the long duration since active magmatism in the Cordillera

The microbial community at Laguna Figueroa, Baja California Mexico - From miles to microns

NASA Technical Reports Server (NTRS)

Stolz, J. F.

1985-01-01

The changes in the composition of the stratified microbial community in the sediments at Laguna Figeroa following floods are studied. The laguna which is located on the Pacific coast of the Baja California peninsula 200 km south of the Mexican-U.S. border is comprised of an evaporite flat and a salt marsh. Data collected from 1979-1983 using Landsat imagery, Skylab photographs, and light and transmission electron microscopy are presented. The flood conditions, which included 1-3 m of meteoric water covering the area and a remanent of 5-10 cm of siliciclastic and clay sediment, are described. The composition of the community prior to the flooding consisted of Microcoleus, Phormidium sp., a coccoid cynanobacteria, Phloroflexus, Ectothiorhodospira, Chloroflexus, Thiocapsa sp., and Chromatium. Following the floods Thiocapsa, Chromatium, Oscillatora sp., Spirulina sp., and Microcoleus are observed in the sediments.

Ceratopetalum (Cunoniaceae) fruits of Australasian affinity from the early Eocene Laguna del Hunco flora, Patagonia, Argentina.

PubMed

Gandolfo, María A; Hermsen, Elizabeth J

2017-03-01

Radially symmetrical, five-winged fossil fruits from the highly diverse early Eocene Laguna del Hunco flora of Chubut Province, Patagonia, Argentina, are named, described and illustrated. The main goals are to assess the affinities of the fossils and to place them in an evolutionary, palaeoecological and biogeographic context. Specimens of fossil fruits were collected from the Tufolitas Laguna del Hunco. They were prepared, photographed and compared with similar extant and fossil fruits using published literature. Their structure was also evaluated by comparing them with that of modern Ceratopetalum (Cunoniaceae) fruits through examination of herbarium specimens. The Laguna del Hunco fossil fruits share the diagnostic features that characterize modern and fossil Ceratopetalum (symmetry, number of fruit wings, presence of a conspicuous floral nectary and overall venation pattern). The pattern of the minor wing (sepal) veins observed in the Patagonian fossil fruits is different from that of modern and previously described fossil Ceratopetalum fruits; therefore, a new fossil species is recognized. An apomorphy (absence of petals) suggests that the fossils belong within crown-group Ceratopetalum . The Patagonian fossil fruits are the oldest known record for Ceratopetalum . Because the affinities, provenance and age of the fossils are so well established, this new Ceratopetalum fossil species is an excellent candidate for use as a calibration point in divergence dating studies of the family Cunoniaceae. It represents the only record of Ceratopetalum outside Australasia, and further corroborates the biogeographic connection between the Laguna del Hunco flora and ancient and modern floras of the Australasian region. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company.

Mapping Glacier Dynamics and Proglacial Wetlands with a Multispectral UAV at 5000m in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Wigmore, O.; Mark, B. G.

2015-12-01

The glaciers of the Cordillera Blanca, Peru are rapidly retreating as a result of rising temperatures, transforming the hydrology and impacting the socio-economic and environmental systems of the Rio Santa basin. Documenting the heterogeneous spatial patterns of these changes to understand processes of water storage and flow is hindered by technologic and logistic challenges. Highly complex topography, cloud cover and coarse spatial resolution limit the application of satellite data while airborne data collection remains costly and potentially dangerous. However, recent developments have made Unmanned Aerial Vehicle (UAV) technology a viable and potentially transformative method for studying glacier dynamics and proglacial hydrology. The extreme altitudes (4000-6700m) of the Cordillera Blanca limit the use of 'off the shelf' UAVs. Therefore we developed a low cost multispectral (visible, near-infrared and thermal infrared) multirotor UAV capable of conducting fully autonomous aerial surveys at elevations over 5000m within the glacial valleys of the Cordillera Blanca. Using this platform we have completed repeat aerial surveys (in 2014 and 2015) of the debris covered Llaca Glacier, generating highly accurate 10-20cm DEM's and 5cm orthomosaics using a structure from motion workflow. Analysis of these data reveals a highly dynamic system with some areas of the glacier losing as much as 16m of vertical elevation, while other areas have gained up to 5m of elevation over one year. The magnitude and direction of these changes appears to be associated with the presence of debris free ice faces and meltwater ponds. Additionally, we have mapped proglacial meadow and wetland systems. Thermal mosaics at 10-20cm resolution are providing novel insights into the hydrologic pathways of glacier meltwater including mapping the distribution of artesian springs that feed these wetland systems. The high spatial resolution of these UAV datasets facilitates a better understanding of the

Margaritasite: a new mineral of hydrothermal origin from the Pena Blanca uranium district, Mexico.

USGS Publications Warehouse

Wenrich, K.J.; Modreski, P.J.; Zielinski, R.A.; Seeley, J.L.

1982-01-01

Margaritasite, (Cs,K,H3O)2(UO2)2V2O8.nH2O (where Cs > K, H3O and n approx 1), a 10.514, b 8.425, c 7.25 A, beta 106.01o, P21/a, Z = 2, is a newly recognized uranium ore mineral named for the Margaritas deposit, Pena Blanca uranium district, Chihuahua, Mexico, at which it was discovered. A Cs-rich analogue of carnotite, margaritasite is the natural equivalent of synthetic Cs-uranyl vanadate (A.M. 43- 799, 50-825). A fine-grained yellow mineral, it is most easily distinguished from carnotite by XRD; X-ray powder patterns (CuKalpha radiation) show that the (001) reflection of margaritasite lies at 12.7o (2theta ), while that of carnotite is found at 13.8o (2theta ). The shift of the (001) reflection in margaritasite reflects the structural changes caused when Cs occupies the sites filled by K in carnotite. Synthesis experiments indicate that margaritasite also differs from carnotite in a higher-T hydrothermal origin. Chemical analyses and XRD data for margaritasite and synthetic Cs- carnotite, and chemical analyses for rocks from Sierra Pena Blanca and vicinity, are tabulated.-J.A.Z.

Set-up of a decision support system to support sustainable development of the Laguna de Bay, Philippines.

PubMed

Nauta, Tjitte A; Bongco, Alicia E; Santos-Borja, Adelina C

2003-01-01

Over recent decades, population expansion, deforestation, land conversion, urbanisation, intense fisheries and industrialisation have produced massive changes in the Laguna de Bay catchment, Philippines. The resulting problems include rapid siltation of the lake, eutrophication, inputs of toxics, flooding problems and loss of biodiversity. Rational and systematic resolution of conflicting water use and water allocation interests is now urgently needed in order to ensure sustainable use of the water resources. With respect to the competing and conflicting pressures on the water resources, the Laguna Lake Development Authority (LLDA) needs to achieve comprehensive management and development of the area. In view of these problems and needs, the Government of the Netherlands was funding a two-year project entitled 'Sustainable Development of the Laguna de Bay Environment'.A comprehensive tool has been developed to support decision-making at catchment level. This consists of an ArcView GIS-database linked to a state-of-the-art modelling suite, including hydrological and waste load models for the catchment area and a three-dimensional hydrodynamic and water quality model (Delft3D) linked to a habitat evaluation module for the lake. In addition, MS Office based tools to support a stakeholder analysis and financial and economic assessments have been developed. The project also focused on technical studies relating to dredging, drinking water supply and infrastructure works. These aimed to produce technically and economically feasible solutions to water quantity and quality problems. The paper also presents the findings of a study on the development of polder islands in the Laguna de Bay, addressing the water quantity and quality problems and focusing on the application of the decision support system.

Possibilities For The LAGUNA Projects At The Fréjus Site

NASA Astrophysics Data System (ADS)

Mosca, Luigi

2010-11-01

The present laboratory (LSM) at the Fréjus site and the project of a first extension of it, mainly aimed at the next generation of dark matter and double beta decay experiments, are briefly reviewed. Then the main characteristics of the LAGUNA cooperation and Design Study network are summarized. Seven underground sites in Europe are considered in LAGUNA and are under study as candidates for the installation of Megaton scale detectors using three different techniques: a liquid Argon TPC (GLACIER), a liquid scintillator detector (LENA) and a Water Cerenkov (MEMPHYS), all mainly aimed at investigation of proton decay and properties of neutrinos from SuperNovae and other astrophysical sources as well as from accelerators (Super-beams and/or Beta-beams from CERN). One of the seven sites is located at Fréjus, near the present LSM laboratory, and the results of its feasibility study are presented and discussed. Then the physics potential of a MEMPHYS detector installed in this site are emphasized both for non-accelerator and for neutrino beam based configurations. The MEMPHYNO prototype with its R&D programme is presented. Finally a possible schedule is sketched.

Constraining Subsurface Structure and Composition Using Seismic Refraction Surveys of Proglacial Valleys in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Glas, R. L.; Lautz, L.; McKenzie, J. M.; Mark, B. G.; Baker, E. A.; Aubry-Wake, C.; Somers, L. D.; Wigmore, O.

2015-12-01

As tropical glaciers rapidly recede in response to climate change, the storage and discharge of groundwater will play an increasing role in regulating river baseflow, particularly during the dry season, when stream flow is currently sustained predominantly by glacial melt. Little is understood regarding the hydrogeologic processes controlling base flow characteristics of low-gradient proglacial valleys of the Cordillera Blanca in Northwestern Peru, which has the world's highest density of tropical glaciers. To better understand the processes of groundwater storage and discharge in proglacial meadows, we completed seismic refraction surveys in three representative valleys of the Cordillera Blanca range: the Quilcayhuanca, Yanamarey, and Pachacoto valleys. The locations of survey transects were chosen based on locations of previous sediment core sampling, GPR lines, and quantification of groundwater-surface water interaction derived from dye and temperature tracing experiments. The seismic surveys consisted of 48 vertical component geophones with 2.5 m spacing. Across the three representative valleys a total of 15 surveys were conducted, covering a distance of 1800 m in cross, down, and oblique-valley directions. Preliminary interpretation of the seismic refraction data indicates a maximum imaging depth of 16 m below land surface, and a transition from glacio-lacustrine sediments to buried saturated talus at a depth of 6 m in the Quilcayhuanca valley. The organic-rich glacio-lacustrine sediments in the Yanamarey valley have seismic velocities ranging from 300 to 800 m/s and are >16 m in thickness at mid- valley. Weathered metasedimentary bedrock in the Pachacoto valley was imaged at ~5 m below the valley surface, exhibiting a p-wave velocity of 3400 m/s. The knowledge of hydrogeologic structure derived from seismic refraction surveys will provide crucial boundary conditions for future groundwater models of the valleys of the Cordillera Blanca.

Geomorphologically effective floods from moraine-dammed lakes in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Emmer, Adam

2017-12-01

Outburst floods originating in moraine-dammed lakes represent a significant geomorphological process as well as a specific type of threat for local communities in the Cordillera Blanca, Peru (8.5°-10° S; 77°-78° W). An exceptional concentration of catastrophic floods has been reported from the Cordillera Blanca in the first half of 20th Century (1930s-1950s), leading to thousands of fatalities. The main objective of this paper is to provide a revised and comprehensive overview of geomorphologically effective floods in the area of interest, using various documentary data sources, verified by analysis of remotely sensed images (1948-2013) and enhanced by original field data. Verified events (n = 28; 4 not mentioned before) are analysed from the perspective of spatiotemporal distribution, pre-flood conditions, causes, mechanisms and geomorphological impacts as well as socioeconomical consequences, revealing certain patterns and similar features. GLOFs are further classified according to their magnitude: 5 extreme events, 8 major events and 15 minor events are distinguished, referring to the quantified geomorphological and socioeconomical impacts. Selected moraine dams and flood deposits are dated using lichenometric dating. Special attention is given to moraine dam breaches - the most frequent type of water release with the most significant consequences. Selected major events and their consequences are studied in detail in a separate section. Finally, a general schematic model of lake formation, growth and post-flood evolution reflecting initial topographical setting and glacier retreat is introduced and the utilization of the obtained results is outlined.

Epithermal uranium deposits in a volcanogenic context: the example of Nopal 1 deposit, Sierra de Pena Blanca, Mexico

NASA Astrophysics Data System (ADS)

Calas, G.; Angiboust, S.; Fayek, M.; Camacho, A.; Allard, T.; Agrinier, P.

2009-12-01

The Peña Blanca molybdenum-uranium field (Chihuahua, Mexico) exhibits over 100 airborne anomalies hosted in tertiary ignimbritic ash-flow tuffs (44 Ma) overlying the Pozos conglomerate and a sequence of Cretaceous carbonate rocks. Uranium occurrences are associated with breccia zones at the intersection of two or more fault systems. Periodic reactivation of these structures associated with Basin and Range and Rio Grande tectonic events resulted in the mobilization of U and other elements by meteoric fluids heated by geothermal activity. Trace element geochemistry (U, Th, REE) provides evidence for local mobilization of uranium under oxidizing conditions. In addition, O- and H-isotope geochemistry of kaolinite, smectite, opal and calcite suggests that argillic alteration proceeded at shallow depth with meteoric water at 25-75 °C. Focussed along breccia zones, fluids precipitated several generations of pyrite and uraninite together with kaolinite, as in the Nopal 1 mine, indicating that mineralization and hydrothermal alteration of volcanic tuffs are contemporaneous. Low δ34S values (~ -24.5 ‰) of pyrites intimately associated with uraninite suggest that the reducing conditions at the origin of the U-mineralization arise from biological activity. Later, the uplift of Sierra Pena Blanca resulted in oxidation and remobilization of uranium, as confirmed by the spatial distribution of radiation-induced defect centers in kaolinites. These data show that tectonism and biogenic reducing conditions can play a major role in the formation and remobilization of uranium in epithermal deposits. By comparison with the other uranium deposits at Sierra Pena Blanca and nearby Sierra de Gomez, Nopal 1 deposit is one of the few deposits having retained a reduced uranium mineralization.

Major QTLs Control Resistance to Rice Hoja Blanca Virus and Its Vector Tagosodes orizicolus

PubMed Central

Romero, Luz E.; Lozano, Ivan; Garavito, Andrea; Carabali, Silvio J.; Triana, Monica; Villareal, Natalia; Reyes, Luis; Duque, Myriam C.; Martinez, César P.; Calvert, Lee; Lorieux, Mathias

2013-01-01

Rice hoja blanca (white leaf) disease can cause severe yield losses in rice in the Americas. The disease is caused by the rice hoja blanca virus (RHBV), which is transmitted by the planthopper vector Tagosodes orizicolus. Because classical breeding schemes for this disease rely on expensive, time-consuming screenings, there is a need for alternatives such as marker-aided selection. The varieties Fedearroz 2000 and Fedearroz 50, which are resistant to RHBV and to the feeding damage caused by T. orizicolus, were crossed with the susceptible line WC366 to produce segregating F2:3 populations. The F3 families were scored for their resistance level to RHBV and T. orizicolus. The F2:3 lines of both crosses were genotyped using microsatellite markers. One major QTL on the short arm of chromosome 4 was identified for resistance to RHBV in the two populations. Two major QTL on chromosomes 5 and 7 were identified for resistance to T. orizicolus in the Fd2000 × WC366 and Fd50 × WC366 crosses, respectively. This comparative study using two distinct rice populations allowed for a better understanding of how the resistance to RHBV and its vector are controlled genetically. Simple marker-aided breeding schemes based on QTL information can be designed to improve rice germplasm to reduce losses caused by this important disease. PMID:24240781

Morphometric or morpho-anatomal and genetic investigations highlight allopatric speciation in Western Mediterranean lagoons within the Atherina lagunae species (Teleostei, Atherinidae)

NASA Astrophysics Data System (ADS)

Trabelsi, M.; Maamouri, F.; Quignard, J.-P.; Boussaïd, M.; Faure, E.

2004-12-01

Current distribution of Atherina lagunae poses an interesting biogeographical problem as this species inhabits widely separate circum-Mediterranean lagoons. Statistical analyses of 87 biometric parameters and genetic variation in a portion of the cytochrome b gene were examined in four populations of A. lagunae from Tunisian and French lagoons. The results suggested a subdivision into two distinct Atherinid groups: one included the French lagoonal sand smelts and the second included the Tunisian ones. Tunisian lagoonal sand smelts were distinguished from the French ones by the lower number of lateral line scales, vertebrae, pectorals and first dorsal fin rays and the higher number of lower and total gillrakers. In addition, A. lagunae from Tunisian lagoons are characterised by short preorbital length, developed operculum, broad interorbital space, larger head, robust body and a relatively small first dorsal fin which is positioned backwards. In addition, intraspecific sequence variation in a portion of the cytochrome b gene was examined in 87 individuals from Tunisia and France. The high correlation between the results of the molecular phylogenetic tree and biometric statistical data analysis suggested that two different sibling species or at least sub-species or semi-species have colonised the lagoons. In addition, our analyses suggested that the evolution of A. lagunae probably occurred in two steps including marine sympatric speciation within the large Atherina boyeri complex and a post-Pleistocene colonisation of the lagoons.

Patagonian and Antarctic dust as recorded in the sediments of Laguna Potrok Aike (Patagonia, Argentina)

NASA Astrophysics Data System (ADS)

Haberzettl, Torsten; Stopp, Annemarie; Lisé-Pronovost, Agathe; Gebhardt, Catalina; Ohlendorf, Christian; Zolitschka, Bernd; von Eynatten, Hilmar; Kleinhanns, Ilka; Pasado Science Team

2010-05-01

Although an increasing number of terrestrial paleoclimatic records from southern South America has been published during the last decade, these archives mostly cover the Lateglacial and/or the Holocene. Only little is known about the Patagonian climate before the Last Glacial Maximum. Here, we present a continuous, high-resolution magnetic susceptibility record for the past 48 ka from the maar lake Laguna Potrok Aike (51°58' S, 70°23' W, southern Patagonia, Argentina). Magnetic susceptibility serves as an excellent parameter for the parallelization of sediment cores all over Laguna Potrok Aike including sediment cores taken within the ICDP (International Continental Scientific Drilling Program) project PASADO (Potrok Aike maar lake Sediment Archive Drilling prOject). Additionally, magnetic susceptibility is assumed to be a proxy for dust deposition in this lake. Distinct similarities were found between the independently dated magnetic susceptibility record from Laguna Potrok Aike and the non-sea-salt calcium (nss-Ca) flux from the EPICA Dome C ice core record (75°06'S, 123°24'E) the latter being a proxy for mineral dust deposition in Antarctica [1]. Comparison of the two records and variations in grain size of the Laguna Potrok Aike sediment records indicate a relatively high aeolian activity in southern South America during the glacial period. During the Holocene climatic conditions driving sediment deposition seem to have been more variable and less dominated by wind compared to glacial times. Although the source of the dust found in Antarctic ice cores often has been attributed to Patagonia [2], we present the first evidence for contemporaneity of aeolian deposition in both the target area (Antarctica) and the major source area (Patagonia). Considering the similarities of the two records, magnetic susceptibility might yield the potential for chronological information: transfer of the ice core age model to a lacustrine sediment record. This would be important

Relación masa-radio para estrellas enanas blancas y la interpretación de recientes mediciones hechas por Hipparcos

NASA Astrophysics Data System (ADS)

Panei, J. A.; Althaus, L. G.; Benvenuto, O. G.

Recientes mediciones de la masa y el radio hechas por Hipparcos de las estrellas enanas blancas 40 Eri B y Procyon B (Shipman, H. & Provencal, J. - ApJ. 1998, 494, 759), sugieren un núcleo compuesto de hierro para dichas estrellas, en lugar de carbono y oxígeno como predice la teoría standard de evolución estelar. Para interpretar estas observaciones, presentamos aquí, relaciones masa-radio para configuraciones degeneradas a temperatura finita para distintas composiciones químicas centrales. Para tal fin hemos calculado secuencias evolutivas de enanas blancas utilizando el código de evolución estelar, desarrollado en el Observatorio de La Plata. Dicho código resuelve las ecuaciones de estructura y evolución estelar mediante la técnica de relajación de Henyey, y esta basado en una descripción física muy detallada y actualizada.

Petrologic Constraints on the Exhumation of the Sierra Blanca Metamorphic Core Complex (AZ)

NASA Astrophysics Data System (ADS)

Koppens, K. M.; Gottardi, R.

2017-12-01

The Sierra Blanca metamorphic core complex (SBMCC), located 90 miles west of Tucson, is part of the southern belt of metamorphic core complexes that stretches across southern Arizona. The SBMCC exposes Jurassic age sedimentary rocks that have been metamorphosed by intruding Late Cretaceous peraluminous granites and pegmatites. Evidence of this magmatic episode includes polysythetic twinning in plagioclase, albite exsolution of potassium feldspar resulting in myrmekitic texture, and garnet, mica and feldspar assemblages. The magmatic fabric is overprinted by a Tertiary (Miocene?) tectonic fabric, associated with the exhumation of the Sierra Blanca metamorphic core along a low-angle detachment fault, forming the SBMCC. The NW-SE elongated dome of metamorphic rocks forms the footwall of the detachment shear zone, and is separated from the hanging wall, composed of Paleozoic and Mesozoic metasedimentary rocks, by a low-angle detachment shear zone. Foliation is defined by gneissic layering and aligned muscovite, and is generally sub-horizontal, defining the dome. The NNW-SSE mineral stretching lineation is expressed by plagioclase and K-feldspar porphyroclasts, and various shear sense indicators are all consistent with a top-to the-NNW shear sense. Lineation trends in a NNW-SSE orientation; however, plunge changes across the domiform shape of the MCC. Much of the deformation is preserved in the blastomylonitic gneiss derived from the peraluminous granite, including epidote porphyroclasts, grain boundary migration in quartz, lozenged amphiboles, mica fish, and retrograde mineral alterations. Detailed petrologic observation and microstructural analysis presented here provide thermomechanical constraints on the evolution of the SBMCC.

Ikaite precipitation in a lacustrine environment - implications for palaeoclimatic studies using carbonates from Laguna Potrok Aike (Patagonia, Argentina)

NASA Astrophysics Data System (ADS)

Oehlerich, Markus; Mayr, Christoph; Griesshaber, Erika; Lücke, Andreas; Oeckler, Oliver M.; Ohlendorf, Christian; Schmahl, Wolfgang W.; Zolitschka, Bernd

2013-07-01

The monoclinic mineral ikaite (CaCO3 · 6H2O) and its pseudomorphs are potentially important archives for palaeoenvironmental reconstructions. Natural ikaite occurs in a small temperature range near freezing point and is reported mainly from marine and only rarely from continental aquatic environments. Ikaite transforms to more stable anhydrous forms of CaCO3 after an increase in temperature or when exposed to atmospheric conditions. The knowledge about conditions for natural ikaite formation, its stable isotope fractionation factors and isotopic changes during transformation to calcite is very restricted. Here, for the first time, primary precipitation of idiomorphic ikaite and its calcite pseudomorphs are reported from a subsaline lake, Laguna Potrok Aike, in southern Argentina. The calculated stable oxygen isotope fractionation factor between lake water and ikaite-derived calcite (αPAI = 1.0324 at a temperature of 4.1 °C) is close to but differs from that of primarily inorganically precipitated calcite. Pseudomorphs after ikaite rapidly disintegrate into calcite powder that is indistinguishable from μm-sized calcite crystals in the sediment record of Laguna Potrok Aike suggesting an ikaite origin of sedimentary calcites. Therefore, the Holocene carbonates of Laguna Potrok Aike have the potential to serve as a recorder of past hydrological variation.

Limnology of Laguna Tortuguero, Puerto Rico

USGS Publications Warehouse

Quinones-Marquez, Ferdinand; Fuste, Luis A.

1978-01-01

The principal chemical, physical and biological characteristics, and the hydrology of Laguna Tortuguero, Puerto Rico, were studied from 1974-75. The lagoon, with an area of 2.24 square kilometers and a volume of about 2.68 million cubic meters, contains about 5 percent of seawater. Drainage through a canal on the north side averages 0.64 cubic meters per second per day, flushing the lagoon about 7.5 times per year. Chloride and sodium are the principal ions in the water, ranging from 300 to 700 mg/liter and 150 to 400 mg/liter, respectively. Among the nutrients, nitrogen averages about 1.7 mg/liter, exceeding phosphorus in a weight ratio of 170:1. About 10 percent of the nitrogen and 40 percent of the phosphorus entering the lagoon is retained. The bottom sediments, with a volume of about 4.5 million cubic meters, average 0.8 and 0.014 percent nitrogen and phosphorus, respectively. (Woodard-USGS)

Spatial distribution of canine zoonotic enteroparasites in Bahía Blanca, Argentina.

PubMed

La Sala, Luciano F; Leiboff, Anastasia; Burgos, Julián M; Costamagna, Sixto R

2015-01-01

The objectives of this research were: (1) to determine the occurrence of zoonotic enteroparasites in dog feces from Bahía Blanca, Argentina; (2) to characterize the spatial distribution of the parasites found in association with the quality of life index (QLI) in neighborhoods of Bahía Blanca; and (3) to determine if the presence of a particular parasite genus in a stool sample was facilitated or impeded by the presence of other parasite genera. Samples of dog stools (n=475) were collected between December 2012 and December 2013 in areas with varying QLI. The association between QLI values and the presence of parasites was analyzed using logistic regression. Overall enteroparasite occurrence was 36.6%. Parasitic forms found included nematode larvae, cysts of Blastocystis spp., Giardia spp., and oocysts of Cryptosporidium spp., and eggs of Ancylostoma caninum, Toxocara canis, cestodes and Trichuris spp. For certain enteroparasites, we detected significant associations between their occurrence and QLI. Feces collected in areas with medium and low QLI were 2.46 and 5.43 times more likely, respectively, to contain A. caninum than stools from the high-QLI area. Samples from areas with low QLI were 2.36 times more likely to contain Trichuris spp. than those from the high QLI area. Regarding protozoa, feces from areas with low QLI were 2.4 times more likely to be positive than those from areas with high QLI. We demonstrated that canine zoonotic parasites have a wide distribution in the study area, and that occurrence is higher in neighborhoods with lower QLI. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Water quality mapping of Laguna de Bay and its watershed, Philippines

NASA Astrophysics Data System (ADS)

Saito, S.; Nakano, T.; Shin, K.; Maruyama, S.; Miyakawa, C.; Yaota, K.; Kada, R.

2011-12-01

Laguna de Bay (or Laguna Lake) is the largest lake in the Philippines, with a surface area of 900 km2 and its watershed area of 2920 km2 (Santos-Borja, 2005). It is located on the southwest part of the Luzon Island and its watershed contains 5 provinces, 49 municipalities and 12 cities, including parts of Metropolitan Manila. The water quality in Laguna de Bay has significantly deteriorated due to pollution from soil erosion, effluents from chemical industries, and household discharges. In this study, we performed multiple element analysis of water samples in the lake and its watersheds for chemical mapping, which allows us to evaluate the regional distribution of elements including toxic heavy metals such as Cd, Pb and As. We collected water samples from 24 locations in Laguna de Bay and 160 locations from rivers in the watersheds. The sampling sites of river are mainly downstreams around the lake, which covers from urbanized areas to rural areas. We also collected well water samples from 17 locations, spring water samples from 10 locations, and tap water samples from 21 locations in order to compare their data with the river and lake samples and to assess the quality of household use waters. The samples were collected in dry season of the study area (March 13 - 17 and May 2 - 9, 2011). The analysis was performed at the Research Institute for Humanity and Nature (RIHN), Japan. The concentrations of the major components (Cl, NO3, SO4, Ca, Mg, Na, and K) dissolved in the samples were determined with ion chromatograph (Dionex Corporation ICS-3000). We also analyzed major and trace elements (Li, B, Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn Ga, Ge, As, Se, Rb, Sr, Y, Zr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Pb and U) with inductively coupled plasma-mass spectrometry (ICP-MS, Agilent Technologies 7500cx). The element concentrations of rivers are characterized by remarkable regional variations. For

Condensate polisher prefiltration study for Laguna Verde Station

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, A.; Oyen, L.C.; Nelson, R.A.

1995-05-01

This paper describes an analysis of the iron and copper in the condensate and the technical and economic assessment of the installation of condensate polisher prefilters in Comision Federal de Electricidad`s Laguna Verde Nuclear Generating Station (LVNGS) north of Veracruz, Mexico. LVNGS is a 654 MWe General Electric BWR plant; Unit 1 has been in commercial operation since July, 1990, and Unit 2 is scheduled to become operational in June, 1995. The primary purpose of this study was to (1) analyze the high iron and copper concentrations in the condensate and feedwater, (2) identify, assess, and evaluate techniques to reducemore » the iron and copper concentrations, and (3) perform a cost-benefit analysis of the installation of implementing the appropriate techniques.« less

Level-2 IPE for the Laguna Verde NPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arellano, J.; De Loera, M.A.; Rea, R.

1996-12-31

In response to generic letter GL 88-20, Comision Federal de Electricidad and Instituto de Investigaciones Electricas have jointly developed the individual plant examination (IPE) for the Laguna Verde nuclear power station unit I (LVNPS). This plant is a 675-MW(electric) boiling water reactor (BWR/5) with a reinforced concrete Mark-II containment. The approach used to fulfill the IPE requirements was to make a level-1 probabilistic risk assessment (IPE level 1) plus a containment performance analysis including the behavior and release of the fission products to the environment (IPE level 2). This paper describes the level-2 portion of the LVNPS IPE, paying specialmore » attention to both some improvements to the traditional analytical methods and to the main results.« less

Rock Magnetic Properties of Laguna Carmen (Tierra del Fuego, Argentina): Implications for Paleomagnetic Reconstruction

NASA Astrophysics Data System (ADS)

Gogorza, C. G.; Orgeira, M. J.; Ponce, F.; Fernández, M.; Laprida, C.; Coronato, A.

2013-05-01

We report preliminary results obtained from a multi-proxy analysis including paleomagnetic and rock-magnetic studies of two sediment cores of Laguna Carmen (53°40'60" S 68°19'0" W, ~83m asl) in the semiarid steppe in northern Tierra del Fuego island, Southernmost Patagonia, Argentina. Two short cores (115 cm) were sampled using a Livingstone piston corer during the 2011 southern fall. Sediments are massive green clays (115 to 70 cm depth) with irregularly spaced thin sandy strata and lens. Massive yellow clay with thin sandy strata continues up to 30 cm depth; from here up to 10 cm yellow massive clays domain. The topmost 10 cm are mixed yellow and green clays with fine sand. Measurements of intensity and directions of Natural Remanent Magnetization (NRM), magnetic susceptibility, isothermal remanent magnetization, saturation isothermal remanent magnetization (SIRM), back field and anhysteretic remanent magnetization at 100 mT (ARM100mT) were performed and several associated parameters calculated (ARM100mT/k and SIRM/ ARM100mT). Also, as a first estimate of relative magnetic grain-size variations, the median destructive field of the NRM (MDFNRM), was determined. Additionally, we present results of magnetic parameters measured with vibrating sample magnetometer (VSM). The stability of the NRM was analyzed by alternating field demagnetization. The magnetic properties have shown variable values, showing changes in both grain size and concentration of magnetic minerals. It was found that the main carrier of remanence is magnetite with the presence of hematite in very low percentages. This is the first paleomagnetic study performed in lakes located in the northern, semiarid fuegian steppe, where humid-dry cycles have been interpreted all along the Holocene from an aeolian paleosoil sequence (Orgeira et el, 2012). Comparison between paleomagnetic records of Laguna Carmen and results obtained in earlier studies carried out at Laguna Potrok Aike (Gogorza et al., 2012

Physical characteristics of the Bahia Blanca estuary (Argentina)

NASA Astrophysics Data System (ADS)

Piccolo, Maria Cintia; Perillo, Gerardo M. E.

1990-09-01

Based on temperature, salinity and current velocity and direction data, the physical characteristics of the Bahia Blanca estuary are described. Data were gathered in vertical profiles made in longitudinal as well as in hourly surveys. Freshwater runoff averages 2 m 3 s -1; however, peak floods may reach 10-50 m 3 s -1. The temperature distribution is quite homogeneous in the estuary. Based on the salinity distribution, the estuary can be divided into two sectors: an inner one showing partially mixed characteristics with a strong tendency to become sectionally homogeneous during runoff conditions similar to the historical averages, and an outer sector which is sectionally homogeneous. Salinity values in the inner sector may be larger than those observed in the inner continental shelf. This is initiated by the restricted circulation in the inner estuary and added to by the tidal washing of back-estuary salt flats and by evaporation processes. Analysis of the residual circulation shows a marked difference in the direction of mass transport. In the deeper regions of the sections (northern flank) the flow reverses with depth, being headward near the bottom. However, net transport is landward in the shallower parts.

Water-quality reconnaissance of Laguna Tortuguero, Vega Baja, Puerto Rico, March 1999-May 2000

USGS Publications Warehouse

Soler-Lopez, Luis; Guzman-Rios, Senen; Conde-Costas, Carlos

2006-01-01

The Laguna Tortuguero, a slightly saline to freshwater lagoon in north-central Puerto Rico, has a surface area of about 220 hectares and a mean depth of about 1.2 meters. As part of a water-quality reconnaissance, water samples were collected at about monthly and near bi-monthly intervals from March 1999 to May 2000 at four sites: three stations inside the lagoon and one station at the artificial outlet channel dredged in 1940, which connects the lagoon with the Atlantic Ocean. Physical characteristics that were determined from these water samples were pH, temperature, specific conductance, dissolved oxygen, dissolved oxygen saturation, and discharge at the outlet canal. Other water-quality constituents also were determined, including nitrogen and phosphorus species, organic carbon, chlorophyll a and b, plankton biomass, hardness, alkalinity as calcium carbonate, and major ions. Additionally, a diel study was conducted at three stations in the lagoon to obtain data on the diurnal variation of temperature, specific conductance, dissolved oxygen, and dissolved oxygen saturation. The data analysis indicates the water quality of Laguna Tortuguero complies with the Puerto Rico Environmental Quality Board standards and regulations.

Glacier Changes in the Cordillera Blanca, Peru, Derived From SPOT5 Imagery, GIS and Field- Based Measurements

NASA Astrophysics Data System (ADS)

Racoviteanu, A.; Arnaud, Y.; Williams, M. W.; Singh Khalsa, S.

2007-12-01

There is urgency in deriving an extensive dataset for deriving glacier changes within the Cordillera Blanca, Peru, in a cost-effective and timely manner. Rapid glacial retreat during the last decades in this area poses a threat for water resources, hydroelectric power and local traditions. While there is some information on decadal changes in glacier extents, there still remains a paucity of mass balance measurements and glacier parameters such as hypsometry, size distribution and termini elevations. Here we investigate decadal changes in glacier parameters for Cordillera Blanca of Peru using data from Système Probatoire d'Observation de la Terre (SPOT) sensor, an old glacier inventory from 1970 aerial photography, field-based mass balance measurements and meteorological observations. Here we focus on: constructing a geospatial glacier inventory from 2003 SPOT scenes; mass balance estimations using remote sensing and field data; frequency distribution of glacier area; changes in termini elevations; hypsometry changes over time; glacier topography (slope, aspect, length/width ratio); AAR vs. mass balance for Artesonraju and Yanamarey benchmark glaciers; precipitation and temperature trends in the region. Over the last 25 years, mean temperatures increases of 0.09 deg.C/yr were greater at lower elevation than the 0.01 deg.C/yr at higher elevations, with little change in precipitation. Comparison of the new SPOT-based glacier inventory with the 1970 inventory shows that glaciers in Cordillera Blanca retreated at a rate of 0.6% per year over the last three decades, with no significant differences in the rate of area loss between E and W side. At lower elevations there is an upward shift of glacier termini along with a decrease in glacier area. Small glaciers are losing more area than large glaciers. Based on the relationship between specific mass balance (bn) and accumulation area ratio (AAR) for the two benchmark glaciers, we predicted a steady-state equilibrium line

Macrogeographic and microgeographic genetic structure of the Chagas' disease vector Triatoma infestans (Hemiptera: Reduviidae) from Catamarca, Argentina.

PubMed

Pérez de Rosas, Alicia R; Segura, Elsa L; Fichera, Laura; García, Beatriz Alicia

2008-07-01

The genetic structure in populations of the Chagas' disease vector Triatoma infestans from six localities belonging to areas under the same insecticide treatment conditions of Catamarca province (Argentina) was examined at macrogeographical and microgeographical scales. A total of 238 insects were typed for 10 polymorphic microsatellite loci. The average observed and expected heterozygosities ranged from 0.319 to 0.549 and from 0.389 to 0.689, respectively. The present results confirm that populations of T. infestans are highly structured. Spatial genetic structure was detectable at macrogeographical and microgeographical levels. Comparisons of the levels of genetic variability between two temporal samples were carried out to assess the impact of the insecticide treatment. The genetic diversity of the population was not significantly affected after insecticide use since different genetic parameters (allele number, observed and expected heterozygosities) remained stable. However, loss of low frequency alleles and not previously found alleles were detected. The effective population size (N(e)) estimated was substantially lower in the second temporal sample than in the first; nevertheless, it is possible that the size of the remnant population after insecticide treatment was still large enough to retain the genetic diversity. Very few individuals did not belong to the local T. infestans populations as determined by assignment analyses, suggesting a low level of immigration in the population. The results of the assignment and first-generation migrant tests suggest male-biased dispersal at microgeographical level.

Identifying wells downstream from Laguna Dam that yield water that will be replaced by water from the Colorado River, Arizona and California

USGS Publications Warehouse

Owen-Joyce, Sandra J.

2000-01-01

This report summarizes a comprehensive study and development of the method documented in Owen-Joyce and others (2000). That report and one for the area upstream from Laguna Dam (Wilson and Owen-Joyce, 1994) document the accounting-surface method to identify wells that yield water that will be replaced by water from the Colorado River. Downstream from Laguna Dam, the Colorado River is the source for nearly all recharge to the river aquifer. The complex surface-water and ground-water system that exists in the area is, in part, the result of more than 100 years of water-resources development. Agriculture is the principal economy and is possible only with irrigation. The construction and operation of canals provides the means to divert and distribute Colorado River water to irrigate agricultural lands on the flood plains and mesas along the Colorado and Gila Rivers, in Imperial and Coachella Valleys, and in the area upstream from Dome along the Gila River. Water is withdrawn from wells for irrigation, dewatering, and domestic use. The area downstream from Laguna Dam borders additional areas of agricultural development in Mexico where Colorado River water also is diverted for irrigation.

Limnology in El Dorado: some surprising aspects of the regulation of phytoplankton productive capacity in a high-altitude Andean lake (Laguna de Guatavita, Colombia).

PubMed

Donato, Jhon; Jimenez, Paola; Reynolds, Colin

2012-09-01

High-altitude mountain lakes remain understudied, mostly because of their relative inaccessibility. Laguna de Guatavita, a small, equatorial, high-altitude crater lake in the Eastern Range of the Colombian Andes, was once of high cultural importance to pre-Columban inhabitants, the original location of the legendary El Dorado. We investigated the factors regulating the primary production in Laguna de Guatavita (4degrees58'50" N - 73degrees46'43" W, alt. 2 935m.a.s.l., area: 0.11km2, maximum depth: 30m), during a series of three intensive field campaigns, which were conducted over a year-long period in 2003-2004. In each, standard profiles of temperature, oxygen concentration and light intensity were determined on each of 16-18 consecutive days. Samples were collected and analysed for chlorophyll and for biologically-significant solutes in GF/F-filtered water (NH4+, NO3(-), NO2(-); soluble reactive phosphorus). Primary production was also determined, by oxygen generation, on each day of the campaign. Our results showed that the productive potential of the lake was typically modest (campaign averages of 45-90mg C/m2.h) but that many of the regulating factors were not those anticipated intuitively. The lake is demonstrably meromictic, reminiscent ofkarstic dolines in higher latitudes, its stratification being maintained by solute- concentration gradients. Light penetration is poor, attributable to the turbidity owing to fine calcite and other particulates in suspension. Net primary production in the mixolimnion of Laguna de Guavita is sensitive to day-to-day variations in solar irradiance at the surface. However, deficiencies in nutrient availability, especially nitrogen, also constrain the capacity of the lake to support a phytoplankton. We deduced that Laguna de Guatavita is something of a limnological enigma, atypical of the common anticipation of a "mountain lake". While doubtlessly not unique, comparable descriptions of similar sites elsewhere are sufficiently

A 20,000-year record of environmental change from Laguna Kollpa Kkota, Bolivia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seltzer, G.O.; Abbott, M.B.

Most records of paleoclimate in the Bolivian Andes date from the last glacial-to-interglacial transition. However, Laguna Kollpa Kkota and other lakes like it, formed more than 20,000 yr BP when glaciers retreated and moraines dammed the drainage of the valleys they are located in. These lakes were protected from subsequent periods of glaciation because the headwalls of these valleys are below the level of the late-Pleistocene glacial equilibrium-line altitude. The chemical, mineral, and microfossil stratigraphies of these glacial lakes provide continuous records of environmental change for the last 20,000 years that can be used to address several problems in paleoclimatemore » specific to tropical-subtropical latitudes. Preliminary results from Laguna Kollpa Kkota indicate that glacial equilibrium-line altitudes were never depressed more than 600 m during the last 20,000 years, suggesting that temperatures were reduced only a few-degrees celsius over this time period. Sedimentation rates and the organic carbon stratigraphy of cores reflect an increase in moisture in the late Pleistocene just prior to the transition to a warmer and drier Holocene. The pollen and diatom concentrations in the sediments are sufficient to permit the high resolution analyses needed to address whether or not there were climatic reversals during the glacial-to-interglacial transition.« less

Assessing the variability of glacier lake bathymetries and potential peak discharge based on large-scale measurements in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Cochachin, Alejo; Huggel, Christian; Salazar, Cesar; Haeberli, Wilfried; Frey, Holger

2015-04-01

Over timescales of hundreds to thousands of years ice masses in mountains produced erosion in bedrock and subglacial sediment, including the formation of overdeepenings and large moraine dams that now serve as basins for glacial lakes. Satellite based studies found a total of 8355 glacial lakes in Peru, whereof 830 lakes were observed in the Cordillera Blanca. Some of them have caused major disasters due to glacial lake outburst floods in the past decades. On the other hand, in view of shrinking glaciers, changing water resources, and formation of new lakes, glacial lakes could have a function as water reservoirs in the future. Here we present unprecedented bathymetric studies of 124 glacial lakes in the Cordillera Blanca, Huallanca, Huayhuash and Raura in the regions of Ancash, Huanuco and Lima. Measurements were carried out using a boat equipped with GPS, a total station and an echo sounder to measure the depth of the lakes. Autocad Civil 3D Land and ArcGIS were used to process the data and generate digital topographies of the lake bathymetries, and analyze parameters such as lake area, length and width, and depth and volume. Based on that, we calculated empirical equations for mean depth as related to (1) area, (2) maximum length, and (3) maximum width. We then applied these three equations to all 830 glacial lakes of the Cordillera Blanca to estimate their volumes. Eventually we used three relations from the literature to assess the peak discharge of potential lake outburst floods, based on lake volumes, resulting in 3 x 3 peak discharge estimates. In terms of lake topography and geomorphology results indicate that the maximum depth is located in the center part for bedrock lakes, and in the back part for lakes in moraine material. Best correlations are found for mean depth and maximum width, however, all three empirical relations show a large spread, reflecting the wide range of natural lake bathymetries. Volumes of the 124 lakes with bathymetries amount to 0

Chemistry of Hot Spring Pool Waters in Calamba and Los Banos and Potential Effect on the Water Quality of Laguna De Bay

NASA Astrophysics Data System (ADS)

Balangue, M. I. R. D.; Pena, M. A. Z.; Siringan, F. P.; Jago-on, K. A. B.; Lloren, R. B.; Taniguchi, M.

2014-12-01

Since the Spanish Period (1600s), natural hot spring waters have been harnessed for balneological purposes in the municipalities of Calamba and Los Banos, Laguna, south of Metro Manila. There are at more than a hundred hot spring resorts in Brgy. Pansol, Calamba and Tadlac, Los Banos. These two areas are found at the northern flanks of Mt. Makiling facing Laguna de Bay. This study aims to provide some insights on the physical and chemical characteristics of hot spring resorts and the possible impact on the lake water quality resulting from the disposal of used water. Initial ocular survey of the resorts showed that temperature of the pool water ranges from ambient (>300C) to as high as 500C with an average pool size of 80m3. Water samples were collected from a natural hot spring and pumped well in Los Banos and another pumped well in Pansol to determine the chemistry. The field pH ranges from 6.65 to 6.87 (Pansol springs). Cation analysis revealed that the thermal waters belonged to the Na-K-Cl-HCO3 type with some trace amount of heavy metals. Methods for waste water disposal are either by direct discharge down the drain of the pool or by discharge in the public road canal. Both methods will dump the waste water directly into Laguna de Bay. Taking in consideration the large volume of waste water used especially during the peak season, the effect on the lake water quality would be significant. It is therefore imperative for the environmental authorities in Laguna to regulate and monitor the chemistry of discharges from the pool to protect both the lake water as well as groundwater quality.

The Point Sal–Point Piedras Blancas correlation and the problem of slip on the San Gregorio–Hosgri fault, central California Coast Ranges

USGS Publications Warehouse

Colgan, Joseph P.; Stanley, Richard G.

2016-01-01

Existing models for large-magnitude, right-lateral slip on the San Gregorio–Hosgri fault system imply much more deformation of the onshore block in the Santa Maria basin than is supported by geologic data. This problem is resolved by a model in which dextral slip on this fault system increases gradually from 0–10 km near Point Arguello to ∼150 km at Cape San Martin, but such a model requires abandoning the cross-fault tie between Point Sal and Point Piedras Blancas, which requires 90–100 km of right-lateral slip on the southern Hosgri fault. We collected stratigraphic and detrital zircon data from Miocene clastic rocks overlying Jurassic basement at both localities to determine if either section contained unique characteristics that could establish how far apart they were in the early Miocene. Our data indicate that these basins formed in the early Miocene during a period of widespread transtensional basin formation in the central Coast Ranges, and they filled with sediment derived from nearby pre-Cenozoic basement rocks. Although detrital zircon data do not indicate a unique source component in either section, they establish the maximum depositional age of the previously undated Point Piedras Blancas section to be 18 Ma. We also show that detrital zircon trace-element data can be used to discriminate between zircons of oceanic crust and arc affinity of the same age, a potentially useful tool in future studies of the California Coast Ranges. Overall, we find no characteristics in the stratigraphy and provenance of the Point Sal and Point Piedras Blancas sections that are sufficiently unique to prove whether they were far apart or close together in the early Miocene, making them of questionable utility as piercing points.

Trace metal partitioning in Thalassia testudinum and sediments in the Lower Laguna Madre, Texas.

PubMed

Whelan, Thomas; Espinoza, Jorge; Villarreal, Xiomara; Cottagoma, Maria

2005-01-01

Seagrass communities dominate the Laguna Madre, which accounts for 25% of the coastal region of Texas. Seagrasses are essential to the health of the Laguna Madre (LM) and have experienced an overall decline in coverage in the Lower Laguna Madre (LLM) since 1967. Little is known on the existing environmental status of the LLM. This study focuses on the trace metal chemistry of four micronutrient metals, Fe, Mn, Cu, and Zn, and two non-essential metals, Pb and As, in the globally important seagrass Thalassia testudinum. Seasonal trends show that concentrations of most essential trace metals increase in the tissue during the summer months. With the exception of (1) Cu in the vertical shoot and root, and (2) Mn in the roots, no significant positive correlation exists between the rhizosphere sediment and T. testudinum tissue. Iron indicates a negative correlation between the morphological units and the rhizosphere sediments. No other significant relationship was found between the sediments and the T. testudinum tissue. Mn was enriched up to 10-fold in the leaf tissue relative to the other morphological units and also enriched relative to the rhizosphere sediments. Both Cu and Mn appear to be enriched in leaf tissue compared to other morphological units and also enriched relative to the Cu and Mn in the rhizoshpere sediments. Sediments cores taken in barren areas were slightly elevated in Zn relative to the rhizosphere sediments, whereas no other metals showed statistical differences between barren sediment cores and rhizosphere sediments. However, no correlation was measured in T. testudinum tissue and Zn in rhizosphere sediments. Previous studies suggested that Fe/Mn ratios could indicate differences between seagrass environments. Our results indicate that there is an influence from the Rio Grande in the Fe/Mn signature in sediments, and that ratio is not reflected in the T. testudinum tissue. The results from this study show that the LLM contains trace metal

Field reconnaissance of the effects of the earthquake of April 13, 1973, near Laguna de Arenal, Costa Rica

USGS Publications Warehouse

Plafker, George

1973-01-01

At about 3:34 a.m. on April 13, 1973, a moderate-sized, but widely-felt, earthquake caused extensive damage with loss of 23 lives in a rural area of about 150 km2 centered just south of Laguna de Arenal in northwestern Costa Rica (fig. 1). This report summarizes the results of the writer's reconnaissance investigation of the area that was affected by the earthquake of April 13, 1973. A 4-day field study of the meizoseismal area was carried out during the period from April 28 through May 1 under the auspices of the U.S. Geological Survey. The primary objective of this study was to evaluate geologic factors that contributed to the damage and loss of life. The earthquake was also of special interest because of the possibility that it was accompanied by surface faulting comparable to that which occurred at Managua, Nicaragua, during the disastrous earthquake of December 23, 1972 (Brown, Ward, and Plafker, 1973). Such earthquake-related surface faulting can provide scientifically valuable information on active tectonic processes at shallow depths within the Middle America arc. Also, identification of active faults in this area is of considerable practical importance because of the planned construction of a major hydroelectrical facility within the meizoseismal area by the Instituto Costarricense de Electricidad (I.C.E.). The project would involve creation of a storage reservoir within the Laguna de Arenal basin and part of the Río Arenal valley with a 75 m-high earthfill dam across Río Arenal at a point about 10 km east of the outlet of Laguna de Arenal.

Carbonate Formation And Diagenesis In Pastos Grandes Laguna (Bolivia): Modern Analog For The South Atlantic Cretaceous Presalt Travertinoid Deposits

NASA Astrophysics Data System (ADS)

Muller, E.; Ader, M.; Gérard, E.; Virgone, A.; Gaucher, E.; Bougeault, C.; Durlet, C.; Moreira, M. A.; Virgile, R.; Vennin, E.; Agogué, H.; Hugoni, M.

2017-12-01

The Cretaceous Presalt travertinoid deposits of the South Atlantic are usually considered as "strange deposits" having poor equivalents in modern environments. Pastos Grandes Laguna, which is located in a 2.9 Ma caldera on the andean-bolivian Altiplano (at 4450 m), is intersected by active faults with hydrothermal fluids and presents a spherulitic plateform with similar sedimentological facies to the Presalt: halite and bedded evaporites, shrub-shaped calcites, ooids, pisolites and various stromatolites. Pastos Grandes Laguna is certainly one of the best modern analog of the Presalt for investigating the on going processes of carbonate deposition and diagenesis and the influence of biology. During two expeditions, we recovered samples of gas, water and microbial mats from the hydrothermal sources to the evaporating zones on the spherulitic plateform. These samples are being analyzed to determine 1) the influence of the gases emitted at the hydrothermal sources (chemical and isotopic composition) on the chemistry of the Laguna and the mineralogy of its sediments and 2) the role of ecosystems that develop in this environment on carbonate formation. Preliminary results on gas composition, corrected for the atmospheric contribution, indicates a magmatic source of CO2 partly mantellic associated with a small crustal contribution. Other initial results have so far indicated that CO2 gas emissions, evaporation, as well as photosynthesis and respiration play a role on water chemistry and carbonate precipitation. This study will contribute to the overall understanding of the role of organisms in sedimentation and the predictive diagenetic evolution of hydrothermal and lacustrine deposits.

Measurements of light-absorbing particles on the glaciers in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Schmitt, C. G.; All, J. D.; Schwarz, J. P.; Arnott, W. P.; Cole, R. J.; Lapham, E.; Celestian, A.

2015-02-01

Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in temperature, increases in light-absorbing particles deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of light-absorbing particles sampled from glaciers during three surveys in the Cordillera Blanca Mountains in Peru. During three research expeditions in the dry seasons (May-August) of 2011, 2012 and 2013, 240 snow samples were collected from 15 mountain peaks over altitudes ranging from 4800 to nearly 6800 m. Several mountains were sampled each of the 3 years and some mountains were sampled multiple times during the same year. Collected snow samples were melted and filtered in the field then later analyzed using the Light Absorption Heating Method (LAHM), a new technique that measures the ability of particles on filters to absorb visible light. LAHM results have been calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). As sample filters often contain dust in addition to BC, results are presented in terms of effective black carbon (eBC). During the 2013 survey, snow samples were collected and kept frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated eBC mass from the LAHM analysis and the SP2 refractory black carbon (rBC) results were well correlated (r2 = 0.92). These results indicate that a substantial portion of the light-absorbing particles in the more polluted regions were likely BC. The 3 years of data show that glaciers in the Cordillera Blanca Mountains close to human population centers have substantially higher levels of eBC (as high as 70 ng g-1) than remote glaciers (as low as 2.0 ng g-1 eBC), indicating that population centers can influence local glaciers by sourcing BC.

Measurements of light absorbing particulates on the glaciers in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Schmitt, C. G.; All, J. D.; Schwarz, J. P.; Arnott, W. P.; Cole, R. J.; Lapham, E.; Celestian, A.

2014-10-01

Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in air temperature, increases in light absorbing particulates deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of light absorbing particulates sampled from glaciers during three surveys in the Cordillera Blanca in Peru. During three research expeditions in the dry seasons (May-August) of 2011, 2012 and 2013, two hundred and forty snow samples were collected from fifteen mountain peaks over altitudes ranging from 4800 to nearly 6800 m. Several mountains were sampled each of the three expeditions and some mountains were sampled multiple times during the same expedition. Collected snow samples were melted and filtered in the field then later analyzed using the Light Absorption Heating Method (LAHM), a new technique that measures the ability of particulates on filters to absorb visible light. LAHM results have been calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). As sample filters often contain dust in addition to BC, results are presented in terms of effective Black Carbon (eBC). During the 2013 survey, snow samples were collected and kept frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated eBC mass from the filter analysis and the SP2 refractory Black Carbon (rBC) results were well correlated (r2 = 0.92). These results indicate that a substantial portion of the light absorbing particulates in the more polluted areas were likely BC. The three years of data show that glaciers in the Cordillera Blanca Mountains close to human population centers have substantially higher levels of eBC (as high as 70 ng g-1) than remote glaciers (as low as 2.0 ng g-1 eBC), indicating that population centers can influence local glaciers by sourcing BC.

Carbon and nitrogen isotope composition of core catcher samples from the ICDP deep drilling at Laguna Potrok Aike (Patagonia, Argentina)

NASA Astrophysics Data System (ADS)

Luecke, Andreas; Wissel, Holger; Mayr*, Christoph; Oehlerich, Markus; Ohlendorf, Christian; Zolitschka, Bernd; Pasado Science Team

2010-05-01

The ICDP project PASADO aims to develop a detailed paleoclimatic record for the southern part of the South American continent from sediments of Laguna Potrok Aike (51°58'S, 70°23'W), situated in the Patagonian steppe east of the Andean cordillera and north of the Street of Magellan. The precursor project SALSA recovered the Holocene and Late Glacial sediment infill of Laguna Potrok Aike and developed the environmental history of the semi-arid Patagonian steppe by a consequent interdisciplinary multi-proxy approach (e.g. Haberzettl et al., 2007). From September to November 2008 the ICDP deep drilling took place and successfully recovered in total 510 m of sediments from two sites resulting in a composite depth of 106 m for the selected main study Site 2. A preliminary age model places the record within the last 50.000 years. During the drilling campaign, the core catcher content of each drilled core run (3 m) was taken as separate sample to be shared and distributed between involved laboratories long before the main sampling party. A total of 70 core catcher samples describe the sediments of Site 2 and will form the base for more detailed investigations on the palaeoclimatic history of Patagonia. We here report on the organic carbon and nitrogen isotope composition of bulk sediment and plant debris of the core catcher samples. Similar investigations were performed for Holocene and Late Glacial sediments of Laguna Potrok Aike revealing insights into the organic matter dynamics of the lake and its catchment as well as into climatically induced hydrological variations with related lake level fluctuations (Mayr et al., 2009). The carbon and nitrogen content of the core catcher fine sediment fraction (<200 µm) is low to very low (around 1 % and 0.1 %, respectively) and requires particular attention in isotope analysis. The carbon isotope composition shows comparably little variation around a value of -26.0 per mil. The positive values of the Holocene and the Late

Quaternary Slip History for the Agua Blanca Fault, northern Baja California, Mexico

NASA Astrophysics Data System (ADS)

Gold, P. O.; Behr, W. M.; Rockwell, T. K.; Fletcher, J. M.

2017-12-01

The Agua Blanca Fault (ABF) is the primary structure accommodating San Andreas-related right-lateral slip across the Peninsular Ranges of northern Baja California. Activity on this fault influences offshore faults that parallel the Pacific coast from Ensenada to Los Angeles and is a potential threat to communities in northern Mexico and southern California. We present a detailed Quaternary slip history for the ABF, including new quantitative constraints on geologic slip rates, slip-per-event, the timing of most recent earthquake, and the earthquake recurrence interval. Cosmogenic 10Be exposure dating of clasts from offset fluvial geomorphic surfaces at 2 sites located along the western, and most active, section of the ABF yield preliminary slip rate estimates of 2-4 mm/yr and 3 mm/yr since 20 ka and 2 ka, respectively. Fault zone geomorphology preserved at the younger site provides evidence for right-lateral surface displacements measuring 2.5 m in the past two ruptures. Luminescence dating of an offset alluvial fan at a third site is in progress, but is expected to yield a slip rate relevant to the past 10 kyr. Adjacent to this third site, we excavated 2 paleoseismic trenches across a sag pond formed by a right step in the fault. Preliminary radiocarbon dates indicate that the 4 surface ruptures identified in the trenches occurred in the past 6 kyr, although additional dating should clarify earthquake timing and the mid-Holocene to present earthquake recurrence interval, as well as the likely date of the most recent earthquake. Our new slip rate estimates are somewhat lower than, but comparable within error to, previous geologic estimates based on soil morphology and geodetic estimates from GPS, but the new record of surface ruptures exposed in the trenches is the most complete and comprehensively dated earthquake history yet determined for this fault. Together with new and existing mapping of tectonically generated geomorphology along the ABF, our constraints

Salt lake Laguna de Fuente de Piedra (S-Spain) as Late Quaternary palaeoenvironmental archive

NASA Astrophysics Data System (ADS)

Höbig, Nicole; Melles, Martin; Reicherter, Klaus

2014-05-01

This study deals with Late Quaternary palaeoenvironmental variability in Iberia reconstructed from terrestrial archives. In southern Iberia, endorheic basins of the Betic Cordilleras are relatively common and contain salt or fresh-water lakes due to subsurface dissolution of Triassic evaporites. Such precipitation or ground-water fed lakes (called Lagunas in Spanish) are vulnerable to changes in hydrology, climate or anthropogenic modifications. The largest Spanish salt lake, Laguna de Fuente de Piedra (Antequera region, S-Spain), has been investigated and serves as a palaeoenvironmental archive for the Late Pleistocene to Holocene time interval. Several sediment cores taken during drilling campaigns in 2012 and 2013 have revealed sedimentary sequences (up to 14 m length) along the shoreline. A multi-proxy study, including sedimentology, geochemistry and physical properties (magnetic susceptibility) has been performed on the cores. The sedimentary history is highly variable: several decimetre thick silty variegated clay deposits, laminated evaporites, and even few-centimetre thick massive gypsum crystals (i.e., selenites). XRF analysis was focussed on valuable palaeoclimatic proxies (e.g., S, Zr, Ti, and element ratios) to identify the composition and provenance of the sediments and to delineate palaeoenvironmental conditions. First age control has been realized by AMS-radiocarbon dating. The records start with approximately 2-3 m Holocene deposits and reach back to the middle of MIS 3 (GS-3). The sequences contain changes in sedimentation rates as well as colour changes, which can be summarized as brownish-beige deposits at the top and more greenish-grey deposits below as well as highly variegated lamination and selenites below ca. 6 m depth. The Younger Dryas, Bølling/Allerød, and the so-called Mystery Interval/Last Glacial Maximum have presumably been identified in the sediment cores and aligned to other climate records. In general, the cores of the Laguna de

Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the lower Laguna Madre, Texas

USGS Publications Warehouse

Mora, Miguel A.

1996-01-01

Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species' diet rather than metabolism. Total PCBs were significantly greater (p < 0.05) in Caspian terns than in the other species. Overall, PCBs in eggs of birds from the Lower Laguna Madre were below concentrations known to affect bird reproduction.

Postglacial history of alpine vegetation, fire, and climate from Laguna de Río Seco, Sierra Nevada, southern Spain

NASA Astrophysics Data System (ADS)

Anderson, R. S.; Jiménez-Moreno, G.; Carrión, J. S.; Pérez-Martínez, C.

2011-06-01

The Sierra Nevada of southern Spain is a landscape with a rich biological and cultural heritage. The range was extensively glaciated during the late Pleistocene. However, the postglacial paleoecologic history of the highest range in southern Europe is nearly completely unknown. Here we use sediments from a small lake above present treeline - Laguna de Río Seco at 3020 m elevation - in a paleoecological study documenting over 11,500 calendar years of vegetation, fire and climate change, addressing ecological and paleoclimatic issues unique to this area through comparison with regional paleoecological sequences. The early record is dominated by Pinus pollen, with Betula, deciduous Quercus, and grasses, with an understory of shrubs. It is unlikely that pine trees grew around the lake, and fire was relatively unimportant at this site during this period. Aquatic microfossils indicate that the wettest conditions and highest lake levels at Laguna de Río Seco occurred before 7800 cal yr BP. This is in contrast to lower elevation sites, where wettest conditions occurred after ca 7800. Greater differences in early Holocene seasonal insolation may have translated to greater snowpack and subsequently higher lake levels at higher elevations, but not necessarily at lower elevations, where higher evaporation rates prevailed. With declining seasonality after ca 8000 cal yr BP, but continuing summer precipitation, lake levels at the highest elevation site remained high, but lake levels at lower elevation sites increased as evaporation rates declined. Drier conditions commenced regionally after ca 5700 cal yr BP, shown at Laguna de Río Seco by declines in wetland pollen, and increases in high elevation steppe shrubs common today ( Juniperus, Artemisia, and others). The disappearance or decline of mesophytes, such as Betula from ca 4000 cal yr BP is part of a regional depletion in Mediterranean Spain and elsewhere in Europe from the mid to late Holocene. On the other hand

Groundwater flow in a closed basin with a saline shallow lake in a volcanic area: Laguna Tuyajto, northern Chilean Altiplano of the Andes.

PubMed

Herrera, Christian; Custodio, Emilio; Chong, Guillermo; Lambán, Luis Javier; Riquelme, Rodrigo; Wilke, Hans; Jódar, Jorge; Urrutia, Javier; Urqueta, Harry; Sarmiento, Alvaro; Gamboa, Carolina; Lictevout, Elisabeth

2016-01-15

Laguna Tuyajto is a small, shallow saline water lake in the Andean Altiplano of northern Chile. In the eastern side it is fed by springs that discharge groundwater of the nearby volcanic aquifers. The area is arid: rainfall does not exceed 200mm/year in the rainiest parts. The stable isotopic content of spring water shows that the recharge is originated mainly from winter rain, snow melt, and to a lesser extent from some short and intense sporadic rainfall events. Most of the spring water outflowing in the northern side of Laguna Tuyajto is recharged in the Tuyajto volcano. Most of the spring water in the eastern side and groundwater are recharged at higher elevations, in the rims of the nearby endorheic basins of Pampa Colorada and Pampa Las Tecas to the East. The presence of tritium in some deep wells in Pampa Colorada and Pampa Las Tecas indicates recent recharge. Gas emission in recent volcanoes increase the sulfate content of atmospheric deposition and this is reflected in local groundwater. The chemical composition and concentration of spring waters are the result of meteoric water evapo-concentration, water-rock interaction, and mainly the dissolution of old and buried evaporitic deposits. Groundwater flow is mostly shallow due to a low permeability ignimbrite layer of regional extent, which also hinders brine spreading below and around the lake. High deep temperatures near the recent Tuyajto volcano explain the high dissolved silica contents and the δ(18)O shift to heavier values found in some of the spring waters. Laguna Tuyajto is a terminal lake where salts cumulate, mostly halite, but some brine transfer to the Salar de Aguas Calientes-3 cannot be excluded. The hydrogeological behavior of Laguna Tuyajto constitutes a model to understand the functioning of many other similar basins in other areas in the Andean Altiplano. Copyright © 2015 Elsevier B.V. All rights reserved.

Geologic Mapping in Nogal Peak Quadrangle: Geochemistry, Intrusive Relations and Mineralization in the Sierra Blanca Igneous Complex, New Mexico

NASA Astrophysics Data System (ADS)

Goff, F.; Kelley, S. A.; Lawrence, J. R.; Cikowski, C. T.; Krier, D. J.; Goff, C. J.; McLemore, V. T.

2011-12-01

Nogal Peak quadrangle is located in the northern Sierra Blanca Igneous Complex (SBIC) and contains most of the White Mountain Wilderness (geologic map is available at http://geoinfo.nmt.edu/publications/maps/geologic/ofgm/details.cfml?Volume=134). The geology of the quad consists of a late Eocene to Oligocene volcanic pile (Sierra Blanca Volcanics, mostly alkali basalt to trachyte) intruded by a multitude of dikes, plugs and three stocks: Rialto, 31.4 Ma (mostly syenite), Three Rivers, ca. 29 to 27 Ma (quartz syenite intruded by subordinate alkali granite), and Bonito Lake, 26.6 Ma (mostly monzonite). Three Rivers stock is partially surrounded by alkali rhyolites that geochemically resemble the alkali granites. The circular shape of the stock and surrounding rhyolites suggests they form the root of a probable caldera. SBIC rocks have compositions typical of those found within the Rocky Mountain alkaline belt and those associated with continental rift zone magmatism. Because the volcanic host rocks are deeply eroded, intrusive relations with the stocks are well exposed. Most contacts at stock margins are near vertical. Roof pendants are common near some contacts and stoped blocks up to 700 m long are found within the Three Rivers stock. Contacts, pendants and stoped blocks generally display some combination of hornfelsing, brecciation, fracturing, faulting and mineralization. Sierra Blanca Volcanics display hydrothermal alteration increasing from argillic in the NW sector of the quad to high-temperature porpylitic near stock margins. Retrograde phyllic alteration occurs within breccia pipes and portions of the stocks. Mineral deposits consist of four types: Placer Au, fissure veins (mostly Ag-Pb-Zn±Au), breccia pipes (Au-Mo-Cu), and porphyry Mo-Cu. A singular pipe on the SW margin of Bonito Lake stock contains sapphire-lazulite-alunite. Although Au has been intermittently mined in the quad since 1865, best production of Au originated around the turn of the last

Recent trends in annual snowline variations in the northern wet outer tropics: case studies from southern Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Veettil, Bijeesh Kozhikkodan; Wang, Shanshan; Bremer, Ulisses Franz; de Souza, Sergio Florêncio; Simões, Jefferson Cardia

2017-07-01

This paper describes the changes in the annual maximum snowlines of a selected set of mountain glaciers at the southern end of the Cordillera Blanca between 1984 and 2015 using satellite images. Furthermore, we analysed the existing glacier records in the Cordillera Blanca since the last glacial maximum to understand the evolution of glaciers in this region over a few centuries. There was a rise in the snowline altitude of glaciers in this region since the late 1990s with a few small glacier advances. Historical to the present El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) records were also analysed to understand whether there was a teleconnection between the glacier fluctuations in the region and the phase changes of ENSO and PDO. We also assessed the variations in three important climatic parameters that influence the glacier retreat—temperature, precipitation, and relative humidity—over a few decades. We calculated the anomalies as well as the seasonal changes in these variables since the mid-twentieth century. There was an increase in temperature during this period, and the decrease in precipitation was not so prominent compared with the temperature rise. There was an exceptionally higher increase in relative humidity since the early 2000s, which is relatively higher than that expected due to the observed rate of warming, and this increase in humidity is believed to be the reason behind the unprecedented rise in the snowline altitudes since the beginning of the twenty-first century.

New geologic slip rates for the Agua Blanca Fault, northern Baja California, Mexico

NASA Astrophysics Data System (ADS)

Gold, P. O.; Behr, W. M.; Fletcher, J. M.; Hinojosa-Corona, A.; Rockwell, T. K.

2015-12-01

Within the southern San Andreas transform plate boundary system, relatively little is known regarding active faulting in northern Baja California, Mexico, or offshore along the Inner Continental Borderland. The inner offshore system appears to be fed from the south by the Agua Blanca Fault (ABF), which strikes northwest across the Peninsular Ranges of northern Baja California. Therefore, the geologic slip rate for the ABF also provides a minimum slip rate estimate for the offshore system, which is connected to the north to faults in the Los Angeles region. Previous studies along the ABF determined slip rates of ~4-6 mm/yr (~10% of relative plate motion). However, these rates relied on imprecise age estimates and offset geomorphic features of a type that require these rates to be interpreted as minima, allowing for the possibility that the slip rate for the ABF may be greater. Although seismically quiescent, the surface trace of the ABF clearly reflects Holocene activity, and given its connectivity with the offshore fault system, more quantitative slip rates for the ABF are needed to better understand earthquake hazard for both US and Mexican coastal populations. Using newly acquired airborne LiDAR, we have mapped primary and secondary fault strands along the segmented western 70 km of the ABF. Minimal development has left the geomorphic record of surface slip remarkably well preserved, and we have identified abundant evidence meter to km scale right-lateral displacement, including new Late Quaternary slip rate sites. We verified potential reconstructions at each site during summer 2015 fieldwork, and selected an initial group of three high potential slip rate sites for detailed mapping and geochronologic analyses. Offset landforms, including fluvial terrace risers, alluvial fans, and incised channel fill deposits, record displacements of ~5-80 m, and based on minimal soil development, none appear older than early Holocene. To quantitatively constrain landform ages

Laguna Madre Water Purification using Biochar from Citrus Peels

NASA Astrophysics Data System (ADS)

Lopez, C.; Al-Qudah, O. M.

2017-12-01

Laguna Madre is an important lagoon in the coast of Texas. It is one of the seven hypersaline lagoons in the world. Due to inflow of water with extreme amounts of phosphorus and nitrates and the low inflow of freshwater, the lagoon has high amount of phosphorus and nitrates which can be harmful for fish and plants situated in the lagoon. The goal is to be able to perform a filtration method with citrus peels biochar, and then to evaluate and compare the produced biochar, zeolite, and activated carbon as an infiltration filter by assessing reductions of nitrogen and phosphorus compounds, as well as sum selected trace elements. Furthermore, the current research will investigate how long the cleaning capacity of biochar lasts and how the performance of the filter changes under an increased load of contaminants. The performance of biochar from different parent materials and recycling options for the used filter materials are also included in this research.

Isotopic characterization of late Neogene travertine deposits at Barrancas Blancas in the eastern Atacama Desert, Chile

USGS Publications Warehouse

Quade, J.; Rasbury, E.T.; Huntington, K.W.; Hudson, Adam; Vonhof, H.; Anchukaitis, K.; Betancourt, Julio L.; Latorre, C.; Pepper, M.

2017-01-01

Here we explore the potential of spring-related, surface and subsurface carbonates as an archive of paleoenvironmental change at Barrancas Blancas, located in the broadest and driest sector of the Atacama Desert at 24.5°S. From these deposits we present a new stable isotopic record of paleoenvironmental conditions over portions of the past ~ 11.5 Ma. U-Pb dates from the carbonates, both surface and subsurface, demonstrate that springs have discharged at this location over much of the last 11.5 Ma, attesting to the exceptional geomorphic stability of the central Atacama. Many of the sampled vein systems line vertical fissures, and formed within the aquifer before groundwater discharged at the surface. Carbonates in such circumstances should not undergo off-gassing and kinetic fractionation prior to formation, simplifying the interpretation of their isotopic composition. Oxygen isotopic compositions of carbonates are generally high (>− 5‰VPDB), and using paleospring water temperatures of 3–13 °C reconstructed from clumped isotopes, point to strongly (up to 50%) evaporated water isotope values, like those associated with the hyperarid core of the Atacama Desert today. Carbon isotopic compositions are also high (≥+3‰ PDB), reflecting a recharge area essentially devoid of plants and dominated by volcanic CO2, as is the case today. Our isotopic results are very similar to those from the Calama Basin to the north, suggesting that the western face of the Andes between 21 and 25°S has been highly evaporative and nearly plantless when these springs discharged over the last 11.5 Ma. The spring carbonates at Barrancas Blancas strongly resemble those found at Devils Hole and Furnace Creek in Death Valley, USA, and as such warrant further exploration as potential archives of climate change.

Selected Hydrologic, Water-Quality, Biological, and Sedimentation Characteristics of Laguna Grande, Fajardo, Puerto Rico, March 2007-February 2009

USGS Publications Warehouse

Soler-López, Luis R.; Santos, Carlos R.

2010-01-01

Laguna Grande is a 50-hectare lagoon in the municipio of Fajardo, located in the northeasternmost part of Puerto Rico. Hydrologic, water-quality, and biological data were collected in the lagoon between March 2007 and February 2009 to establish baseline conditions and determine the health of Laguna Grande on the basis of preestablished standards. In addition, a core of bottom material was obtained at one site within the lagoon to establish sediment depositional rates. Water-quality properties measured onsite (temperature, pH, dissolved oxygen, specific conductance, and water transparency) varied temporally rather than areally. All physical properties were in compliance with current regulatory standards established for Puerto Rico. Nutrient concentrations were very low and in compliance with current regulatory standards (less than 5.0 and 1.0 milligrams per liter for total nitrogen and total phosphorus, respectively). The average total nitrogen concentration was 0.28 milligram per liter, and the average total phosphorus concentration was 0.02 milligram per liter. Chlorophyll a was the predominant form of photosynthetic pigment in the water. The average chlorophyll-a concentration was 6.2 micrograms per liter. Bottom sediment accumulation rates were determined in sediment cores by modeling the downcore activities of lead-210 and cesium-137. Results indicated a sediment depositional rate of about 0.44 centimeter per year. At this rate of sediment accretion, the lagoon may become a marshland in about 700 to 900 years. About 86 percent of the community primary productivity in Laguna Grande was generated by periphyton, primarily algal mats and seagrasses, and the remaining 14 percent was generated by phytoplankton in the water column. Based on the diel studies the total average net community productivity equaled 5.7 grams of oxygen per cubic meter per day (2.1 grams of carbon per cubic meter per day). Most of this productivity was ascribed to periphyton and macrophytes

Looking for Biosignatures in Carbonate Microbialites from the Laguna Negra, Argentinian Andes

NASA Astrophysics Data System (ADS)

Boidi, F. J.; Gomez, F. J.; Fike, D. A.; Bradley, A. S.; Farías, M. E.; Beeler, S.

2015-12-01

The distinction between biotic and abiotic control on microbialites formation and its signatures is relevant since stromatolites are considered the oldest evidence for life on Earth and a target for astrobiological research. The Laguna Negra is a shallow hypersaline lake placed at the Andes, Northwest Argentina, where carbonate microbialites and microbial mats develop. It is a unique system where microbial influence on carbonate precipitation and potential preserved biosignatures in the microbialites can be studied. Here we compare three distinct microbialites systems: carbonate laminar crusts with no visible microbial mats, stromatolites and dm-size oncoids, both related with different microbial mats. Our goal is to unravel the biotic controls on their formation, and the biosignatures there recorded. Laminar crusts are composed of stacked regular and isopachous carbonate lamina. Oncoids laminae are typically characterized by irregular hybrid micro-textures, composed of alternating micritic and botryoidal laminae, and the stromatolites are mostly composed by irregular micritic laminae. Sulfur isotopes of carbonate associated sulphate show similar values but they show differences in the pyrite sulfur isotopes suggesting differences in the fractionation degree, possibly related to sulphate reducing bacteria and variable sulphate reservoirs in the case of stromatolites and oncoids. δ13C fractionation between organic carbon and carbonates suggests photosynthesis, but other metabolisms cannot yet be discarded. 16S rDNA data of the microbial communities associated with the carbonate structures indicate the presence of these taxonomic groups and those that are known to influence carbonate precipitation, particularly in the stromatolites associated microbial community. Our data indicate significant differences between the three systems in terms of stable isotopes, textures and associated microbial diversity, suggesting a microbial control on stromatolites and oncoids

Evidence for Multiple Late Quaternary Glaciations in the Southernmost Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Smith, J. A.; Rodbell, D. T.; Ramage, J. M.

2007-12-01

Surface-exposure dating with in-situ-produced cosmogenic isotopes has provided the basis for a growing framework of glacial chronologies in the tropical Andes. In the Peruvian Andes, long chronologies (>400 ka) with relatively small local last glacial maximum (LLGM) advances have been reported for the central Cordillera Blanca (ca. 9°30'S) and Junin Plain (11°00'S), whereas preliminary data suggest a shorter record (<40 ka) in the intervening Cordillera Huayhuash (10°15'S). These seemingly contradictory findings raise several questions: Was the LLGM a relatively minor event in the Peruvian Andes, far exceeded by bigger, older advances? Which combination of geographic and geomorphic factors increases the likelihood that evidence of older advances will be preserved? With these questions in mind, we sought a site with both high peaks and a high-altitude plateau. The glaciated Nevado Jeulla Rajo massif (10°00'S, 77°16'W, peaks ca. 5600 masl) marks the southern end of the Cordillera Blanca and the Callejon de Huaylas valley in the central Peruvian Andes. The Conococha Plain (ca. 4050 masl) borders the western side of the massif. Large lateral moraines extend onto the Conococha Plain from the west-facing valleys and multiple moraine loops lie upvalley, closer to active ice margins. Surface-exposure dating (10Be) indicates that the largest lateral moraines from Jeullesh Valley are compound features deposited during the LLGM (ca. 30 ka) and a late-glacial readvance (ca. 16 ka). The LLGM/late-glacial moraines cross-cut an older pair of lateral moraines (ca. 70 ka) that may provide evidence for a smaller advance during marine isotope stage 4. Although the LLGM/late-glacial moraines are impressively large (ca. 150 m high), they do not represent the maximum ice extent in the region. Fluvial outwash deposits beyond the termini of the moraines on the Conococha Plain are underlain by lodgement till that is up to 20 m thick and extends ca. 6 km across the width of the Plain

Empirical-statistical downscaling of reanalysis data to high-resolution air temperature and specific humidity above a glacier surface (Cordillera Blanca, Peru)

NASA Astrophysics Data System (ADS)

Hofer, Marlis; MöLg, Thomas; Marzeion, Ben; Kaser, Georg

2010-06-01

Recently initiated observation networks in the Cordillera Blanca (Peru) provide temporally high-resolution, yet short-term, atmospheric data. The aim of this study is to extend the existing time series into the past. We present an empirical-statistical downscaling (ESD) model that links 6-hourly National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis data to air temperature and specific humidity, measured at the tropical glacier Artesonraju (northern Cordillera Blanca). The ESD modeling procedure includes combined empirical orthogonal function and multiple regression analyses and a double cross-validation scheme for model evaluation. Apart from the selection of predictor fields, the modeling procedure is automated and does not include subjective choices. We assess the ESD model sensitivity to the predictor choice using both single-field and mixed-field predictors. Statistical transfer functions are derived individually for different months and times of day. The forecast skill largely depends on month and time of day, ranging from 0 to 0.8. The mixed-field predictors perform better than the single-field predictors. The ESD model shows added value, at all time scales, against simpler reference models (e.g., the direct use of reanalysis grid point values). The ESD model forecast 1960-2008 clearly reflects interannual variability related to the El Niño/Southern Oscillation but is sensitive to the chosen predictor type.

Digital aeromagnetic data and derivative products from a helicopter survey over the town of Blanca and surrounding areas, Alamosa and Costilla counties, Colorado

USGS Publications Warehouse

Bankey, Viki; Grauch, V.J.S.; ,

2004-01-01

This CD-ROM contains digital data, image files, and text files describing data formats and survey procedures for aeromagnetic data collected during a helicopter geophysical survey in southern Colorado during October 2003. The survey covers the town of Blanca and surrounding communities in Alamosa and Costilla Counties. Several derivative products from these data are also presented, including reduced-to-pole, horizontal gradient magnitude, and downward continued grids and images.

A comprehensive analysis of the performance characteristics of the Mount Laguna solar photovoltaic installation

NASA Technical Reports Server (NTRS)

Shumka, A.; Sollock, S. G.

1981-01-01

This paper represents the first comprehensive survey of the Mount Laguna Photovoltaic Installation. The novel techniques used for performing the field tests have been effective in locating and characterizing defective modules. A comparative analysis on the two types of modules used in the array indicates that they have significantly different failure rates, different distributions in degradational space and very different failure modes. A life cycle model is presented to explain a multimodal distribution observed for one module type. A statistical model is constructed and it is shown to be in good agreement with the field data.

Glacier changes since Local Last Glacial Maximum in the South-West slope of Nevado Hualcán, Cordillera Blanca, Peru, deduced from moraine mapping and GIS-based analysis

NASA Astrophysics Data System (ADS)

Giráldez, Claudia; Palacios, David; Haeberli, Wilfried; Úbeda, Jose; Schauwecker, Simone; Torres, Judith

2014-05-01

Anticipating and assessing hazards and risks associated with the shrinking of surface and subsurface ice in cold mountain chains is facilitated by empirical-quantitative data on present and past rates of change, as well as by a general understanding of related landforms and landscape evolution through time. Rock/ice avalanches and devastating outburst floods from glacial lakes indeed constitute a major cause of severe damage in populated mountain areas such as the Cordillera Blanca whose combination of tectonic, topographic and glaciological characteristics make it a threatened region. This study focuses on the Río Chucchún catchment above the city of Carhuaz, which was recently affected by a flood/debris flow from a rock/ice avalanche impacting a recently grown lake (Laguna 513). Traces left by past glaciations strongly affect the current geomorphodinamic behaviour of the catchment. For instance, a prominent sediment-filled glacial overdeepening behind Younger Dryas (YD) moraines (Pampa de Shonquil) with its retention function strongly influenced the chain of processes initiated by the outburst of Laguna 513. The aim of this study is to reconstruct earlier glacial phases in the SW slope of Nevado Hualcán (Río Chucchún catchment), in order to compile quantitative information on surface areas and Equilibrium Line Altitudes (ELAs). To do so, glacier stages were assigned to five different glacial phases, through photointerpretation and moraine cartography: 2003; 1962; Hualcán-I-LIA (15th to 18th centuries); Hualcán-II-YD (~12,5 ka BP); and Hualcán-III-LLGM (~34 to 21 ka BP). Glacial stages Hualcán-I-LIA, Hualcán-II-YD and Hualcán-III-LLGM present relative dating based on previous studies from different authors in the Peruvian Andes. Once glaciers were delimited, their surface areas and Equilibrium Line Altitudes (ELAs) were calculated. For ELA estimation three different methods were used: the mid-range elevation, the Accumulation Area Ratio (AAR), and the

Secondary forest succession and tree planting at the Laguna Cartagena and Cabo Rojo wildlife refuges in southwestern Puerto Rico

Treesearch

P.L. Weaver; J.J. Schwagerl

2008-01-01

Secondary forest succession and tree planting are contributing to the recovery of the Cabo Rojo refuge (Headquarters and Salinas tracts) and Laguna Cartagena refuge (Lagoon and Tinaja tracts) of the Fish and Wildlife Service in southwestern Puerto Rico. About 80 species, mainly natives, have been planted on 44 ha during the past 25 y in an effort to reduce the threat...

First Results of the Expedition to the Highest Lake on Earth: Studying a Martian Paleolake in Bolivia and the Survival Strategies Developed by Living Organisms

NASA Technical Reports Server (NTRS)

Cabrol, N. A.; Grin, E. A.; McKay, C. P.; Friedmann, I.; Diaz, D. Chong; Demergasso, C.; Kisse, K.; Grigorszky, I.; Friedmann, R. Ocampo; Murbach, M. S.

2003-01-01

Between October 16th and November 9th 2002, the first NASA Ames DDF Licancabur multidisciplinary expedition initiated the investigation of the biology and environment for life in the highest lake on Earth located at the summit of the Licancabur volcano (6017 m/20,056 ft) at the boundary of Chile and Bolivia. The low oxygen, low atmospheric pressure, high-UV radiation, average temperature, volcano-tectonic and hydrothermal environment make the site a close analog to Martian paleolakes 3.5 billion years ago. The overall goal of the project is to understand through a series of high altitude scientific expeditions what strategies life is using to defend itself against killer-level UV radiation and environmental extreme conditions at this altitude. Several other lakes are located at 4300 m at the foot of the Licancabur volcano (hereafter named laguna Blanca and Laguna Verde). They were also investigated using identical experiments and methods as for the summit lake in order to compare the results and better understand the evolution of survival strategies at transitioning elevations. The lagunas are geothermally heated and many springs provide water at various temperatures. Sources of heat are also suspected for the summit lake as its surface water temperature was measured during the successful ascent at +6 C in a -9 C ambient crater environment (with a wind chill factor of -25 C with a wind blowing almost constantly). Results of this project are expected to provide critical keys to help searching and identifying potential sites for life (extant/extinct) on Mars and developing instruments, experiments and technologies for future missions.

Trace elements in mineral separates of the Pena Blanca Spring aubrite - Implications for the evolution of the aubrite parent body

NASA Technical Reports Server (NTRS)

Lodders, K.; Palme, H.; Wlotzka, F.

1993-01-01

A detailed chemical study is conducted of the Pena Blanca Spring aubrite in order to clarify both the origin of the aubrite parent body (APB) and its relation to the enstatite chondrites. The distribution of REE among aubritic minerals cannot be the result of fractional distillation, which would occur if high degrees of partial melting had occurred on the APB. The REE distributions instead indicate a complete equilibrium of oldhamite and other phases, so that a brief nonequilibrium melting episode must have led to the segregation of metal and sulfides.

Paired moraine-dammed lakes: a key landform for glaciated high mountain areas in the tropical Andes of Peru

NASA Astrophysics Data System (ADS)

Iturrizaga, Lasafam

2016-04-01

The tropical mountain range of the Cordillera Blanca hosts one of the main concentrations of proglacial lakes in high-mountain settings worldwide, which have formed as a result of the dominant trend of modern glacier retreat. Based on empirical data from field research in over 20 valleys and the analysis of air and satellite images, a genetic classification of major lake types with their barriers and a generalized model for the distribution of the present lakes and paleolakes was set up. The origin of the lakes and their recurrent distribution pattern are associated with the individual stages of the Pleistocene to modern glaciation and their corresponding geomorphological landforms. Characteristic repetitive moraine sequences are found in the upper parts of numerous valleys of the Cordillera Blanca. In terms of the spatial arrangement of the lake types, combined lakes are classified as a distinct composite lake type. These lakes occur at nearly the same elevation or at successively lower elevations, and form characteristic lake sequences of two or more lakes. They may occur as multi-moraine-dammed lakes or mixed combined lakes such as moraine-rock-dammed lakes or multi-debris-dammed lakes. From special interest are in this study the paired moraine-dammed lakes (e.g. Lagunas Qoyllurcochas, Lagunas Safuna Alta and Baja). They are composed of the Great Endmoraine (GEM), primarily formed during the Little Ice Age and earlier, and the pre-GEM, formed during the Holocene. Both moraines are located in rather close vicinity to each other at a distance of 1-3 km. In contrast to the prominent sharp-crested GEM, the pre-GEM is a low-amplitude end-moraine complex, which usually does not exceed a few meters to tens of meters in height. The latter is often composed of several inserted moraine ridges or an irregular hummocky moraine landscape. It is argued here that the process of formation of these combined lakes is mainly controlled by a combination of distinct topographical

Role of body condition score and body weight in the control of seasonal reproduction in Blanca Andaluza goats.

PubMed

Gallego-Calvo, L; Gatica, M C; Guzmán, J L; Zarazaga, L A

2014-12-30

The reproductive activity of 84 female Blanca Andaluza goats was monitored over 17 months to determine the role of body condition score (BCS) and body weight (BW) in its control. Following a 3×2 factorial experimental design, the animals were allocated to three groups: low BCS (≤2.50, n=24), medium BCS (BCS=2.75-3.00, n=31) and high BCS (≥3.25, n=29). The same animals, irrespective of the BCS group categorization, were also divided into two groups depending on BW: low BW (≤40kg, n=44) and high BW (>40kg, n=40). Oestrus was evaluated daily using vasectomised males. The ovulation rate was assessed by trans-rectal ultrasonography after the identification of oestrus. Ovulations were determined by monitoring the plasma progesterone concentration weekly. The BCS and BW were recorded once a week and nutritional status adjusted to maintain the initial differences in BW and BCS between the groups. Both BCS and BW had a significant (at least P<0.05) influence on the onset, the end, and the duration of the breeding season, with longer periods of reproductive activity recorded in does with a BCS of ≥2.75 and BW of >40kg. No significant interaction between these variables was observed. Some (11.7%) of the does in the groups with animals of BCS≥2.75 had ovulations during seasonal anoestrus. None of the does with a BCS of ≤2.5 had ovulations during seasonal anoestrus. The ovulation rate of the first and last oestrus was influenced by BW (P<0.01). These results demonstrate that Blanca Andaluza goats show marked reproductive seasonality that is clearly and independently modulated by BCS and BW. Copyright © 2014 Elsevier B.V. All rights reserved.

A High-Resolution Reconstruction of Late Holocene Environmental Change from Laguna Ek'Naab, Northern Holmul Region, Peten, Guatemala

NASA Astrophysics Data System (ADS)

Anderson, L.; Wahl, D.; Estrada-Belli, F.

2015-12-01

Widespread demographic shifts in the southern Maya lowlands at the end of the Classic period have been attributed to environmental change caused by human activity and/or climate variability. Fire was essential to landscape modification and was a primary agent of environmental change associated with prehispanic land use. While several studies have provided insight into the dynamic relationship between natural and anthropogenic drivers of change, defining the specific interplay between natural environmental change, human modification of the environment, and cultural response to changes remains a persistent challenge. Here we present the results of a multi-proxy study that reconstructs fire history, agricultural land use, and environmental change during and after Pre-Columbian Maya settlement. Results are interpreted in the context of settlement history as inferred from archaeological mapping around the study site. Our findings suggest landscape disturbance, as indicated by erosion, local burning, and nearby maize agriculture, was at its peak during the Early Classic period. This disturbance was likely due to large-scale settlement at the nearby site of Witzna'. All proxies indicate a slow decline in disturbance into the Late Classic period, beginning around 1300 cal yr BP. Cival and Chanchich, two proximal site centers to the south of Laguna Ek'Naab, supported their largest populations during the Late Preclassic and Late Classic, with little or no settlement during the Early Classic. The data from Laguna Ek'Naab suggests that Witzna' may have been an important center during the Early Classic. Whether the decreasing environmental degradation after 1240 cal yr BP is do to a decline in local population or changing land use strategies is not discernable based on the data thus far. However, the near complete absence of burning and continued decrease in erosion from 1240-1090 cal yr BP suggests little anthropogenic activity in the area. Burning resumes in the watershed

Distribution and community structure of ichthyoplankton in Laguna Madre seagrass meadows: Potential impact of seagrass species change

USGS Publications Warehouse

Tolan, J.M.; Holt, S.A.; Onuf, C.P.

1997-01-01

Seasonal ichthyoplankton surveys were made in the lower Laguna Madre, Texas, to compare the relative utilization of various nursery habitats (shoal grass, Halodule wrightii; manatee grass, Syringodium filiforme;, and unvegetated sand bottom) for both estuarine and offshore-spawned larvae. The species composition and abundance of fish larvae were determined for each habitat type at six locations in the bay. Pushnet ichthyoplankton sampling resulted in 296 total collections, yielding 107,463 fishes representing 55 species in 24 families. A broad spectrum of both the biotic and physical habitat parameters were examined to link the dispersion and distribution of both pre-settlement and post-settlement larvae to the utilization of shallow seagrass habitats. Sample sites were grouped by cluster analysis (Ward's minimum variance method) according to the similarity of their fish assemblages and subsequently examined with a multiple discriminant function analysis to identify important environmental variables. Abiotic environmental factors were most influential in defining groups for samples dominated by early larvae, whereas measures of seagrass complexity defined groups dominated by older larvae and juveniles. Juvenile-stage individuals showed clear habitat preference, with the more shallow Halodule wrightii being the habitat of choice, whereas early larvae of most species were widely distributed over all habitats. As a result of the recent shift of dominance from Halodule wrightii to Syringodium filiforme, overall reductions in the quality of nursery habitat for fishes in the lower Laguna Madre are projected.

Tropical ocean-atmospheric forcing of Late Glacial and Holocene glacier fluctuations in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Stansell, Nathan D.; Licciardi, Joseph M.; Rodbell, Donald T.; Mark, Bryan G.

2017-05-01

Evaluating the timing and style of past glacier fluctuations in the tropical Andes is important for our scientific understanding of global environmental change. Terrestrial cosmogenic nuclide ages on moraine boulders combined with 14C-dated clastic sediment records from alpine lakes document glacial variability in the Cordillera Blanca of Peru during the last 16 ka. Late Glacial ice extents culminated at the start of the Antarctic Cold Reversal and began retracting prior to the Younger Dryas. Multiple moraine crests dating to the early Holocene mark brief readvances or stillstands that punctuated overall retreat of the Queshque Valley glacier terminus during this interval. Glaciers were less extensive during the middle Holocene before readvancing during the latest Holocene. These records suggest that tropical Atlantic and Pacific ocean-atmospheric processes exerted temporally variable forcing of Late Glacial and Holocene glacial changes in the Peruvian Andes.

Recalibration of the yellow Rhizocarpon growth curve in the Cordillera Blanca (Peru) and implications for LIA chronology

NASA Astrophysics Data System (ADS)

Jomelli, V.; Grancher, D.; Brunstein, D.; Solomina, O.

2008-01-01

A new lichen dating method and new moraine observations enabled us to improve the chronology of glacier advances in the Cordillera Blanca (Peru) during the Little Ice Age (LIA). Our results reveal that an early LIA glacial advance occurred around AD 1330 ± 29. However, a second major glacial advance at the beginning of the 17th century overlapped the earlier stage for most glaciers. Hence, this second glacial stage, dated from AD 1630 ± 27, is considered as the LIA maximum glacial advance in the Cordillera Blanca. During the 17th-18th centuries, at least three glacial advances were recorded synchronously for the different glaciers (AD 1670 ± 24, 1730 ± 21, and 1760 ± 19). The moraines corresponding to the two first stages are close to the one in 1630 suggesting a slow recession of about 18% in the total length of the glacier. From the LIA maximum extent to the beginning of the 20th century, the 24 glaciers have retreated a distance of about 1000 m, corresponding to a reduction of 30% in their length. This rate is comparable to that observed during the 20th century. Estimates of palaeo-Equilibrium Line Altitudes show an increase in altitude of about 100 m from the LIA maximum glacial extension at the beginning of the 17th century to the beginning of the 20th century. Because long time series are not available for precipitation and temperature, this glacial retreat is difficult to explain by past climate changes. However, there is a fair correspondence between changes in glacier length and the δ18O recorded in the Quelccaya ice core at a century timescale. Our current knowledge of tropical glaciers and isotope variations leads us to suggest that this common tropical signal reflects a change from a wet LIA to the drier conditions of today. Finally, a remarkable synchronicity is observed with glacial variations in Bolivia, suggesting a common regional climatic pattern during the LIA.

New method for assessing the susceptibility of glacial lakes to outburst floods in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Emmer, A.; Vilímek, V.

2014-09-01

This paper presents a new and easily repeatable method for assessing the susceptibility of glacial lakes to outburst floods (GLOFs) within the Peruvian region of the Cordillera Blanca. The presented method was designed to: (a) be repeatable (from the point of view of the demands on input data), (b) be reproducible (to provide an instructive guide for different assessors), (c) provide multiple results for different GLOF scenarios and (d) be regionally focused on the lakes of the Cordillera Blanca. Based on the input data gained from remotely sensed images and digital terrain models/topographical maps, the susceptibility of glacial lakes to outburst floods is assessed using a combination of decision trees for clarity and numerical calculation for repeatability and reproducibility. A total of seventeen assessed characteristics are used, of which seven have not been used in this context before. Also, several ratios and calculations are defined for the first time. We assume that it is not relevant to represent the overall susceptibility of a particular lake to outburst floods by one result (number), thus it is described in the presented method by five separate results (representing five different GLOF scenarios). These are potentials for (a) dam overtopping resulting from a fast slope movement into the lake, (b) dam overtopping following the flood wave originating in a lake situated upstream, (c) dam failure resulting from a fast slope movement into the lake, (d) dam failure following the flood wave originating in a lake situated upstream and (e) dam failure following a strong earthquake. All of these potentials include two or three components and theoretically range from 0 to 1. The presented method was verified on the basis of assessing the pre-flood conditions of seven lakes which have produced ten glacial lake outburst floods in the past and ten lakes which have not. A comparison of these results showed that the presented method successfully identified lakes

Niebla ceruchis from Laguna Figueroa: dimorphic spore morphology and secondary compounds localized in pycnidia and apothecia

NASA Technical Reports Server (NTRS)

Enzien, M.; Margulis, L.

1988-01-01

During and after the floods of 1979-80 Niebla ceruchis growing epiphytically on Lycium brevipes was one of the dominant aspects of the vegetation in the coastal dunal complex bordering the microbial mats at Laguna Figueroa, Baja California Norte, Mexico. The lichen on denuded branches of Lycium was far more extensively distributed than Lycium lacking lichen. Unusual traits of this Niebla ceruchis strain, namely localization of lichen compounds in the mycobiont reproductive structures (pycnidia and apothecia) and simultaneous presence of bilocular and quadrilocular ascospores, are reported. The abundance of this coastal lichen cover at the microbial mat site has persisted through April 1988.

Characterizing the impacts of the 2006 New Year's flood in the Laguna de Santa Rosa floodplain, Sonoma County, CA

NASA Astrophysics Data System (ADS)

Flint, L. E.; Curtis, J. A.; Flint, A. L.

2006-12-01

The Laguna de Santa Rosa (Laguna), the largest tributary to the Russian River located in Sonoma County, California, occupies a relatively flat low-lying area west of the Santa Rosa Plain. From December 12, 2005 to January 6, 2006 the Laguna experienced heavy flooding, with peak flows on New Year's Day of over 185 m3/s, at a location that experiences median flows of less than 14 m3/s. The objectives of this study were to (1) analyze precipitation intensities and amounts for the region to establish the conditions under which flooding occurred, (2) measure and map inundation areas and floodplain sediment deposition, and (3) compare field data with a GIS sediment deposition potential map. Spatial variations in intensities and total volumes of precipitation correlate well with evidence of local flooding throughout the region, particularly in the mountains to the east and southeast of Santa Rosa. Total precipitation for the month of December was 200 percent of normal, and maximum hourly intensities reached 20 mm/hour during the storm. High water marks and floodplain deposition sites were mapped using kinematic GPS surveying with post-processed differential correction, and sediment deposition was measured. The surveyed data were superimposed on an available two-foot-interval contour map to create an inundation map and a GIS point coverage of sediment deposition. Landscape attributes relevant to floodplain sedimentation were assessed and a sediment deposition potential map was created at the 30-m scale using a matrix of landscape characteristics that included: land use; roughness (influenced by vegetation type and density); channel and hillslope sediment sources (influenced by soils, geology, and cutbank erosion); slope and topography; and geomorphic terrain type. A calculation of sediment deposition potential was developed within a GIS that accounts for all contributing factors and illustrates that floodplain deposition is dominated by localized sedimentation, reflecting

Tracing society in climate change: Societal negotiations and physical dynamics of water under climate change conditions in the Cordillera Blanca region, Peru

NASA Astrophysics Data System (ADS)

Neuburger, Martina; Gurgiser, Wolfgang; Maussion, Fabien; Singer, Katrin; Kaser, Georg

2017-04-01

Natural scientists observe and project changes in precipitation and temperature at different spatio-temporal scales and investigate impacts on glaciers and hydrological regimes. Simultaneously, social groups experience ecological phenomena as linked to climate change and integrate them into their understanding of nature and their logics of action, while political actors refer to scientific results as legitimization to focus on adaptation and mitigation strategies on global, national and regional/local level. However, natural and socio-political changes on various scales (regarding time and space) are not directly interlinked, but are communicated by energy and material flows, by discourses, power relations and institutional regulations. In this context, it remains still unclear how natural dynamics are (dis)entangled with societal processes in their historical dimensions and in their interrelations from global via national to regional and local scales. Considering the Cordillera Blanca region in Peru as an example, we analyze the intertwining of scales (global, national, regional, local) and spheres (natural, political, societal) to detect entanglements and disconnections of observed processes. Using the methodology of a time line, we present precipitation variability and glacier recession at different scales, estimate qualitative water availability and investigate the links to the implementation of international and national political programs on climate change adaptation in the Cordillera Blanca region focusing on water and agrarian programs. Finally, we include supposedly contradictory reports of rural population on climate change and related impacts on water availability and agricultural production to analyze the (dis)entanglement due to changing power relations and dominant discourses.

Microbial community composition and trophic role along a marked salinity gradient in Laguna Puilar, Salar de Atacama, Chile.

PubMed

Dorador, Cristina; Fink, Patrick; Hengst, Martha; Icaza, Gonzalo; Villalobos, Alvaro S; Vejar, Drina; Meneses, Daniela; Zadjelovic, Vinko; Burmann, Lisa; Moelzner, Jana; Harrod, Chris

2018-05-09

The geological, hydrological and microbiological features of the Salar de Atacama, the most extensive evaporitic sedimentary basin in the Atacama Desert of northern Chile, have been extensively studied. In contrast, relatively little attention has been paid to the composition and roles of microbial communities in hypersaline lakes which are a unique feature in the Salar. In the present study biochemical, chemical and molecular biological tools were used to determine the composition and roles of microbial communities in water, microbial mats and sediments along a marked salinity gradient in Laguna Puilar which is located in the "Los Flamencos" National Reserve. The bacterial communities at the sampling sites were dominated by members of the phyla Bacteroidetes, Chloroflexi, Cyanobacteria and Proteobacteria. Stable isotope and fatty acid analyses revealed marked variability in the composition of microbial mats at different sampling sites both horizontally (at different sites) and vertically (in the different layers). The Laguna Puilar was shown to be a microbially dominated ecosystem in which more than 60% of the fatty acids at particular sites are of bacterial origin. Our pioneering studies also suggest that the energy budgets of avian consumers (three flamingo species) and dominant invertebrates (amphipods and gastropods) use minerals as a source of energy and nutrients. Overall, the results of this study support the view that the Salar de Atacama is a heterogeneous and fragile ecosystem where small changes in environmental conditions may alter the balance of microbial communities with possible consequences at different trophic levels.

Method to identify wells that yield water that will be replaced by water from the Colorado River downstream from Laguna Dam in Arizona and California

USGS Publications Warehouse

Owen-Joyce, Sandra J.; Wilson, Richard P.; Carpenter, Michael C.; Fink, James B.

2000-01-01

Accounting for the use of Colorado River water is required by the U.S. Supreme Court decree, 1964, Arizona v. California. Water pumped from wells on the flood plain and from certain wells on alluvial slopes outside the flood plain is presumed to be river water and is accounted for as Colorado River water. The accounting-surface method developed for the area upstream from Laguna Dam was modified for use downstream from Laguna Dam to identify wells outside the flood plain of the lower Colorado River that yield water that will be replaced by water from the river. Use of the same method provides a uniform criterion of identification for all users pumping water from wells by determining if the static water-level elevation in the well is above or below the elevation of the accounting surface. Wells that have a static water-level elevation equal to or below the accounting surface are presumed to yield water that will be replaced by water from the Colorado River. Wells that have a static water-level elevation above the accounting surface are presumed to yield river water stored above river level. The method is based on the concept of a river aquifer and an accounting surface within the river aquifer. The river aquifer consists of permeable sediments and sedimentary rocks that are hydraulically connected to the Colorado River so that water can move between the river and the aquifer in response to withdrawal of water from the aquifer or differences in water-level elevations between the river and the aquifer. The subsurface limit of the river aquifer is the nearly impermeable bedrock of the bottom and sides of the basins that underlie the Yuma area and adjacent valleys. The accounting surface represents the elevation and slope of the unconfined static water table in the river aquifer outside the flood plain of the Colorado River that would exist if the river were the only source of water to the river aquifer. The accounting surface was generated by using water

Characterization of cyanobacterial communities from high-elevation lakes in the Bolivian Andes

NASA Astrophysics Data System (ADS)

Fleming, Erich D.; Prufert-Bebout, Leslie

2010-06-01

The Bolivian Altiplano is a harsh environment for life with high solar irradiation (visible and UVR), below freezing temperatures, and some of the lowest precipitation rates on the planet. However, microbial life is visibly abundant in small isolated refugia of spring or snowmelt-fed lakes. In this study, we characterized the cyanobacterial composition of a variety of microbial mats present in three lake systems: Laguna Blanca, Laguna Verde (elevation 4300 m), and a summit lake in the Licancabur Volcano cone (elevation 5970 m). These lakes and their adjacent geothermal springs present an interesting diversity of environments within a geographically small region (5 km2). From these sites, 78 cyanobacterial cultures were isolated in addition to ˜400 cyanobacterial 16S rRNA gene sequences from environmental genomic DNA. Based on microscopy, cultivation, and molecular analyses, these communities contained many heterocytous, nitrogen-fixing cyanobacteria (e.g., Calothrix, Nostoc, Nodularia) as well as a large number of cyanobacteria belonging to the form-genus Leptolyngbya. More than a third (37%) of all taxa in this study were new species (≤96% 16S rRNA gene sequence identity), and 11% represented new and novel taxa distantly related (≤93% identity) to any known cyanobacteria. This is one of the few studies to characterize cyanobacterial communities based on both cultivation-dependent and cultivation-independent analyses.

Downscaling reanalysis data to high-resolution variables above a glacier surface (Cordillera Blanca, Peru)

NASA Astrophysics Data System (ADS)

Hofer, Marlis; Mölg, Thomas; Marzeion, Ben; Kaser, Georg

2010-05-01

Recently initiated observation networks in the Cordillera Blanca provide temporally high-resolution, yet short-term atmospheric data. The aim of this study is to extend the existing time series into the past. We present an empirical-statistical downscaling (ESD) model that links 6-hourly NCEP/NCAR reanalysis data to the local target variables, measured at the tropical glacier Artesonraju (Northern Cordillera Blanca). The approach is particular in the context of ESD for two reasons. First, the observational time series for model calibration are short (only about two years). Second, unlike most ESD studies in climate research, we focus on variables at a high temporal resolution (i.e., six-hourly values). Our target variables are two important drivers in the surface energy balance of tropical glaciers; air temperature and specific humidity. The selection of predictor fields from the reanalysis data is based on regression analyses and climatologic considerations. The ESD modelling procedure includes combined empirical orthogonal function and multiple regression analyses. Principal component screening is based on cross-validation using the Akaike Information Criterion as model selection criterion. Double cross-validation is applied for model evaluation. Potential autocorrelation in the time series is considered by defining the block length in the resampling procedure. Apart from the selection of predictor fields, the modelling procedure is automated and does not include subjective choices. We assess the ESD model sensitivity to the predictor choice by using both single- and mixed-field predictors of the variables air temperature (1000 hPa), specific humidity (1000 hPa), and zonal wind speed (500 hPa). The chosen downscaling domain ranges from 80 to 50 degrees west and from 0 to 20 degrees south. Statistical transfer functions are derived individually for different months and times of day (month/hour-models). The forecast skill of the month/hour-models largely depends on

DNA barcoding of fishes of Laguna de Bay, Philippines.

PubMed

Aquino, Luis Miguel G; Tango, Jazzlyn M; Canoy, Reynand Jay C; Fontanilla, Ian Kendrich C; Basiao, Zubaida U; Ong, Perry S; Quilang, Jonas P

2011-08-01

Laguna de Bay, the largest lake in the Philippines, is an important part of the country's fisheries industry. It is also home to a number of endemic fishes including Gobiopterus lacustris (Herre 1927) of family Gobiidae, Leiopotherapon plumbeus (Kner 1864) of family Terapontidae, Zenarchopterus philippinus (Peters 1868) of family Hemiramphidae and Arius manillensis Valenciennes 1840 of family Ariidae. Over the years, a steady decline has been observed in the abundance and diversity of native fishes in the lake due to anthropogenic disturbances. In this study, a total of 71 specimens of 18 different species belonging to 18 genera, 16 families, and seven orders were DNA barcoded using the mitochondrial cytochrome c oxidase subunit I (COI) gene. All of the fish species were discriminated by their COI sequences and one endemic species G. lacustris, showing deep genetic divergence, was highlighted for further taxonomic investigation. Average Kimura 2-parameter genetic distances within species, family, and order were 1.33%, 18.91%, and 24.22%, respectively. These values show that COI divergence increases as taxa become less exclusive. All of the COI sequences obtained were grouped together according to their species designation in the Neighbor-joining tree that was constructed. This study demonstrated that DNA barcoding has great potential as a tool for fast and accurate species identification and also for highlighting species that warrant further taxonomic investigation.

Frequency of event deposits reflecting glacial/interglacial conditions during the last ca. 50,000 years in the south Patagonian maar lake Laguna Potrok Aike, Argentina

NASA Astrophysics Data System (ADS)

Kliem, Pierre; Hahn, Annette; Ohlendorf, Christian; Zolitschka, Bernd; Pasado Science Team

2010-05-01

Laguna Potrok Aike is a 100m deep maar lake located in the dry steppe of southern Patagonia. The catchment area of >200km² mainly consists of till from Bella Vista and Río Ciaike Glaciations as well as of alkali-olivine basalts of the Pali Aike Volcanic Field. Today's regional climate is affected by the Southern Hemispheric Westerlies and the rainshadow effect of the north-south striking Andean mountain chain. Since lakes are valuable terrestrial paleoclimate archives, sediments of Laguna Potrok Aike should reflect shifts of mid latitude wind and pressure fields as well as precipitation changes in southeastern South America. Aiming at the reconstruction of past climate, the deep drilling at Laguna Potrok Aike was accomplished in the framework of the ICDP project PASADO during Sept. to Dec. 2008. By correlation of three holes drilled at Site 2 ca. 700 m south of the lake's center, a composite profile of 106.09 mcd (meters composite depth) was established. According to the lowermost 14C-age of aquatic macro remains from 80.6 mcd, the entire record comprises at least 50,000 years. The initial lithological description indicates that 50.74 m (i.e. 47.8%) of the sediment record consists of remobilized sediment (turbidity currents; homogenites; ball and pillow structures, gravel layers, slumps). Such deposits are almost absent in the top 12 mcd, where laminated clays and silts dominate. Correlation with an existing piston core allows a temporal relation to the Holocene. Apart from obviously remobilized deposits Holocene sediments are distinguished from Late Glacial deposits by a lower frequency of coarse silt/fine sand layers within a silt/clay matrix. Frequency and thickness of remobilized deposits increase with sediment depth. Most reworked sections are composed of three units: (1) a dark, coarse and fining upward base overlain by (2) a homogeneous layer of silt and (3) clay capped by a relatively thin light colored clay layer. Such sequences were often described as

Proglacial hydrology in the tropical Andes: lessons from the Cordillera Blanca, Peru (Invited)

NASA Astrophysics Data System (ADS)

McKenzie, J. M.; Mark, B. G.; Baraer, M.

2009-12-01

Understanding the complexities of tropical Andean hydrology is critical for managing modern water resources and interpreting paleohydrologic records. Glaciers are the most visible component of these systems, responding to global climate change and acting as critical hydrologic reservoirs. Tropical Andean glaciers are undergoing rapid retreat with complex impacts on the downstream hydrology. Groundwater is also an important component of the Andean regional hydrologic system, but its contribution is difficult to assess due to remote site access, minimal baseline data, and lack of continuous historical discharge and precipitation measurements. We have synthesized hydrochemical data from synoptically sampled glacial melt water, groundwater, precipitation, and stream discharge collected intermittently between 1998 and July 2008 throughout the Callejon de Huaylas, a 5000 km2 watershed that drains the western side of the Cordillera Blanca in northern Perú. Our data from 2004 to 2006 show systematic annual shifts in the isotopic ratios (δ18O and δ2H) of river water, indicating an increase in glacial melt water input, and we are able to use these changes across the Cordillera Blanca to estimate an average increase of 1.6 (± 1.1) % in the specific discharge of the glacierized basins. Enhanced total stream discharge in more glacierized catchments (>20% glacier area) is demonstrated by a significant positive trend in a 43-year discharge anomaly record. Our hydrochemical basin characterization method (HBCM) uses chemical mass balance mixing to quantify the contribution of glacial melt water, groundwater, and surface runoff to streams for different valleys and nested watersheds in the Callejon de Huaylas. The Yanamarey basin (7% glaciated) has been observed since 1998 and the HBCM results show good agreement with measured stream discharge (maximum R2 of 0.99) for monthly cumulative values. These results suggest that for most of the studied years groundwater is the main

The ambient acoustic environment in Laguna San Ignacio, Baja California Sur, Mexico.

PubMed

Seger, Kerri D; Thode, Aaron M; Swartz, Steven L; Urbán, Jorge R

2015-11-01

Each winter gray whales (Eschrichtius robustus) breed and calve in Laguna San Ignacio, Mexico, where a robust, yet regulated, whale-watching industry exists. Baseline acoustic environments in LSI's three zones were monitored between 2008 and 2013, in anticipation of a new road being paved that will potentially increase tourist activity to this relatively isolated location. These zones differ in levels of both gray whale usage and tourist activity. Ambient sound level distributions were computed in terms of percentiles of power spectral densities. While these distributions are consistent across years within each zone, inter-zone differences are substantial. The acoustic environment in the upper zone is dominated by snapping shrimp that display a crepuscular cycle. Snapping shrimp also affect the middle zone, but tourist boat transits contribute to noise distributions during daylight hours. The lower zone has three source contributors to its acoustic environment: snapping shrimp, boats, and croaker fish. As suggested from earlier studies, a 300 Hz noise minimum exists in both the middle and lower zones of the lagoon, but not in the upper zone.

Response of shoal grass, Halodule wrightii, to extreme winter conditions in the Lower Laguna Madre, Texas

USGS Publications Warehouse

Hicks, D.W.; Onuf, C.P.; Tunnell, J.W.

1998-01-01

Effects of a severe freeze on the shoal grass, Halodule wrightii, were documented through analysis of temporal and spatial trends in below-ground biomass. The coincidence of the second lowest temperature (-10.6??C) in 107 years of record, 56 consecutive hours below freezing, high winds and extremely low water levels exposed the Laguna Madre, TX, to the most severe cold stress in over a century. H. wrightii tolerated this extreme freeze event. Annual pre- and post-freeze surveys indicated that below-ground biomass estimated from volume was Unaffected by the freeze event. Nor was there any post-freeze change in biomass among intertidal sites directly exposed to freezing air temperatures relative to subtidal sites which remained submerged during the freezing period.

Uranium mobility and accumulation along the Rio Paguate, Jackpile Mine in Laguna Pueblo, NM.

PubMed

Blake, Johanna M; De Vore, Cherie L; Avasarala, Sumant; Ali, Abdul-Mehdi; Roldan, Claudia; Bowers, Fenton; Spilde, Michael N; Artyushkova, Kateryna; Kirk, Matthew F; Peterson, Eric; Rodriguez-Freire, Lucia; Cerrato, José M

2017-04-19

The mobility and accumulation of uranium (U) along the Rio Paguate, adjacent to the Jackpile Mine, in Laguna Pueblo, New Mexico was investigated using aqueous chemistry, electron microprobe, X-ray diffraction and spectroscopy analyses. Given that it is not common to identify elevated concentrations of U in surface water sources, the Rio Paguate is a unique site that concerns the Laguna Pueblo community. This study aims to better understand the solid chemistry of abandoned mine waste sediments from the Jackpile Mine and identify key hydrogeological and geochemical processes that affect the fate of U along the Rio Paguate. Solid analyses using X-ray fluorescence determined that sediments located in the Jackpile Mine contain ranges of 320 to 9200 mg kg -1 U. The presence of coffinite, a U(iv)-bearing mineral, was identified by X-ray diffraction analyses in abandoned mine waste solids exposed to several decades of weathering and oxidation. The dissolution of these U-bearing minerals from abandoned mine wastes could contribute to U mobility during rain events. The U concentration in surface waters sampled closest to mine wastes are highest during the southwestern monsoon season. Samples collected from September 2014 to August 2016 showed higher U concentrations in surface water adjacent to the Jackpile Mine (35.3 to 772 μg L -1 ) compared with those at a wetland 4.5 kilometers downstream of the mine (5.77 to 110 μg L -1 ). Sediments co-located in the stream bed and bank along the reach between the mine and wetland had low U concentrations (range 1-5 mg kg -1 ) compared to concentrations in wetland sediments with higher organic matter (14-15%) and U concentrations (2-21 mg kg -1 ). Approximately 10% of the total U in wetland sediments was amenable to complexation with 1 mM sodium bicarbonate in batch experiments; a decrease of U concentration in solution was observed over time in these experiments likely due to re-association with sediments in the reactor. The findings

Onboard Science Insights and Vehicle Dynamics from Scale-Model Trials of the Titan Mare Explorer (TiME) Capsule at Laguna Negra, Chile.

PubMed

Lorenz, Ralph D; Cabrol, Nathalie A

2018-05-01

A scale model of the proposed Titan Mare Explorer capsule was deployed at the Planetary Lake Lander field site at Laguna Negra, Chile. The tests served to calibrate models of wind-driven drift of the capsule and to understand its attitude motion in the wave field, as well as to identify dynamic and acoustic signatures of shoreline approach. This information enables formulation of onboard trigger criteria for near-shore science data acquisition. Key Words: Titan-Vehicle dynamics-Science autonomy-Lake. Astrobiology 18, 607-618.

Laguna Negra Virus Infection Causes Hantavirus Pulmonary Syndrome in Turkish Hamsters (Mesocricetus brandti).

PubMed

Hardcastle, K; Scott, D; Safronetz, D; Brining, D L; Ebihara, H; Feldmann, H; LaCasse, R A

2016-01-01

Laguna Negra virus (LNV) is a New World hantavirus associated with severe and often fatal cardiopulmonary disease in humans, known as hantavirus pulmonary syndrome (HPS). Five hamster species were evaluated for clinical and serologic responses following inoculation with 4 hantaviruses. Of the 5 hamster species, only Turkish hamsters infected with LNV demonstrated signs consistent with HPS and a fatality rate of 43%. Clinical manifestations in infected animals that succumbed to disease included severe and rapid onset of dyspnea, weight loss, leukopenia, and reduced thrombocyte numbers as compared to uninfected controls. Histopathologic examination revealed lung lesions that resemble the hallmarks of HPS in humans, including interstitial pneumonia and pulmonary edema, as well as generalized infection of endothelial cells and macrophages in major organ tissues. Histologic lesions corresponded to the presence of viral antigen in affected tissues. To date, there have been no small animal models available to study LNV infection and pathogenesis. The Turkish hamster model of LNV infection may be important in the study of LNV-induced HPS pathogenesis and development of disease treatment and prevention strategies. © The Author(s) 2015.

Diurnal vocal activity of gray whales in Laguna San Ignacio, BCS, Mexico

NASA Astrophysics Data System (ADS)

Guerra, Melania; Thode, Aaron; Wisdom, Sheyna; Gonzalez, Sergio; Urban, Jorge; Sumich, James

2005-09-01

Three sets of portable horizontal acoustic arrays were deployed during a week in February 2005 to gather acoustic recordings of gray whales (Eschrichtius robustus) in Laguna San Ignacio, one of the three major breeding/calving lagoons in Baja California, Mexico. These arrays, which were constructed by attaching a pair of autonomous flash-memory acoustic sensors to a rope, were deployed for 36 consecutive hours on two occasions, spatially covering the narrowest point of the lagoon near Punta Piedra, the area of the highest concentration of whales. Additionally a single hydrophone was deployed off a small boat to record during friendly encounters with single whales and cow/calf pairs. Each recorder's time series was analyzed for Type 1 gray whale sounds (called pops), which are pulsive, broadband, and have substantial acoustic energy between 100 and 600 Hz. The number of automated acoustic detections per hour can be compared with population sizes estimated by two visual surveys conducted by scientists of the Autonomous University of Baja California Sur, La Paz. The results of several automated analyses of both the bottom-mounted and boat-deployed recordings will be presented, with a focus on potential diurnal patterns in the vocal activity.

Estimating floodplain sedimentation in the Laguna de Santa Rosa, Sonoma County, CA

USGS Publications Warehouse

Curtis, Jennifer A.; Flint, Lorraine E.; Hupp, Cliff R.

2013-01-01

We present a conceptual and analytical framework for predicting the spatial distribution of floodplain sedimentation for the Laguna de Santa Rosa, Sonoma County, CA. We assess the role of the floodplain as a sink for fine-grained sediment and investigate concerns regarding the potential loss of flood storage capacity due to historic sedimentation. We characterized the spatial distribution of sedimentation during a post-flood survey and developed a spatially distributed sediment deposition potential map that highlights zones of floodplain sedimentation. The sediment deposition potential map, built using raster files that describe the spatial distribution of relevant hydrologic and landscape variables, was calibrated using 2 years of measured overbank sedimentation data and verified using longer-term rates determined using dendrochronology. The calibrated floodplain deposition potential relation was used to estimate an average annual floodplain sedimentation rate (3.6 mm/year) for the ~11 km2 floodplain. This study documents the development of a conceptual model of overbank sedimentation, describes a methodology to estimate the potential for various parts of a floodplain complex to accumulate sediment over time, and provides estimates of short and long-term overbank sedimentation rates that can be used for ecosystem management and prioritization of restoration activities.

Ichthyoplankton spatial pattern in the inner shelf off Bahía Blanca Estuary, SW Atlantic Ocean

NASA Astrophysics Data System (ADS)

Hoffmeyer, Mónica Susana; Clara, Menéndez María; Florencia, Biancalana; Mabel, Nizovoy Alicia; Ramón, Torres Eduardo

2009-09-01

This study focuses on the composition, abundance and distribution of ichthyoplankton in the inner shelf area off Bahía Blanca Estuary on the SW Atlantic Ocean during late spring. Eggs and larvae of Brevoortia aurea, Engraulis anchoita, Parona signata, Sciaenidae spp. - such as Cynoscion guatucupa and Micropogonias furnieri -, and Odontesthes argentinensis were found. Species richness was low probably as a result of season and shallow depths. Ichthyoplankton abundance reached values close to 10 000 per 10 m -3 (eggs) and 4000 per 10 m -3 (larvae) and displayed a spatial distribution pattern with maximum abundance values restricted to a band parallel to the coast. Differences between egg and larval patterns, probably derived from a different displacement and hydrodynamic behavior, were observed. Egg and larvae distribution patterns were found related with spawning areas and to directly depend on salinity and mesozooplankton. The larvae distribution pattern, in particular, was found to inversely depend on particulate organic carbon. In addition, the geographic location of egg and larvae maxima strongly coincided with a saline front reported for this area in springtime, thus suggesting a direct relationship with it.

Organotin compounds in Brachidontes rodriguezii mussels from the Bahía Blanca Estuary, Argentina.

PubMed

Quintas, Pamela Y; Arias, Andrés H; Oliva, Ana L; Domini, Claudia E; Alvarez, Mónica B; Garrido, Mariano; Marcovecchio, Jorge E

2017-11-01

Levels of tributyltin and its breakdown compounds, including the first record of monobutyltin (MBT) in history for Latin America, were determined in native mussels (Brachidontes rodriguezii) by means of CG-MS, after extraction/derivatization assisted by ultrasound. The samples were collected in 2013 in Bahía Blanca Estuary (Argentina) at 6 sites, which reflect different levels of maritime activities. Total butyltins (TBts = TBT+ DBT+ MBT) levels ranged from 19.64 to 180.57ng Sn g -1 dry weight. According to the Oslo-Paris commission, the results indicated that 73.9% of mussels could be under biological effects risks associated with TBT pollution. In accordance with the calculated bioaccumulation factors, approximately 56% of samples appeared to have accumulated TBT through the sediments. All sampling sites were shown to be impacted by organotin compounds (OTCs) showing variable levels through seasons, which could be related with the variation of the water temperature. Degradation index analyses suggested aged inputs of TBT possibly under a general degradation process at the area of study. In addition, the occurrence of DBT and MBT could not be uniquely attributed to the degradation pathway of the TBT; in fact, results outlined the possible contribution of some punctual and diffuse sources at the area such as proximity to plastic industries, industrial effluents, sewage outlets and domestic wastewaters. Copyright © 2017 Elsevier Inc. All rights reserved.

Climate variability during the deglaciation and Holocene in a high-altitude alpine lake deduced from the sedimentary record from Laguna Seca, Sierra Nevada, southern Iberian Peninsula

NASA Astrophysics Data System (ADS)

Camuera, Jon; Jiménez-Moreno, Gonzalo; José Ramos-Román, María; García-Alix, Antonio; Jiménez-Espejo, Francisco; Anderson, R. Scott

2017-04-01

High-resolution X-ray fluorescence (XRF), magnetic susceptibility (MS), color and lithological analyses have been carried out on a 3.6 m-long sediment core from Laguna Seca, a high-elevation dry lake from Sierra Nevada mountain range, southern Spain. This is the longest sedimentary record retrieved from an alpine lake in southern Iberian Peninsula. Besides, alpine lakes are very sensitive environments to climate changes and previous studies showed that Laguna Seca could provide an excellent record to identify millennial-scale climate variations during deglaciation and the whole Holocene. XRF analyses, in particular high calcium and low K/Ca ratios, show aridity phases, very well represented during Last Glacial Maximum (LGM) and the Younger Dryas (YD). Arid events are also shown at ca. 8.1 ka BP, ca. 4.4 ka BP and the latest Holocene. On the other hand, negative values in calcium and positive values in K/Ca appear in the Bølling-Allerød (BA) and during the early Holocene until ca. 6 ka BP, indicating more humidity and higher run-off. A progressive aridification trend is also observed in the Holocene, changing from more humid conditions during the early Holocene to more aridity during the late Holocene.

Investigation of environmental pollution effects on stone monuments in the case of Santa Maria La Blanca, Seville (Spain)

NASA Astrophysics Data System (ADS)

Ortiz, P.; Vázquez, M. A.; Ortiz, R.; Martin, J. M.; Ctvrtnickova, T.; Mateo, M. P.; Nicolas, G.

2010-09-01

The aim of the study was to characterize specimens submitted to the effects of weathering in an urban atmosphere. Samples investigated were stones covered by crusts and deposits of thickness ranging from micrometers to millimetres due to traffic pollutants and mineral dust. The pieces were collected in the Church of Santa Maria La Blanca in Seville (South Spain). In the Historical Centre of this city, the traffic is the main source of sulphur oxides. Several analytical techniques have been employed to determine composition of specimens: OM, XRD, XRF, SEM-EDX and LIBS. The main weathering form was gypsum (CaSO4ṡ2H2O), and it has its source in sulphur oxides from traffic. Over this alteration layer, the deposits of atmospheric particles have been found. According to LIBS results, these particles can be composed of Al, Si, Ba, K, Na, Ti, V, Mg and Ca, while XRF technique also detect S, Fe, Mn and P. These atmospheric particles can have an anthropogenic or terrigenous origin, including the weathering of the building materials and its restoration products.

Spatiotemporal variability and differentiation between anthropogenic and natural contamination of heavy metals of surface water: a case study in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Guittard, A.; Baraer, M.; McKenzie, J. M.; Mark, B. G.; Fernandez, A.; Walsh, E.; Santos Perez, A.

2015-12-01

The Rio Santa, Peru, drains the western slopes of the glacierized Cordillera Blanca and provides water resources at almost all levels of the watershed. As it flows away from the valleys of the Cordillera Blanca, the Rio Santa takes out pollution from numerous sources, including acid mine drainage and natural sulfide oxidation by-products. The Rio Santa dry season discharge decline that is projected to be a consequence of glaciers retreat will probably have implications for the evolution of water pollution. This threat makes the characterization of the actual contamination mechanisms of primary importance. The present study focuses, first, on the spatiotemporal variability of heavy metal contamination across the entire Rio Santa Watershed and secondly on differentiating anthropogenic and natural contaminated sites. First, a macroscale sampling has been done during the summer 2013 to provide an overview of the contamination by trace metal, in water, suspended sediments and riverbed sediments. In addition, 30 water samples were taken from a point next to the city of Huaraz at a frequency of once every 2 weeks and analyzed for trace metals. Secondly, in order to identify hydrochemical contaminant origin dependant signatures in the Rio Santa watershed, 5 areas of known contamination origins were sampled during the summer 2014.Spatially speaking, we observed that most pollution is located in the south of the watershed, and that a large part of the arsenic that reaches the Santa in an aqueous phase does not make it to the outlet but remains trapped in the riverbed. Annual variation in water shows a very unusual fluctuation in Mn compare to other trace metal which are relatively stable. By differencing anthropogenic and natural sites and by considering glaciers melt and decrease water in future what would be the impact of the part of natural contaminated sites versus anthropogenic, mining and cities, on the water quality? Preliminary results show that anthropogenic sites

Proglacial Hydrogeology of the Cordillera Blanca (Peru): Integrating Field Observations with Hydrogeophysical Inversions to Inform Groundwater Flow Simulations and Conceptual Models

NASA Astrophysics Data System (ADS)

Glas, R. L.; Lautz, L.; McKenzie, J. M.; Moucha, R.; Mark, B. G.

2017-12-01

Geological and depositional conditions of the glaciated Cordillera Blanca in Peru have given way to proglacial aquifer systems that contribute substantially to regional streams and rivers, particularly during the dry season. As glacial retreat accelerates, the dry season water budget will be increasingly dominated by groundwater inputs, although predictions of future groundwater quantities require estimations of groundwater storage capacity, aquifer extents, and groundwater residence time. We present a characterization of the sediment structure in a prototypical proglacial valley in the central portion of the range, the Quilcayhuanca Valley. Northern and Central valleys of the Cordillera Blanca feature ubiquitous talus deposits that line the steep granite walls, and have become partially buried beneath lacustrine sediments deposited in proglacial lake beds. The portion of the talus still exposed near the valley walls provides recharge to deeper portions of the valley aquifers that underlie lacustrine clay, resulting in a confined aquifer system that is connected to the surface via perennial springs. Seismic refraction surveys reveal an interface separating relatively slow ( 400-800 m/s) and fast ( 2500 m/s) p-wave velocities. The depth of this refractor coincides with the depth to buried talus observed in drilling records. Electrical resistivity tomography profiles of the same transect show depths near the buried talus to be relatively conductive (10-100 Ωm). At these depths, we hypothesize that electrical conductance is elevated by saturated clay particles in the sediment matrix of the talus deposit. The resistivity models all show a more resistive ( 700 Ω m) region at depth, likely corresponding to a more hydraulically conductive material. The resistive zone is interpreted to be a deeper portion of a buried talus deposit that did not accumulate clay in the matrix. Other possibilities include a thick deposit of gravelly glacial outwash, or a relatively clay

Sr Isotopes and Migration of Prairie Mammoths (Mammuthus columbi) from Laguna de las Cruces, San Luis Potosi, Mexico

NASA Astrophysics Data System (ADS)

Solis-Pichardo, G.; Perez-Crespo, V.; Schaaf, P. E.; Arroyo-Cabrales, J.

2011-12-01

Asserting mobility of ancient humans is a major issue for anthropologists. For more than 25 years, Sr isotopes have been used as a resourceful tracer tool in this context. A comparison of the 87Sr/86Sr ratios found in tooth enamel and in bone is performed to determine if the human skeletal remains belonged to a local or a migrant. Sr in bone approximately reflects the isotopic composition of the geological region where the person lived before death; whereas the Sr isotopic system in tooth enamel is thought to remain as a closed system and thus conserves the isotope ratio acquired during childhood. Sr isotope ratios are obtained through the geologic substrate and its overlying soil, from where an individual got hold of food and water; these ratios are in turn incorporated into the dentition and skeleton during tissue formation. In previous studies from Teotihuacan, Mexico we have shown that a three-step leaching procedure on tooth enamel samples is important to assure that only the biogenic Sr isotope contribution is analyzed. The same Sr isotopic tools can function concerning ancient animal migration patterns. To determine or to discard the mobility of prairie mammoths (Mammuthus columbi) found at Laguna de las Cruces, San Luis Potosi, México the leaching procedure was applied on six molar samples from several fossil remains. The initial hypothesis was to use 87Sr/86Sr values to verify if the mammoth population was a mixture of individuals from various herds and further by comparing their Sr isotopic composition with that of plants and soils, to confirm their geographic origin. The dissimilar Sr results point to two distinct mammoth groups. The mammoth population from Laguna de Cruces was then not a family unit because it was composed by individuals originated from different localities. Only one individual was identified as local. Others could have walked as much as 100 km to find food and water sources.

The energy balance of tropical Glaciar Artesonraju, Cordillera Blanca, Perú - AWS-measurements and numerical modeling

NASA Astrophysics Data System (ADS)

Galos, S.; Mölg, T.; MacDonell, S.; Großhauser, M.; Marzeion, B.

2012-04-01

Like in most regions of the world, tropical glaciers in the Peruvian Andes have experienced considerable mass loss during the last decades. In order to better understand and correctly interpret the ongoing glacier changes in this region, we need to examine the driving processes behind these changes. Therefore we installed several automatic weather stations (AWS) in the Cordillera Blanca mountain range. Two of these stations are situated in the ablation area of Glaciar Shallap and Glaciar Artesonraju, while four other stations were established in the vicinity of the two glaciers. The resulting eight year record of meteorological data is analyzed and finally used as input for a physically based numerical energy and mass balance model, which in a first step was applied to the ablation zone of Glaciar Artesonraju (8.96° S / 77.63° W). In July 2010, eddy covariance measurements were carried out on the glacier surface. The resulting data was used to calibrate the parametrization scheme for the turbulent fluxes of sensible and latent heat. Finally the model output was validated against ablation data from a sonic ranger and from single stake ablation measurements. The model results were interpreted with special respect to the seasonal fluctuation in atmospheric moisture (tropical wet / dry season).

Distribution, vertical position and ecological implications of shallow gas in Bahía Blanca estuary (Argentina)

NASA Astrophysics Data System (ADS)

Bravo, M. E.; Aliotta, S.; Fiori, S.; Ginsberg, S.

2018-03-01

There has been a growing interest in the study of shallow gas due its importance in relation to the marine environment, climate change and human activities. In Bahía Blanca estuary, Argentina, shallow gas has a wide distribution. Acoustic turbidity and blanking are the main seismic evidence for the presence of shallow gas in the estuary. The former prevails in the inner sector of the estuary where gas is either near or in contact with the seabed. Gas deposits are generally associated with paleochannels corresponding to the Holocene paleodeltaic environment. Distribution studies of shallow gas in this estuary are necessary because its presence implies not only a geological risk for harbor activities but also because it may have noxious effects on the marine ecosystem, mainly on benthic communities. The comparison of benthic communities at a gas site (GS) with those at a control site (CS) indicated that gas could generate impoverishment in terms of individuals' abundance (GS: N = 357; CS: N = 724). Also, diversity indices showed great differences in the community structure at each site. This indicates that methane gas may act as a natural disturbance agent in estuarine ecosystems. The presence of gas in seabed sediments must therefore be taken into account when distribution studies are conducted of estuarine benthic communities.

Magma-tectonic Interaction at Laguna del Maule, Chile

NASA Astrophysics Data System (ADS)

Keranen, K. M.; Peterson, D. E.; Miller, C. A.; Garibaldi, N.; Tikoff, B.; Williams-Jones, G.

2016-12-01

The Laguna del Maule Volcanic Field (LdM), Chile, the largest concentration of rhyolite <20 kyr globally, exhibits crustal deformation at rates higher than any non-erupting volcano. The interaction of large magmatic systems with faulting is poorly understood, however, the Chaitén rhyolitic system demonstrated that faults can serve as magma pathways during an eruption. We present a complex fault system at LdM in close proximity to the magma reservoir. In March 2016, 18 CHIRP seismic reflection lines were acquired at LdM to identify faults and analyze potential spatial and temporal impacts of the fault system on volcanic activity. We mapped three key horizons on each line, bounding sediment packages between Holocene onset, 870 ybp, and the present date. Faults were mapped on each line and offset was calculated across key horizons. Our results indicate a system of normal-component faults in the northern lake sector, striking subparallel to the mapped Troncoso Fault SW of the lake. These faults correlate to prominent magnetic lineations mapped by boat magnetic data acquired February 2016 which are interpreted as dykes intruding along faults. We also imaged a vertical fault, interpreted as a strike-slip fault, and a series of normal faults in the SW lake sector near the center of magmatic inflation. Isochron and fault offset maps illuminate areas of growth strata and indicate migration and increase of fault activity from south to north through time. We identify a domal structure in the SW lake sector, coincident with an area of low magnetization, in the region of maximum deformation from InSAR results. The dome experienced 10 ms TWT ( 10 meters) of uplift throughout the past 16 kybp, which we interpret as magmatic inflation in a shallow magma reservoir. This inflation is isolated to a 1.5 km diameter region in the hanging wall of the primary normal fault system, indicating possible fault-facilitated inflation.

Diagnosing the imbalance of Yanamarey Glacier in the Cordillera Blanca of Peru

NASA Astrophysics Data System (ADS)

Hastenrath, Stefan; Ames, Alcides

1995-03-01

A detailed glaciological observation program was conducted on the Yanamarey Glacier in the Cordillera Blanca of Peru, including the monitoring of net balance and ice flow velocity during 1977-1988 and mappings of the surface topography in 1973, 1982, and 1988. These observations are here evaluated to combine net balance, surface lowering, and ice flow into a consistent picture of the mode of operation of a tropical glacier on the scale of a decade. The glacier extends between 5100 and 4500 m with a total area of 9×105 m2 and length of about 1.3 km. Maximum flow velocity is 17.4 m yr-1 and maximum volume flux 336×103 m3 yr-1. In the ablation area, net balance is about -6 m yr-1 and surface lowering 3 m yr-1. About half of the mean annual water discharge from the glacier of 80 L s-1 is not renewed by precipitation but supplied by the ice thinning. The rate of surface lowering of 1.5 m yr-1 liquid water equivalent translates to a glacier average departure heat supply for melting of 16 W m-2. Sensitivity analyses indicate that this could be produced by a cloudiness increase of less than one tenth, an air temperature decrease of 2°C, an increment in specific humidity of less than 1 g kg-1, or some combination of heat budget processes. Such changes in the atmospheric environment would be required to stabilize the glacier at its recent volume. As another indication of the recent imbalance, the maximum volume flux is found some 100 m below the equilibrium line altitude. Under continuation of the recent climatic conditions, the glacier may survive for more than half a century.

Water Resources and Groundwater in a Glaciated Andean Watershed (Cordillera Blanca, Peru)

NASA Astrophysics Data System (ADS)

McKenzie, J. M.; Gordon, R.; Baraer, M.; Lautz, L.; Mark, B. G.; Wigmore, O.; Chavez, D.; Aubry-Wake, C.

2014-12-01

It is estimated that almost 400 million people live in watersheds where glaciers provide at least 10% of the runoff, yet many questions remain regarding the impact of climate change and glacier recession on water resources derived from these high mountain watersheds. We present research from the Cordillera Blanca, Peru, an area with the highest density of glaciers in the tropics. While glacier meltwater buffers stream discharge throughout the range, groundwater is a major component of dry season runoff, contributing up to 50-70% of outflow in some tributaries. In order to predict future changes to water resources it is critical to understand how groundwater can offset future hydrologic stress by maintaining stream baseflow, including recharge mechanisms, subsurface pathways, storage, and net fluxes to rivers. We present a synthesis of results based on hydrologic modeling, drilling/piezometers, geophysics, and artificial and natural hydrologic tracers. Our findings show that 'pampas', low-relief mountain valleys, are critical for baseflow generation by storing groundwater on interannual timescales. Pampas have a total area of ~65 km2 and are comprised of unconsolidated glacial, talus, lacustrine and wetland (bofedales) deposits. The valleys commonly have buried talus aquifers that are overlain by low permeability, glaciolacustrine deposits. Glaciofluvial outwash deposits and small wetlands also act as unconfined aquifers. These groundwater systems appear to be primarily recharged by wet season precipitation, and at higher elevations also by glacial meltwater. Additionally a ubiquitous feature in the valleys are springs, often located at the base of talus deposits, which generate a large hydrologic flux within the hydrologic systems. While glaciers are the most visible and vulnerable component of the Andean waterscape, we argue that it is crucial to understand the complete mountain hydrologic cycle, including groundwater, in order to understand the ongoing

Analysis of the ecosystem structure of Laguna Alvarado, western Gulf of Mexico, by means of a mass balance model

NASA Astrophysics Data System (ADS)

Cruz-Escalona, V. H.; Arreguín-Sánchez, F.; Zetina-Rejón, M.

2007-03-01

Alvarado is one of the most productive estuary-lagoon systems in the Mexican Gulf of Mexico. It has great economic and ecological importance due to high fisheries productivity and because it serves as a nursery, feeding, and reproduction area for numerous populations of fishes and crustaceans. Because of this, extensive studies have focused on biology, ecology, fisheries (e.g. shrimp, oysters) and other biological components of the system during the last few decades. This study presents a mass-balanced trophic model for Laguna Alvarado to determine it's structure and functional form, and to compare it with similar coastal systems of the Gulf of Mexico and Mexican Pacific coast. The model, based on the software Ecopath with Ecosim, consists of eighteen fish groups, seven invertebrate groups, and one group each of sharks and rays, marine mammals, phytoplankton, sea grasses and detritus. The acceptability of the model is indicated by the pedigree index (0.5) which range from 0 to 1 based on the quality of input data. The highest trophic level was 3.6 for marine mammals and snappers. Total system throughput reached 2680 t km -2 year -1, of which total consumption made up 47%, respiratory flows made up 37% and flows to detritus made up 16%. The total system production was higher than consumption, and net primary production higher than respiration. The mean transfer efficiency was 13.8%. The mean trophic level of the catch was 2.3 and the primary production required to sustain the catch was estimated in 31 t km -2 yr -1. Ecosystem overhead was 2.4 times the ascendancy. Results suggest a balance between primary production and consumption. In contrast with other Mexican coastal lagoons, Laguna Alvarado differs strongly in relation to the primary source of energy; here the primary producers (seagrasses) are more important than detritus pathways. This fact can be interpreted a response to mangrove deforest, overfishing, etc. Future work might include the compilation of

Lateglacial and Holocene climatic changes in south-eastern Patagonia inferred from carbonate isotope records of Laguna Potrok Aike (Argentina)

NASA Astrophysics Data System (ADS)

Oehlerich, M.; Mayr, C.; Gussone, N.; Hahn, A.; Hölzl, S.; Lücke, A.; Ohlendorf, C.; Rummel, S.; Teichert, B. M. A.; Zolitschka, B.

2015-04-01

First results of strontium, calcium, carbon and oxygen isotope analyses of bulk carbonates from a 106 m long sediment record of Laguna Potrok Aike, located in southern Patagonia are presented. Morphological and isotopic investigations of μm-sized carbonate crystals in the sediment reveal an endogenic origin for the entire Holocene. During this time period the calcium carbonate record of Laguna Potrok Aike turned out to be most likely ikaite-derived. As ikaite precipitation in nature has only been observed in a narrow temperature window between 0 and 7 °C, the respective carbonate oxygen isotope ratios serve as a proxy of hydrological variations rather than of palaeotemperatures. We suggest that oxygen isotope ratios are sensitive to changes of the lake water balance induced by intensity variations of the Southern Hemisphere Westerlies and discuss the role of this wind belt as a driver for climate change in southern South America. In combination with other proxy records the evolution of westerly wind intensities is reconstructed. Our data suggest that weak SHW prevailed during the Lateglacial and the early Holocene, interrupted by an interval with strengthened Westerlies between 13.4 and 11.3 ka cal BP. Wind strength increased at 9.2 ka cal BP and significantly intensified until 7.0 ka cal BP. Subsequently, the wind intensity diminished and stabilised to conditions similar to present day after a period of reduced evaporation during the "Little Ice Age". Strontium isotopes (87Sr/86Sr ratio) were identified as a potential lake-level indicator and point to a lowering from overflow conditions during the Glacial (∼17 ka cal BP) to lowest lake levels around 8 ka cal BP. Thereafter the strontium isotope curve resembles the lake-level curve which is stepwise rising until the "Little Ice Age". The variability of the Ca isotope composition of the sediment reflects changes in the Ca budget of the lake, indicating higher degrees of Ca utilisation during the period with

Impact of Water Resorts Development along Laguna de Bay on Groundwater Resources

NASA Astrophysics Data System (ADS)

Jago-on, K. A. B.; Reyes, Y. K.; Siringan, F. P.; Lloren, R. B.; Balangue, M. I. R. D.; Pena, M. A. Z.; Taniguchi, M.

2014-12-01

Rapid urbanization and land use changes in areas along Laguna de Bay, one of the largest freshwater lake in Southeast Asia, have resulted in increased economic activities and demand for groundwater resources from households, commerce and industries. One significant activity that can affect groundwater is the development of the water resorts industry, which includes hot springs spas. This study aims to determine the impact of the proliferation of these water resorts in Calamba and Los Banos, urban areas located at the southern coast of the lake on the groundwater as a resource. Calamba, being the "Hot Spring Capital of the Philippines", presently has more than 300 resorts, while Los Banos has at least 38 resorts. Results from an initial survey of resorts show that the swimming pools are drained/ changed on an average of 2-3 times a week or even daily during peak periods of tourist arrivals. This indicates a large demand on the groundwater. Monitoring of actual groundwater extraction is a challenge however, as most of these resorts operate without water use permits. The unrestrained exploitation of groundwater has resulted to drying up of older wells and decrease in hot spring water temperature. It is necessary to strengthen implementation of laws and policies, and enhance partnerships among government, private sector groups, civil society and communities to promote groundwater sustainability.

The stratified microbial community at Laguna Figueroa, Baja California, Mexico: A possible model for prephanerozoic laminated microbial communities preserved in cherts

NASA Astrophysics Data System (ADS)

Stolz, John F.; Margulis, Lynn

1984-12-01

The microbial mat community of the evaporite flat at North Pond, Laguna Figueroa (Baja California, Mexico) was actively involved in the production of laminated sediments prior to 1978. Heavy rains in 1979 and 1980 flooded the mat with 1 and 3 meters of meteoric water respectively. The flooding deposited up to 10 cm of silicoclastic sediment over theMicrocoleus-dominated mat and resulted in the cessation of laminated sediment deposition. In 1982, the surface had been recolonized by species of cyanobacteria (Spirulina, Oscillatoria) and purple photosynthetic bacteria (Chromatium, Thiocapsa). The silicoclastic sediments and residual evaporites, which overlaid the laminated sediment, had been reworked into an anaerobic, sulfide-rich mud and contained well preserved sheaths of filamentous and coccoid bacteria.

Polycyclic aromatic hydrocarbons in water, mussels ( Brachidontes sp., Tagelus sp.) and fish ( Odontesthes sp.) from Bahía Blanca Estuary, Argentina

NASA Astrophysics Data System (ADS)

Arias, Andres H.; Spetter, Carla V.; Freije, Rubén H.; Marcovecchio, Jorge E.

2009-10-01

Polycyclic aromatic hydrocarbons (PAHs), one of the major groups of anthropogenic environmental pollutants, were firstly identified and measured in coastal waters, native mussels and fish of an industrialized South American estuary. The aim of this study was to measure the PAHs concentrations and evaluate distribution and sources in surface seawater, native mussels ( Brachidontes sp. and Tagelus sp.) and fish ( Odontesthes sp.) from various coastal sites of the Bahía Blanca Estuary, in order to put the estuary in a global context and assess it ecotoxicological risk. For this, 40 samples of surface water were collected between August 2004 and February 2006 and analyzed by GC/MS for 17 PAHs, including the 16 EPA priority PAHs. In addition, main physicochemical parameters, nutrients and pigments were simultaneously obtained as key parameters to evaluate possible relationships. Finally, several native mussel communities and fish specimens were also analyzed for PAHs contents. The area of study is located at the Argentinean coast and presents an intensive human and industrial activity at the north shoreline. Total PAHs (Σ17 PAHs) in whole surface waters ranged from undetected to more than 4 μg/l. Seasonal PAHs levels relationship with master parameters suggested a relationship between the phytoplankton microbiological cycling and the dissolved/suspended PAHs occurrence in water. In addition, Cluster Analysis was performed to identify the homogeneous groups of individual PAHs in water and Principal Component Analysis to extract underlying common factors. The result of PCA was similar to that of the cluster analysis; both could differentiate two subsets of pyrogenic sources and a petrogenic origin. PAHs levels in indigenous mussels ( Brachidontes sp. and Tagelus sp.) ranged from 348 to 1597 ng/g (dry weight). Fish specimens ( Odontesthes sp.) showed a mean concentration of 1095 ng/g d.w. in whole tissues. Mussel source ratios and PCA results were in good agreement with

A ~20,000 year history of glacial variability in the tropical Andes recorded in lake sediments from the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Stansell, N.; Rodbell, D. T.; Moy, C. M.

2010-12-01

Pro-glacial lake sediments from the Cordillera Blanca, Peru contain continuous records of climate variability spanning the Last Glacial Maximum to present day. Here we present results from two alpine lake basins in the Queshgue Valley (9.8°S, 77.3°W) that contain high-resolution records of clastic sediment deposition for the last ~20,000 years. Radiocarbon-dated sediment cores were scanned at 0.5 to 1.0 cm resolution using a profiling x-ray fluorescence scanner for major and minor element distributions. In addition, we measured down-core variations in magnetic susceptibility, organic carbon, biogenic silica and calcium carbonate. Samples of bedrock and sediments from glacial moraines in the Queshgue watershed were analyzed using an ICP-MS in order to fingerprint and trace the source of glacial sediments deposited in the lakes. The bedrock is dominated by a combination of granodiorite with high Sr concentrations and meta-sedimentary rocks with high Zr values. Because the glacial sediments proximal to the modern glacier terminus are composed mostly of the granodiorite end-member, we interpret changes in Sr and clastic sediment concentrations in the lake sediment profiles as proxies for past glacial variability. Preliminary results indicate that glaciers retreated soon after ~14,500 cal yr BP and remained less extensive during the remaining late Glacial Stage and early Holocene. Gradually increasing clastic sediments through the middle and late Holocene indicate that glaciers became progressively larger, or more erosive towards present day. However, this overall Holocene trend of increasing glacier extent was interrupted by multiple periods of centennial- to millennial-scale ice margin retreat. For example, relative peaks in clastic sediments occurred from ~14,500 to 6000, 5600 to 5000, 4600 to 4200, 3600 to 3200, 2800 to 2700, 2400 to 2200, 1750 to 1550, 1100 to 900 cal yr BP, and during the Little Ice Age (~700 to 50 cal yr BP), while periods of low clastic

Assessment of the physicochemical conditions sediments in a polluted tidal flat colonized by microbial mats in Bahía Blanca Estuary (Argentina).

PubMed

Spetter, C V; Buzzi, N S; Fernández, E M; Cuadrado, D G; Marcovecchio, J E

2015-02-28

The aim of this work is to assess the physicochemical conditions of the supratidal sediments colonized by microbial mats at two sites from Rosales Harbor (Bahía Blanca Estuary, Argentina) close to sewage discharge. Both sites differed in the size grain. No differences in pH, Eh and temperature were observed. Moisture retention and chlorophyll a concentration were significantly different between sites and sediment layers. Heavy metals and organic matter content were significantly higher in SII. No statistical differences were found in porewater nutrients concentration, being higher in SI (except DSi). The presence of Escherichia coli in water and sediment (1000 CFU/100 mL - uncountable and 35-40 CFU g(-1) dw, respectively) evidenced microbial contamination in the study area. The relationships between the physicochemical parameters evaluated and the influence of the sewage discharge allow defining two different areas in the Rosales Harbor despite the proximity and the presence of microbial mats.

Deglaciation in the High Andes - a Record from Laguna Piuray (Cusco, Peru)

NASA Astrophysics Data System (ADS)

Nederbragt, A.; Thurow, J.; Brumsack, H.; Lowe, J.; Pearce, R.; Ramsey, C.

2007-12-01

The Peruvian Andes lie in a crucial location for paleoclimate investigation. Fluctuating Pacific and Atlantic air masses compete for long-term dominance of the region, with the El-Nino Southern Oscillation (ENSO) system causing further variability. A laminated glacial/interglacial sediment sequence (6m) exposed around the shores of Laguna Piuray, near Cusco, offers not only the potential to reconstruct the climate history of the area but also to test for strength and frequency of the Atlantic monsoonal and Pacific ENSO influence. A suite of continuous cores was collected from deep trenches. The sedimentary record is characterized by postglacial diatom-rich chalk overlying organic-rich clayey chalk. Between these units are 3 distinct organic layers (80% TOC) deposited between 12-14 cal. kyr BP (14C). The base of the record is probably as old as 25kyrs (U/Th). We obtained a multi- proxy record of the section including continuous XRF scanning data of the entire sequence, and stable isotopes, XRF, XRD, TOC, biogenic opal, and carbonate analysis of discrete samples as well as a relative paleotemperature record from analyses of soil biomarkers. All the data profiles we obtained show a pronounced increase in temperature and decrease in precipitation at 13.8kyrs and are in good correlation with published regional Andean records using single proxies. Our results confirm that the Deglaciation Cold Reversal in central South America is not identical to the Younger Dryas event in the Northern Hemisphere.

Incidence of organochlorine pesticides and the health condition of nestling ospreys (Pandion haliaetus) at Laguna San Ignacio, a pristine area of Baja California Sur, Mexico.

PubMed

Rivera-Rodríguez, Laura B; Rodríguez-Estrella, Ricardo

2011-01-01

We identified and quantified organochlorine (OC) pesticide residues in the plasma of 28 osprey (Pandion haliaetus) nestlings from a dense population in Laguna San Ignacio, a pristine area of Baja California Sur, Mexico, during the 2001 breeding season. Sixteen OC pesticides were identified and quantified. α-, β-, δ- and γ-hexachlorocyclohexane, heptaclor, heptachlor epoxide, endosulfan I and II, endosulfan-sulfate, p,p'-DDE, p,p'-DDD, aldrin, dieldrin, endrin, endrin aldehyde, and endrin ketone were the OCs found in the plasma of nestlings, ranging from 0.002 to 6.856 pg/μl (parts per billion). No differences were found in the concentration of pesticides between genders (P > 0.05). In our work, the concentrations detected in the plasma were lower than those reported to be a threat for the species and that affect the survival and reproduction of birds. The presence of OC pesticides in the remote Laguna San Ignacio osprey population is an indication of the ubiquitous nature of these contaminants. OCs are apparently able to travel long distances from their source to the study area. A significant relationship between hemoglobin and mean corpuscular hemoglobin concentrations and OC concentrations were found suggesting that a potential effect on the health of chicks may exist in this osprey population caused by the OC, e.g. anemia. The total proteins were positively correlated with α-BHC, endosulfan I, and p,p'-DDD. It has been suggested that OC also affects competitive interactions and population status over the long term in vertebrate species, and our results could be used as reference information for comparison with other more exposed osprey populations.

The microbial community at laguna Figueroa, Baja California Mexico: From miles to microns

NASA Astrophysics Data System (ADS)

Stolz, John F.

1985-12-01

Laguna Figueroa is a lagoonal complex on the Pacific coast of the Baja California penisula 200 km south of the Mexican-United States border. The hypersaline lagoon is 16 km long and 2 3 km wide with a salt marsh and evaporite flat and is separated from the ocean by a barrier dune and beach. At the salt marsh-evaporite flat interface a stratified microbial community dominated byMicrocoleus chthonoplastes is depositing laminated sediments. Similar stratiform deposits with associated microbial mat communities have been found in cherts of the Fig Tree Group, South Africa which are 3.4 GE in age. Heavy rains in the winters of 1978 1979 and 1979 1980 flooded the evaporite flat with 1 3 meters of meteoric water and buried the laminated sediment under 5 10 cm of siliciclastic and clay sediment. These flooding events had a dramatic effect on the composition of the mat community. TheMicrocoleus dominated community, with species ofChloroflexus sp. and anEctothiorhodospira-like filamentous purple phototroph, disappeared leaving a community dominated by the purple phototrophsChromatium sp. andThiocapsa sp. Recolonization of the surface by species of the cyanobacteriaOscillatoria sp. andSpirulina sp. preceded the return of theMicrocoleus community. Field conditions were monitored by ground based observations and supplemented with LandSat and Skylab imagery. The microbial community was studied with light microscopy and transmission electron microscopy. The change in dominating microbial species was correlated with the episodes of flooding.

The energy balance on the surface of a tropical glacier tongue. Investigations on glacier Artesonraju, Cordillera Blanca, Perú.

NASA Astrophysics Data System (ADS)

Juen, I.; Mölg, T.; Wagnon, P.; Cullen, N. J.; Kaser, G.

2006-12-01

The Cordillera Blanca in Perú is situated in the Outer Tropics spanning from 8 to 10 ° South. Solar incidence and air temperature show only minor seasonal variations whereas precipitation occurs mainly from October to April. An energy balance station was installed on the tongue of glacier Artesonraju (4850 m a.s.l.) in March 2004. In this study each component of the energy balance on the glacier surface is analysed separately over a full year, covering one dry and one wet season. During the dry season glacier melt at the glacier tongue is app. 0.5 m we per month. In the wet season glacier melt is twice as much with 1 m we per month. This is due to higher energy fluxes and decreased sublimation during the wet season. With an energy balance model that has already been proved under tropical climate conditions (Mölg and Hardy, 2004) each energy flux is changed individually to evaluate the change in the amount of glacier melt. First results indicate that a change in humidity related variables affects glacier melt very differently in the dry and wet season, whereas a change in air temperature changes glacier melt more constantly throughout the year.

Late Holocene Lake Level Fluctuations at Laguna Arapa, Peru and Connections to Human Demography

NASA Astrophysics Data System (ADS)

Hillman, A. L.; Abbott, M. B.; Werne, J. P.; Arkush, E.; Thompson, L. G.; Ferland, T.; Holmes, E.; Puhnaty, C.; Woods, A.

2016-12-01

The relationship between variations in hydroclimate and human demography on the Peruvian Altiplano has significant implications for understanding how people in the past have adapted to changes in freshwater resources. To investigate these human-environmental interactions, this project presents a 2,000 year sediment record from Laguna Arapa, a large lake that is <20 km NW of Lake Titicaca. Using sedimentology and stratigraphy as well as a suite of organic geochemical proxies including fecal 5β-stanols and leaf waxes (long chain n-alkanoic acids), we aim to tie together proxies of human population with indicators of regional hydroclimate. Preliminary results of sedimentology and stratigraphy show notable transitions from sand to silt to clay, suggesting rising lake level sequences at 500 and 700 AD. The last 1,300 years of sediment are characterized by alternating layers of organic rich material with abundant charcoal and black inorganic clay, suggesting intermittent periods of aridity and/or anthropogenic fire-setting. These layers are particularly frequent during the Medieval Climate Anomaly, which was characterized by dry and warm conditions. These results agree well with other records of hydroclimate from regional lakes as well as accumulation rate and temperature from the Quelccaya ice cap. Organic geochemical work is currently in progress and shows promise for linking together proxies of human demography with hydroclimate to understand the relationship between human settlement and climate change.

U-Sries Disequilibra in Soils, Pena Blanca Natural Analog, Chihuahua, Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

D. French; E. Anthony; P. Goodell

2006-03-16

The Nopal I uranium deposit located in the Sierra Pena Blanca, Mexico. The deposit was mined in the early 1980s, and ore was stockpiled close by. This stockpile area was cleared and is now referred to as the Prior High Grade Stockpile (PHGS). Some of the high-grade boulders from the site rolled downhill when it was cleared in the 1990s. For this study soil samples were collected from the alluvium surrounding and underlying one of these boulders. A bulk sample of the boulder was also collected. Because the Prior High Grade Stockpile had no ore prior to the 1980s amore » maximum residence time for the boulder is about 25 years, this also means that the soil was at background as well. The purpose of this study is to characterize the transport of uranium series radionuclides from ore to the soil. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. Isotopes of the uranium series decay chain detected include {sup 210}Pb, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 214}Pb, and {sup 214}Bi. Peak areas for each isotope are determined using gamma-ray spectroscopy with a Canberra Ge (Li) detector and GENIE 2000 software. The boulder sample is close to secular equilibrium when compared to the standard BL-5 (Beaver Lodge Uraninite from Canada). Results for the soils, however, indicate that some daughter/parent pairs are in secular disequilibrium. These daughter/parent (D/P) ratios include {sup 230}Th/{sup 234}U, which is greater than unity, {sup 226}Ra/{sup 230}Th, which is also greater than unity, and {sup 210}Pb/{sup 214}Bi, which is less than unity. The gamma-ray spectrum for organic material lacks {sup 230}Th peaks, but contains {sup 234}U and {sup 226}Ra, indicating that plants preferentially incorporate {sup 226}Ra. Our results, combined with previous studies require multistage history of mobilization of the uranium series radionuclides. Earlier studies at the ore zone could limit the time span for

Distinguishing megathrust from intraplate earthquakes using lacustrine turbidites (Laguna Lo Encañado, Central Chile)

NASA Astrophysics Data System (ADS)

Van Daele, Maarten; Araya-Cornejo, Cristian; Pille, Thomas; Meyer, Inka; Kempf, Philipp; Moernaut, Jasper; Cisternas, Marco

2017-04-01

One of the main challenges in seismically active regions is differentiating paleo-earthquakes resulting from different fault systems, such as the megathrust versus intraplate faults in subductions settings. Such differentiation is, however, key for hazard assessments based on paleoseismic records. Laguna Lo Encañado (33.7°S; 70.3°W; 2492 m a.s.l.) is located in the Central Chilean Andes, 50 km east of Santiago de Chile, a metropole with about 7,000,000 inhabitants. During the last century the study area experienced 3 large megathrust earthquakes (1906, 1985 and 2010) and 2 intraplate earthquakes (1945 and 1958) (Lomnitz, 1960). While the megathrust earthquakes cause Modified Mercalli Intensities (MMIs) of VI to VII at the lake (Van Daele et al., 2015), the intraplate earthquakes cause peak MMIs up to IX (Sepúlveda et al., 2008). Here we present a turbidite record of Laguna Lo Encañado going back to 1900 AD. While geophysical data (3.5 kHz subbottom seismic profiles and side-scan sonar data) provides a bathymetry and an overview of the sedimentary environment, we study 15 short cores in order to understand the depositional processes resulting in the encountered lacustrine turbidites. All mentioned earthquakes triggered turbidites in the lake, which are all linked to slumps in proximal areas, and are thus resulting from mass wasting of the subaquatic slopes. However, turbidites linked to the intraplate earthquakes are additionally covered by turbidites of a finer-grained, more clastic nature. We link the latter to post-seismic erosion of onshore landslides, which need higher MMIs to be triggered than subaquatic mass movements (Howarth et al., 2014). While intraplate earthquakes can cause MMIs up to IX and higher, megathrust earthquakes do not cause sufficiently high MMIs at the lake to trigger voluminous onshore landslides. Hence, the presence of these post-seismic turbidites allows to distinguish turbidites triggered by intraplate earthquakes from those

Coastal landscape evolution on the western margin of the Bahía Blanca Estuary (Argentina) mirrors a non-uniform sea-level fall after the mid-Holocene highstand

NASA Astrophysics Data System (ADS)

Pratolongo, Paula; Piovan, María Julia; Cuadrado, Diana G.; Gómez, Eduardo A.

2017-08-01

Sedimentary descriptions and radiocarbon ages from two cores obtained from coastal plains along the western margin of the Bahía Blanca Estuary (Argentina) were integrated with previous information on landscape patterns and plant associations to infer landscape evolution during the mid-to-late Holocene. The study area comprises at least two marine terraces of different elevations. The old marine plain (OMP), at an average elevation of 5 m above mean tidal level (MTL), is a nearly continuous flat surface. The Recent marine plain (RMP), 2 to 3 m above MTL, is a mosaic of topographic highs and elongated depressions that may correspond to former tidal channels. Mollusks at the base of the OMP core (site elevation 5.09 m above MTL), with ages between 5,660 ± 30 and 5,470 ± 30 years BP, indicate a subtidal setting near the inland limits of the marine ingression. The sandy bottom of the core is interpreted as the last stage of the transgressive phase, followed by a tight sequence of dark laminated muds topped by a thick layer of massive gray muds. The RMP core (site elevation 1.80 m above MTL) has a similar sedimentary sequence, but unconformities appear at lower elevations and the massive mud deposits are less developed. The thickness of the grayish mud layer is a major difference between the OMP and RMP cores, but deeper layers have similar ages, suggesting a common origin at the end of the transgressive phase. The overlying massive muds would correspond to rapid sedimentation during a high sea-level stillstand or slow regression. It is proposed that, after a rapid sea-level drop to about 3 m above MTL, a flat and continuous surface corresponding to the OMP emerged, and more recent coastal dynamics shaped the dissected landscape of the RMP. For the Bahía Blanca Estuary, smooth regressive trends have been proposed after the mid-Holocene highstand, but also stepped curves. A stillstand or slowly dropping sea level was described around 3,850 ± 100 years BP, as well as

Hydrological and depositional processes associated with recent glacier recession in Yanamarey catchment, Cordillera Blanca (Peru).

PubMed

López-Moreno, J I; Valero-Garcés, B; Mark, B; Condom, T; Revuelto, J; Azorín-Molina, C; Bazo, J; Frugone, M; Vicente-Serrano, S M; Alejo-Cochachin, J

2017-02-01

In this study, we investigate changes in the glaciated surface and the formation of lakes in the headwater of the Querococha watershed in Cordillera Blanca (Peru) using 24 Landsat images from 1975 to 2014. Information of glacier retreat was integrated with available climate data, the first survey of recent depositional dynamics in proglacial Yanamarey Lake (4600m a.s.l.), and a relatively short hydrological record (2002-2014) at the outlet of Yanamarey Lake. A statistically significant temperature warming (0.21°C decade -1 for mean annual temperature) has been detected in the region, and it caused a reduction of the glacierized area since 1975 from 3.5 to 1.4km -2 . New small lakes formed in the deglaciated areas, increasing the flooded area from1.8ha in 1976 to 2.8ha in 2014. A positive correlation between annual rates of glacier recession and runoff was found. Sediment cores revealed a high sedimentation rate (>1cmyr -1 ) and two contrasted facies, suggesting a shift toward a reduction of meltwater inputs and higher hydrological variability likely due to an increasing role of precipitation on runoff during the last decades. Despite the age control uncertainties, the main transition likely occurred around 1998-2000, correlating with the end of the phase with maximum warming rates and glacier retreat during the 1980s and 1990s, and the slowing down of expansion of surface lake-covered surface. With this hydrological - paleolimnological approach we have documented the association between recent climate variability and glacier recession and the rapid transfer of hydroclimate signal to depositional and geochemical processes in high elevation Andean environments. This, study also alerts about water quality risks as proglacial lakes act as secondary reservoirs that trap trace and minor elements in high altitude basins. Copyright © 2016 Elsevier B.V. All rights reserved.

Early and mid-Holocene age for the Tempanos moraines, Laguna San Rafael, Patagonian Chile

NASA Astrophysics Data System (ADS)

Harrison, Stephan; Glasser, Neil F.; Duller, Geoff A. T.; Jansson, Krister N.

2012-01-01

Data about the nature and timing of Holocene events from the Southern Hemisphere, especially in southern South America, are required to provide insight into the extent and nature of past climate change in a region where land-based records are restricted. Here we present the first use of single grain Optically Stimulated Luminescence (OSL) dating of a moraine sequence recording glacial advance along the western side of the Patagonian Icefields. Dates from the Tempanos moraines at Laguna San Rafael (LSR) show that the San Rafael Glacier (SRG) advanced to maximum Holocene positions during the period 9.3 to 9.7 ka and at 5.7 ka. Outwash lying beneath the moraine in its northern portion, dated to 7.7 ka, indicates that the glacier front was also advanced at this time. Since these advances span both the regional early Holocene warm-dry phase (11.5 ka to 7.8 ka) and the subsequent cooling and rise in precipitation in the mid-late Holocene (since 6.6 ka) we infer that the advances of the SRG are not simply climate-driven, but that the glacier has also probably responded strongly to non-climatic stimuli such as internal ice dynamics and the transition between calving and non-calving. Many westwards-flowing glaciers in Patagonia were probably calving during much of the Late Pleistocene and Holocene, so we conclude that establishing robust glacial chronologies where climatic and non-climatic factors cannot be distinguished is likely to remain a challenge.

A record of uranium-series transport at Nopal I, Sierra Pena Blanca, Mexico: Implications for natural uranium deposits and radioactive waste repositories

DOE PAGES

Denton, J. S.; Goldstein, S. J.; Paviet, P.; ...

2016-04-10

Studies of uranium-series (U-series) disequilibria within and around ore deposits provide valuable information on the extent and timing of actinide mobility, via mineral-fluid interaction, over a range of spatial and temporal scales. Such information is useful in studies of analogs of high-level nuclear-waste repositories, as well as for mining and mineral extraction sites, locations of previous nuclear weapons testing, and legacy nuclear waste contamination. In this study we present isotope dilution mass spectrometry U-series measurements for fracture-fill materials (hematite, goethite, kaolinite, calcite, dolomite and quartz) from one such analog; the Nopal I uranium ore deposit situated at Peña Blanca inmore » the Chihuahua region of northern Mexico. The ore deposit is located in fractured, unsaturated volcanic tuff and fracture-fill materials from surface fractures as well as fractures in a vertical drill core have been analyzed. High uranium concentrations in the fracture-fill materials (between 12 and 7700 ppm) indicate uranium mobility and transport from the deposit. Furthermore, uranium concentrations generally decrease with horizontal distance away from the deposit but in this deposit there is no trend with depth below the surface.« less

Monitoring tropical debris-covered glacier dynamics from high-resolution unmanned aerial vehicle photogrammetry, Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Wigmore, Oliver; Mark, Bryan

2017-11-01

The glaciers of the Cordillera Blanca, Peru, are rapidly retreating and thinning as a result of climate change, altering the timing, quantity and quality of water available to downstream users. Furthermore, increases in the number and size of proglacial lakes associated with these melting glaciers is increasing potential exposure to glacier lake outburst floods (GLOFs). Understanding how these glaciers are changing and their connection to proglacial lake systems is thus of critical importance. Most satellite data are too coarse for studying small mountain glaciers and are often affected by cloud cover, while traditional airborne photogrammetry and lidar are costly. Recent developments have made unmanned aerial vehicles (UAVs) a viable and potentially transformative method for studying glacier change at high spatial resolution, on demand and at relatively low cost.Using a custom designed hexacopter built for high-altitude (4000-6000 m a. s. l. ) operation, we completed repeat aerial surveys (2014 and 2015) of the debris-covered Llaca Glacier tongue and proglacial lake system. High-resolution orthomosaics (5 cm) and digital elevation models (DEMs) (10 cm) were produced and their accuracy assessed. Analysis of these datasets reveals highly heterogeneous patterns of glacier change. The most rapid areas of ice loss were associated with exposed ice cliffs and meltwater ponds on the glacier surface. Considerable subsidence and low surface velocities were also measured on the sediments within the pro-glacial lake, indicating the presence of extensive regions of buried ice and continued connection to the glacier tongue. Only limited horizontal retreat of the glacier tongue was observed, indicating that measurements of changes in aerial extent alone are inadequate for monitoring changes in glacier ice quantity.

Insights from analyzing and modelling cascading multi-lake outburst flood events in the Santa Cruz Valley (Cordillera Blanca, Perú)

NASA Astrophysics Data System (ADS)

Emmer, Adam; Mergili, Martin; Juřicová, Anna; Cochachin, Alejo; Huggel, Christian

2016-04-01

Since the end of Little Ice Age, the Cordillera Blanca of Perú has experienced tens of lake outburst floods (LOFs), resulting in the loss of thousands of lives and significant material damages. Most commonly involving glacial lakes, such events are often directly or indirectly related to glacier retreat. Here we analyze an event on 8th February 2012 involving four lakes and affecting two valleys (Santa Cruz and Artizón) in the northern part of the Cordillera Blanca. Using the combination of field data, satellite images, digital elevation model (DEM) and GIS-based modelling approaches, the main objectives are: (i) to better understand complex multi-lake outburst flood and related foregoing and induced geomorphological processes; and (ii) to evaluate and discuss the suitability, potentials and limitations of the r.avaflow model for modelling such complex process chains. Analyzing field geomorphological evidence and remotely-sensed images, we reconstruct the event as follows: a landslide from the recently deglaciated left lateral moraine of Lake Artizón Alto (4 639 m a.s.l.), characterized by steep slopes and a height of more than 200 m produced a displacement wave which overtopped the bedrock dam of the lake. The resulting flood wave breached the dam of the downstream moraine-/landslide-dammed Lake Artizón Bajo (4 477 m a.s.l.), decreasing the lake level by 10 m and releasing 3 x 105 m3 of water. Significant amounts of material were eroded from the steeper parts of the Artizón Valley (mean slope >15°) and deposited further downstream in the flatter part of the Santa Cruz Valley (mean slope <2°; confluence of the two valleys at 3 985 m a.s.l.). The flood affected two debris cone-dammed lakes (Jatuncocha and Ichiccocha) in the Santa Cruz Valley. Some minor damages to the dam of Lake Jatuncocha were documented. Geomprohological evidence of the event was observed more than 20 km downstream from Lake Artizón Alto. The described multi-LOF event was employed as a

76 FR 16689 - Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-25

..., Raton Muni/Crews Field, RNAV (GPS) RWY 25, Orig Ruidoso, NM, Sierra Blanca Rgnl, CAPITAN ONE Graphic DP Ruidoso, NM, Sierra Blanca Rgnl, GPS RWY 24, Orig-A, CANCELLED Ruidoso, NM, Sierra Blanca Rgnl, RNAV (GPS...

Recent glacier retreat and lake formation in the Querecocha watershed, Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

López Moreno, J.; Valero-Garces, B.; Revuelto, J.; Azorín-Molina, C.; Bazo, J.; Cochachin, A.; Fontaneda, S.; Mark, B. G.

2013-12-01

In the Andes, and specifically in the Peruvian mountains a marked decrease of the glaciated area has occurred since the end of the Little Ice Age, and it has been accelerated since the last decades of the 20th century. As a result of the glacier retreat new pro-glaciar lakes are originated, and often the area and volume of existing ones increases. The study of these newly-formed lakes and their recent evolution may provide a better understanding of the hydrological and geomorphological evolution of deglaciated areas, and a better evaluation of the risk of glacial lakes outburst floods (GLOFS). In this work, we use 26 annual Landsat Thematic Mapper images from 1975 to 2010 to determine changes of the glaciated surface, snow line elevation and lakes formation in the headwaters of the Querecocha watershed in Cordillera Blanca (Perú). We also present the information derived from 10 short sediment cores (up to 50 cm long) retrieved along several transects in Yanamarey Lake. Both data sets inform of the sediment yield and lake development in recently deglaciated environments of the Andes. Results demonstrate that only one third of the surface covered by ice in 1975 remained in 2010. In this period, snowline has shifted up more than 100 meters in elevation in both, Yanamarey North and South areas respectively. At the same time, new lakes have been formed very quickly in these deglaciated areas. Preliminary 137Cs dating of Yanamarey sediment core indicates that at least the top 50 cm of the lake sequence deposited after 1960. This is coherent with the Landsat image of 1975 that showed the current surface of the lake still covered by ice. The high sediment rate (> 1 cm/yr) in the lake demonstrates the very high sediment yield in these geomorphically active settings. The sediment cores are composed of cm-thick sequences defined by grain-size (silt-clay) common in proglacial lakes reflecting the variability of hydrological response associated to the glacier retreat in the

Continued Rapid Uplift at Laguna del Maule Volcanic Field (Chile) from 2007 through 2014

NASA Astrophysics Data System (ADS)

Le Mével, H.; Feigl, K. L.; Cordova, L.; DeMets, C.; Lundgren, P.

2014-12-01

The current rate of uplift at Laguna del Maule (LdM) volcanic field in Chile is among the highest ever observed geodetically for a volcano that is not actively erupting. Using data from interferometric synthetic aperture radar (InSAR) and the Global Positioning System (GPS) recorded at five continuously operating stations, we measure the deformation field with dense sampling in time (1/day) and space (1/hectare). These data track the temporal evolution of the current unrest episode from its inception (sometime between 2004 and 2007) to vertical velocities faster than 200 mm/yr that continue through (at least) July 2014. Building on our previous work, we evaluate the temporal evolution by analyzing data from InSAR (ALOS, TerraSAR-X, TanDEM-X) and GPS [http://dx.doi.org/ 10.1093/gji/ggt438]. In addition, we consider InSAR data from (ERS, ENVISAT, COSMO-Skymed, and UAVSAR), as well as constraints from magneto-telluric (MT), seismic, and gravity surveys. The goal is to test the hypothesis that a recent magma intrusion is feeding a large, existing magma reservoir. What will happen next? To address this question, we analyze the temporal evolution of deformation at other large silicic systems such as Yellowstone, Long Valley, and Three Sisters, during well-studied episodes of unrest. We consider several parameterizations, including piecewise linear, parabolic, and Gaussian functions of time. By choosing the best-fitting model, we expect to constrain the time scales of such episodes and elucidate the processes driving them.

New measurements of particulates in glacial snow and ice in the Cordillera Blanca mountains of Peru

NASA Astrophysics Data System (ADS)

All, J.; Schmitt, C.; Celestian, A. J.; Rucks, M.; Arnott, W. P.; Cole, R.

2012-12-01

During the local dry season (June/July) of 2011 and 2012, the American Climber Science Program (organized with the assistance of the American Alpine Club) conducted scientific expeditions in Huascaran National Park in Peru. The Park is located in the Cordillera Blanca mountain range and contains the world's largest collection of tropical mountain glaciers. One component of the environmental research program was sampling particulates on glacier surfaces by means of snow collection and filtration. Over 150 samples were collected during the two expeditions by volunteer climbers working with scientists in the field. Glacier snows were collected on over fifteen peaks throughout the range at altitudes from 4800 to nearly 6800 meters. Snow samples were kept frozen until the climber-scientists returned to basecamp - at which point they were rapidly melted and then immediately filtered through 0.7 micron PallFlex tissuequartz filters. The particulates captured on the filters have been analyzed for their bulk heat absorption properties as well as to determine the properties of individual particles through X-ray diffraction for bulk mineral identification, and Raman microscopy for chemical mapping of minerals. Preliminary results indicate that snow age, altitude, as well as geographic location (with respect to urban areas, mines, and predominant wind direction) all play significant roles in the amount and types of contaminants. Multiple locations were sampled during both expeditions as well as at different times during the same climbing season. Results include the relative heating capacity of the samples at various wavelengths as well as mineral composition information across the range. Local weather patterns and geographic observations will be used to identify potential sources of contaminants. Sampling will continue under the American Climber Science Program in 2013 and beyond.

Basic diagnosis of solid waste generated at Agua Blanca State Park to propose waste management strategies.

PubMed

Laines Canepa, José Ramón; Zequeira Larios, Carolina; Valadez Treviño, Maria Elena Macías; Garduza Sánchez, Diana Ivett

2012-03-01

State parks are highly sensitive areas of great natural importance and tourism value. Herein a case study involving a basic survey of solid waste which was carried out in 2006 in Agua Blanca State Park, Macuspana, Tabasco, Mexico with two sampling periods representing the high and low tourist season is presented. The survey had five objectives: to find out the number of visitors in the different seasons, to consider the daily generation of solid waste from tourist activities, to determine bulk density, to select and quantify sub-products; and to suggest a possible treatment. A daily average of 368 people visited the park: 18,862 people in 14 days during the high season holiday (in just one day, Easter Sunday, up to 4425 visitors) and 2092 visitors in 43 days during the low season. The average weight of the generated solid waste was 61.267 kg day(-1) and the generated solid waste average per person was 0.155 kg person(-1 ) day(-1). During the high season, the average increased to 0.188 kg person(-1 ) day(-1) and during the low season, the average decreased to 0.144 kg person(-1 ) day(-1). The bulk density average was 75.014 kg m(-3), the maximum value was 92.472 kg m(-3) and the minimum was 68.274 kg m(-3). The sub-products comprised 54.52% inorganic matter; 32.03% organic matter, 10.60% non-recyclable and 2.85% others. Based on these results, waste management strategies such as reuse/recycling, aerobic and anaerobic digestion, the construction of a manual landfill and the employment of a specialist firm were suggested.

75 FR 19609 - Newspapers Used for Publication of Legal Notices in the Southwestern Region, Which Includes...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-15

... Mexico. Rita Blanca National Grassland in Cimarron County, Oklahoma Notices published in:-- ``Boise City News'', Boise City, Oklahoma. Rita Blanca National Grassland in Dallam County, Texas Notices published...'', Clayton, New Mexico. Rita Blanca National Grassland in Cimarron County, Oklahoma published in:--``Boise...

76 FR 75866 - Newspapers Used for Publication of Legal Notices in the Southwestern Region, Which Includes...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-05

... in: --``Union County Leader'', Clayton, New Mexico. Rita Blanca National Grassland in Cimarron County, Oklahoma notices published in:--``Boise City News'', Boise City, Oklahoma. Rita Blanca National Grassland... Mexico published in:--``Union County Leader'', Clayton, New Mexico. Rita Blanca National Grassland in...

Hydrologic, water-quality, and biological assessment of Laguna de las Salinas, Ponce, Puerto Rico, January 2003-September 2004

USGS Publications Warehouse

Soler-López, Luis R.; Gómez-Gómez, Fernando; Rodríguez-Martínez, Jesús

2005-01-01

The Laguna de Las Salinas is a shallow, 35-hectare, hypersaline lagoon (depth less than 1 meter) in the municipio of Ponce, located on the southern coastal plain of Puerto Rico. Hydrologic, water-quality, and biological data in the lagoon were collected between January 2003 and September 2004 to establish baseline conditions. During the study period, rainfall was about 1,130 millimeters, with much of the rain recorded during three distinct intense events. The lagoon is connected to the sea by a shallow, narrow channel. Subtle tidal changes, combined with low rainfall and high evaporation rates, kept the lagoon at salinities above that of the sea throughout most of the study. Water-quality properties measured on-site (temperature, pH, dissolved oxygen, specific conductance, and Secchi disk transparency) exhibited temporal rather than spatial variations and distribution. Although all physical parameters were in compliance with current regulatory standards for Puerto Rico, hyperthermic and hypoxic conditions were recorded during isolated occasions. Nutrient concentrations were relatively low and in compliance with current regulatory standards (less than 5.0 and 1.0 milligrams per liter for total nitrogen and total phosphorus, respectively). The average total nitrogen concentration was 1.9 milligrams per liter and the average total phosphorus concentration was 0.4 milligram per liter. Total organic carbon concentrations ranged from 12.0 to 19.0 milligrams per liter. Chlorophyll a was the predominant form of photosynthetic pigment in the water. The average chlorophyll a concentration was 13.4 micrograms per liter. Chlorophyll b was detected (detection limits 0.10 microgram per liter) only twice during the study. About 90 percent of the primary productivity in the Laguna de Las Salinas was generated by periphyton such as algal mats and macrophytes such as seagrasses. Of the average net productivity of 13.6 grams of oxygen per cubic meter per day derived from the diel

Lithologic controls on mineralization at the Lagunas Norte high-sulfidation epithermal gold deposit, northern Peru

NASA Astrophysics Data System (ADS)

Cerpa, Luis M.; Bissig, Thomas; Kyser, Kurt; McEwan, Craig; Macassi, Arturo; Rios, Hugo W.

2013-06-01

The 13.1-Moz high-sulfidation epithermal gold deposit of Lagunas Norte, Alto Chicama District, northern Peru, is hosted in weakly metamorphosed quartzites of the Upper Jurassic to Lower Cretaceous Chimú Formation and in overlying Miocene volcanic rocks of dacitic to rhyolitic composition. The Dafne and Josefa diatremes crosscut the quartzites and are interpreted to be sources of the pyroclastic volcanic rocks. Hydrothermal activity was centered on the diatremes and four hydrothermal stages have been defined, three of which introduced Au ± Ag mineralization. The first hydrothermal stage is restricted to the quartzites of the Chimú Formation and is characterized by silice parda, a tan-colored aggregate of quartz-auriferous pyrite-rutile ± digenite infilling fractures and faults, partially replacing silty beds and forming cement of small hydraulic breccia bodies. The δ34S values for pyrite (1.7-2.2 ‰) and digenite (2.1 ‰) indicate a magmatic source for the sulfur. The second hydrothermal stage resulted in the emplacement of diatremes and the related volcanic rocks. The Dafne diatreme features a relatively impermeable core dominated by milled slate from the Chicama Formation, whereas the Josefa diatreme only contains Chimú Formation quartzite clasts. The third hydrothermal stage introduced the bulk of the mineralization and affected the volcanic rocks, the diatremes, and the Chimú Formation. In the volcanic rocks, classic high-sulfidation epithermal alteration zonation exhibiting vuggy quartz surrounded by a quartz-alunite and a quartz-alunite-kaolinite zone is observed. Company data suggest that gold is present in solid solution or micro inclusions in pyrite. In the quartzite, the alteration is subtle and is manifested by the presence of pyrophyllite or kaolinite in the silty beds, the former resulting from relatively high silica activities in the fluid. In the quartzite, gold mineralization is hosted in a fracture network filled with coarse alunite

Microbial enumeration of different functional groups and bacterial behavior in acid basic conditions of a biotoxic landfill leachate of Bahía Blanca, Argentina.

PubMed

Yunes, Fabiana; Baldini, Mónica D; Gómez, Marisa A

2009-05-01

Leachate is liquid waste from refuse biological decomposition or rainwater percolation in a landfill. This research focused on leachate produced by a landfill in Bahia Blanca, Buenos Aires, Argentina. The research studied the main microbial populations involved in wastewater treatment, analyzed the behavior of bacteria isolated from leachate at different pH values, and appraised leachate biotoxicity. The number of bacteria varied by type, ranging from 1 x 10(4) to 1 x 10(5) CUF/mL aerobic heterotrophic bacteria (AHB); 1 x 10(3) to 1 x 10(5) CUF/mL anaerobic heterotrophic bacteria (ANHB); 1 x 10(5) to 1 x 10(6) CUF/mL sulfite-reducing bacteria (SRB); 1 x 10(3) to 1 x 10(6) NMP/mL nitrate-reducing bacteria (NRB); and 1 x 10(2) to 1 x 10(4) NMP/mL ammonium-oxidizing bacteria (AOB). Several microbial strains developed at pH 5, 7, and 10. These pH values changed to 9 in the culture media after a 48-hour incubation. Leachate was used to water lettuce seeds (Lactuca sativa capitata). Its toxicity was proved by full inhibition of plant development.

Linking microbial assemblages to paleoenvironmental conditions from the Holocene and Last Glacial Maximum times in Laguna Potrok Aike sediments, Argentina

NASA Astrophysics Data System (ADS)

Vuillemin, Aurele; Ariztegui, Daniel; Leavitt, Peter R.; Bunting, Lynda

2014-05-01

Laguna Potrok Aike is a closed basin located in the southern hemisphere's mid-latitudes (52°S) where paleoenvironmental conditions were recorded as temporal sedimentary sequences resulting from variations in the regional hydrological regime and geology of the catchment. The interpretation of the limnogeological multiproxy record developed during the ICDP-PASADO project allowed the identification of contrasting time windows associated with the fluctuations of Southern Westerly Winds. In the framework of this project, a 100-m-long core was also dedicated to a detailed geomicrobiological study which aimed at a thorough investigation of the lacustrine subsurface biosphere. Indeed, aquatic sediments do not only record past climatic conditions, but also provide a wide range of ecological niches for microbes. In this context, the influence of environmental features upon microbial development and survival remained still unexplored for the deep lacustrine realm. Therefore, we investigated living microbes throughout the sedimentary sequence using in situ ATP assays and DAPI cell count. These results, compiled with pore water analysis, SEM microscopy of authigenic concretions and methane and fatty acid biogeochemistry, provided evidence for a sustained microbial activity in deep sediments and pinpointed the substantial role of microbial processes in modifying initial organic and mineral fractions. Finally, because the genetic material associated with microorganisms can be preserved in sediments over millennia, we extracted environmental DNA from Laguna Potrok Aike sediments and established 16S rRNA bacterial and archaeal clone libraries to better define the use of DNA-based techniques in reconstructing past environments. We focused on two sedimentary horizons both displaying in situ microbial activity, respectively corresponding to the Holocene and Last Glacial Maximum periods. Sequences recovered from the productive Holocene record revealed a microbial community adapted to

Evaporative concentration of arsenic in groundwater: health and environmental implications, La Laguna Region, Mexico.

PubMed

Ortega-Guerrero, Adrián

2017-10-01

High arsenic concentrations in groundwater have been documented in La Laguna Region (LLR) in arid northern Mexico, where arsenic poisoning is both chronic and endemic. A heated debate has continued for decades on its origin. LLR consisted of a series of ancient connected lakes that developed at the end of a topographic depression under closed basin conditions. This study addresses the isotopic, chemical composition of the groundwater and geochemical modeling in the southeasternmost part of the LLR to determine the origin of arsenic. Groundwater samples were obtained from a carbonate and granular aquifers and from a clayey aquitard at terminal Viesca Lake. Results show that groundwater originated as meteoric water that reached the lakes mainly via abundant springs in the carbonate aquifer and perennial flooding of the Nazas-Aguanaval Rivers. Paleo-lake water underwent progressive evaporation as demonstrated by the enrichment of δ 18 O, δ 2 H and characteristic geochemical patterns in the granular aquifer and aquitard that resulted in highly saline (>90,000 mS/cm), arsenic-rich (up to 5000 μg/L) paleo-groundwater (>30,000 years BP). However, adsorption or co-precipitation on iron oxides, clay-mineral surfaces and organic carbon limited arsenic concentration in the groundwater. Arsenic-rich groundwater and other solutes are advancing progressively from the lacustrine margins toward the main granular aquifer, due to reversal of hydraulic gradients caused by intensive groundwater exploitation and the reduction in freshwater runoff provoked by dam construction on the main rivers. Desorption of arsenic will incorporate additional concentrations of arsenic into the groundwater and continue to have significant negative effects on human health and the environment.

[Distribution patterns and bioerosion of the sea urchin Centrostephanus coronatus (Diadematoida: Diadematidae), at the reef of Playa Blanca, Colombian Pacific].

PubMed

Toro-Farmer, Gerardo; Cantera, Jaime R; Londoño-Cruz, Edgardo; Orozco, Carlos; Neira, Raul

2004-03-01

Regular sea-urchins are one of the main bioeroding organisms affecting coral reefs around the world. The abundance, distribution and bioerosion rate of the sea-urchin Centrostephanus coronatus, were determined in different reef zones of Playa Blanca fringing reef (Gorgona Island, Colombian pacific coast) during 1997 and 1998. The erosion rates were determined calcinating the gut content of the sea-urchins to eliminate all organic components and preserve the inorganic portion of calcium carbonate. C. coronatus showed the highest densities towards the central zones of the reef (plain-crest and front) (12.4 ind/m2; range 0-48 ind/m2). The highest mean bioerosion rate was 0.103 kgCaCO3/m2/yr in the reef plain-crest (0-0.69 kgCaCO3/m2/yr). In the other zones, (back reef and reef front) the mean bioerosion rates were 0.071 (range 0-0.39) and 0.052 (range 0-0.31) kgCaCO3/m2/yr respectively. According to the present data, it can be seen that the destruction of coralline skeletons, produced in this reef by sea-urchins is rather low, compared with the abrasion caused by these organisms in other places of the world. However, the combined action of C. coronatus and other bioeroding organisms (borers and grazers). along with some adverse environmental factors to corals, can be causing a negative balance between normal processes of reef accretion-destruction in Gorgona Island reefs.

Solar and Volcanic Modulation of Little Ice Age Climate in the Tropical Andes, Venezuela

NASA Astrophysics Data System (ADS)

Polissar, P. J.; Abbott, M. B.; Wolfe, A. P.; Rull, V.; Bezada, M.

2004-12-01

The underlying causes of late-Holocene climate variability in the tropics are incompletely understood. Here, we report a 1500-year reconstruction of climate history in the Venezuelan Andes using lake sediment records from four sites. This reconstruction is based upon accelerator mass spectrometry (AMS) radiocarbon and Pb-210 dating, sedimentology, magnetic susceptibility, geochemistry, pollen and stable isotope (C, N) measurements. In the Laguna Mucubaji watershed four distinct glacial advances occurred between 1250 and 1810 A.D. The earliest advance began during an extended period of higher global volcanic activity. The subsequent three advances were coincident with minima in solar activity (reconstructed from Be-10 and C-14 records). The Mucubají glacial activity in the Venezuelan Andes coincides with other records of Little Ice Age (LIA) glacial advances in S. America. Comparison of modern glacier equilibrium line altitudes (ELAs) in Venezuela with the Mucubaji LIA glacier ELA indicates an ELA depression of at least 300 m. Both a decline in temperature and increase in precipitation are required to explain the ELA depression. The precipitation increase is supported by increased catchment erosion recorded in L. Blanca sediments. Pollen records from two sites in the Venezuelan Andes also indicate wetter and colder conditions during the LIA.

Testing Pixel Translation Digital Elevation Models to Reconstruct Slip Histories: An Example from the Agua Blanca Fault, Baja California, Mexico

NASA Astrophysics Data System (ADS)

Wilson, J.; Wetmore, P. H.; Malservisi, R.; Ferwerda, B. P.; Teran, O.

2012-12-01

We use recently collected slip vector and total offset data from the Agua Blanca fault (ABF) to constrain a pixel translation digital elevation model (DEM) to reconstruct the slip history of this fault. This model was constructed using a Perl script that reads a DEM file (Easting, Northing, Elevation) and a configuration file with coordinates that define the boundary of each fault segment. A pixel translation vector is defined as a magnitude of lateral offset in an azimuthal direction. The program translates pixels north of the fault and prints their pre-faulting position to a new DEM file that can be gridded and displayed. This analysis, where multiple DEMs are created with different translation vectors, allows us to identify areas of transtension or transpression while seeing the topographic expression in these areas. The benefit of this technique, in contrast to a simple block model, is that the DEM gives us a valuable graphic which can be used to pose new research questions. We have found that many topographic features correlate across the fault, i.e. valleys and ridges, which likely have implications for the age of the ABF, long term landscape evolution rates, and potentially provide conformation for total slip assessments The ABF of northern Baja California, Mexico is an active, dextral strike slip fault that transfers Pacific-North American plate boundary strain out of the Gulf of California and around the "Big Bend" of the San Andreas Fault. Total displacement on the ABF in the central and eastern parts of the fault is 10 +/- 2 km based on offset Early-Cretaceous features such as terrane boundaries and intrusive bodies (plutons and dike swarms). Where the fault bifurcates to the west, the northern strand (northern Agua Blanca fault or NABF) is constrained to 7 +/- 1 km. We have not yet identified piercing points on the southern strand, the Santo Tomas fault (STF), but displacement is inferred to be ~4 km assuming that the sum of slip on the NABF and STF is

Diabrotica collicola (Coleoptera: Chrysomelidae)a new species of leaf beetle from Argentina Discussion and key to some similar species of the Diabrotica virgifera group

USDA-ARS?s Scientific Manuscript database

The new species Diabrotica collicola Cabrera & Cabrera Walsh is described and illustrated based on specimens collected from Balcozna, Catamarca Province (Argentina). A full description is provided and includes morphological characters of the mouthparts, hind wing venation, binding patch, metendoster...

Geologic studies in the Sierra de Pena Blanca, Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Reyes-Cortes, Ignacio Alfonso

The Sierra del Cuervo has been endowed with uranium mineralization, which has attracted many geological studies, and recently the author was part of a team with the goal of selecting a site of a radioactive waste repository. The first part of the work adds to the regional framework of stratigraphy and tectonics of the area. It includes the idea of a pull apart basin development, which justifies the local great thickness of the Cuervo Formation. It includes the regional structural frame work and the composite stratigraphic column of the Chihuahua Trough and the equivalent Cretaceous Mexican Sea. The general geologic features of the NE part of the Sierra del Cuervo are described, which include the folded ignimbrites and limestones in that area; the irregular large thicknesses of the Cuervo Formation; and the western vergence of the main folding within the area. Sanidine phenocrystals gave ages of 54.2 Ma and 51.8 Ma ± 2.3 Ma. This is the first time these dates have been reported in print. This age indicates a time before the folded structures which outcrop in the area, and 44 Ma is a date after the Cuervo Formation was folded. The Hidalgoan orogeny cycle affected the rocks between this lapse of time. Since then the area has been partially affected by three tensional overlapped stages, which resulted in the actual Basin and Range physiography. The jarosite related to the tectonic activity mineralization has been dated by the Ar-Ar method and yields an age of 9.8 Ma. This is the first report of a date of mineralization timing at Pena Blanca Uranium District in the Sierra del Cuervo. These are some of the frame work features that justify the allocation of a radioactive waste repository in the Sierra del Cuervo. An alluvial fan system within the Boquilla Colorada microbasin was selected as the best target for more detailed site assessment. The study also included the measurement of the alluvium thicknesses by geoelectric soundings; studies of petrography and weathered

Dynamics of a large, restless, rhyolitic magma system at Laguna del Maule, southern Andes, Chile

USGS Publications Warehouse

Singer, Brad S.; Andersen, Nathan L.; Le Mével, Hélène; Feigl, Kurt L.; DeMets, Charles; Tikoff, Basil; Thurber, Clifford H.; Jicha, Brian R.; Cardonna, Carlos; Córdova, Loreto; Gil, Fernando; Unsworth, Martyn J.; Williams-Jones, Glyn; Miller, Craig W.; Fierstein, Judith; Hildreth, Edward; Vazquez, Jorge A.

2014-01-01

Explosive eruptions of large-volume rhyolitic magma systems are common in the geologic record and pose a major potential threat to society. Unlike other natural hazards, such as earthquakes and tsunamis, a large rhyolitic volcano may provide warning signs long before a caldera-forming eruption occurs. Yet, these signs—and what they imply about magma-crust dynamics—are not well known. This is because we have learned how these systems form, grow, and erupt mainly from the study of ash flow tuffs deposited tens to hundreds of thousands of years ago or more, or from the geophysical imaging of the unerupted portions of the reservoirs beneath the associated calderas. The Laguna del Maule Volcanic Field, Chile, includes an unusually large and recent concentration of silicic eruptions. Since 2007, the crust there has been inflating at an astonishing rate of at least 25 cm/yr. This unique opportunity to investigate the dynamics of a large rhyolitic system while magma migration, reservoir growth, and crustal deformation are actively under way is stimulating a new international collaboration. Findings thus far lead to the hypothesis that the silicic vents have tapped an extensive layer of crystal-poor, rhyolitic melt that began to form atop a magmatic mush zone that was established by ca. 20 ka with a renewed phase of rhyolite eruptions during the Holocene. Modeling of surface deformation, magnetotelluric data, and gravity changes suggest that magma is currently intruding at a depth of ~5 km. The next phase of this investigation seeks to enlarge the sets of geophysical and geochemical data and to use these observations in numerical models of system dynamics.

The NS3 protein of Rice hoja blanca tenuivirus suppresses RNA silencing in plant and insect hosts by efficiently binding both siRNAs and miRNAs

PubMed Central

Hemmes, Hans; Lakatos, Lóránt; Goldbach, Rob; Burgyán, József; Prins, Marcel

2007-01-01

RNA silencing plays a key role in antiviral defense as well as in developmental processes in plants and insects. Negative strand RNA viruses such as the plant virus Rice hoja blanca tenuivirus (RHBV) replicate in plants and in their insect transmission vector. Like most plant-infecting viruses, RHBV encodes an RNA silencing suppressor, the NS3 protein, and here it is demonstrated that this protein is capable of suppressing RNA silencing in both plants and insect cells. Biochemical analyses showed that NS3 efficiently binds siRNA as well as miRNA molecules. Binding of NS3 is greatly influenced by the size of small RNA molecules, as 21 nucleotide (nt) siRNA molecules are bound > 100 times more efficiently than 26 nt species. Competition assays suggest that the activity of NS3 is based on binding to siRNAs prior to strand separation during the assembly of the RNA-induced silencing complex. In addition, NS3 has a high affinity for miRNA/miRNA* duplexes, indicating that its activity might also interfere with miRNA-regulated gene expression in both insects and plants. PMID:17513697

Modeling non-steady state radioisotope transport in the vadose zone--A case study using uranium isotopes at Pena Blanca, Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ku, T. L.; Luo, S.; Goldstein, S. J.

2009-06-01

Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leadsmore » to a linear relationship between reciprocal U concentration and {sup 234}U/{sup 238}U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and {alpha}-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Pena Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced {sup 234}U/{sup 238}U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using {sup 234}U/{sup 238}U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.« less

Microgravity changes at the Laguna del Maule volcanic field: Magma-induced stress changes facilitate mass addition

NASA Astrophysics Data System (ADS)

Miller, C. A.; Le Mével, H.; Currenti, G.; Williams-Jones, G.; Tikoff, B.

2017-04-01

Time-dependent, or 4-D, microgravity changes observed at the Laguna del Maule volcanic field, Chile, since 2013, indicate significant (1.5 × 1011 kg) ongoing mass injection. Mass injection is focused along the Troncoso fault, and subparallel structures beneath the lake at 1.5-2 km depth, and is best modeled by a vertical rectangular prism source. The low-density change (156 to 307 kg/m3) and limited depth extent suggest a mechanism of hydrothermal fluid intrusion into existing voids, or voids created by the substantial uplift, rather than deeper-sourced dike intrusion of rhyolite or basalt magma. Although the gravity changes are broadly spatially coincident with ongoing surface deformation, existing models that explain the deformation are deeper sourced and cannot explain the gravity changes. To account for this discrepancy and the correspondence in time of the deformation and gravity changes, we explore a coupled magmatectonic interaction mechanism that allows for shallow mass addition, facilitated by deeper magma injection. Computing the strain, and mean, normal, and Coulomb stress changes on northeast trending faults, caused by the opening of a sill at 5 km depth, shows an increase in strain and mean and normal stresses along these faults, coincident with the areas of mass addition. Seismic swarms in mid-2012 to the west and southwest of the mass intrusion area may be responsible for dynamically increasing permeability on the Troncoso fault, promoting influx of hydrothermal fluids, which in turn causes larger gravity changes in the 2013 to 2014 interval, compared to the subsequent intervals.

Waterbirds and human-related threats to their conservation in Laguna Cuyutlán, Colima, México.

PubMed

Mellink, Eric; Riojas-López, Mónica

2009-01-01

Laguna Cuyutlán, the only large wetland in a span of 1,150 km along the Pacific coast of Mexico, has been neglected as to its importance for waterbird conservation. At least 25 waterbird species nest there, with some of their colonies being very relevant, and at least 61 waterbird species use the lagoon during their non-breeding season. This lagoon has been subject to several structural modifications, including levees and artificial channels which connect it to the sea, while water supply from continental sources has diminished, although its role has not been assessed yet. Salt extraction and artisanal fishery, the main economic activities, do not seem to pose a threat to waterbirds. Among potential threats to this acquatic ecosystem, are the raw sewage discharges that exist near urban areas, and pesticides from the surrounding agricultural lands might reach the lagoon. Seemingly, the most serious threat comes from waterway development in connection with a re-gasification plant to be built, and planned future port expansion, which could potentially increase water levels and alter important habitats for nesting and foraging. We recommend that: the area be declared an Important Bird Area; the development of the re-gasification plant and future port includes a levee to prevent alterations in water level in the remaining sections of the lagoon; supply of exogenous chemicals and waste products be prevented and monitored; alleged benefits from water interchange between the lagoon and the sea through artificial channels should be re-evaluated; and the role of fresh water supplies to the lagoon should be paid attention to.

Evolución de estrellas enanas blancas de Helio de masa baja e intermedia

NASA Astrophysics Data System (ADS)

Althaus, L. G.; Benvenuto, O. G.

Numerosas observaciones realizadas particularmente en los últimos dos años parecen confirmar que las enanas blancas (EB) de helio de masa baja e intermedia son el resultado de la evolución de sistemas binarios cercanos. Con el objeto de realizar una adecuada interpretación de estos objetos son necesarios modelos de EBs de helio lo más detallado posibles. En este estudio presentamos cálculos detallados de la evolución de EBs de helio con masas entre M=0.1Msolar y M=0.5Msolar a intervalos de 0.05Msolar . Para ello, hemos tenido en cuenta los efectos de temperatura finita mediante un código de evolución estelar lo más actualizado posible. En particular, el transporte de energía es descripto en el marco del nuevo modelo para la convección turbulenta desarrollado por Canuto - Mazzitelli. Además hemos considerado la nueva ecuación de estado para plasmas de helio de Saumon et al. y nuevas opacidades radiativas OPAL. Las pérdidas por neutrinos fueron asimismo tenidas en cuenta. Excepto para las EBs más masivas, nuestros modelos iniciales están ubicados en las cercanías de la correspondiente línea de Hayashi para configuraciones de helio. Nuestros resultados muestran que existe una región prohibida en el diagrama observacional HR donde ninguna EB de helio puede encontrarse. Dicha región es para log{(L/Lsolar )}>= -0.25 and log{Teff} >= 4.45. Hemos encontrado también que los tracks evolutivos en el diagrama HR en el dominio de alta luminosidad (pre - EB) son fuertemente afectados por la eficiencia convectiva y que las pérdidas por neutrinos son importantes en los modelos más masivos. Finalmente hemos analizado la estructura de la zona convectiva externa encontrando que la teoría de Canuto - Mazzitelli conduce a un perfil convectivo muy diferente del dado por cualquier versión de la popular teoría de la mixing length. Si bién este comportamiento es decisivo en el contexto de las inestabilides pulsacionales, los radios y gravedades superficiales de

Availability of ground water in parts of the Acoma and Laguna Indian Reservations, New Mexico

USGS Publications Warehouse

Dinwiddie, George A.; Motts, Ward Sundt

1964-01-01

The need for additional water has increased in recent years on the Acoma and Laguna Indian Reservations in west-central New Mexico because the population and per capita use of water have increased; the tribes also desire water for light industry, for more modern schools, and to increase their irrigation program. Many wells have been drilled in the area, but most have been disappointing because of small yields and poor chemical quality of the water. The topography in the Acoma and Laguna Indian Reservations is controlled primarily by the regional and local dip of alternating beds of sandstone and shale and by the igneous complex of Mount Taylor. The entrenched alluvial valley along the Rio San Jose, which traverses the area, ranges in width from about 0.4 mile to about 2 miles. The climate is characterized by scant rainfall, which occurs mainly in summer, low relative humidity, and large daily fluctuations of temperature. Most of the surface water enters the area through the Rio San Jose. The average annual streamflow past the gaging station Rio San Jose near Grants, N. Mex. is about 4,000 acre-feet. Tributaries to the Rio San Jose within the area probably contribute about 1,000 acre-feet per year. At the present time, most of the surface water is used for irrigation. Ground water is obtained from consolidated sedimentary rocks that range in age from Triassic to Cretaceous, and from unconsolidated alluvium of Quaternary age. The principal aquifers are the Dakota Sandstone, the Tres Hermanos Sandstone Member of the Mancos Shale, and the alluvium. The Dakota Sandstone yields 5 to 50 gpm (gallons per minute) of water to domestic and stock wells. The Tres Hermanos sandstone Member generally yields 5 to 20 gpm of water to domestic and stock wells. Locally, beds of sandstone in the Chinle and Morrison Formations, the Entrada Sandstone, and the Bluff Sandstone also yield small supplies of water to domestic and stock wells. The alluvium yields from 2 gpm to as much as 150

Environmental Perturbations, Behavioral Change, and Population Response in a Long-term Northern Elephant Seal Study

DTIC Science & Technology

2010-09-30

Nicholas Island and Piedras Blancas. A team of three researchers, Autumn-Lynn Harrison, Nikky Teutschel, and Greg Breed, conducted resights at San...Nicholas Island. Pat Morris conducted resights at Piedras Blancas. Both surveys occurred January 29-February 1, 2010. RESULTS Analysis of shouthern...had not seen an elephant seal with a green flipper tag in 20 years of observations. Of the 55 tags detected on females at Piedras Blancas, eight

Northwestern Argentina as seen from the Apollo 7 spacecraft

NASA Technical Reports Server (NTRS)

1968-01-01

Puna de Atacama area of northwestern Argentina, Provinces of Salta and Catamarca, as seen from the Apollo 7 spacecraft during its 154th revolution of the earth. Photographed from an altitude of 175 nautical miles, at ground elapsed time of 243 hours and 58 minutes.

Modeling of U-series Radionuclide Transport Through Soil at Pena Blanca, Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Pekar, K. E.; Goodell, P. C.; Walton, J. C.; Anthony, E. Y.; Ren, M.

2007-05-01

The Nopal I uranium deposit is located at Pena Blanca in Chihuahua, Mexico. Mining of high-grade uranium ore occurred in the early 1980s, with the ore stockpiled nearby. The stockpile was mostly cleared in the 1990s; however, some of the high-grade boulders have remained there, creating localized sources of radioactivity for a period of 25-30 years. This provides a unique opportunity to study radionuclide transport, because the study area did not have any uranium contamination predating the stockpile in the 1980s. One high-grade boulder was selected for study based upon its shape, location, and high activity. The presumed drip-line off of the boulder was marked, samples from the boulder surface were taken, and then the boulder was moved several feet away. Soil samples were taken from directly beneath the boulder, around the drip-line, and down slope. Eight of these samples were collected in a vertical profile directly beneath the boulder. Visible flakes of boulder material were removed from the surficial soil samples, because they would have higher concentrations of U-series radionuclides and cause the activities in the soil samples to be excessively high. The vertical sampling profile used 2-inch thicknesses for each sample. The soil samples were packaged into thin plastic containers to minimize the attenuation and to standardize sample geometry, and then they were analyzed by gamma-ray spectroscopy with a Ge(Li) detector for Th-234, Pa-234, U-234, Th-230, Ra-226, Pb-214, Bi-214, and Pb-210. The raw counts were corrected for self-attenuation and normalized using BL-5, a uranium standard from Beaverlodge, Saskatchewan. BL-5 allowed the counts obtained on the Ge(Li) to be referenced to a known concentration or activity, which was then applied to the soil unknowns for a reliable calculation of their concentrations. Gamma ray spectra of five soil samples from the vertical profile exhibit decreasing activities with increasing depth for the selected radionuclides

Tdp studies and tests for C. A. Energia Electrica de Venezuela (enelven) at planta ramon laguna, units RL-17 and RL-10. Volume 2. Unit RL-10 boiler condition assessment report. Export trade information

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-03-28

The study, conducted by Babcock and Wilcox, was funded by the U.S. Trade and Development agency on behalf of Enelven. In order to maximize generated power output and minimize operating costs at Planta Ramon Laguna, tests were done to evaluate the condition of equipment at the plant. In order to identify any damage and determine the operating output of each unit, assessments were done of the furnaces, boilers, generators and boiler feed pumps being used in the plant. The report presents the results of these tests. This is the second of three volumes and it includes the following section: (1)more » Condition Assessment of Unit RL-10 Boiler.« less

Laguna Potrok Aike, Argentina: the first non-tropical environmental record in South America extending far beyond the Late-Glacial - a progress report

NASA Astrophysics Data System (ADS)

Zolitschka, B.; Anselmetti, F.; Ariztegui, D.; Corbella, H.; Francus, P.; Gebhardt, C.; Lücke, A.; Ohlendorf, C.; Schäbitz, F.; Pasado Science Team

2009-04-01

Within the framework of the ICDP-funded "Potrok Aike maar lake sediment archive drilling project" (PASADO) an international team of scientists carried out interdisciplinary research at the unique mid-Pleistocene (770 ka) maar lake of Laguna Potrok Aike in southern Patagonia (Province of Santa Cruz, Argentina). This lake is very sensitive to variations in southern hemispheric wind and pressure systems and thus holds a unique and continuous lacustrine record of climatic and ecological variability of global significance. Moreover, Southern Patagonia with its many active volcanoes is an ideal location to better understand the regional history of volcanism. These are two challenging geo-scientific themes that need to be tackled, especially as both of them have an increasing socio-economic relevance. Three months of drilling activities that finished last November 2008 were carried out by DOSECC from the drilling platform R/V "Kerry Kelts". More than 500 m of lacustrine sediments were recovered. This sedimentary archive will provide (1) new insights into the processes of regional back arc volcanism within the Pali Aike Volcanic Field itself as well as the more distant explosive volcanism of the Andean mountain chains; and, (2) high-resolution (decadal) quantitative climate and environmental reconstructions supported by multiple dating and stratigraphic correlations. Marine - ice core - terrestrial linkages will be emphasized as well as the incorporation of results from global climate modelling simulations for the last ca. 100 ka. The two drilled sites in the central deep basin of Laguna Potrok Aike have been selected based on four seismic surveys carried out between 2003 and 2005. Sediments were recovered at both drilled sites down to a subbottom depth of slightly more than 100 m using the GLAD800 drill rig with the hydraulic piston corer tool (HPC) at water depths varying between 95 and 100 m. The total core recovery is 94%. On-site core logging with the multi sensor

Modeling non-steady state radioisotope transport in the vadose zone - A case study using uranium isotopes at Peña Blanca, Mexico

NASA Astrophysics Data System (ADS)

Ku, T. L.; Luo, S.; Goldstein, S. J.; Murrell, M. T.; Chu, W. L.; Dobson, P. F.

2009-10-01

Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leads to a linear relationship between reciprocal U concentration and 234U/ 238U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and α-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Peña Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced 234U/ 238U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using 234U/ 238U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.

A new venomous scorpion responsible for severe envenomation in Argentina: Tityus confluens.

PubMed

de Roodt, Adolfo R; Lago, Néstor R; Salomón, Oscar D; Laskowicz, Rodrigo D; Neder de Román, Lilia E; López, Raúl A; Montero, Teresa E; Vega, Valeria Del V

2009-01-01

In Argentina the scorpions of medical importance belong to the genus Tityus (T.), particularly the species T. trivittatus, the only scorpion whose sting is recognized to be associated with severe human envenoming and death. This genus is distributed from the north of the Patagonian region to the center and some provinces in the north of the country. During the period 2003-2006 four children died following scorpion stings, of which one was certainly and three were probably by T. confluens. In 2006, in the province of Tucumán, a girl died by scorpion envenoming and the scorpion responsible for the death, found in her shoe, was T. confluens. We thus studied the toxicity of venom gland homogenates from T. confluens from the provinces of Jujuy and Catamarca, and of crude venom from specimens from Catamarca and the province of La Rioja. The lethal potencies of the telson homogenates were 7.0 and 18.6microg/g for Jujuy and Catamarca, respectively, while the lethal potency of the crude venom was 0.7microg/g. Injected mice showed generalized congestion and hepatic lesions. Pancreatic damage was observed in some animals. Lungs showed congestion and foci of hemorrhage and mild edema. The heart showed injury in the muscular fibers. The venom showed high reactivity against anti-T. trivittatus antivenom and against two anti-T. serrulatus antivenoms. The anti-T. trivittatus antivenom neutralized the lethal activity of T. confluens venom. In addition, the venom reacted very slightly against an anti-Centruroides antivenom. Therefore, the stings of this scorpion must be considered of risk for humans to the same degree as the stings of T. trivittatus.

Rickettsia bellii, Rickettsia amblyommii, and Laguna Negra hantavirus in an Indian reserve in the Brazilian Amazon.

PubMed

de Barros Lopes, Lívia; Guterres, Alexandro; Rozental, Tatiana; Carvalho de Oliveira, Renata; Mares-Guia, Maria Angélica; Fernandes, Jorlan; Figueredo, José Ferreira; Anschau, Inês; de Jesus, Sebastião; V Almeida, Ana Beatriz M; Cristina da Silva, Valéria; Gomes de Melo Via, Alba Valéria; Bonvicino, Cibele Rodrigues; D'Andrea, Paulo Sérgio; Barreira, Jairo Dias; Sampaio de Lemos, Elba Regina

2014-04-17

The purpose of this study was to identify the presence of rickettsia and hantavirus in wild rodents and arthropods in response to an outbreak of acute unidentified febrile illness among Indians in the Halataikwa Indian Reserve, northwest of the Mato Grosso state, in the Brazilian Amazon. Where previously surveillance data showed serologic evidence of rickettsia and hantavirus human infection. The arthropods were collected from the healthy Indian population and by flagging vegetation in grassland or woodland along the peridomestic environment of the Indian reserve. Wild rodents were live-trapped in an area bordering the reserve limits, due the impossibility of capturing wild animals in the Indian reserve. The wild rodents were identified based on external and cranial morphology and karyotype. DNA was extracted from spleen or liver samples of rodents and from invertebrate (tick and louse) pools, and the molecular characterization of the rickettsia was through PCR and DNA sequencing of fragments of two rickettsial genes (gltA and ompA). In relation to hantavirus, rodent serum samples were serologically screened by IgG ELISA using the Araraquara-N antigen and total RNA was extracted from lung samples of IgG-positive rodents. The amplification of the complete S segment was performed. A total of 153 wild rodents, 121 louse, and 36 tick specimens were collected in 2010. Laguna Negra hantavirus was identified in Calomys callidus rodents and Rickettsia bellii, Rickettsia amblyommii were identified in Amblyomma cajennense ticks. Zoonotic diseases such as HCPS and spotted fever rickettsiosis are a public health threat and should be considered in outbreaks and acute febrile illnesses among Indian populations. The presence of the genome of rickettsias and hantavirus in animals in this Indian reserve reinforces the need to include these infectious agents in outbreak investigations of febrile cases in Indian populations.

Holocene History of the Chocó Rain Forest from Laguna Piusbi, Southern Pacific Lowlands of Colombia

NASA Astrophysics Data System (ADS)

Behling, Hermann; Hooghiemstra, Henry; Negret, Alvaro José

1998-11-01

A high-resolution pollen record from a 5-m-long sediment core from the closed-lake basin Laguna Piusbi in the southern Colombian Pacific lowlands of Chocó, dated by 11 AMS 14C dates that range from ca. 7670 to 220 14C yr B.P., represents the first Holocene record from the Chocó rain forest area. The interval between 7600 and 6100 14C yr B.P. (500-265 cm), composed of sandy clays that accumulated during the initial phase of lake formation, is almost barren of pollen. Fungal spores and the presence of herbs and disturbance taxa suggest the basin was at least temporarily inundated and the vegetation was open. The closed lake basin might have formed during an earthquake, probably about 4400 14C yr B.P. From the interval of about 6000 14C yr B.P. onwards, 200 different pollen and spore types were identified in the core, illustrating a diverse floristic composition of the local rain forest. Main taxa are Moraceae/Urticaceae, Cecropia,Melastomataceae/Combretaceae, Acalypha, Alchornea,Fabaceae, Mimosa, Piper, Protium, Sloanea, Euterpe/Geonoma, Socratea,and Wettinia.Little change took place during that time interval. Compared to the pollen records from the rain forests of the Colombian Amazon basin and adjacent savannas, the Chocó rain forest ecosystem has been very stable during the late Holocene. Paleoindians probably lived there at least since 3460 14C yr B.P. Evidence of agricultural activity, shown by cultivation of Zea maissurrounding the lake, spans the last 1710 yr. Past and present very moist climate and little human influence are important factors in maintaining the stable ecosystem and high biodiversity of the Chocó rain forest.

Impact of Hot Spring Resort Development on the Groundwater Discharge in the Southeast Part of Laguna De Bay, Luzon, Philippines

NASA Astrophysics Data System (ADS)

Siringan, F. P.; Lloren, R. B.; Mancenido, D. L. O.; Jago-on, K. A. B.; Pena, M. A. Z.; Balangue-Tarriela, M. I. R.; Taniguchi, M.

2014-12-01

Direct groundwater seepage in a lake (DGSL) can be a major component to its water and nutrient budget. Groundwater extraction around a lake may affect the DGSL, thus it can be expected that it would also impact the lake. In the Philippines, Laguna de Bay which is the second largest freshwater lake in South-east Asia and used primarily for fisheries, is under significant water development pressure. Along the southern coast of the lake, in the Calamba-Los Banos area, rapid urbanization and development of the water resort industry, including hot spring spas, are expected to have led to a rapid increase in groundwater extraction. This study aims to establish the effect of this development to the DGSL in this part of the lake. As a first step, we utilized towed electrical resistivity (ER) profiling to identify and map the potential and type of groundwater seepage off the southern coast of the lake. SRTM digital elevation models and synthetic aperture radar images were used to delineate lineaments which are potential fractures that cut across the study area. ER profiles indicate widespread occurrence of GDL across the shallower parts of the lake. In the more offshore, deeper parts of the lake, DGSL appears to be more limited possibly due to more muddy sediments there. However, in this area, narrow, vertical high resistivity columns cut through the lake floor suggesting more discrete GDLs possibly controlled by faults.

Preliminary Seismic Velocity Structure Results from Ambient Noise and Teleseismic Tomography: Laguna del Maule Volcanic Field, Chile

NASA Astrophysics Data System (ADS)

Wespestad, C.; Thurber, C. H.; Zeng, X.; Bennington, N. L.; Cardona, C.; Singer, B. S.

2016-12-01

Laguna del Maule Volcanic Field is a large, restless, rhyolitic system in the Southern Andes that is being heavily studied through several methods, including seismology, by a collaborative team of research institutions. A temporary array of 52 seismometers from OVDAS (the Southern Andean Volcano Observatory), PASSCAL (Portable Array Seismic Studies of the Continental Lithosphere), and the University of Wisconsin-Madison was used to collect the 1.3 years worth of data for this preliminary study. Ambient noise tomography uses surface wave dispersion data obtained from noise correlation functions (NCFs) between pairs of seismic stations, with one of each pair acting as a virtual source, in order to image the velocity structure in 3-D. NCFs were computed for hour-long time windows, and the final NCFs were obtained with phase-weighted stacking. The Frequency-Time Analysis technique was then utilized to measure group velocity between station pairs. NCFs were also analyzed to detect temporal changes in seismic velocity related to magmatic activity at the volcano. With the surface wave data from ambient noise, our small array aperture limits our modeling to the upper crust, so we employed teleseismic tomography to study deeper structures. For picking teleseismic arrivals, we tested two different correlation and stacking programs, which utilize adaptive stacking and multi-channel cross-correlation, to get relative arrival time data for a set of high quality events. Selected earthquakes were larger than magnitude 5 and between 30 and 95 degrees away from the center of the array. Stations that consistently show late arrivals may have a low velocity body beneath them, more clearly visualized via a 3-D tomographic model. Initial results from the two tomography methods indicate the presence of low-velocity zones at several depths. Better resolved velocity models will be developed as more data are acquired.

Local climate change induced by groundwater overexploitation in a high Andean arid watershed, Laguna Lagunillas basin, northern Chile

NASA Astrophysics Data System (ADS)

Scheihing, Konstantin; Tröger, Uwe

2018-05-01

The Laguna Lagunillas basin in the arid Andes of northern Chile exhibits a shallow aquifer and is exposed to extreme air temperature variations from 20 to -25 °C. Between 1991 and 2012, groundwater levels in the Pampa Lagunillas aquifer fell from near-surface to 15 m below ground level (bgl) due to severe overexploitation. In the same period, local mean monthly minimum temperatures started a declining trend, dropping by 3-8 °C relative to a nearby reference station. Meanwhile, mean monthly maximum summer temperatures shifted abruptly upwards by 2.7 °C on average in around 1996. The observed air temperature downturns and upturns are in accordance with detected anomalies in land-surface temperature imagery. Two major factors may be causing the local climate change. One is related to a water-table decline below the evaporative energy potential extinction depth of 2 m bgl, which causes an up-heating of the bare soil surface and, in turn, influences the lower atmosphere. At the same time, the removal of near-surface groundwater reduces the thermal conductivity of the upper sedimentary layer, which consequently diminishes the heat exchange between the aquifer (constant heat source of 10 °C) and the lower atmosphere during nights, leading to a severe dropping of minimum air temperatures. The observed critical water-level drawdown was 2-3 m bgl. Future and existing water-production projects in arid high Andean basins with shallow groundwater should avoid a decline of near-surface groundwater below 2 m bgl and take groundwater-climate interactions into account when identifying and monitoring potential environmental impacts.

Malaria transmission in two localities in north-western Argentina

PubMed Central

Dantur Juri, María J; Zaidenberg, Mario; Claps, Guillermo L; Santana, Mirta; Almirón, Walter R

2009-01-01

Background Malaria is one of the most important tropical diseases that affects people globally. The influence of environmental conditions in the patterns of temporal distribution of malaria vectors and the disease has been studied in different countries. In the present study, ecological aspects of the malaria vector Anopheles (Anopheles) pseudopunctipennis and their relationship with climatic variables, as well as the seasonality of malaria cases, were studied in two localities, El Oculto and Aguas Blancas, in north-western Argentina. Methods The fluctuation of An. pseudopunctipennis and the malaria cases distribution was analysed with Random Effect Poisson Regression. This analysis takes into account the effect of each climatic variable on the abundance of both vector and malaria cases, giving as results predicted values named Incidence Rate Radio. Results The number of specimens collected in El Oculto and Aguas Blancas was 4224 (88.07%) and 572 (11.93%), respectively. In El Oculto no marked seasonality was found, different from Aguas Blancas, where high abundance was detected at the end of spring and the beginning of summer. The maximum mean temperature affected the An. pseudopunctipennis fluctuation in El Oculto and Aguas Blancas. When considering the relationship between the number of malaria cases and the climatic variables in El Oculto, maximum mean temperature and accumulated rainfall were significant, in contrast with Aguas Blancas, where mean temperature and humidity showed a closer relationship to the fluctuation in the disease. Conclusion The temporal distribution patterns of An. pseudopunctipennis vary in both localities, but spring appears as the season with better conditions for mosquito development. Maximum mean temperature was the most important variable in both localities. Malaria cases were influenced by the maximum mean temperature in El Oculto, while the mean temperature and humidity were significant in Aguas Blancas. In Aguas Blancas peaks of

Pinniped Hearing in Complex Acoustic Environments

DTIC Science & Technology

2012-09-30

Piedras Blancas, is located just north of Cambria, California and is quickly expanding as one of the largest northern elephant seal colonies along the...acoustically sampled at the Año Nuevo breeding colony, and 46 individuals were similarly studied at the Piedras Blancas breeding colony during the 2011-12

Increased Concentrations of Short-Lived Decay-Series Radionuclides in Groundwaters Underneath the Nopal I Uranium Deposit at Pena Blanca, Mexico

NASA Astrophysics Data System (ADS)

Luo, S.; Ku, T.; Todd, V.; Murrell, M. T.; Dinsmoor, J. C.

2007-05-01

The Nopal I uranium ore deposit at Pena Blanca, Mexico, located at > 200 meters above the groundwater table, provides an ideal natural analog for quantifying the effectiveness of geological barrier for isolation of radioactive waste nuclides from reaching the human environments through ground water transport. To fulfill such natural analog studies, three wells (PB1, PB2, and PB3 respectively) were drilled at the site from the land surface down to the saturated groundwater zone and ground waters were collected from each of these wells through large- volume sampling/in-situ Mn-filter filtration for analyses of short-lived uranium/thorium-series radionuclides. Our measurements from PB1 show that the groundwater standing in the hole has much lower 222Rn activity than the freshly pumped groundwater. From this change in 222Rn activity, we estimate the residence time of groundwater in PB1 to be about 20 days. Our measurements also show that the activities of short-lived radioisotopes of Th (234Th), Ra (228Ra, 224Ra, 223Ra), Rn (222Rn), Pb (210Pb), and Po (210Po) in PB1, PB2, and PB3 are all significantly higher than those from the other wells near the Nopal I site. These high activities provide evidence for the enrichment of long-lived U and Ra isotopes in the groundwater as well as in the associated adsorbed phases on the fractured aquifer rocks underneath the ore deposit. Such enrichment suggests a rapid dissolution of U and Ra isotopes from the uranium ore deposit in the vadose zone and the subsequent migration to the groundwater underneath. A reactive transport model can be established to characterize the in-situ transport of radionuclides at the site. The observed change of 222Rn activity at PB1 also suggests that the measured high radioactivityies in ground waters from the site isare not an artifact of drilling operations. However, further studies are needed to assess if or to what extent the radionuclide migration is affected by the previous mining activities at

Emerging Glacial Lakes in the Cordillera Blanca, Peru: A Case Study at Arteson Glacier

NASA Astrophysics Data System (ADS)

Chisolm, R. E.; Mckinney, D. C.; Gomez, J.; Voss, K.

2012-12-01

Tropical glaciers are an essential component of the water resources systems in the mountainous regions where they are located, and a warming climate has resulted in the accelerated retreat of Andean glaciers in recent decades. The shrinkage of Andean glaciers influences the flood risk for communities living downstream as new glacial lakes have begun to form at the termini of some glaciers. As these lakes continue to grow in area and volume, they pose an increasing risk of glacial lake outburst floods (GLOFs). Ice thickness measurements have been a key missing link in studying the tropical glaciers in Peru and how climate change is likely to impact glacial melt and the growth of glacial lakes. Ground penetrating radar (GPR) has rarely been applied to glaciers in Peru to measure ice thickness, and these measurements can tell us a lot about how a warming climate will affect glacier mass balance. This study presents GPR data taken in July 2012 at the Arteson glacier in the Cordillera Blanca, Peru. A new lake has begun to form at the terminus of the Arteson glacier, and this lake has key features, including overhanging ice and loose rock likely to create landslides, that could trigger a catastrophic GLOF if the lake continues to grow. This new lake is part of a series of three lakes that have formed below the Arteson glacier. The two lower lakes, Artesonraju and Paron, are much larger so that if there were an avalanche or landslide into the new lake below Arteson glacier, the impact could potentially be more catastrophic than a GLOF from one single lake. Estimates of how the lake mass balance is likely to evolve due to the retreating glacier are key to assessing the flood risk from this dynamic three-lake system. Because the glacier mass balance and lake mass balance are closely linked, the ice thickness measurements and measurements of the bed slope of the Arteson glacier and underlying bedrock give us a clue to how the lake is likely to evolve. GPR measurements of

Microbial Diversity in Sediment Ecosystems (Evaporites Domes, Microbial Mats, and Crusts) of Hypersaline Laguna Tebenquiche, Salar de Atacama, Chile.

PubMed

Fernandez, Ana B; Rasuk, Maria C; Visscher, Pieter T; Contreras, Manuel; Novoa, Fernando; Poire, Daniel G; Patterson, Molly M; Ventosa, Antonio; Farias, Maria E

2016-01-01

We combined nucleic acid-based molecular methods, biogeochemical measurements, and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity, and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions, and an endoevaporite were compared with: The V4 hypervariable region of the 16S rRNA gene was amplified by pyrosequencing to analyze the total microbial diversity (i.e., bacteria and archaea) in bulk samples, and in addition, in detail on a millimeter scale in one microbial mat and in one evaporite. Archaea were more abundant than bacteria. Euryarchaeota was one of the most abundant phyla in all samples, and particularly dominant (97% of total diversity) in the most lithified ecosystem, the evaporite. Most of the euryarchaeal OTUs could be assigned to the class Halobacteria or anaerobic and methanogenic archaea. Planctomycetes potentially also play a key role in mats and rhizome-associated concretions, notably the aerobic organoheterotroph members of the class Phycisphaerae. In addition to cyanobacteria, members of Chromatiales and possibly the candidate family Chlorotrichaceae contributed to photosynthetic carbon fixation. Other abundant uncultured taxa such as the candidate division MSBL1, the uncultured MBGB, and the phylum Acetothermia potentially play an important metabolic role in these ecosystems. Lithifying microbial mats contained calcium carbonate precipitates, whereas endoevoporites consisted of gypsum, and halite. Biogeochemical measurements revealed that based on depth profiles of O2 and sulfide, metabolic activities were much higher in the non-lithifying mat (peaking in the least lithified systems) than in lithifying mats with the lowest activity in endoevaporites. This trend in decreasing microbial activity reflects the increase in salinity, which may play an important role in the biodiversity.

Numerical modeling perspectives on zircon crystallization and magma reservoir growth at the Laguna del Maule volcanic field, central Chile

NASA Astrophysics Data System (ADS)

Andersen, N. L.; Dufek, J.; Singer, B. S.

2017-12-01

Magma reservoirs in the middle to upper crust are though to accumulate incrementally over 104 -105 years. Coupled crystallization ages and compositions of zircon are a potentially powerful tracer of reservoir growth and magma evolution. However, complex age distributions and disequilibrium trace element partitioning complicate the interpretation of the zircon record in terms of magmatic processes. In order to make quantitative predictions of the effects of magmatic processes that contribute reservoir growth and evolution—such as cooling and crystallization, magma recharge and mixing, and rejuvenation and remelting of cumulate-rich reservoir margins—we develop a model of zircon saturation and growth within a numerical framework of coupled thermal transfer, phase equilibrium, and magma dynamics. We apply this model to the Laguna del Maule volcanic field (LdM), located in central Chile. LdM has erupted at least 40 km3 of rhyolite from 36 vents distributed within a 250 km2 lake basin. Ongoing unrest demonstrates the large, silicic magma system beneath LdM remains active to this day. Zircon from rhyolite erupted between c. 23 and 1.8 ka produce a continuous distribution of 230Th-238U ages ranging from eruption to 40 ka, as well as less common crystal domains up to 165 ka and rare xenocrysts. Zircon trace element compositions fingerprint compositionally distinct reservoirs that grew within the larger magma system. Despite the dominantly continuous distributions of ages, many crystals are characterized by volumetrically substantial, trace element enriched domains consistent with rapid crystal growth. We utilize numerical simulations to assess the magmatic conditions required to catalyze these "blooms" of crystallization and the magma dynamics that contributed to the assembly of the LdM magma system.

Microbial Diversity in Sediment Ecosystems (Evaporites Domes, Microbial Mats, and Crusts) of Hypersaline Laguna Tebenquiche, Salar de Atacama, Chile

PubMed Central

Fernandez, Ana B.; Rasuk, Maria C.; Visscher, Pieter T.; Contreras, Manuel; Novoa, Fernando; Poire, Daniel G.; Patterson, Molly M.; Ventosa, Antonio; Farias, Maria E.

2016-01-01

We combined nucleic acid-based molecular methods, biogeochemical measurements, and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity, and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions, and an endoevaporite were compared with: The V4 hypervariable region of the 16S rRNA gene was amplified by pyrosequencing to analyze the total microbial diversity (i.e., bacteria and archaea) in bulk samples, and in addition, in detail on a millimeter scale in one microbial mat and in one evaporite. Archaea were more abundant than bacteria. Euryarchaeota was one of the most abundant phyla in all samples, and particularly dominant (97% of total diversity) in the most lithified ecosystem, the evaporite. Most of the euryarchaeal OTUs could be assigned to the class Halobacteria or anaerobic and methanogenic archaea. Planctomycetes potentially also play a key role in mats and rhizome-associated concretions, notably the aerobic organoheterotroph members of the class Phycisphaerae. In addition to cyanobacteria, members of Chromatiales and possibly the candidate family Chlorotrichaceae contributed to photosynthetic carbon fixation. Other abundant uncultured taxa such as the candidate division MSBL1, the uncultured MBGB, and the phylum Acetothermia potentially play an important metabolic role in these ecosystems. Lithifying microbial mats contained calcium carbonate precipitates, whereas endoevoporites consisted of gypsum, and halite. Biogeochemical measurements revealed that based on depth profiles of O2 and sulfide, metabolic activities were much higher in the non-lithifying mat (peaking in the least lithified systems) than in lithifying mats with the lowest activity in endoevaporites. This trend in decreasing microbial activity reflects the increase in salinity, which may play an important role in the biodiversity. PMID:27597845

Plasma Cholinesterase Activity in Female Green Turtles Chelonia mydas Nesting in Laguna de Terminos, Mexico Related to Organochlorine Pesticides in Their Eggs.

PubMed

Rivas-Hernández, Gerardo; May-Uc, Yaneli; Noreña-Barroso, Elsa; Cobos-Gasca, Víctor; Rodríguez-Fuentes, Gabriela

2018-01-01

The inhibition of cholinesterase (ChE) activity has been used as a biomarker of exposure to organophosphate and carbamate insecticides. ChE of nesting female green turtles (Chelonia mydas) were biochemically characterized using two substrates, acetylthiocholine iodide and butyrylthiocholine iodide, and three ChE inhibitors (eserine sulfate, BW284C51 and iso-OMPA). The results indicated that BChE is the predominant plasma ChE in female C. mydas, but with atypical properties that differ from those found in human BChE. Eggs from green turtles nesting at two sites in Laguna de Terminos contained µg g -1 (wet weight) quantities of organochlorine (OC) pesticides. Drins (aldrin, dieldrin, endrin, endrin ketone, endrin aldehyde) were found at the highest concentrations with no significant differences in the concentrations in eggs collected at the two sampling sites. A negative relationship was found between levels of OC pesticides in eggs and BChE activity in the plasma of female turtles laying the eggs. Since OC pesticides are not cholinesterase inhibitors, we hypothesized that this inverse relationship may be related to an antagonistic effect between OCs and organophosphate pesticides and mobilization of OCs from the fatty tissues of the female turtles into their eggs. However, further study is required to verify the hypothesis. It is also possible that other contaminants, such as petroleum hydrocarbons are responsible for the modulation of cholinesterase activity in female turtles.

Tdp studies and tests for C. A. Energia Electrica de Venezuela (enelven) at planta ramon laguna, units RL-17 and RL-10. Volume 1. Executive summary, RL-17 test report, and gas conversion proposals. Export trade information

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-03-28

The study, conducted by Babcock and Wilcox, was funded by the U.S. Trade and Development agency on behalf of Enelven. In order to maximize generated power output and minimize operating costs at Planta Ramon Laguna, tests were done to evaluate the condition of equipment at the plant. In order to identify any damage and determine the operating output of each unit, assessments were done of the furnaces, boilers, generators and boiler feed pumps being used in the plant. The report presents the results of these tests. This is the first of three volumes and it is divided into the followingmore » sections: (1) Executive Summary; (2) Hydrogen Damage Assessment; (3) RL-17 Gas Conversion Proposal; (4) RL-10 and RL-11 Gas Conversion Proposals.« less

Foraging behavior of redheads (Aythya americana) wintering in Texas and Louisiana

USGS Publications Warehouse

Woodin, M.C.; Michot, T.C.

2006-01-01

Redheads, Aythya americana, concentrate in large numbers annually in traditional wintering areas along the western and northern rim of the Gulf of Mexico. Two of these areas are the Laguna Madre of Texas and Chandeleur Sound of Louisiana. We collected data on 54,340 activities from 103 redhead flocks in Texas and 51,650 activities from 57 redhead flocks in Louisiana. Males and females fed similarly, differing neither in levels of feeding (percent of all birds in flock that were feeding) (p>0.90) nor in percentages of birds feeding by diving, tipping, dipping, or gleaning from the surface (p>0.10). The foraging level of redheads in the upper Laguna Madre region was relatively constant throughout two winters. Foraging of redheads in early winter in Louisiana was significantly greater than redhead foraging in the upper Laguna Madre, but by late winter, foraging by redheads in Louisiana had declined to the same level as that shown by redheads foraging in the upper Laguna Madre. The overall foraging level of redheads from Chandeleur Sound was greater (41%) than that of redheads in the upper Laguna Madre (26%), yet it was quite similar to the 46% foraging level reported for redheads from the lower Laguna Madre. Redheads in the upper Laguna Madre region of Texas fed more by diving than did those in the Chandeleur Sound and the lower Laguna Madre. Diving increased in frequency in late winter. Greater reliance by redheads on diving in January and February indicates that the birds altered their foraging to feed in deeper water, suggesting that the large concentrations of redheads staging at this time for spring migration may have displaced some birds to alternative foraging sites. Our results imply that the most likely period for food resources to become limiting for wintering redheads is when they are staging in late winter. ?? Springer 2006.

Modelling cascading and erosional processes for glacial lake outburst floods in the Quillcay catchment, Huaraz, Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Baer, Patrick; Huggel, Christian; Frey, Holger; Chisolm, Rachel; McKinney, Daene; McArdell, Brian; Portocarrero, Cesar; Cochachin, Alejo

2016-04-01

Huaraz as the largest city in Cordillera Blanca has faced a major disaster in 1941, when an outburst flood from Lake Palcacocha killed several thousand people and caused widespread destruction. Recent studies on glacial lake outburst flood (GLOF) modelling and early warning systems focussed on Lake Palcacocha which has regrown after the 1941 event, from a volume of half a million m3 in 1974 to a total volume of more than 17 million m3 today. However, little research has been conducted so far concerning the situation of other lakes in the Quillcay catchment, namely Lake Tullparaju (12 mill. m3) and Cuchillacocha (2.5 mill. m3), which both also pose a threat to the city of Huaraz. In this study, we modelled the cascading processes at Lake Tullparaju and Lake Cuchillacocha including rock/ice avalanches, flood wave propagation in the lake and the resulting outburst flood and debris flows. We used the 2D model RAMMS to simulate ice avalanches. Model output was used as input for analytical 2D and 3D calculations of impact waves in the lakes that allowed us to estimate dam overtopping wave height. Since the dimension of the hanging glaciers above all three lakes is comparable, the scenarios in this study have been defined similar to the previous study at Lake Palcacocha. The flow propagation model included sediment entrainment in the steeper parts of the catchment, adding up to 50% to the initial flow volume. The results for total travel time as well as for inundated areas and flow depth and velocity in the city of Huaraz are comparable to the previous studies at Lake Palcacocha. This underlines the importance of considering also these lakes within an integral hazard analysis for the city of Huaraz. A main challenge for modelling GLOFs in the Quillcay catchment using RAMMS is the long runout distance of over 22 km combined with the very low slope gradient of the river. Further studies could improve the process understanding and could focus on more detailed investigations

Acoustic Response and Detection of Marine Mammals Using an Advanced Digital Acoustic Recording Tag(Rev 3)

DTIC Science & Technology

2007-03-13

Victor Gonzalez, University of La Laguna. Fieldwork was supported by University of La Laguna and Governments of El Hierro and the Canary Islands...team in El Hierro and the Field team in Liguria. Fieldwork support was provided by Universidad de La Laguna (ULL), BluWest, NATO Undersea Research...Center (NURC), and Governments of El Hierro and the Canary Islands. Some of Peter Madsen’s work was supported by a Steno Fellowship from the

Uranium-rich opal from the Nopal I uranium deposit, Peña Blanca, Mexico: Evidence for the uptake and retardation of radionuclides

NASA Astrophysics Data System (ADS)

Schindler, Michael; Fayek, Mostafa; Hawthorne, Frank C.

2010-01-01

The Nopal I uranium deposit of the Sierra Peña Blanca, Mexico, has been the focus of numerous studies because of its economic importance and its use as a natural analog for nuclear-waste disposal in volcanic tuff. Secondary uranyl minerals such as uranophane, Ca[(UO 2)(SiO 3OH)] 2(H 2O) 5, and weeksite, (K,Na) 2[(UO 2) 2(Si 5O 13)](H 2O) 3, occur in the vadose zone of the deposit and are overgrown by silica glaze. These glazes consist mainly of opal A, which contains small particles of uraninite, UO 2, and weeksite. Close to a fault between brecciated volcanic rocks and welded tuff, a greenish silica glaze coats the altered breccia. Yellow silica glazes from the center of the breccia pipe and from the high-grade pile coat uranyl-silicates, predominantly uranophane and weeksite. All silica glazes are strongly zoned with respect to U and Ca, and the distribution of these elements indicates curved features and spherical particles inside the coatings. The concentrations of U and Ca correlate in the different zones and both elements inversely correlate with the concentration of Si. Zones within the silica glazes contain U and Ca in a 1:1 ratio with maximum concentrations of 0.08 and 0.15 at.% for the greenish and yellow glazes, respectively, suggesting trapping of either Ca 1U 1-aqueous species or -particles in the colloidal silica. X-ray photoelectron spectroscopy (XPS), Fourier-transform infra-red spectroscopy (FTIR), and oxygen-isotope ratios measured by secondary-ion mass spectrometry (SIMS) indicate higher U 6+/U 4+ ratios, higher proportions of Si-OH groups and lower δ 18O values for the greenish silica glaze than for the yellow silica glaze. These differences in composition reflect increasing brecciation, porosity, and permeability from the center of the breccia pipe (yellow silica glaze) toward the fault (green silica glaze), where the seepage of meteoric water and Eh are higher.

Distribution of Magma and Hydrothermal Fluids Beneath the Laguna del Maule Volcanic Field, Central Chile Using Magnetotelluric Data

NASA Astrophysics Data System (ADS)

Unsworth, M. J.; Cordell, D. R.; Diaz, D.; Reyes, V.

2016-12-01

Geodetic data has shown that the surface around the Laguna del Maule volcanic field in central Chile has been moving upwards at rates in excess of 19 cm/yr since 2007 over a 200 km2 area. It has been hypothesized that this ground deformation is due to the inflation of a magma body beneath the lake. InSAR deformation modeling and gravity inversion suggest that the depth to the magma body is between 3 km b.s.l. and 0 km (at sea level). This magma body is a likely source for the large number of rhyolitic eruptions at this location over the last 25 ka. A dense broadband magnetotelluric (MT) array was collected from 2009 to 2015 and inverted using the ModEM inversion algorithm to produce a three-dimensional electrical resistivity model. The presence of a large surface conductor (<0.5 Ωm; 2.3 km a.s.l.) spatially coincident with the lake bed has the potential to attenuate signal and decrease resolution beneath the area of inflation. Additional broadband MT data were collected in 2016 and this new data suggest there is a mid-depth, weakly conductive feature (5 Ωm; 1 km b.s.l.) coincident with the area of maximum inflation which is resolvable despite the low-resistivity surface layer. There are many conductive features which lie on the perimeter of the zone of inflation including a large low-resistivity zone (<5 Ωm) at 5 km depth (3 km b.s.l.) north-west of the lake and a large low-resistivity zone (<10 Ωm) at 5 km depth (3 km b.s.l) north of the lake. The complex, three-dimensional model structure is supported by phase tensor analysis showing poorly-defined strike and high beta skew values (>3) at periods >2 s. The conductive features identified could be interpreted as either hydrothermal systems or magma and further analysis will contribute to better understanding this dynamic system.

9. Photographic copy of photograph. (Source: U.S. Department of Interior. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Photographic copy of photograph. (Source: U.S. Department of Interior. Office of Indian Affairs. Indian Irrigation Service. Annual Report, Fiscal Year 1928 Vol I. Irrigation District #4, California and Southern Arizona, RG 75, BIA-Phoenix, Box 40, National Archives, Pacific Southwest Region) Photographer unknown. CASA BLANCA CANAL, HEADING AND FLUME, APRIL 10, 1928 - San Carlos Irrigation Project, Casa Blanca Canal, Gila River, Coolidge, Pinal County, AZ

10. Photographic copy of photograph. (Source: U.S. Department of Interior. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. Photographic copy of photograph. (Source: U.S. Department of Interior. Office of Indian Affairs. Indian Irrigation Service. Annual Report, Fiscal Year 1928. Vol I. Irrigation District #4, California and Southern Arizona, RG 75, BIA-Phoenix, Box 40, National Archives, Pacific Southwest Region) Photographer unknown. CASA BLANCA CANAL, HEADING AND FLUME, APRIL 10, 1928 - San Carlos Irrigation Project, Casa Blanca Canal, Gila River, Coolidge, Pinal County, AZ

Short-term variability on mesozooplankton community in a shallow mixed estuary (Bahía Blanca, Argentina): Influence of tidal cycles and local winds

NASA Astrophysics Data System (ADS)

Menéndez, María C.; Piccolo, María C.; Hoffmeyer, Mónica S.

2012-10-01

The short-term dynamics of zooplankton in coastal ecosystems are strongly influenced by physical processes such as tides, riverine runoff and winds. In this study, we investigated the short-term changes of the representative taxa within mesozooplankton in relation to the semidiurnal tidal cycles. Also, we evaluated the influence of local winds on this short-term variability. Sampling was carried out bimonthly from December 2004 to April 2006 in a fixed point located in the inner zone of the Bahía Blanca Estuary, Argentina. Mesozooplankton samples were taken by pumps during 14-h tidal cycles at 3-h intervals, from surface and bottom. Vertical profiles of temperature and salinity as well as water samples to determine suspended particulate matter were acquired at each sampling date. All data concerning winds were obtained from a meteorological station and water level was recorded with a tide gauge. Holoplankton dominated numerically on meroplankton and adventitious fraction. Concerning holoplanktonic abundance, the highest values were attained by the calanoid copepods Acartia tonsa and Eurytemora americana. Meroplankton occurred mainly as barnacle larvae while benthic harpacticoids and Corophium sp. dominated the adventitious component. Semidiurnal tide was the main influence on the A. tonsa variability. However, noticeable differences in the abundance pattern as function of wind intensity were detected. Meroplankton abundance did not show a clear variation along the tidal cycle. Distributional pattern of harpacticoids seemed to be mainly modulated by velocity asymmetries in the tidal currents, in the same way as suspended particulate matter. However, the Corophium sp. distribution indicated probable behavioural responses associated with tides. The obtained results show how variable the mesozooplankton community structure can be over short-term time scales in mesotidal temperate estuaries. This variability should be taken into account for any zooplankton monitoring

Rio San Jose Action Memo

EPA Pesticide Factsheets

This memorandum requests approval for a time-critical removal action at the II residential properties that compose the Rio San Jose Radiation Site located in Laguna, Mesita, Paraje, and Seama, Pueblo of Laguna located in Cibola County, New Mexico.

Imaging the Laguna del Maule Volcanic Field, central Chile using magnetotellurics: Evidence for crustal melt regions laterally-offset from surface vents and lava flows

NASA Astrophysics Data System (ADS)

Cordell, Darcy; Unsworth, Martyn J.; Díaz, Daniel

2018-04-01

Magnetotelluric (MT) data were collected at the Laguna del Maule volcanic field (LdMVF), located in central Chile (36°S, 70.5°W), which has been experiencing unprecedented upward ground deformation since 2007. These data were used to create the first detailed three-dimensional electrical resistivity model of the LdMVF and surrounding area. The resulting model was spatially complex with several major conductive features imaged at different depths and locations around Laguna del Maule (LdM). A near-surface conductor (C1; 0.5 Ωm) approximately 100 m beneath the lake is interpreted as a conductive smectite clay cap related to a shallow hydrothermal reservoir. At 4 km depth, a strong conductor (C3; 0.3 Ωm) is located beneath the western edge of LdM. The proximity of C3 to the recent Pleistocene-to-Holocene vents in the northwest LdMVF and nearby hot springs suggests that C3 is a hydrous (>5 wt% H2O), rhyolitic partial melt with melt fraction >35% and a free-water hydrothermal component. C3 dips towards, and is connected to, a deeper conductor (C4; 1 Ωm). C4 is located to the north of LdM at >8 km depth below surface and is interpreted as a long-lived, rhyolitic-to-andesitic magma reservoir with melt fractions less than 35%. It is hypothesized that the deeper magma reservoir (C4) is providing melt and hydrothermal fluids to the shallower magma reservoir (C3). A large conductor directly beneath the LdMVF is not imaged with MT suggesting that any mush volume beneath LdM must be anhydrous (<2 wt% H2O), low temperature and low melt fraction (<25%) in order to go undetected. The presence of large conductors to the north has important implications for magma dynamics as it suggests that material may have a significant lateral component (>10 km) as it moves from the deep magma reservoir (C4) to create small, ephemeral volumes of eruptible melt (C3). It is hypothesized that there may be a north-south contrast in physical processes affecting the growth of melt-rich zones

76 FR 5196 - Aransas National Wildlife Refuge Complex, Aransas, Calhoun, and Refugio Counties, TX; Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-28

... recreational development, the protection of natural resources, and the conservation of endangered or threatened.... We completed a thorough analysis of impacts on the human environment, which we included in the EA.../STRC/laguna/Index_Laguna.html . At the following libraries: Library Address Phone number Victoria...

Evaluating Connectivity between Marine Protected Areas Using CODAR High-Frequency Radar

DTIC Science & Technology

2010-06-01

SMCA/SMR, (6) Big Creek SMCA/SMR, (7) Piedras Blancas SMCA/SMR, (8) Cambria SMCA/White Rock SMCA, (9) Pt. Buchon SMCA/SMR, and (10) Vandenberg SMR...52 grid- points, (7) Piedras Blancas 47 grid-points, (8) Cambria 20 grid-points, (9) Pt. Buchon 45 grid- points, and (10) the Vandenberg MPA had 62...COLUMN HEADERS. Back-projected from: (Sorted north- to-south) Año Nuevo Soquel Canyon Portuguese Ledge Point Lobos Point Sur Big Creek Piedras

Status of soil-transmitted helminth infections in schoolchildren in Laguna Province, the Philippines: Determined by parasitological and molecular diagnostic techniques.

PubMed

Mationg, Mary Lorraine S; Gordon, Catherine A; Tallo, Veronica L; Olveda, Remigio M; Alday, Portia P; Reñosa, Mark Donald C; Bieri, Franziska A; Williams, Gail M; Clements, Archie C A; Steinmann, Peter; Halton, Kate; Li, Yuesheng; McManus, Donald P; Gray, Darren J

2017-11-01

Soil-transmitted helminths (STH) are the most common parasitic infections in impoverished communities, particularly among children. Current STH control is through school-based mass drug administration (MDA), which in the Philippines is done twice annually. As expected, MDA has decreased the intensity and prevalence of STH over time. As a result, the common Kato Katz (KK) thick smear method of detecting STH is less effective because it lacks sensitivity in low intensity infections, making it difficult to measure the impact of deworming programs. A cross-sectional study was carried out over a four-week period from October 27, 2014 until November 20, 2014 in Laguna province, the Philippines. Stool samples were collected from 263 schoolchildren, to determine the prevalence of STH and compare diagnostic accuracy of multiplex quantitative polymerase chain reaction (qPCR) with the KK. A large discrepancy in the prevalence between the two techniques was noted for the detection of at least one type of STH infection (33.8% by KK vs. 78.3% by qPCR), Ascaris lumbricoides (20.5% by KK vs. 60.8% by qPCR) and Trichuris trichiura (23.6% by KK vs. 38.8% by qPCR). Considering the combined results of both methods, the prevalence of at least one type of helminth infection, A. lumbricoides, and T. trichiura were 83.3%, 67.7%, and 53.6%, respectively. Sensitivity of the qPCR for detecting at least one type of STH infection, A. lumbricoides, and T. trichiura were 94.1%, 89.9%, and 72.3% respectively; whereas KK sensitivity was 40.6%, 30.3%, and 44.0%, respectively. The qPCR method also detected infections with Ancylostoma spp. (4.6%), Necator americanus (2.3%), and Strongyloides stercoralis (0.8%) that were missed by KK. qPCR may provide new and important diagnostic information to improve assessment of the effectiveness and impact of integrated control strategies particularly in areas where large-scale STH control has led to low prevalence and/or intensity of infection.

Rock-magnetic proxies of wind intensity and dust since 51,200 cal BP from lacustrine sediments of Laguna Potrok Aike, southeastern Patagonia

NASA Astrophysics Data System (ADS)

Lisé-Pronovost, Agathe; St-Onge, Guillaume; Gogorza, Claudia; Haberzettl, Torsten; Jouve, Guillaume; Francus, Pierre; Ohlendorf, Christian; Gebhardt, Catalina; Zolitschka, Bernd

2015-02-01

The sedimentary archive from Laguna Potrok Aike is the only continuous record reaching back to the last Glacial period in continental southeastern Patagonia. Located in the path of the Southern Hemisphere westerly winds and in the source region of dust deposited in Antarctica during Glacial periods, southern Patagonia is a vantage point to reconstruct past changes in aeolian activity. Here we use high-resolution rock-magnetic and physical grain size data from site 2 of the International Continental scientific Drilling Program (ICDP) Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO) in order to develop magnetic proxies of dust and wind intensity at 52°S since 51,200 cal BP. Rock-magnetic analysis indicates the magnetic mineral assemblage is dominated by detrital magnetite. Based on the estimated flux of magnetite to the lake and comparison with distal dust records from the Southern Ocean and Antarctica, kLF is interpreted as a dust indicator in the dust source of southern Patagonia at the millennial time scale, when ferrimagnetic grain size and coercivity influence are minimal. Comparison to physical grain-size data indicates that the median destructive field of isothermal remanent magnetization (MDFIRM) mostly reflects medium to coarse magnetite bearing silts typically transported by winds for short-term suspension. Comparison with wind-intensity proxies from the Southern Hemisphere during the last Glacial period and with regional records from Patagonia since the last deglaciation including marine, lacustrine and peat bog sediments as well as speleothems reveals similar variability with MDFIRM up to the centennial time scale. MDFIRM is interpreted as a wind-intensity proxy independent of moisture changes for southeastern Patagonia, with stronger winds capable of transporting coarser magnetite bearing silts to the lake.

A measurement of the cosmic ray spectrum and composition at the knee

NASA Astrophysics Data System (ADS)

Fowler, J. W.; Fortson, L. F.; Jui, C. C. H.; Kieda, D. B.; Ong, R. A.; Pryke, C. L.; Sommers, P.

2001-03-01

The energy spectrum and primary composition of cosmic rays with energy between 3×10 14 and 3×10 16 eV have been studied using the CASA-BLANCA detector. CASA consisted of 957 surface scintillation stations; BLANCA consisted of 144 angle-integrating Cherenkov light detectors located at the same site. CASA measured the charged particle distribution of air showers, while BLANCA measured the lateral distribution of Cherenkov light. The data are interpreted using the predictions of the CORSIKA air shower simulation coupled with four different hadronic interaction codes. The differential flux of cosmic rays measured by BLANCA exhibits a knee in the range of 2-3 PeV with a width of approximately 0.5 decades in primary energy. The power law indices of the differential flux below and above the knee are -2.72±0.02 and -2.95±0.02, respectively. We present our data both as a mean depth of shower maximum and as a mean nuclear mass. A multi-component fit using four elemental species suggests the same composition trends exhibited by the mean quantities, and also indicates that QGSJET and VENUS are the preferred hadronic interaction models. We find that an initially mixed composition turns lighter between 1 and 3 PeV, and then becomes heavier with increasing energies above 3 PeV.

Argentina: Nationality, Demography and Security

DTIC Science & Technology

1993-04-22

1978. 4. Palacio H. "Historia de la Argentina", Ed. Pefiatillo, Buenos Aires, 1973. 5. Randle, P.H. and others. " La Conciencia Territorial Ed. Oikos...Mendoza, San Juan and San Luis declared their sovereignty. In 1820, Cordoba and La Rioja separated; for a while, they formed the Cordoba of Tucuman...different centers of power in America: 1. One current from Peru came from the north and founded San Salvador de Jujuy, Salta, Tucuman, Catamarca, La Rioja

Rapid uplift during 2007-2012 at Laguna del Maule volcanic field, Andean Southern Volcanic Zone, Chile

NASA Astrophysics Data System (ADS)

Le Mevel, H.; Feigl, K.; Ali, T.; Cordova V., M. L.; DeMets, C.; Singer, B. S.

2012-12-01

The Laguna del Maule (LdM) volcanic field includes an unusual concentration of post-glacial rhyolitic lava coulees and domes, dated between 24 to 2 thousand years old that cover more than 100 square kilometers and erupted from 24 vents that encircle a 20-km-diameter lake basin on the range crest. The recent concentration of rhyolite is unparalleled in the Southern Volcanic Zone of the Andes. Moreover, the western portion of the LdM volcanic field has experienced rapid uplift since 2007, leading to questions about the current configuration of the magmatic system and processes that drive the ongoing inflation. We aim to quantify the active deformation of the LdM volcanic field and its evolution with time. To do so, we use interferometric synthetic aperture radar (InSAR) data acquired by three satellite missions: Envisat in 2003 and 2004, ALOS between 2007 and 2010, and TerraSAR-X in 2012. An interferogram spanning March 2003 to February 2004 "shows no deformation" (Fournier et al., 2010). From 2007 through 2012, however, the shortening of the satellite-to-ground distance revealed a range change rate of greater than 200 mm/yr along the radar line of sight. The deformation includes a circular area 20 km in diameter centered on the western portion of the circle of young rhyolite domes. To analyze the InSAR results, we employ the General Inversion for Phase Technique (GIPhT; Feigl and Thurber, 2009; Ali and Feigl, 2012). We have considered several hypotheses to interpret this deformation. Artefacts such as orbital errors, atmospheric perturbations or topographic contribution cannot account for the observed signal. We also reject the hypothesis of uplift due to gravitational unloading of the crust based on our modeling of independently measured lake level variations over the observed time interval. We thus attribute the deformation to the intrusion of magma into the upper crust below the southwest region of the LdM volcanic field. The best fit to the InSAR data is

Earth observation taken by the Expedition 35 crew

NASA Image and Video Library

2013-04-20

ISS035-E-025019 (20 April 2013) --- One of the Expedition 35 crew members aboard the Earth-orbiting International Space Station used a 400 millimeter lens to record this photograph highlighting water of different color within sub basins of the Laguna (lake) Verde in the high Andes of northwest Argentina. The lake floor as a local low point lies at 4095 meters (13,438 feet) above sea level, whereas the peak of the local volcano west of the lake (not shown) reaches almost 3000 meters higher (or about 6818 meters, 22,368 feet). Laguna Verde (58 kilo meters wide, 36 kilometers long) often appears green, giving rise to its formal name. The image shows the turquoise tint in the central sub basin (image center), with a yellow to black tinge to water in the southern sub basin at image left (also known locally as Laguna Negra). The northernmost basin at image right appears quite black, and the large gray zone comprising much of the rest of Laguna Verde is likely a combination of shallow water, only inches deep, and sunglint reflecting off the water surface. The reason for the color differences lays in the fact the many different families of salt-loving organisms occupy hypersaline lakes such as Laguna Verde. These appear as different colors ? often bright -- depending on the salinities and temperatures of each water body or sub basin. The rest of the lake floor is dry and appears white from the build-up of thick salt deposits. Parallel lines around the southern sub basin (Laguna Negro) indicate prior shorelines of this shrinking water body ? evaporation removes water but leaves ephemeral shorelines marked with white salt.

English Non-Uniformity: A Non-Adult Form of Ethnic English.

ERIC Educational Resources Information Center

Stout, Steven Owen

The paper examines interpretive aspects of English non-uniformity among fifth and sixth grade Native Americans at Laguna Elementary School, Laguna, New Mexico. Speaker assessments of instances of uninflected "be" are ordered to form an implicational scale. The variability in the students' assessment pattern is compared to previous inter-ethnic…

The effects on photosynthetic CO{sub 2} assimilation to long-term elevation of atmospheric CO{sub 2} concentration: An assessment of the response of Trifolium Repens L. cv. Blanca grown at F.A.C.E.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, C.E.

1994-11-01

Understanding how photosynthetic capacity acclimates to elevated CO{sub 2} concentrations is vital in predicting the response of important grassland species such as Trifolium repens. Previous studies of acclimatization have been carried out in artificial experimental conditions, such as acrylic greenhouses or controlled environment chambers. The advent of FACE technology has enabled a large area of crop to be fumigated in the field, providing more realistic growing conditions. Pure stands of Trifolium repens L. cv. Blanca grown at either 355 or 600{mu}mol mol{sup -1} CO{sub 2} were examined, and their photosynthetic response to elevated Ca determined via gas exchange studies. Ratesmore » of photosynthesis of young, fully expanded leaves were increased between 21 and 36% when grown and measured at elevated CO{sub 2}. This increase in A corresponded to a decrease in g{sub S} of between 18 and 52%. No acclimation effect was observed in the most frequently cut stands, whilst the response of stands clipped only 4 times per year was more variable. When down regulation of V{sub cmax} did occur, this was not nearly as marked as that which occurred in 3 other temperate species (Chrysanthemum leucanthemum, Ranunculus friesianus, Plantago lanceolata (L.) J. & C. Presl.), at similar growth regimes. No acclimation of stomatal frequency, SI or pore length was found to occur in the enriched clover stands.« less

Mapping of available heavy metals in Catamarca (Argentina)

NASA Astrophysics Data System (ADS)

Roca, N.; Pazos, M. S.; Bech, J.

2009-04-01

Copper, iron, manganese and zinc are four essential elements for plant growth. Mapping heavy metal migration and distribution in soils is a preliminary step in assessing heavy metal availability in soils. However, data of qualitative and quantitative trace elements composition of soils of Argentina are scarce. Despite the small amounts required by plants, agricultural soils are usually deficient in one or more micronutrients, therefore, their concentration in plant tissues falls below the levels that allow optimal growth. Soil nature plays a fundamental role in the availability of micronutrients and their behaviour at a soil-plant level. The aim of this study is to determine the plant availability and areas of deficiency in agricultural soils with risk of salinization. The presented maps have been elaborated on the basis of the information provided by the monochromatic aerial photographs, scale 1:7000 and projected using the topographic information of the National Topographic Maps. Soils were sampled according to the spatial variation of soil types and land use. Sampling points were geo-referenced. Soil samples were analyzed at the laboratory for complete physicochemical and mineralogical characteristics. The percentage of organic matter is the determining factor in the presence and distribution of the available metals in the soils of the studied area, being the top horizon the one of greatest accumulation. CuDTPA, FeDPTA and MnDPTA are mobile within the profile, whereas ZnDPTA remains adsorbed without vertical displacement. ZnDTPA is the only available metal which also shows differences due to soil salinity and textural classes. However, soil geochemical conditions imply low extractability and a certain difficulty for micronutrient absorption by plants.

Uniform Distribution of Yttrium and Heavy Rare Earth Elements in Round Top Mountain Rhyolite Deposit , Sierra Blanca Texas, USA: Data, Significance, and Origin

NASA Astrophysics Data System (ADS)

Pingitore, N. E., Jr.; Clague, J. W.; Gorski, D.

2014-12-01

The Round Top Mountain peraluminous rhyolite, exposed at the surface in Sierra Blanca, Hudspeth County, west Texas, USA, is enriched in yttrium and heavy rare earth elements (YHREEs). Other potentially valuable elements in the deposit include Be, Li, U, Th, Sn, F, Nb, and Ta. Texas Rare Earth Resources Corp. proposes to extract the YHREEs from the host mineral variety yttrofluorite by inexpensive heap leaching with dilute sulfuric acid, which also releases some of the Be, Li, U, F, and Th from other soluble minor minerals. Data: Feldspars and quartz comprise 90-95% of the rhyolite, with pheonocrysts of up to 250 microns set in an aphanitic matrix that hosts the typically sub-micron target yttrofluorite. Reverse circulation cuttings from some 100 drill holes, two drill cores, and outcrop and trench observations suggest striking physical homogeneity through this billion-plus ton surface-exposed laccolith, about 1200 feet high and a mile in diameter (375 x 1600 m). Gray to pink, and other minor hues, color variation derives from magnetite—hematite redox reaction. Plots of Y, 13 REEs, U, Th, and Nb analyses from over 1500 samples collected from 64 drill holes (color codes in figure) exhibit remarkably little variation in the concentration of these elements with geographic position or depth within the laccolith. Importance: Uniform mineralization grades help insure against the mining production surprises often associated with vein deposits and heterogeneous open pit deposits. At Round Top, mine feedstock can be relatively constant over the life of the mine (multiple decades), so the mechanical mining process can be optimized early on and not need expensive alterations later. Likewise, the chemical and physical parameters of the heap leach can be perfected. The sensitive and expensive process of extraction of elements and element groups from the pregnant leach solution and purification also can be optimized. Origin: The remarkable homogeneity of the YHREE distribution

Genetic diversity and conservation status of managed vicuña (Vicugna vicugna) populations in Argentina.

PubMed

Anello, M; Daverio, M S; Romero, S R; Rigalt, F; Silbestro, M B; Vidal-Rioja, L; Di Rocco, F

2016-02-01

The vicuña (Vicugna vicugna) was indiscriminately hunted for more than 400 years and, by the end of 1960s, it was seriously endangered. At that time, a captive breeding program was initiated in Argentina by the National Institute of Agricultural Technology (INTA) with the aim of preserving the species. Nowadays, vicuñas are managed in captivity and in the wild to obtain their valuable fiber. The current genetic status of Argentinean vicuña populations is virtually unknown. Using mitochondrial DNA and microsatellite markers, we assessed levels of genetic diversity of vicuña populations managed in the wild and compared it with a captive population from INTA. Furthermore, we examined levels of genetic structure and evidence for historical bottlenecks. Overall, all populations revealed high genetic variability with no signs of inbreeding. Levels of genetic diversity between captive and wild populations were not significantly different, although the captive population showed the lowest estimates of allelic richness, number of mitochondrial haplotypes, and haplotype diversity. Significant genetic differentiation at microsatellite markers was found between free-living populations from Jujuy and Catamarca provinces. Moreover, microsatellite data also revealed genetic structure within the Catamarca management area. Genetic signatures of past bottlenecks were detected in wild populations by the Garza Williamson test. Results from this study are discussed in relation to the conservation and management of the species.

U.S. Fish and Wildlife Service refuges and other nearby reserves in Southwestern Puerto Rico

Treesearch

Peter L. Weaver; Joseph J. Schwagerl

2009-01-01

The main purpose of this paper is to summarize information about the Cabo Rojo and Laguna Cartagena National Wildlife Refuges in southwestern Puerto Rico. The Cabo Rojo (Headquarters and Salinas tracts) and Laguna Cartagena (Lagoon and Tinaja tracts) occupy 1174 ha and are part of the 10 231-ha Caribbean system of nine refuges. Their major geologic and physiographic...

27 CFR 9.201 - Sloughhouse.

Code of Federal Regulations, 2012 CFR

2012-04-01

... estuary and Alta Mesa Road, on the western boundary of section 4, T5N, R7E. From the beginning point... Dorado and Sacramento-Amador County line to the County line's intersection with the Laguna estuary, 0.75...) 17.5 miles along the meandering Laguna estuary, crossing over the Sloughhouse map, and return to the...

27 CFR 9.201 - Sloughhouse.

Code of Federal Regulations, 2013 CFR

2013-04-01

... estuary and Alta Mesa Road, on the western boundary of section 4, T5N, R7E. From the beginning point... Dorado and Sacramento-Amador County line to the County line's intersection with the Laguna estuary, 0.75...) 17.5 miles along the meandering Laguna estuary, crossing over the Sloughhouse map, and return to the...

27 CFR 9.201 - Sloughhouse.

Code of Federal Regulations, 2014 CFR

2014-04-01

... estuary and Alta Mesa Road, on the western boundary of section 4, T5N, R7E. From the beginning point... Dorado and Sacramento-Amador County line to the County line's intersection with the Laguna estuary, 0.75...) 17.5 miles along the meandering Laguna estuary, crossing over the Sloughhouse map, and return to the...

Tdp studies and tests for C. A. Energia Electrica de Venezuela (enelven) at planta ramon laguna, units RL-17 and RL-10. Volume 3. Unit RL-10 turbine generator condition assessment report and units RL-10 and RL-11 boiler feed pump conditon assessment report. Export trade information

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-03-28

The study, conducted by Babcock and Wilcox, was funded by the U.S. Trade and Development agency on behalf of Enelven. In order to maximize generated power output and minimize operating costs at Planta Ramon Laguna, tests were done to evaluate the condition of equipment at the plant. In order to identify any damage and determine the operating output of each unit, assessments were done of the furnaces, boilers, generators and boiler feed pumps being used in the plant. The report presents the results of these tests. This is the last of three volumes and it is divided into the followingmore » sections: (1) Condition Assessment of Unit RL-10 Turbine-Generator; (2) Condition Assessment of Unit RL-10 and RL-11 Boiler Feed Pumps.« less

Rapid uplift in Laguna del Maule volcanic field of the Andean Southern Volcanic zone (Chile) 2007-2012

NASA Astrophysics Data System (ADS)

Feigl, Kurt L.; Le Mével, Hélène; Tabrez Ali, S.; Córdova, Loreto; Andersen, Nathan L.; DeMets, Charles; Singer, Bradley S.

2014-02-01

The Laguna del Maule (LdM) volcanic field in Chile is an exceptional example of postglacial rhyolitic volcanism in the Southern Volcanic Zone of the Andes. By interferometric analysis of synthetic aperture radar (SAR) images acquired between 2007 and 2012, we measure exceptionally rapid deformation. The maximum vertical velocity exceeds 280 mm yr-1. Although the rate of deformation was negligible from 2003 January to 2004 February, it accelerated some time before 2007 January. Statistical testing rejects, with 95 per cent confidence, four hypotheses of artefacts caused by tropospheric gradients, ionospheric effects, orbital errors or topographic relief, respectively. The high rate of deformation is confirmed by daily estimates of position during several months in 2012, as measured by analysis of signals transmitted by the Global Positioning System (GPS) and received on the ground at three stations around the reservoir forming the LdM. The fastest-moving GPS station (MAU2) has a velocity vector of [-180 ± 4, 46 ± 2, 280 ± 4] mm yr-1 for the northward, eastward and upward components, respectively, with respect to the stable interior of the South America Plate. The observed deformation cannot be explained by changes in the gravitational load caused by variations in the water level in the reservoir. For the most recent observation time interval, spanning 44 d in early 2012, the model that best fits the InSAR observations involves an inflating sill at a depth of 5.2 ± 0.3 km, with length 9.0 ± 0.3 km, width 5.3 ± 0.4 km, dip 20 ± 3° from horizontal and strike 14 ± 5° clockwise from north, assuming a rectangular dislocation in a half-space with uniform elastic properties. During this time interval, the estimated rate of tensile opening is 1.1 ± 0.04 m yr-1, such that the rate of volume increase in the modelled sill is 51 ± 5 million m3 yr-1 or 1.6 ± 0.2 m3 s-1. From 2004 January to 2012 April the total increase in volume was at least 0.15 km3 over the 5.2-yr

Occurrences of ikaite and pseudomorphs after ikaite in Patagonian lakes - crystal morphologies and stable isotope composition

NASA Astrophysics Data System (ADS)

Oehlerich, Markus; Mayr, Christoph; Griesshaber, Erika; Ohlendorf, Christian; Zolitschka, Bernd; Sánchez-Pastor, Nuria; Kremer, Barbara; Lücke, Andreas; Oeckler, Oliver; Schmahl, Wolfgang

2010-05-01

Ikaite (CaCO3•6H2O), a hydrated calcium carbonate mineral occasionally found in marine sediments, has so far rarely been reported from non-marine sites. Modern ikaite and calcitic pseudomorphs after ikaite were recently discovered in Patagonian Argentina at the polymictic lakes of Laguna Potrok Aike (51°57´S, 70°23´W) and Laguna Cháltel (49°57´S, 71°07´W), respectively. Both lakes are of volcanic origin and have phosphorous-rich, alkaline waters, but differ in altitude (790 m asl and 110 m asl for Laguna Cháltel and Laguna Potrok Aike, respectively) and water temperature. The aim of this study is (1) to investigate conditions for the formation of ikaite and its transformation to more stable, water-free carbonate pseudomorphs after ikaite and (2) to assess the potential of ikaite and calcite pseudomorphs after ikaite as a paleoenvironmental tool in freshwater lakes. Crystallographic, morphological and isotopic characteristics of the pseudomorphs were investigated. Ikaite crystals were found (in September 2008) primarily on aquatic macrophytes and cyanobacteria colonies at Laguna Potrok Aike. Ikaite crystals transformed quickly to calcite pseudomorphs after ikaite after recovery from the cool lake water (4°C). The crystal structure of ikaite was investigated with single crystal X-ray diffraction on samples that were permanently kept cold (in the lake water). At Laguna Cháltel calcite pseudomorphs after ikaite were discovered in littoral sediment cores from 25 m water depth. The mm-sized, porous, polycrystalline calcium carbonate aggregates from the 104 cm long sediment core of Laguna Cháltel are morphologically pseudomorphs after ikaite. SEM and XRD analyses highlight that these pseudomorphs consist of several µm-small calcite crystals in a calcitic matrix. The shape of these micro-crystals changes from rounded to fibrous with increasing sediment depth. Some specimens show casts of cyanobacteria trichomes. The oxygen isotopic composition of calcite

Late Pleistocene equilibrium-line reconstructions in the northern Peruvian Andes

USGS Publications Warehouse

Rodbell, D.T.

1992-01-01

ELA reconstructions using the toe-to-headwall-altitude ratio method for paleoglaciers in the Cordilleras Blanca and Oriental, northern Peruvian Andes indicate that ELAs during the last glacial maximum (LGM; marine isotope stage 2)) were c.4300 m in the Cordillera Blanca, c.3900-3600 m on the west side of the Cordillera Oriental, and c.3200 m on the east (Amazon Basin) side of the Cordillera Oriental. Comparison with estimated modern ELAs and glaciation thresholds indicate that ELA depression ranged from c.700 m in the Cordillera Blanca to c.1200 m on the east side of the Cordillera Oriental. Palynological evidence for drier conditions during the LGM in the tropical Andes suggests that ELA depression of this amount involved a temperature reduction (>5-6??C) that greatly exceeded the tropical sea-surface temperature depression estimates of CLIMAP (<2??C). The west to east increase in ELA depression during the LGM indicates that the steep modern precipitation gradients may have been even steeper during the LGM. -from Author

Earth Observation taken by the Expedition 14 crew

NASA Image and Video Library

2006-10-13

ISS014-E-05615 (14 Oct. 2006) --- Bahia Blanca, Buenos Aires Province, Argentina is featured in this image photographed by an Expedition 14 crewmember on the International Space Station. The port city of Bahia Blanca lies almost 600 kilometers southwest of Buenos Aires on the southern rim of the Argentine economic heartland. This small city of 275,000 people is captured in one frame which shows its position near the mouth of the Arroyo Naposta. The salt flats (gray) and wetlands bordering this estuary, characterized by twisting, light colored tidal channels and dark swamps, lie mainly on the south side of the river. The yellow tinge to the water surfaces arises from the partial sunglint reflection on this particular day. The name Bahia Blanca (White Bay) derives from the white color of the salt and was applied to the major bay--noted by Magellan as he probed the coast of South America for a passage to the Pacific Ocean in 1520--and then to the city at the head of this bay. Highways, airline routes and pipelines from oil and gas fields to the west and south all converge on Bahia Blanca. The city is a major cultural center and historically has acted as a gateway for immigration. Higher ground on the north side of the estuary affords stable ground for the growth of the city and for intensive agriculture, a mainstay of the Argentine economy. The city is set back from the waterfront where an industrial park, a petrochemical center, and dockyards (white ellipse) are located.

Crustal seismicity associated to rpid surface uplift at Laguna del Maule Volcanic Complex, Southern Volcanic Zone of the Andes

NASA Astrophysics Data System (ADS)

Cardona, Carlos; Tassara, Andrés; Gil-Cruz, Fernando; Lara, Luis; Morales, Sergio; Kohler, Paulina; Franco, Luis

2018-03-01

Laguna del Maule Volcanic Complex (LMVC, Southern Andes of Chile) has been experiencing large rates (ca. 30 cm/yr) of surface uplift as detected since 2008 by satellite geodetic measurements. Previous works have modeled the source of this deformation as an inflating rectangular sub-horizontal sill underlying LMVC at 5 km depth, which is supposedly related to an active process of magmatic replenishment of a shallow silicic reservoir. However little is known about the tectonic context on which this activity is taking place, particularly its relation with crustal seismicity that could help understanding and monitoring the current deformation process. Here we present the first detailed characterization of the seismic activity taking place at LMVC and integrate it with structural data acquired in the field in order to illuminate the possible connection between the ongoing process of surface uplift and the activation of crustal faults. Our main finding is the recognition of repetitive volcano-tectonic (VT) seismic swarms that occur periodically between 2011 and 2014 near the SW corner of the sill modeled by InSAR studies. A cross-correlation analysis of the waveforms recorded for these VT events allows identifying three different seismic families. Families F1 and F3 share some common features in the stacked waveform and its locations, which markedly differ from those of family F2. Swarms belonging to this later family are more energetic and its energy was increasing since 2011 to a peak in January 2013, which coincide with maximum vertical velocities detected by local GPS stations. This points to a common process relating both phenomena. The location of VT seismic swarms roughly coincides with the intersection of a NE-SW lineament with a WNW-ESE lineament. The former shows clear field evidences of dextral strike-slip that are fully consistent with one nodal plane of focal mechanism for well-recorded F2 events. The conjugate nodal plane of these focal mechanisms could

Lamanema chavezi (Nematoda: Molineidae): epidemiological data of the infection in South American camelids of Northwest Argentina.

PubMed

Cafrune, M M; Marín, R E; Rigalt, F A; Romero, S R; Aguirre, D H

2009-12-23

Faecal samples from llamas (n=708), vicuñas (n=171) and guanacos (n=4) were obtained between December 2004 and May 2009 in three Provinces of Northwest Argentina (Jujuy, Salta and Catamarca) to know the distribution, prevalence and intensity of Lamanema chavezi infection in these South American camelid species (SACs). Faeces were examined by a sedimentation-flotation technique using a Cl(2)Zn+ClNa solution (specific gravity=1.59). Eggs of L. chavezi occurred in 30.3% of 89 llama herds and in 18.5% of 708 llamas sampled with a mean intensity of 271.8 eggs/g (EPG) of faeces (range 20-2120). The highest values for all parameters of the infection were registered in llamas from Catamarca Province. Significant differences (P<0.001, Fisher's exact test) were detected only for the lower prevalence in llamas from Jujuy respect to those from the other two Provinces. The overall individual prevalence of L. chavezi in llamas was lower than in reports from adult domestic camelids of neighbour countries while mean intensity was higher. The individual prevalence of L. chavezi in guanacos was 75.0%, with a mean intensity of 66.0 EPG (range 40-120) while no vicuñas were detected as infected. Most of infected SACs were located at the phytogeographical region of Andean Patagonic Domain with a dispersion ranging between 22 degrees 10' and 26 degrees 40' South latitude.

Magma injection into a long-lived reservoir to explain geodetically measured uplift: Application to the 2007-2014 unrest episode at Laguna del Maule volcanic field, Chile.

PubMed

Le Mével, Hélène; Gregg, Patricia M; Feigl, Kurt L

2016-08-01

Moving beyond the widely used kinematic models for the deformation sources, we present a new dynamic model to describe the process of injecting magma into an existing magma reservoir. To validate this model, we derive an analytical solution and compare its results to those calculated using the Finite Element Method. A Newtonian fluid characterized by its viscosity, density, and overpressure (relative to the lithostatic value) flows through a vertical conduit, intruding into a reservoir embedded in an elastic domain, leading to an increase in reservoir pressure and time-dependent surface deformation. We apply our injection model to Interferometric Synthetic Aperture Radar (InSAR) data from the ongoing unrest episode at Laguna del Maule (Chile) volcanic field that started in 2007. Using a grid search optimization, we minimize the misfit to the InSAR displacement data and vary the three parameters governing the analytical solution: the characteristic timescale τ P for magma propagation, the maximum injection pressure, and the inflection time when the acceleration switches from positive to negative. For a spheroid with semimajor axis a = 6200 m, semiminor axis c = 100 m, located at a depth of 4.5 km in a purely elastic half-space, the best fit to the InSAR displacement data occurs for τ P =9.5 years and an injection pressure rising up to 11.5 MPa for 2 years. The volume flow rate increased to 1.2 m 3 /s for 2 years and then decreased to 0.7 m 3 /s in 2014. In 7.3 years, at least 187 × 10 6 m 3 of magma was injected.

Magma injection into a long-lived reservoir to explain geodetically measured uplift: Application to the 2007-2014 unrest episode at Laguna del Maule volcanic field, Chile

NASA Astrophysics Data System (ADS)

Le Mével, Hélène; Gregg, Patricia M.; Feigl, Kurt L.

2016-08-01

Moving beyond the widely used kinematic models for the deformation sources, we present a new dynamic model to describe the process of injecting magma into an existing magma reservoir. To validate this model, we derive an analytical solution and compare its results to those calculated using the Finite Element Method. A Newtonian fluid characterized by its viscosity, density, and overpressure (relative to the lithostatic value) flows through a vertical conduit, intruding into a reservoir embedded in an elastic domain, leading to an increase in reservoir pressure and time-dependent surface deformation. We apply our injection model to Interferometric Synthetic Aperture Radar (InSAR) data from the ongoing unrest episode at Laguna del Maule (Chile) volcanic field that started in 2007. Using a grid search optimization, we minimize the misfit to the InSAR displacement data and vary the three parameters governing the analytical solution: the characteristic timescale τP for magma propagation, the maximum injection pressure, and the inflection time when the acceleration switches from positive to negative. For a spheroid with semimajor axis a = 6200 m, semiminor axis c = 100 m, located at a depth of 4.5 km in a purely elastic half-space, the best fit to the InSAR displacement data occurs for τP=9.5 years and an injection pressure rising up to 11.5 MPa for 2 years. The volume flow rate increased to 1.2 m3/s for 2 years and then decreased to 0.7 m3/s in 2014. In 7.3 years, at least 187 × 106 m3 of magma was injected.

Policy Options to Address Crucial Communication Gaps in the Incident Command System

DTIC Science & Technology

2012-09-01

California Department of Forestry and Fire Protection COML Communications Unit Leader COMT Communication Technician EBRPD East Bay Regional Parks...Laguna Fire 1970 - One of California’s Worst Wildfires.” Available at http://www.cccarto.com/cal_wildfire/laguna/fire.html, Accessed August 10, 2012...NIMS - The Evolution of the National Incident Management System.” Fire Rescue Magazine, August 2011. 15 compatibility, and department emergency

Expanding Geophysical and Geochemical Investigation of Causes of Extraordinary Unrest at the Laguna del Maule (Rhyolitic) Volcanic Field, Southern Andes, Chile

NASA Astrophysics Data System (ADS)

Singer, B. S.

2014-12-01

The Laguna del Maule Volcanic Field, Chile, includes an unusually large and recent concentration of silicic eruptions. Since 2007 the crust here has been inflating at an astonishing rate of 25 cm/yr. Findings thus far lead to the hypothesis that the silicic vents have tapped an extensive layer of crystal-poor, rhyolitic melt that began to form atop a magmatic mush zone that was established by ~20 ka with a renewed phase of rhyolite eruptions during the Holocene. Modeling of surface deformation, magnetotelluric data, and gravity changes suggest that magma is currently intruding at a depth of ~5 km. Swarms of volcano-tectonic and long period earthquakes, mostly of M < 2, have occurred beneath the most recent rhyolite coulees on the southwestern and southern margins of the 20 km diameter ring of silicic vents. With support from the US NSF and the Chilean government (SERNAGEOMIN and OVDAS) we are seizing the unique opportunity to investigate, over the next 5 years, the dynamics of this large rhyolitic system while magma migration, reservoir growth, and crustal deformation are actively underway. This collaboration involves scientists and students at: University of Wisconsin-Madison, Georgia Tech, Cornell, University of Alberta, Simon Fraser University, University of Chile-Santiago, CONICET/University of San Juan-Argentina, Nanyang Technological University-Singapore, SERNAGEOMIN, OVDAS, USGS, and SEGEMAR-Argentina. Team members will be introduced in this presentation. Our approach includes augmenting the OVDAS array of 6 permanent seisic stations with 40 additional instruments to conduct tomographic, receiver function and ambient noise studies. We continue to collect 4-D gravity data from 37 stations. Surface deformation is monitored via cGPS at 5 permanent receivers and InSAR data. A magnetotelluric survey across the Andes at 36o S is planned. Geochemical studies include mineral zoning and U-Th disequilibrium of zircons to constrain the timing of magma intrusion and

Short Time Scale Evolution of Microbiolites in Rapidly Receding Altiplanic Lakes: Learning How to Recognize Changing Signatures of Life

NASA Technical Reports Server (NTRS)

Cabrol, N. A.; Grin, E. A.; Borics, G.; Kiss, A.; Fike, D.; Kovacs, G.; Hock, A.; Kiss, K.; Acs, E.; Sivila, R.

2004-01-01

As part of the exploration of high altitude lakes as analogs to Martian paleolakes environment, we are investigating a remarkably large and diverse field of lacustrine stromatolites located at 4,365m in the Bolivian Altiplano (22 deg 47 00 min S and 67 deg 47.00 min W).The field is composed of both early Holocene fossil structures located on paleoshorelines and present-day active cyanobacterial communities on the shore and at the bottom of the current Laguna Blanca and Verde. Its physical environment, broad diversity of morphologies, and their associated spatial heterogeneity, origin, and scale offer a unique opportunity to explore microbiolites in conditions reminiscent of early Earth and Mars. At this altitude and latitude, UV radiation levels are enhanced (40% higher than sea level) and harmful to microorganisms living in shallow waters which provide only minimal protection from UV. Similar conditions prevailed on early Earth when the ozone layer had yet to be formed in the atmosphere. Compared to those studied at sea levels, these stromatolites could yield new insights about the earliest terrestrial forms of life. Moreover, the combination of physical and geological environment of this site is exceptionally analogous to conditions believed to be prevalent on Mars at the end of the Noachian (3.5 Ga ago), allowing to test the potential for forming stromatolites in martian paleolakes and learn how to identify their fossil record remotely. Our overarching goal is to generate new astrobiological information on high-altitude stromatolites as clues to early biospheres with implications for Earth and Mars. Our two central objectives are: (1) characterize the biological, geological, and mineralogical features and significance of this field, and to identify geo-signatures such as morphology, geology, chronostratigraphy, mineralogy and biosignatures, and (2) to facilitate remote-sensing and ground robotic detection capabilities for future astrobiological missions to Mars.

Plagioclase-free Back-Arc Basalts from Caviahue, Argentina

NASA Astrophysics Data System (ADS)

Hesse, A.; Varekamp, J. C.

2006-12-01

Back-arc basalts and basaltic andesites occur in a N-S oriented graben east of the Copahue Caviahue volcanic complex, Province of Neuquen, Argentina. Lava flows and cinder cones are recent features of the modern topography and probably are of Pleistocene-Holocene age. Samples were collected along a 200 km stretch between Zapala and El Huecu. Lava and scoria samples from the Laguna Blanca and Zapala region have MgO contents up to 8.5 %, with Cr and Ni resp. at 250 and 180 ppm. These rocks carry olivine with small spinel inclusions, rare clinopyroxene, but lack plagioclase phenocrysts. Further north, andesitic samples occur with two pyroxenes and plagioclase. Major and trace element analyses show normal increases in incompatible elements with decreasing MgO for the more evolved group of samples. The more Mg-rich samples, however, show variable enrichments in K, Ba (up to 400 ppm) and other incompatible elements, but lack negative Nb anomalies. The plagioclase-free rocks lack negative Eu anomalies and have up to 750 ppm Sr. The whole rock suite (from 2.1-8.5 % MgO) has a Th/U ratio of ~4, Sm/Yb ~2.5 and La/Sm ~ 3.5. Sr and Nd isotope data of a cinder cone sample (5.5 % MgO, distinct negative Nb anomaly) are just outside the N-MORB field, resp. at 0.703295 and 0.512924 (Varekamp et al., GSA Spec Paper 407, 2006). We tentatively interpret these rocks as melts from a mantle with variable contributions of a heavily fractionated residue of subducted sediment and ocean floor, which have subsequently undergone some crystal fractionation. The suppression of plagioclase crystallization may result from water added to the back arc mantle region from the subducted complex, but the typical arc signatures such as negative Nb anomalies are lacking in these rocks.

Environmental Impact Analysis Process. Preliminary Draft Environmental Impact Statement Construction and Operation of Space Launch Complex 7. Volume 2. Appendices

DTIC Science & Technology

1988-11-15

3 Sincerely, William H. Ehorn3Suerintenent United States Department of the Interior FISH AND WILDLIFE SERVICE LAGUNA NIGUEL FIELD OFFICE 24000 Avila...Road Laguna Niguel, California 92656 Ma’ 19, 1988 Department of the Air Force Headquarters Space Division (AFSC) Los Angeles Air Force Station P. 0...agricultural supply, and ground water recharge. In addition, all minor streams and tributaries in the central coastal region, including Honda Creek and Jalama

Controls on the long term earthquake behavior of an intraplate fault revealed by U-Th and stable isotope analyses of syntectonic calcite veins

NASA Astrophysics Data System (ADS)

Williams, Randolph; Goodwin, Laurel; Sharp, Warren; Mozley, Peter

2017-04-01

U-Th dates on calcite precipitated in coseismic extension fractures in the Loma Blanca normal fault zone, Rio Grande rift, NM, USA, constrain earthquake recurrence intervals from 150-565 ka. This is the longest direct record of seismicity documented for a fault in any tectonic environment. Combined U-Th and stable isotope analyses of these calcite veins define 13 distinct earthquake events. These data show that for more than 400 ka the Loma Blanca fault produced earthquakes with a mean recurrence interval of 40 ± 7 ka. The coefficient of variation for these events is 0.40, indicating strongly periodic seismicity consistent with a time-dependent model of earthquake recurrence. Stochastic statistical analyses further validate the inference that earthquake behavior on the Loma Blanca was time-dependent. The time-dependent nature of these earthquakes suggests that the seismic cycle was fundamentally controlled by a stress renewal process. However, this periodic cycle was punctuated by an episode of clustered seismicity at 430 ka. Recurrence intervals within the earthquake cluster were as low as 5-11 ka. Breccia veins formed during this episode exhibit carbon isotope signatures consistent with having formed through pronounced degassing of a CO2 charged brine during post-failure, fault-localized fluid migration. The 40 ka periodicity of the long-term earthquake record of the Loma Blanca fault is similar in magnitude to recurrence intervals documented through paleoseismic studies of other normal faults in the Rio Grande rift and Basin and Range Province. We propose that it represents a background rate of failure in intraplate extension. The short-term, clustered seismicity that occurred on the fault records an interruption of the stress renewal process, likely by elevated fluid pressure in deeper structural levels of the fault, consistent with fault-valve behavior. The relationship between recurrence interval and inferred fluid degassing suggests that pore fluid pressure

Living and dying with glaciers: people's historical vulnerability to avalanches and outburst floods in Peru

NASA Astrophysics Data System (ADS)

Carey, Mark

2005-07-01

Human populations worldwide are vulnerable to natural disasters. Certain conditions—such as geographical location or people's income level—can affect the degree to which natural disasters impact people's homes and livelihoods. This paper suggests that vulnerability to natural disasters increases when local people, scientists, and policymakers do not communicate and trust each other. Additionally, a breakdown in interaction and confidence among these groups can disrupt the implementation of sound science or well-intentioned policies. This case study analyzes how local people, scientists, and government officials responded to glacier hazards in Peru's Cordillera Blanca mountain range. Cordillera Blanca glacier retreat since the late-19th century has triggered some of the world's most deadly avalanches and glacial lake outburst floods. Although a Peruvian glaciology and lakes security office has "controlled" 35 Cordillera Blanca glacial lakes, 30 glacier disasters have killed nearly 30,000 people in this region since 1941. A lack of local faith in government officials and scientists as well as the State's failure to follow scientists' warnings about potential disasters have endangered or led to the death of thousands of local residents, many of which remain living in hazard zones today.

Geochemistry of thermal fluids in NW Honduras: New perspectives for exploitation of geothermal areas in the southern Sula graben

NASA Astrophysics Data System (ADS)

Capaccioni, Bruno; Franco, Tassi; Alberto, Renzulli; Orlando, Vaselli; Marco, Menichetti; Salvatore, Inguaggiato

2014-06-01

The results of a geochemical survey on thermal waters and, for the first time for this site, gas discharges in five geothermal sites (Azacualpa "La Cueva", Río Ulua, Río Gualcarque, El Olivar and Laguna de Agua Caliente) in NW Honduras are here presented and discussed. El Olivar and Laguna de Agua Caliente, in the southern part of the Sula graben are very close to a Quaternary basaltic field, whereas Azacualpa "La Cueva", Río Ulua and Río Gualcarque, located to the southwest of the Yojoa Lake, direcly emerge from the Cretaceous limestone deposits. The measured temperatures range between 37.5 and 104.8 °C. "Mature", alkaline, Na-SO4 thermal waters discharge from Azacualpa "La Cueva", while those from El Olivar and Laguna de Agua Caliente are "immature" and show a Na-HCO3 composition. Chemical equilibria of waters and gases from the Azacualpa "La Cueva" thermal springs indicate temperatures ranging from 150 to 200 °C. Conversely, gas discharges from El Olivar and Laguna de Agua Caliente have attained a partial chemical equilibrium in the liquid phase at slightly higher temperatures (200-250 °C), although gas-gas faster reactions involving CO seem to be adjusted in an isothermally separated vapor phase. Unlike Azacualpa, SiO2 geothermometer at El Olivar and Laguna de Agua Caliente indicates equilibrium temperatures for the liquid phase much lower than those calculated for the gas phase (≤ 120 °C). We conclude that thermal waters from the Azacualpa area likely represent the direct emergence of a water dominated reservoir having temperatures ≤ 150-200 °C. By contrast, at El Olivar and Laguna de Agua Caliente hot springs are supplied by a boiling shallow aquifer fed by a vapor phase rising from a steam-dominated zone. The above geochemical model is consistent with a geothermal reservoir hosted within the Cretaceous carbonate sequences of the Yojoa Group in the whole investigated sites. The reservoir extensively crops out in the Azacualpa area whereas the

Wirelessly controlled micro- and nanostructures for bioapplications

NASA Astrophysics Data System (ADS)

Lindo, Andre Machado

Apresentar uma contribuicao para a caracterizacao e compreensao do comportamento hidrodinâmico da laguna Ria de Aveiro, baseada num estudo experimental e num estudo de modelacao numerica, e o objectivo deste trabalho. As caracteristicas hidrologicas da Ria de Aveiro foram investigadas atraves da realizacao de varias campanhas de amostragem, tendo sido efectuadas medicoes de altura de agua, salinidade, temperatura da agua e velocidade da corrente em varias estacoes distribuidas ao longo de quatro canais principais da laguna. None

Hydrologic characteristics of lagoons at San Juan, Puerto Rico, during an October 1974 tidal cycle

USGS Publications Warehouse

Gómez-Gómez, Fernando; Ellis, S.R.

1983-01-01

Flow and water-quality changes were studied during a period of intense rainfall in the San Juan Lagoon system. The study covered a 25-hour period beginning 0900 hours 22 October, 1974. Precipitation during the study period averaged 70 millimeters. Sampling stations were located at Boca de Cangrejos, the main ocean outlet; Canal Pinones between Laguna de Pinones and Laguna La Torrecilla; Canal Suarez between Laguna San Jose, connects to Laguna La Torrecilla; and Cano de Martin Pena between Laguna San Jose and Bahia de San Juan. In addition water-elevation recording gages were installed at each lagoon. Water samples from the canal stations were analyzed for organic carbon, nitrogen and phosphorus species, and suspended sediment. Specific-conductance measurements were used with the chemical data to estimate the runoff contributions of nutrients. Runoff into the lagoon, system during the study period was about 2.8 million cubic meters, or about 70 percent of the average precipitation. The runoff contributed chemical loadings to the lagoons of 95,000 kilograms total-organic carbon; 2,700 kilograms of total phosphorus; and 10,000 kilograms of total Khjeldhal nitrogen. A comparison with a prior study during which there was no significant rain, show that dry-period loadings are less than 10 percent of the wet-period loadings. At the end of the study period the system had not reached equilibrium, and the lagoons retained 80 percent of the water inflows from 50 to 90 percent of the chemical loads. Nearly 95 percent of the water outflows occurred at the Boca de Cangrejos sea outlet. The three lagoons and interconnecting canals form a very complex hydraulic system that is difficult to study using traditional techniques. A model of the system will facilitate management to improve the quality of water in the lagoons.

Just add water and the Colorado River still reaches the sea.

PubMed

Glenn, Edward P; Flessa, Karl W; Cohen, Michael J; Nagler, Pamela L; Rowell, Kirsten; Zamora-Arroyo, Francisco

2007-07-01

A recent article in Environmental Management by All argued that flood flows in North America's Colorado River do not reach the Gulf of California because they are captured and evaporated in Laguna Salada, a below sea-level lakebed near the mouth of the river. We refute this hypothesis by showing that (1) due to its limited area, the Laguna Salada could have evaporated less than 10% of the flood flows that have occurred since 1989; (2) low flow volumes preferentially flow to the Gulf rather than Laguna Salada; (3) All's method for detecting water surface area in the Laguna Salada appears to be flawed because Landsat Thematic Mapper images of the lakebed show it to be dry when All's analyses said it was flooded; (4) direct measurements of salinity at the mouth of the river and in the Upper Gulf of California during flood flows in 1993 and 1998 confirm that flood waters reach the sea; and (5) stable oxygen isotope signatures in clam shells and fish otoliths recorded the dilution of seawater with fresh water during the 1993 and 1998 flows. Furthermore, All's conclusion that freshwater flows do not benefit the ecology of the marine zone is incorrect because the peer-reviewed literature shows that postlarval larval shrimp populations increase during floods, and the subsequent year's shrimp harvest increases. Furthermore, freshwater flows increase the nursery area for Gulf corvina (Cynoscion othonopterus), an important commercial fish that requires estuarine habitats with salinities in the range of 26-38 per thousand during its natal stages. Although flood flows are now much diminished compared to the pre-dam era, they are still important to the remnant wetland and riparian habitats of the Colorado River delta and to organisms in the intertidal and marine zone. Only a small fraction of the flood flows are evaporated in Laguna Salada.

Integrated satellite InSAR and slope stability modeling to support hazard assessment at the Safuna Alta glacial lake, Peru

NASA Astrophysics Data System (ADS)

Cochachin, Alejo; Frey, Holger; Huggel, Christian; Strozzi, Tazio; Büechi, Emanuel; Cui, Fanpeng; Flores, Andrés; Saito, Carlos

2017-04-01

The Safuna glacial lakes (77˚ 37' W, 08˚ 50' S) are located in the headwater of the Tayapampa catchment, in the northernmost part of the Cordillera Blanca, Peru. The upper lake, Laguna Safuna Alta at 4354 m asl has formed in the 1960s behind a terminal moraine of the retreating Pucajirca Glacier, named after the peak south of the lakes. Safuna Alta currently has a volume of 15 x 106 m3. In 2002 a rock fall of several million m3 from the proximal left lateral moraine hit the Safuna Alta lake and triggered an impact wave which overtopped the moraine dam and passed into the lower lake, Laguna Safuna Baja, which absorbed most of the outburst flood from the upper lake, but nevertheless causing loss in cattle, degradation of agricultural land downstream and damages to a hydroelectric power station in Quitaracsa gorge. Event reconstructions showed that the impact wave in the Safuna Alta lake had a runup height of 100 m or more, and weakened the moraine dam of Safuna Alta. This fact, in combination with the large lake volumes and the continued possibility for landslides from the left proximal moraine pose a considerable risk for the downstream settlements as well as the recently completed Quitaracsa hydroelectric power plant. In the framework of a project funded by the European Space Agency (ESA), the hazard situation at the Safuna Alta lake is assessed by a combination of satellite radar data analysis, field investigations, and slope stability modeling. Interferometric analyses of the Synthetic Aperture Radar (InSAR) of ALOS-1 Palsar-1, ALOS-2 Palsar-2 and Sentinel-1 data from 2016 reveal terrain displacements of 2 cm y-1 in the detachment zone of the 2002 rock avalanche. More detailed insights into the characteristics of these terrain deformations are gained by repeat surveys with differential GPS (DGPS) and tachymetric measurements. A drone flight provides the information for the generation of a high-resolution digital elevation model (DEM), which is used for the

The Nd-, Sr- and Pb-isotopic character of lavas from Taal, Laguna de Bay and Arayat volcanoes, southwestern Luzon, Philippines: Implications for arc magma petrogenesis

USGS Publications Warehouse

Mukasa, S.B.; Flower, M.F.J.; Miklius, Asta

1994-01-01

Following the amalgamation of a collage of pre-Neogene terranes largely by strike-slip and convergence mechanisms to form the Philippine islands, volcanic chains, related to oppositely dipping subduction zones, developed along the eastern and western margins of the archipelago. There is ample field evidence that this volcanic activity, predominantly calc-alkaline in chemical character, had commenced by the Oligocene. Volcanoes resulting from subduction along the Manila-Negros trench in the west (e.g. Taal, Laguna de Bay and Arayat) form a high-angle linear array, trending away from the MORE field on Pb-isotopic covariation diagrams; have the highest Sr- and lowest Nd-isotopic compositions, of the two chains (but nevertheless plotting above bulk earth on the 87Sr/86Sr versus 143Nd/144Nd covariation diagram); and exhibit Sm/Nd and Rb/Sr values that are lower and higher, respectively, than the estimated values for bulk earth. While the Sm/Nd and Rb/Sr characteristics are common to both chains, volcanoes associated with the Philippine-East Luzon trench have Pb-isotopic compositions that fall in the Indian Ocean MORB field and that require time-integrated evolution in a high Th/U environment. They also have higher Nd- and lower Sr-isotopic ratios. The source materials of Philippine volcanoes, therefore, have undergone varied recent enrichments in LILE, as indicated by the decoupling of isotopic and elemental ratios. These enrichments, particularly for the western volcanoes, cannot be entirely due to small degrees of partial melting in the mantle wedge, considering that they were accompanied by elevations in radiogenic Pb. Elevated Pb ratios are best explained by the introduction of subducted, continentally derived sediments. The sedimentary component in the western volcanoes is probably the South China Sea sediments derived largely from Eurasia. That this component is not available in the Philippine-East Luzon trench is reflected by the fact that the eastern volcanoes

The Cordon del Portillo Permian magmatism, Mendoza, Argentina, plutonic and volcanic sequences at the western margin of Gondwana

NASA Astrophysics Data System (ADS)

Gregori, Daniel; Benedini, Leonardo

2013-03-01

The Cerro Punta Blanca, Cerro Bayo and Cerro Punta Negra stocks, parts of the Cordillera Frontal Composite Batholith, cropping out in the Cordón del Portillo, records the Gondwana magmatic development of the Cordillera Frontal of Mendoza, in western Argentina. In this area, the San Rafael Orogenic phase, that represents the closure of the Late Carboniferous-Early Permian marine basins, begins at 284 Ma, and ceased before 276 Ma. The Cerro Punta Blanca, Cerro Bayo and Cerro Punta Negra stocks represent a post-orogenic magmatism and are equivalents to the Choiyoi Group. The Gondwana magmatic activity in the Cordón del Portillo area can be divided into two stages. The Cerro Punta Blanca stock (c.a. 276 Ma) represents an early post-orogenic, subduction-related magmatism similar to the basic-intermediate section of the Choiyoi Group (c.a. 277 Ma). The late post-orogenic second event was recorded by the Cerro Bayo (262 Ma) and Cerro Punta Negra stocks which represent a transition between subduction-related and intra-plate magmatism. This event represents the intrusive counterpart of the acidic facies of the upper section of the Choiyoi Group (c.a. 273 Ma). This extensional condition continued during the Triassic when the Cacheuta basin developed.

Glaucoma diagnostic capacity of optic nerve head haemoglobin measures compared with spectral domain OCT and HRT III confocal tomography.

PubMed

Mendez-Hernandez, Carmen; Rodriguez-Uña, Ignacio; Gonzalez-de-la Rosa, Manuel; Arribas-Pardo, Paula; Garcia-Feijoo, Julian

2016-11-01

The computer program laguna onhe determines optic nerve head haemoglobin (ONH Hb) on retinal photographs based on detecting colour differences. This study compares the diagnostic capacity of Laguna ONhE with that of spectral domain optical coherence tomography (OCT) and confocal tomography (HRT III). In a prospective, observational, cross-sectional study, glaucomatous (n = 66) and healthy (n = 52) eyes were examined by Spectralis OCT, HRT III and Laguna ONhE. The following Laguna ONhE variables were determined: ONH Hb across the vertical disc diameter (8&20 Hb), estimated cup-disc ratio (C/D) and the glaucoma discriminant function (GDF), which combines the slope of Hb amount with the mean in 8&20 Hb. The three diagnostic methods were compared by calculating areas under ROC curves (AUCs). Correlations between variables were assessed through Spearman's rho coefficient. Areas under ROC curves (AUCs) were 0.785 (95% CI: 0.700-0.863) for GDF, 0.807 (95% CI: 0.730-0.883) for OCT retinal nerve fibre layer thickness (OCT-RNFL) and 0.714 (95% CI: 0.618-0.810) and 0.721 (95% CI: 0.628-0.815) for the HRT III variable GPS (glaucoma probability score) and vertical C/D ratio, respectively. Glaucoma discriminant function (GDF) was correlated with OCT-RNFL (0.587, p 0.001; 0.507, p 0.045; and -0.119, p 0.713 for mild, moderate and advanced glaucoma, respectively), mostly so with inferior OCT-RNFL (0.622; p < 0.001). Glaucoma discriminant function (GDF)-HRT III correlations were lower (rim area 0.471, p < 0.0001; rim/disc area 0.426, p < 0.0001; vertical C/D -0.413, p < 0.0001; GPS -0.408, p < 0.0001; rim volume 0.341, p < 0.0001). Similar diagnostic power was observed for Laguna ONhE, Spectralis OCT and HRT III. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Argentina

NASA Image and Video Library

2017-12-08

Acquisition Date: February 28, 1985 The Sierra de Velasco Mountains dominate this image in northern Argentina. The Catamarca province is in the northern part of the image, and the La Rioja province is to the south. The streams are fed by runoff from the snow in the Andes Mountains to the north. These intermittent streams can dry up rapidly. The larger urban area near the bottom of the image is La Rioja, the capital of the province of La Rioja. Credit: NASA/GSFC/Landsat/USGS To learn more about Landsat and to see the orginal high res file go to: landsat.usgs.gov/gallery_view.php?category=greenflag&...

Satellite-derived NDVI, LST, and climatic factors driving the distribution and abundance of Anopheles mosquitoes in a former malarious area in northwest Argentina.

PubMed

Dantur Juri, María Julia; Estallo, Elizabet; Almirón, Walter; Santana, Mirta; Sartor, Paolo; Lamfri, Mario; Zaidenberg, Mario

2015-06-01

Distribution and abundance of disease vectors are directly related to climatic conditions and environmental changes. Remote sensing data have been used for monitoring environmental conditions influencing spatial patterns of vector-borne diseases. The aim of this study was to analyze the effect of the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS), and climatic factors (temperature, humidity, wind velocity, and accumulated rainfall) on the distribution and abundance of Anopheles species in northwestern Argentina using Poisson regression analyses. Samples were collected from December, 2001 to December, 2005 at three localities, Aguas Blancas, El Oculto and San Ramón de la Nueva Orán. We collected 11,206 adult Anopheles species, with the major abundance observed at El Oculto (59.11%), followed by Aguas Blancas (22.10%) and San Ramón de la Nueva Orán (18.79%). Anopheles pseudopunctipennis was the most abundant species at El Oculto, Anopheles argyritarsis predominated in Aguas Blancas, and Anopheles strodei in San Ramón de la Nueva Orán. Samples were collected throughout the sampling period, with the highest peaks during the spring seasons. LST and mean temperature appear to be the most important variables determining the distribution patterns and major abundance of An. pseudopunctipennis and An. argyritarsis within malarious areas. © 2015 The Society for Vector Ecology.

Seasonal variation in chaetognath and parasite species assemblages along the northeastern coast of the Yucatan Peninsula.

PubMed

Lozano-Cobo, Horacio; Prado-Rosas, María Del Carmen Gómez Del; Sánchez-Velasco, Laura; Gómez-Gutiérrez, Jaime

2017-03-30

Chaetognaths are abundant carnivores with broad distributions that are intermediate hosts of trophically transmitted parasites. Monthly variations in chaetognath and parasite species distributions, abundance, prevalence, and intensity related to seasonal environmental changes were recorded in 2004 and 2005 in Laguna Nichupté, a coral reef, and the adjoining continental shelf of Quintana Roo, Mexico. Of 12 chaetognath species plus Sagitta spp., only 5 (Ferosagitta hispida, Flaccisagitta enflata, Sagitta spp., Serratosagitta serratodentata, and Pterosagitta draco) were parasitized. These species were parasitized with 33 types of flatworms and unidentified cysts (likely protozoan ciliates), having an overall mean prevalence of 6%. Digenean metacercaria larvae numerically dominated the parasite assemblages. Cluster analysis defined 2 chaetognath species assemblages. One included 7 species inside Laguna Nichupté, where F. hispida was numerically dominant (98.9%); the other contained 13 chaetognath species in the continental shelf-coral reef region, where F. enflata was abundant (53%). Canonical correspondence analysis showed that Laguna Nichupté had highly variable and hostile conditions (relatively low salinity and high temperature) for chaetognath species except for F. hispida. The higher density of F. hispida promoted greater parasite diversity (23 types), dominated by Brachyphallus sp. metacercariae. F. enflata prevailed in the continental shelf-coral reef area, which had stable high salinity and relatively low temperature. Monilicaecum and unidentified digenean 'type g' infected 5 chaetognath species on the continental shelf. Distinct primary hosts (mollusks and copepods) and contrasting environmental conditions (salinity, dissolved oxygen concentration, and temperature) between Laguna Nichupté and the continental shelf promoted distinct chaetognath species assemblages, resulting in distinct parasite diversity and prevalence patterns.

Earth Observations taken by Expedition 30 crewmember

NASA Image and Video Library

2011-11-22

ISS030-E-005118 (22 Nov. 2011) --- A dust plume over the Bahia Blanca, Argentina is featured in this image photographed by an Expedition 30 crew member on the International Space Station. This panoramic view of eastern Argentina and the Atlantic coastline is centered near Bahia Blanca, which is also highlighted by sun glint. The oblique view looks generally westward (and downwards) from the orbital position of the space station towards a large plume of dust blowing southeastward from the interior and over the open Atlantic Ocean. The only significant cloud cover was located offshore (upper left). Northwestern and central Argentina are subject to frequent dust storms where a combination of extensive late Pleistocene loess?fine sediments deposited by wind and typically associated with former continental glaciers?and strong, dry westerly winds descending from the Andes, known locally as the pampero sucio, combine to produce sudden and extensive clouds of the fine soil. The particular dust event illustrated by the image covers much of the province of Rio Negro and the southern parts of the provinces of La Pampa and Buenos Aires as well as the coastal waters between the Gulf of San Matias (upper left) and Bahia Blanca (center), located approximately 330 kilometers to the northeast. The area illustrated by the image includes the agriculturally productive southern Pampas plain region where it transitions to the drier, less productive low hills and valleys of northern Patagonia. A docked Russian Progress spacecraft is visible at upper right.

A study of microseismicity in northern Baja California, Mexico

NASA Technical Reports Server (NTRS)

Johnson, T. L.; Koczynski, T.; Madrid, J.

1976-01-01

Five microearthquake instruments were operated for 2 months in 1974 in a small mobile array deployed at various sites near the Agua Blanca and San Miguel faults. An 80-km-long section of the San Miguel fault zone is presently active seismically, producing the vast majority of recorded earthquakes. Very low activity was recorded on the Agua Blanca fault. Events were also located near normal faults forming the eastern edge of the Sierra Juarez suggesting that these faults are active. Hypocenters on the San Miguel fault range in depth from 0 to 20 km although two-thirds are in the upper 10 km. A composite focal mechanism showing a mixture of right-lateral and dip slip, east side up, is similar to a solution obtained for the 1956 San Miguel earthquake which proved consistent with observed surface deformation.

Historical bac-barrier shoreline changes, Padre Island National Seashore, Texas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prouty, J.S.

1989-09-01

Historical progradation rates of the Laguna Madre shoreline at Padre Island National Seashore have varied considerably, largely in response to rainfall fluctuations and perhaps grazing pressure. Analysis of aerial photographs indicates that near the northern margin of the National Seashore the shoreline prograded at an average rate of 26 ft/year between 1941 and 1950. The average rate of progradation increased to 42 ft/year between 1950 and 1964. Average rates then slowed in the late 1960s, and since 1969 the shoreline has prograded at an average rate of only 1 ft/year. Some areas of the shoreline are presently eroding. Early mapsmore » and accounts suggest that a century ago North Padre Island was largely vegetated. Overgrazing and a series of droughts in the late 19th and early 20th centuries denuded the island, and prevailing winds blew sand westward across the island into Laguna Madre. With higher than average rainfall in the past 2 decades and less grazing, the island has significantly revegetated. Winds now carry less sand to Laguna Madre; reduced sand supply is a major cause of present-day shoreline retreat.« less

Rapid uplift in Laguna del Maule volcanic field of the Andean Southern Volcanic Zone (Chile) measured by satellite radar interferometry

NASA Astrophysics Data System (ADS)

Feigl, K.; Ali, T.; Singer, B. S.; Pesicek, J. D.; Thurber, C. H.; Jicha, B. R.; Lara, L. E.; Hildreth, E. W.; Fierstein, J.; Williams-Jones, G.; Unsworth, M. J.; Keranen, K. M.

2011-12-01

The Laguna del Maule (LdM) volcanic field of the Andean Southern Volcanic Zone extends over 500 square kilometers and comprises more than 130 individual vents. As described by Hildreth et al. (2010), the history has been defined from sixty-eight Ar/Ar and K-Ar dates. Silicic eruptions have occurred throughout the past 3.7 Ma, including welded ignimbrite associated with caldera formation at 950 ka, small rhyolitic eruptions between 336 and 38 ka, and a culminating ring of 36 post-glacial rhyodacite and rhyolite coulees and domes that encircle the lake. Dating of five post-glacial flows implies that these silicic eruptions occurred within the last 25 kyr. Field relations indicate that initial eruptions comprised modest volumes of mafic rhyodacite magma that were followed by larger volumes of high silica rhyolite. The post-glacial flare-up of silicic magmatism from vents distributed around the lake, is unprecedented in the history of this volcanic field. Using satellite radar interferometry (InSAR), Fournier et al. (2010) measured uplift at a rate of more than 180 mm/year between 2007 and 2008 in a round pattern centered on the west side of LdM. More recent InSAR observations suggest that rapid uplift has continued from 2008 through early 2011. In contrast, Fournier et al. found no measurable deformation in an interferogram spanning 2003 through 2004. In this study, we model the deformation field using the General Inversion of Phase Technique (GIPhT), as described by Feigl and Thurber (2009). Two different models fit the data. The first model assumes a sill at ~5 km depth has been inflating at a rate of more than 20 million cubic meters per year since 2007. The second model assumes that the water level in the lake dropped at a rate of 20 m/yr from January 2007 through February 2010, thus reducing the load on an elastic simulation of the crust. The rate of intrusion inferred from InSAR is an order of magnitude higher than the average rate derived from well-dated arc

Surveillance for White-Nose Syndrome in the bat community at El Malpais National Monument, New Mexico, 2011

USGS Publications Warehouse

Valdez, Ernest W.

2012-01-01

From late winter to summer 2011, the U.S. Geological Survey Arid Lands Field Station conducted mist-netting efforts at El Malpais National Monument and on adjacent lands belonging to Bureau of Land Management and U.S. Forest Service to detect the occurrence of white-nose syndrome or causal fungal agent (Geomyces destructans). During this assessment, 421 bats belonging to 8 species were documented at El Malpais National Monument and adjacent lands. None of these captures showed evidence for the presence of white-nose syndrome or G. destructans, but it is possible that the subtle signs of some infections may not have been observed. Throughout the field efforts, Laguna de Juan Garcia was the only water source located on El Malpais National Monument and was netted on June 20 and 27, July 25, and August 2, 2011. During these dates, a total of 155 bats were captured, belonging to eight species including: Corynorhinus townsendii (Townsend's Big-Eared Bat), Eptesicus fuscus (Big Brown Bat), Lasionycterics noctivagans (Silver-Haired Bat), Myotis ciliolabrum (Small-Footed Myotis), M. evotis (Long-eared myotis), M. thysanodes (Fringed Myotis), M. volans (Long-Legged Myotis), and Tadarida brasiliensis (Brazilian Free-Tailed Bat). Overall, Laguna de Juan Garcia had the greatest number of captures (79 bats) during one night compared to the other sites netted on adjacent lands and had the greatest species diversity of 8 species netted, not including Euderma maculatum (Spotted Bat) that was detected by its audible calls as it flew overhead. Laguna de Juan Garcia is an important site to bats because of its accessibility by all known occurring species, including the less-maneuverable T. brasiliensis that is known to form large colonies in the park. Laguna de Juan Garcia is also important as a more permanent water source during drought conditions in the earlier part of the spring and summer, as observed in 2011.

Diurnal time-activity budgets of redheads (Aythya americana) wintering in seagrass beds and coastal ponds in Louisiana and Texas

USGS Publications Warehouse

Michot, T.C.; Woodin, M.C.; Adair, S.E.; Moser, E.B.

2006-01-01

Diurnal time-activity budgets were determined for wintering redheads (Aythya americana) from estuarine seagrass beds in Louisiana (Chandeleur Sound) and Texas (Laguna Madre) and from ponds adjacent to the Laguna Madre. Activities differed (p<0.0001) by location, month, and diurnal time period. Resting and feeding were the most frequent activities of redheads at the two estuarine sites, whereas drinking was almost nonexistent. Birds on ponds in Texas engaged most frequently in resting and drinking, but feeding was very infrequent. Redheads from the Louisiana estuarine site rested less than birds in Texas at either the Laguna Madre or freshwater ponds. Redheads in Louisiana fed more than birds in Texas; this was partially because of weather differences (colder temperatures in Louisiana), but the location effect was still significant even when we adjusted the model for weather effects. Redheads in Louisiana showed increased resting and decreased feeding as winter progressed, but redheads in Texas did not exhibit a seasonal pattern in either resting or feeding. In Louisiana, birds maintained a high level of feeding activity during the early morning throughout the winter, whereas afternoon feeding tapered off in mid- to late-winter. Texas birds showed a shift from morning feeding in early winter to afternoon feeding in late winter. Males and females at both Chandeleur Sound and Laguna Madre showed differences in their activities, but because the absolute difference seldom exceeded 2%, biological significance is questionable. Diurnal time-activity budgets of redheads on the wintering grounds are influenced by water salinities and the use of dietary fresh water, as well as by weather conditions, tides, and perhaps vegetation differences between sites. The opportunity to osmoregulate via dietary freshwater, vs. via nasal salt glands, may have a significant effect on behavioral allocations. ?? Springer 2006.

Herbivory on shoalgrass by wintering redheads in Texas

USGS Publications Warehouse

Mitchell, C.A.; Custer, T.W.; Zwank, P.J.

1994-01-01

An estimated 80% of redheads (Aythya americana) winter on the Laguna Madre of south Texas and Mexico and feed almost exclusively on shoalgrass (Halodule wrightii) rhizomes. Shoalgrass abundance has decreased by 60% over the past 30 years, and because the effects of shoalgrass loss on wintering redheads are unknown, we initiated a study to define habitat selection criteria and document the effect of wintering redheads on shoalgrass in the lower Laguna Madre, Texas. Redheads consumed an average of 75% of shoalgrass rhizome biomass at collection sites each winter. When rhizome biomass was grazed to a mean biomass of ltoreq 0.18 g dry mass/core (approximately 10 g dry mass/ml), shoalgrass did not recover to its previous level the following growing season. Thirty-three percent of the sites (10) were grazed below 0.18 g dry mass/core during both years of the study, while 64% (19) were grazed below 0.18 g during 1 or the other of the 2 winters. Ramet number was positively correlated (P lt 0.001, r-2 = 0.54) with rhizome biomass; however, this relationship was influenced by grazing intensity. Heavy grazing reduced the amount of rhizome attached to each ramet compared with ungrazed ramets. Grazing had no effect on root biomass (P = 0.388), rhizome moisture content (P = 0.553), or soil magnesium, phosphorous, and potassium (P = 0.102, 0.499, 0.162, respectively). Redhead presence increased (P = 0.042) soil nitrogen levels. Foraging areas selected by redheads within the lower Laguna Madre had lower (P = 0.026) salinities (24 ppt) than areas not selected (35 ppt). Redheads did not select foraging areas in relation to crude protein levels in rhizomes. Shoalgrass habitat in the Laguna Madre should be protected from further losses and enhanced where possible.

Phytochemical Composition, Anti-inflammatory, and Antiproliferative Activity of Whole Wheat Flour

USDA-ARS?s Scientific Manuscript database

Five wheat cultivars (Macon, Louise, WestBred 936, Alpowa, and Blanca Grande) were evaluated for phenolics composition, carotenoid, and tocopherol composition, anti-inflammatory activity, and antiproliferative activity against HT-29 cells. Total ferulic acid ranged from 451.7-731.3 µg/g , with the ...

Recent temperature trends in the South Central Andes reconstructed from sedimentary chrysophyte stomatocysts in Laguna Escondida (1742 m a.s.l., 38°28 S, Chile)

NASA Astrophysics Data System (ADS)

De Jong, R.; Schneider, T.; Hernández-Almeida, I.; Grosjean, M.

2016-02-01

In this study we present a quantitative, high resolution reconstruction of past austral winter length in the Chilean Andes at 38°S from AD 1920 to 2009. For Laguna Escondida, a nearly pristine lake situated on the flanks of the Andes at 1740 m above sea level, past variability in the duration of the winter season (Days T4 °C) was reconstructed. Because high elevation meteorological stations are absent in this region, the reconstruction provides novel insights into recent temperature trends in the central-southern Andes. As a cold-season temperature proxy, we used chrysophyte stomatocysts. This novel proxy for cold season temperature was so far applied successfully in the European Alps and Pyrenees but has not yet been tested in the Southern Hemisphere. The reconstruction in this study was based on a newly developed Transfer Function to estimate Days T4 °C (number of consecutive days with surface water temperatures at or below 4 °C) from sedimentary stomatocyst assemblages (R2boot = 0.8, RMSEPboot = 28.7 days (= half the standard deviation)). To develop a high quality TF model, sediment traps and thermistors were placed in thirty remote lakes along an altitude gradient (420-2040 m a.s.l.). Complete materials and data were collected in 24 lakes after one year. Detailed statistical analyses indicate that modern stomatocysts primarily respond to the length of the cold season. The TF model was then applied to the sedimentary stomatocysts from a 210Pb-dated short core of L. Escondida. Comparison to independent reanalysis data showed that reconstructed changes in Days T4°C provides detailed information on winter-spring temperature variability since AD 1920. The reconstruction shows that recent warming (onset in AD 1980) in the southern Chilean Andes was not exceptional in the context of the past century. This is in strong contrast to studies from the Northern Hemisphere. The finding is also in contrast to the cooling temperature trends which were detected using

76 FR 67792 - Additional Designations, Foreign Narcotics Kingpin Designation Act

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-02

..., Baja California, Mexico; DOB 14 Nov 1968; Alt. DOB 14 Nov 1966; POB Culiacan, Sinaloa, Mexico; Citizen... Costa Bella, Ensenada, Baja California, Mexico; (ENTITY) [SDNTK] 2. AUTODROMO CULIACAN RACE PARK, Blvd. Universitarios No. 196 Ote., Piso 4, Colonia Tierra Blanca, Culiacan, Sinaloa, Mexico; Carretera Libre, Culiacan...

Seismic Discrimination of Earthquakes and Explosions, with Application to the Southwestern United States

DTIC Science & Technology

1979-03-22

multi-station discriminants than by those based on network averages. In spite of this situ - ation, average a posteriori probabilities were sometimes...Technology, Pasadena, California. Allen, C. R., L. T. Silver, and F. G. Stehi (1960). Agua Blanca fault - a major transverse structure of northern Baja

78 FR 69705 - Notice of Availability of the Draft Resource Management Plan Amendment and Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-20

... Resource Area, CO AGENCY: Bureau of Land Management, Interior. ACTION: Notice of availability. SUMMARY: In... any of the following methods: Email: BLM_CO[email protected] . Fax: 719-655-2502. Mail: BLM--Blanca Wetlands RMPA/EA, 46525 State Highway 114, Saguache, CO 81149. Copies of the draft RMPA and...

Sulfate Deposition in Regolith Exposed in Trenches on the Plains Between the Spirit Landing Site and Columbia Hills in Gusev Crater, Mars

NASA Technical Reports Server (NTRS)

Wang, Alian; Haskin, L. A.; Squyres, S. W.; Arvidson, R.; Crumpler, L.; Gellert, R.; Hurowitz, J.; Schroeder, C.; Tosca, N.; Herkenhoff, K.

2005-01-01

During its exploration within Gusev crater between sol 01 and sol 158, the Spirit rover dug three trenches (Fig. 1) to expose the subsurface regolith [1, 2, 9]. Laguna trench (approx. 6 cm deep, approx.203 m from the rim of Bonneville crater) was dug in Laguna Hollow at the boundary of the impact ejecta from Bonneville crater and the surrounding plains. The Big Hole trench (approx. 6-7 cm deep) and The Boroughs trench (approx. 11 cm deep) were dug in the plains between the Bonneville crater and the Columbia Hills (approx.556 m and approx.1698 m from the rim of Bonneville crater respectively). The top, wall and floor regolith of the three trenches were investigated using the entire set of Athena scientific instruments [10].

Wiggling Its Way to Discovery

NASA Technical Reports Server (NTRS)

2004-01-01

This image shows the Mars Exploration Rover Spirit's view from its new location inside the shallow depression dubbed 'Laguna Hollow.' To get a better look at the soil making up the hollow, Spirit drove forward a bit, wiggled its wheels, then turned and backed up. The result - a scrape on the floor and a clod of dirt stuck on one of Spirit's wheels - told scientists that the soil is sticky and reminiscent of that observed at the airbag drag mark nicknamed 'Magic Carpet.' Spirit will further investigate this disturbed patch of soil with its robotic arm beginning today (Feb. 19, 2004). It will also dig a trench at 'Laguna Hollow' with one of its wheels. This fish-eye image was taken by the rover's hazard-avoidance camera.

The Nopal 1 Uranium Deposit: an Overview

NASA Astrophysics Data System (ADS)

Calas, G.; Allard, T.; Galoisy, L.

2007-05-01

The Nopal 1 natural analogue is located in the Pena Blanca uranium district, about 50 kms north of Chihuahua City, Mexico. The deposit is hosted in tertiary ignimbritic ash-flow tuffs, dated at 44 Ma (Nopal and Colorados formations), and overlying the Pozos conglomerate formation and a sequence of Cretaceous carbonate rocks. The deposit is exposed at the ground surface and consists of a near vertical zone extending over about 100 m with a diameter of 40 m. An interesting characteristic is that the primary mineralization has been exposed above the water table, as a result of the uplift of the Sierra Pena Blanca, and subsequently oxidized with a remobilization of hexavalent uranium. The primary mineralization has been explained by various genetic models. It is associated to an extensive hydrothermal alteration of the volcanic tuffs, locally associated to pyrite and preserved by an intense silicification. Several kaolinite parageneses occur in fissure fillings and feldspar pseudomorphs, within the mineralized breccia pipe and the barren surrounding rhyolitic tuffs. Smectites are mainly developed in the underlying weakly welded tuffs. Several radiation-induced defect centers have been found in these kaolinites providing a unique picture of the dynamics of uranium mobilization (see Allard et al., this session). Another evidence of this mobilization is given by the spectroscopy of uranium-bearing opals, which show characteristic fluorescence spectra of uranyl groups sorbed at the surface of silica. By comparison with the other uranium deposits of the Sierra Pena Blanca and the nearby Sierra de Gomez, the Nopal 1 deposit is original, as it is one of the few deposits hving retained a reduced uranium mineralization.

Wind erosion risk in the southwest of Buenos Aires Province, Argentina, and its relationship to the productivity index

NASA Astrophysics Data System (ADS)

Silenzi, Juan C.; Echeverría, Nora E.; Vallejos, Adrián G.; Bouza, Mariana E.; De Lucia, Martín P.

2012-01-01

Wind erosion risk (WER) for soils of each municipality in the southwest (SW) of Buenos Aires Province (10,491,172 ha) was determined using the wind erosion equation (WEQ) model. WER results from multiplying the soil erodibility index (" I") of the soil by the climatic factor ( C). WER (Mg ha -1 year -1) of each municipality was: Bahía Blanca: 22.4, Coronel Dorrego: 18.6, Coronel Pringles: 4.5, Coronel Rosales: 48.2, Coronel Suárez: 4.5, Guaminí: 3.0, Patagones: 104.6, Puan: 12.2, Saavedra: 3.0, Tornquist: 6.8, and Villarino: 31.7. The maximum weighted average of " I" (Mg ha -1 year -1) corresponded to Coronel Rosales (87.6), Patagones (87.2), Villarino (85.7), Puan (67.9); Guaminí (59.6), Coronel Dorrego (53.1), and Bahía Blanca (39.3); the remaining municipalities ranged between 34.9 and 32.1 Mg ha -1 year -1. The highest C (%) corresponded to Patagones (120), Bahía Blanca (57), Coronel Rosales (55), Villarino (37), Coronel Dorrego (35), Tornquist (21), and Puan (18); for the remaining municipalities it was 14%. The productivity index (PI) is known to establish a numerical value of the productive capacity of lands. The relationship between WER and PI, weighted averages, in all the studied municipalities was fitted by means of a linear model, WER (Mg ha -1 year -1) = 95.23 - 2.09 * PI (%) ( R2 = 66%), and a second-order polynomial model, WER (Mg ha -1 year -1) = 139.41 - 5.86 * PI (%) + 0.07 * PI 2 (%) ( R2 = 74%). No statistically significant relationship was found between WER and PI for each municipality.

Reading a 400,000-year record of earthquake frequency for an intraplate fault

NASA Astrophysics Data System (ADS)

Williams, Randolph T.; Goodwin, Laurel B.; Sharp, Warren D.; Mozley, Peter S.

2017-05-01

Our understanding of the frequency of large earthquakes at timescales longer than instrumental and historical records is based mostly on paleoseismic studies of fast-moving plate-boundary faults. Similar study of intraplate faults has been limited until now, because intraplate earthquake recurrence intervals are generally long (10s to 100s of thousands of years) relative to conventional paleoseismic records determined by trenching. Long-term variations in the earthquake recurrence intervals of intraplate faults therefore are poorly understood. Longer paleoseismic records for intraplate faults are required both to better quantify their earthquake recurrence intervals and to test competing models of earthquake frequency (e.g., time-dependent, time-independent, and clustered). We present the results of U-Th dating of calcite veins in the Loma Blanca normal fault zone, Rio Grande rift, New Mexico, United States, that constrain earthquake recurrence intervals over much of the past ˜550 ka—the longest direct record of seismic frequency documented for any fault to date. The 13 distinct seismic events delineated by this effort demonstrate that for >400 ka, the Loma Blanca fault produced periodic large earthquakes, consistent with a time-dependent model of earthquake recurrence. However, this time-dependent series was interrupted by a cluster of earthquakes at ˜430 ka. The carbon isotope composition of calcite formed during this seismic cluster records rapid degassing of CO2, suggesting an interval of anomalous fluid source. In concert with U-Th dates recording decreased recurrence intervals, we infer seismicity during this interval records fault-valve behavior. These data provide insight into the long-term seismic behavior of the Loma Blanca fault and, by inference, other intraplate faults.

Outbreak of Tagosodes orizicolus (Muir) in Texas rice

USDA-ARS?s Scientific Manuscript database

The rice planthopper, Tagosodes orizicolus, is reported for the first time in Texas, where it is superabundant in rice fields in four counties (Brazoria, Colorado, Harris, and Wharton). The species is a known vector of the viral disease hoja blanca, which can reduce yields up to 50%, and hopper burn...

75 FR 14463 - Notice of Inventory Completion: U.S. Department of the Interior, Bureau of Indian Affairs...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-25

..., New Mexico; Pueblo of Isleta, New Mexico; Pueblo of Picuris, New Mexico; Pueblo of Pojoaque, New..., New Mexico; Pueblo of Laguna, New Mexico; Pueblo of Nambe, New Mexico; Pueblo of Picuris, New Mexico...

Seismic influence in the Quaternary uplift of the Central Chile coastal margin, preliminary results.

NASA Astrophysics Data System (ADS)

Valdivia, D.; del Valle, F.; Marquardt, C.; Elgueta, S.

2017-12-01

In order to quantify the influence of NW striking potentially seismogenic normal faults over the longitudinal variation of the Central Chile Coastal margin uplift, we measured Quaternary marine terraces, which represent the tectonic uplift of the coastal margin. Movement in margin oblique normal faults occurs by co-seismic extension of major subduction earthquakes and has occurred in the Pichilemu fault, generating a 7.0 Mw earthquake after the 2010 8.8 Mw Maule earthquake.The coastal area between 32° and 34° S was selected due to the presence of a well-preserved sequence of 2 to 5 Quaternary marine terraces. In particular, the margin oblique normal NW-trending, SW-dipping Laguna Verde fault, south of Valparaiso (33° S) puts in contact contrasting morphologies: to the south, a flat coast with wide marine terraces is carved in both, Jurassic plutonic rocks and Neogene semi-consolidated marine sediments; to the north, a steeper scarp with narrower marine terraces, over 120 m above the corresponding ones in the southern coast, is carved in Jurassic plutonic rocks.We have collected over 6 months microseimic data, providing information on seismic activity and underground geometry of the Laguna Verde fault. We collected ca. 100 systematic measurements of fringes at the base of paleo coastal scarps through field mapping and a 5 m digital elevation model. These fringes mark the maximum sea level during the terrace's carving.The heights of these fringes range between 0 and 250 masl. We estimate a 0.7 mm/yr slip rate for the Laguna Verde fault based on the height difference between corresponding terraces north- and southward, with an average uplift rate of 0.3 mm/yr for the whole area.NW striking normal faults, besides representing a potential seismic threat to the near population on one of the most densely populated areas of Chile, heavily controls the spatial variation of the coastal margin uplift. In Laguna Verde, the uplift rate differs more than three times northward

Hydrogeochemical exploration of geothermal prospects in the Tecuamburro Volcano region, Guatemala

USGS Publications Warehouse

Janik, C.J.; Goff, F.; Fahlquist, L.; Adams, A.I.; Alfredo, Roldan M.; Chipera, S.J.; Trujillo, P.E.; Counce, D.

1992-01-01

Chemical and isotopic analyses of thermal and nonthermal waters and of gases from springs and fumaroles are used to evaluate the geothermal potential of the Tecuamburro Volcano region, Guatemala. Chemically distinct geothermal surface manifestations generally occur in separate hydrogeologic areas within this 400 km2 region: low-pressure fumaroles with temperatures near local boiling occur at 1470 m elevation in a sulfur mine near the summit of Tecuamburro Volcano; non-boiling acid-sulfate hot springs and mud pots are restricted to the Laguna Ixpaco area, about 5 km NNW of the sulfur mine and 350-400 m lower in elevation; steam-heated and thermal-meteoric waters are found on the flanks of Tecuamburro Volcano and several kilometers to the north in the andesitic highland, where the Infernitos fumarole (97??C at 1180 m) is the primary feature; neutral-chloride hot springs discharge along Rio Los Esclavos, principally near Colmenares at 490 m elevation, about 8-10 km SE of Infernitos. Maximum geothermometer temperatures calculated from Colmenares neutral-chloride spring compositions are ???180??C, whereas maximum subsurface temperatures based on Laguna Ixpaco gas compositions are ???310??C. An exploration core hole drilled to a depth of 808 m about 0.3 km south of Laguna Ixpaco had a bottom-hole temperature of 238??C but did not produce sufficient fluids to confirm or chemically characterize a geothermal reservoir. Hydrogeochemical data combined with regional geologic interpretations indicate that there are probably two hydrothermal-convection systems, which are separated by a major NW-trending structural boundary, the Ixpaco fault. One system with reservoir temperatures near 300??C lies beneath Tecuamburro Volcano and consists of a large vapor zone that feeds steam to the Laguna Ixpaco area, with underlying hot water that flows laterally to feed a small group of warm, chloriderich springs SE of Tecuamburro Volcano. The other system is located beneath the Infernitos

A 150-year record of polycyclic aromatic compound (PAC) deposition from high Andean Cajas National Park, southern Ecuador.

PubMed

Bandowe, Benjamin A Musa; Fränkl, Lea; Grosjean, Martin; Tylmann, Wojciech; Mosquera, Pablo V; Hampel, Henrietta; Schneider, Tobias

2018-04-15

The temporal profiles of polycyclic aromatic compounds (PACs) in lake sediments reflect past changes in emissions, transport and deposition of these pollutants and, thus, record natural and anthropogenic processes. We document fluxes of PACs [(polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (OPAHs) and azaarenes (AZAs)] deposited in two tropical high-altitude lakes in the Cajas National Park (Ecuadorian Andes, 2°50'S, 79°10'W). In remote and high elevation Laguna Fondococha (4130m a.s.l.), the temporal fluxes of OPAHs and AZAs were similar to those of PAHs suggesting similar sources. A significant increase of PAC deposition after the 1950s reflects Ecuador's economic development. PAH fluxes were relatively low (∑27PAHs (without retene and perylene): 0.86-11.21ngcm -2 yr -1 ) with a composition pattern typical for long-range atmospheric transport (high 9-fluorenone/fluorene ratios) and biomass burning (30% low molecular weight PAHs). PAHs diagnostic of high temperature combustion (industry, traffic) make up 20-25% of total PAHs. Perylene concentrations increase linearly with increasing sediment depth suggesting diagenetic in-situ production. At lower elevations (Laguna Llaviucu, 3140m a.s.l.) and closer to urban areas, PAC fluxes in the past decades were 4-5 times higher than in the remote high-elevation lake. Laguna Llaviucu also showed higher concentrations of high molecular weight pyrogenic PAHs and a greater diversity of AZAs. Individual OPAHs and AZAs reflect mainly combustion activities. In Laguna Llaviucu, which is at a lower elevation (3140m a.s.l.) and closer to the city, molecular ratios suggest short-range atmospheric transport and deposition of PACs. A very foggy climate (170 rainy days per year) with the precipitation maximum at 3500m removes PACs very efficiently (by wet deposition) from the atmosphere at very short distances from emission sources. This partly explains why L. Llaviucu shows higher fluxes of PACs than the higher elevation L

75 FR 18086 - Changes in Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-09

..., 2009; The Hume, Mayor, City of Elk Sacramento Bee. Grove, 8401 Laguna Palms Way, Elk Grove, CA 95758... 1059). of Sacramento County 19, 2009; The Peters, Chair, (08-09-1760P). Sacramento Bee. Sacramento...

eLearning--Theories, Design, Software and Applications

ERIC Educational Resources Information Center

Ghislandi, Patrizia, Ed.

2012-01-01

Chapters in this book include: (1) New e-Learning Environments: e-Merging Networks in the Relational Society (Blanca C. Garcia); (2) Knowledge Building in E-Learning (Xinyu Zhang and Lu Yuhao); (3) E-Learning and Desired Learning Outcomes (Ralph Palliam); (4) Innovative E-Learning Solutions and Environments for Small and Medium Sized Companies…

Release of ‘UI Platinum’ hard white spring wheat

USDA-ARS?s Scientific Manuscript database

‘UI Platinum’ (Reg. No. CV------, PI 672533) hard white spring wheat (Triticum aestivum L.) was developed by the Idaho Agricultural Experiment Station and released in 2014. UI Platinum was derived from the cross ‘Blanca Grande’ x ‘Jerome’ and tested under experimental numbers A01178S, IDO694, and I...

Oak Canyon Action Memo

EPA Pesticide Factsheets

This memorandum requests approval for a time-critical removal action at the 27 residential properties that compose the Oak Canyon Site located in the Village of Paguate, Pueblo of Laguna, near Cibola County, New Mexico.

Exploring impacts of El Niño Southern Oscillation on Meteorological Forcing within the Glaciated Llanganuco Valley, Peru

NASA Astrophysics Data System (ADS)

Covert, J. M.; Hellstrom, R. A.

2015-12-01

El Niño Southern Oscillation (ENSO) is known to be the primary modulator of inter-annual weather patterns in the Andes, but its impact in the Cordillera Blanca (White Range) is not fully understood. In 2004 an autonomous sensor network (ASN) was installed in the Llanganuco Valley in the Cordillera Blanca, Peru consisting of two automatic weather stations (AWS) located at the base and upper ridge of the valley connected by four air temperature/humidity micro-loggers at equal elevation intervals. The ASN permits high resolution evaluations of the micro-scale meteorology within the valley. Twenty-four hour composites and monthly averages of wind, solar insolation, air temperature profiles, and precipitation obtained from the ASN were analyzed for the historical wet and dry seasons between the years of 2005 and 2015. The evidence suggests that teleconnections exist between eastern equatorial Pacific Ocean sea surface temperatures and meteorological forcing within the Valley. Comparisons between the two AWS units reveal similar ENSO impacts during the wet season that are not replicated in the dry season. We found that warm and cold ENSO create anomalies that appear unique to this region of the outer Tropics. Warm ENSO phases promote wetter than normal dry seasons and dryer than normal wet seasons and visa versa for cold phases of ENSO. Air temperature is strongly positively correlated to warm ENSO phases during the wet season and depends on elevation during the dry season. Insolation is negatively correlated to warm ENSO phases at higher elevations with weak positive correlation at lower elevations. We attribute observed seasonality, in part, to interactions between channeling of synoptic flow and thermally driven winds. Although the sporadic availability of data prevents definitive conclusions at this time, recent improvements in the ASN infrastructure will facilitate deeper understanding of ENSO impacts on meteorological forcing within pro-glacial valleys of the

The application of an MPM-MFM method for simulating weapon-target interaction.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, X.; Zou, Q.; Zhang, D. Z.

2005-01-01

During the past two decades, Los Alamos National Laboratory (LANL) has developed computational algorithms and software for analysis of multiphase flow suitable for high-speed projectile penetration of metallic and nonmetallic materials, using a material point method (MPM)-multiphase flow method (MFM). Recently, ACTA has teamed with LANL to advance a computational algorithm for simulating complex weapon-target interaction for penetrating and exploding munitions, such as tank rounds and artillery shells, as well as non-exploding kinetic energy penetrators. This paper will outline the mathematical basis for the MPM-MFM method as implemented in LANL's CartaBlanca code. CartaBlanca, written entirely in Java using object-oriented design,more » is used to solve complex problems involving (a) failure and penetration of solids, (b) heat transfer, (c) phase change, (d) chemical reactions, and (e) multiphase flow. We will present its application to the penetration of a steel target by a tungsten cylinder and compare results with time-resolved experimental data published by Anderson, et. al., Int. J. Impact Engng., Vol. 16, No. 1, pp. 1-18, 1995.« less

Return of the Tarahumara frog to Arizona

Treesearch

James C. Rorabaugh; Stephen F. Hale; Michael J. Sredl; Craig Ivanyi

2005-01-01

The last wild Tarahumara frog (Rana tarahumarae) in Arizona was found dead in Big Casa Blanca Canyon, Santa Rita Mountains, in May 1983. However, the species is still well represented in the majority of its range in the northern Sierra Madre Occidental and adjacent Sky Islands of Sonora and Chihuahua. Plans to re-establish R. tarahumarae...

26 CFR 301.7514-1 - Seals of office.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) South Texas District (Austin) Southern California District (Laguna Niguel) Southwest District (Phoenix...: Austin Cincinnati Memphis Kansas City Ogden Office of Director of Customer Service Centers in: Andover Atlanta Austin Baltimore Brookhaven Buffalo Cincinnati Cleveland Dallas Denver Fresno Indianapolis...

26 CFR 301.7514-1 - Seals of office.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) South Texas District (Austin) Southern California District (Laguna Niguel) Southwest District (Phoenix...: Austin Cincinnati Memphis Kansas City Ogden Office of Director of Customer Service Centers in: Andover Atlanta Austin Baltimore Brookhaven Buffalo Cincinnati Cleveland Dallas Denver Fresno Indianapolis...

26 CFR 301.7514-1 - Seals of office.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) South Texas District (Austin) Southern California District (Laguna Niguel) Southwest District (Phoenix...: Austin Cincinnati Memphis Kansas City Ogden Office of Director of Customer Service Centers in: Andover Atlanta Austin Baltimore Brookhaven Buffalo Cincinnati Cleveland Dallas Denver Fresno Indianapolis...

Baja Earthquake, Radar Image and Colored Height

NASA Image and Video Library

2010-04-05

The topography surrounding the Laguna Salada Fault in the Mexican state of Baja, California, is shown in this perspective view with data from NASA Shuttle Radar Topography Mission where a 7.2 earthquake struck on April 4, 2010.

Earth observations taken during STS-83 mission

NASA Image and Video Library

2016-08-24

STS083-749-084 (4-8 April 1997) --- Laguna Oja De Liebre, Baja, gray whale breeding ground Laguna Oja De Liebre, Baja (Scammons Lagoon) is located on the west coast in the plains of the central Baja. This lagoon and others like it along the Baja coast are used for breeding grounds for the gray whale. One group of gray whales inhabits the Sea of Okhotsk in summer, migrating south in winter then breed off southern Korea. The other summers in the Bering and Chukchi seas and travels south to winter breeding grounds along the coast of Baja California. The gray whale was hunted almost to extinction by 1925 but was placed under complete international protection and since the 1940s has increased in numbers. The white grids seen in the photo are commercial salt ponds.

Comprehensive dental services for an underserved and medically compromised population provided through a community partnership and service learning.

PubMed

Chávez, Elisa M; LaBarre, Eugene; Fredekind, Richard; Isakson, Paul

2010-01-01

The University of the Pacific, Arthur A. Dugoni School of Dentistry in San Francisco established a comprehensive dental care program at Laguna Honda Hospital, a public, skilled nursing facility. The program had three goals: (1) to provide dental students and residents an opportunity to provide oral health care for adults who were frail and medically compromised who could not come into the clinics, (2) to increase students' access to patients who needed removable prosthodontics, and (3) to fulfill Pacific's commitment to public service. Laguna Honda and Pacific pooled their resources to bring comprehensive dental care to patients who were not able to access the dental school clinics. The long-term goals are to restore and maintain the oral health of those who reside in the facility, and to educate future dentists to provide oral health care for similar populations.

Application of Inter-Simple Sequence Repeat Markers in the Analysis of Populations of the Chagas Disease Vector Triatoma infestans (Hemiptera, Reduviidae)

PubMed Central

Pérez de Rosas, Alicia R.; Restelli, María F.; Fernández, Cintia J.; Blariza, María J.; García, Beatriz A.

2017-01-01

Here we apply inter-simple sequence repeat (ISSR) markers to explore the fine-scale genetic structure and dispersal in populations of Triatoma infestans. Five selected primers from 30 primers were used to amplify ISSRs by polymerase chain reaction. A total of 90 polymorphic bands were detected across 134 individuals captured from 11 peridomestic sites from the locality of San Martín (Capayán Department, Catamarca Province, Argentina). Significant levels of genetic differentiation suggest limited gene flow among sampling sites. Spatial autocorrelation analysis confirms that dispersal occurs on the scale of ∼469 m, suggesting that insecticide spraying should be extended at least within a radius of ∼500 m around the infested area. Moreover, Bayesian clustering algorithms indicated genetic exchange among different sites analyzed, supporting the hypothesis of an important role of peridomestic structures in the process of reinfestation. PMID:28115670

A new species of bark beetle, Dendroctonus mesoamericanus sp nov. (Curculionidae: Scolytinae), in southern Mexico and Central America

Treesearch

Francisco Armendariz-Toledano; Alicia Nino; Brian T. Sullivan; Lawrence R. Kirkendall; Gerado Zunig

2015-01-01

The bark beetle Dendroctonus mesoamericanus sp. nov. is described from a population in Parque Nacional Lagunas de Montebello, La Trinitaria, Chiapas, Mexico. This species belongs to the D. frontalis complex, which includes D. adjunctus Blandford 1897, D. approximatus Dietz 1890, D....

Pena blanca natural analogue project: summary of activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levy, Schon S; Goldstein, Steven J; Abdel - Fattah, Amr I

2010-12-08

The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill core. Datafrom site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

76 FR 23649 - Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition and Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-27

... field research), the potential global population of free-ranging Morelet's crocodiles in 2004 was... will include monitoring and harvest of Morelet's crocodiles and hybrids for scientific research (CITES... Biosphere Reserve, Laguna de T[eacute]rminos Biosphere Reserve, Hampolol Wildlife Conservation and Research...

WATER COLUMN DATA AND SPECTRAL IRRADIANCE MODEL

EPA Science Inventory

Water samples collected monthly, for 18 months, from six sites in the Laguna Madre were analyzed to identify and quantify phytopigments using High Performance Liquid Chromatography (HPLC). In addition, water column pigment and nutrient data were acquired at 12 stations in Upper ...

Ground Wave Emergency Network. Final Operational Capability. Environmental Assessment for Southern Nevada Relay Node, Site No. RN 8W918NV

DTIC Science & Technology

1993-03-05

Supervisor, Fish and Wildlife Service, Ventura, California Field Supervisor, Fish and Wildlife Service, Laguna Nigel, California Assistant Regional...the weight regressions developed by Dr. Michael Weinstein for the tortoises at the Honda project. If a tortoise is determined to be underweight, the

STABLE CARBON ISOTOPE EVIDENCE FOR COUPLING BETWEEN SEDIMENTARY BACTERIA AND SEAGRASSES IN A SUB-TROPICAL LAGOON

EPA Science Inventory

We measured stable carbon isotope ratios (d13C) in phospholipid fatty acids (PLFAs) to identify the primary carbon source utilized by sedimentary bacteria in Lower Laguna Madre, Texas, which is a seagrass dominated lagoon. Comparisons were made between three differing habitat ty...

Baja Earthquake Perspective View

NASA Image and Video Library

2010-04-05

The topography surrounding the Laguna Salada Fault in the Mexican state of Baja, California, is shown in this combined radar image and topographic view with data from NASA Shuttle Radar Topography Mission where a 7.2 earthquake struck on April 4, 2010.

Comparative oceanography of coastal lagoons

NASA Technical Reports Server (NTRS)

Kjerfve, Bjorn

1986-01-01

The hypothesis that physical lagoon characteristics and variability depend on the channel connecting the lagoon to the adjacent coastal ocean is evaluated. The geographical, hydrological, and oceanographic characteristics of 10 lagoon systems are described and analyzed; these oceanographic features are utilized to classify the lagoon systems. Choked lagoons (Laguna Joyuda, Coorong, Lake St.Lucia, Gippsland Lakes, Lake Songkla/Thale Luang/Thale Noi, and Lagoa dos Patos) are prevalent on coasts with high wave energy and low tidal range; restricted lagoons (Lake Pontchartrain and Laguna de Terminos) are located on low/medium wave energy coasts with a low tidal range; and leaky lagoons (Mississippi Sound and Belize Lagoon/Chetumal Bay) are connected to the ocean by wide tidal passes that transmit oceanic effects into the lagoon with a minimum of resistance. The data support the hypothesis that the nature of the connecting channel controls system functions.

New Mexico Pueblos Confront the Atomic Age.

ERIC Educational Resources Information Center

Barry, Tom

1979-01-01

While mineral development in Indian Country offers economic benefits, it can also pollute the air and water and destroy the land itself. Article describes three different approaches that Laguna, Acoma and Santo Domingo Pueblos are using to deal with exploitation of their natural resources. (DS)

Foreword

NASA Astrophysics Data System (ADS)

Benisty, Henri; Kawakami, Shojiro; Norris, David J.; Soukoulis, Costas M.

2004-10-01

The Fifth International Symposium on Photonic and Electromagnetic Crystal Structures (PECS-V) was held in Kyoto, Japan (2004). The Symposium followed the format of previous international meetings held at Laguna Beach, USA (1999), Sendai, Japan (2000), St. Andrews, UK (2001) and Los Angeles, USA (2002).

78 FR 64248 - Notice Pursuant to The National Cooperative Research and Production Act of 1993; DVD Copy Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-28

..., Shenzhen, PEOPLE'S REPUBLIC OF CHINA; Smart Electronics Manufacturing Service Philippine, Calamba City, Laguna, PHILIPPINES; SoJean International Co., Ltd., His-Chih City, Taipei Hsien, TAIWAN; and YuCha (Hong...; CyberLink Corporation, Shindian City, Taipei, TAIWAN; D&M Holdings Inc., Chuo-ku, Tokyo, JAPAN; Daesung...

SEAGRASS STRESS RESPONSE MODEL: THE IMPORTANCE OF LIGHT, TEMPERATURE, SEDIMENTATION AND GEOCHEMISTRY

EPA Science Inventory

Our objective is to define interactions between seagrass and water-column and sediment stressors. The model was developed and optimized for sediments in Thalassia testudinum seagrass beds of Lower Laguna Madre, Texas, USA and is composed of a plant sub-model and a sediment diagen...

Preliminary investigation of exceptionally strong winds in mountainous areas of New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reynolds, R.D.; Barnett, K.M.

1980-10-01

The mean wind speed in four mountainous areas in New Mexico were sampled for one year using wind data accumulators. The sites studied were: (1) San Augustin Pass, 15 miles northeast of Las Cruces; (2) Sierra Grande, an isolated peak midway between Raton and Clayton; (3) Buck Mountain, 10 miles northeast of Sierra Blanca Peak near Ruidoso, and (4) Palomas Mesa, 20 miles west-southwest of Tucumcari.

Reinstatement of the genus Colopalpus Pritchard and Baker (1958) and re-description of Colopalpus matthyssei Pritchard and Baker (1958), the type species of this genus (Acari, Tenuipalpidae)

USDA-ARS?s Scientific Manuscript database

Pritchard and Baker (1958) erected the genus Colopalpus with Tenuipalpus matthyssei (Pritchard and Baker) a species described from Laguna, The Philippines, as the type species. Meyer (1979) treated the genus as a junior synonym of Tenuipalpus Donnadieu. In this paper, we re-describe the female, male...

Western dwarf mistletoe infects understory Jeffrey pine seedlings on Cleveland National Forest, California

Treesearch

Robert F. Scharpf; Detlev Vogler

1986-01-01

Many young, understory Jeffrey pines (Pinus jeffreyi Grev. & Balf.) were found to be infected by western dwarf mistletoe (Arceuthobium campylopodum Engelm.) on Laguna Mountain, Cleveland National Forest, in southern California. Under heavily infected overstory, about three-fourths of the young pines (about 15 years old on the...

Evaluation of the Teaching Performance of University Lecturers: Comparison between Mexico and Spain

ERIC Educational Resources Information Center

Diaz, Matilde; Borges, Africa; Valadez, Dolores; Zambrano, Rogelio

2015-01-01

Comparative educational studies allow the study of the differences and similarities between different educational systems. This research, which consists on an educational evaluation, has studied the teaching behavior of ten university lecturers from a Spanish university--the University of La Laguna--, and seven from a Mexican…

COASTAL BEND BAYS & ESTUARIES PROGRAM IMPLEMENTATION REVIEW 2004

EPA Science Inventory

The Coastal Bend Bays & Estuaries Program, Inc. (CBBEP) is a nonprofit 501(c)(3)organization. The CBBEP project area encompasses 12 counties coincident with the Coastal Bend Council of Governments and extends from the Land-Cut in the Laguna Madre, through the Corpus Christi Bay s...

Pollen collection and honey bee forager distribution in cantaloupe

USDA-ARS?s Scientific Manuscript database

Honey bee (Apis mellifera, L.) pollen collection and forager distribution were examined during the summer of 2002 in a cantaloupe (Cucumis melo, L., Cruiser cv.) field provided with plastic mulch and drip irrigation. The experimental site was located near the INIFAP Campo Experimental La Laguna, Ma...

Pre-Hispanic agricultural decline prior to the Spanish Conquest in southern Central America

NASA Astrophysics Data System (ADS)

Taylor, Zachary P.; Horn, Sally P.; Finkelstein, David B.

2013-08-01

Archeological and paleoenvironmental records from southern Central America attribute population collapse to the Spanish Conquest about 500 years ago. Paleoclimate records from the circum-Caribbean have shown evidence of severe, regional droughts that contributed to the collapse of the Mayan Civilization, but there are few records of these droughts in southern Central America and no records of their effects on prehistoric populations in the region. Here we present a high-resolution lake sediment record of prehistoric agricultural activities using bulk sediment stable carbon isotopes from Laguna Zoncho, Costa Rica. We find isotopic evidence that agriculture was nearly absent from the watershed approximately 220 years prior to the Spanish arrival in Costa Rica and identify two distinct periods of agricultural decline, 1150-970 and 860-640 cal yr BP, which correspond to severe droughts in central Mexico. We attribute decreases in agriculture to a weakened Central American monsoon, which would have shortened the growing season at Laguna Zoncho, reduced crop yields, and negatively affected prehistoric populations.

Closure Report for Corrective Action Unit 574: Neptune, Nevada National Security Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

NSTec Environmental Restoration

Corrective Action Unit (CAU) 574 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Neptune' and consists of the following two Corrective Action Sites (CASs), located in Area 12 of the Nevada National Security Site: (1) CAS 12-23-10, U12c.03 Crater (Neptune); and (2) CAS 12-45-01, U12e.05 Crater (Blanca). This Closure Report presents information supporting closure of CAU 574 according to the FFACO (FFACO, 1996 [as amended March 2010]) and the Streamlined Approach for Environmental Restoration Plan for CAU 574 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2011). The following activities were performedmore » to support closure of CAU 574: (1) In situ external dose rate measurements were collected using thermoluminescent dosimeters at CAS 12-45-01, U12e.05 Crater (Blanca). (2) Total effective dose rates were determined at both sites by summing the internal and external dose rate components. (3) A use restriction (UR) was implemented at CAS 12-23-10, U12c.03 Crater (Neptune). Areas that exceed the final action level (FAL) of 25 millirems per year (mrem/yr) based on the Occasional Use Area exposure scenario are within the existing use restricted area for CAU 551. The 25-mrem/yr FAL is not exceeded outside the existing CAU 551 UR for any of the exposure scenarios (Industrial Area, Remote Work Area, and Occasional Use Area). Therefore, the existing UR for CAU 551 is sufficient to bound contamination that exceeds the FAL. (4) An administrative UR was implemented at CAS 12-45-01, U12e.05 Crater (Blanca) as a best management practice (BMP). The 25-mrem/yr FAL was not exceeded for the Remote Work Area or Occasional Use Area exposure scenarios; therefore, a UR is not required. However, because the 25-mrem/yr FAL was exceeded for the Industrial Area exposure scenario, an administrative UR was established as a BMP. UR documentation is included as Appendix B. The UR at CAS 12-23-10, U12c.03 Crater

Updated Distribution Records for Anopheles vagus (Diptera: Culicidae) in the Republic of Philippines, and Considerations Regarding Its Secondary Vector Roles in Southeast Asia

DTIC Science & Technology

2011-01-01

larvae were collected from three habitats (rice fields, irrigation ditches and drainage ditches) in Laguna Province in July 2002 using a plastic dipper ...Wilkerson et al. (2003). The rDNA ITS2 was amplified, and polymerase chain reaction (PCR) products were directly sequenced using Big Dye 3.0 (Applied

Overwash Processes and Foredune Ecology, Nauset Spit, Massachusetts.

DTIC Science & Technology

1984-12-01

played a major role in the infilling of Laguna Madre behind Padre Island, Texas. Washover deposits were subsequently reworked by the wind, which...flowering grass that establishes mats of vegetation in the high marsh. Spa-tin patens var. monogyna is erect, somewhat taller , later flowering, and grows in

47 CFR 73.202 - Table of Allotments.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Tecopa 288A, 291A Trona 247A Twentynine Palms 270A Wasco 224A Waterford 294A Westley *238A Willow Creek 253A, 258A Willows 292A Wofford Heights 251A COLORADO Akron 279C1 Arriba 240A Aspen 228A Blanca 249C2... Glenville 299A Marlinton 292A St Marys *287A Wardensville 239A White Sulphur Springs 227A WISCONSIN Ashland...

47 CFR 73.202 - Table of Allotments.

Code of Federal Regulations, 2014 CFR

2014-10-01

... *298A Tecopa 288A Trona 247A Twentynine Palms 270A Wasco 224A Waterford 294A Westley *238A Willow Creek 258A Willows 292A Wofford Heights 251A COLORADO Akron 279C1 Blanca 249C2 Crested Butte 246C3 Dinosaur... 292A St Marys *287A Wardensville 239A White Sulphur Springs 227A WISCONSIN Ashland *275A Augusta *268C3...

77 FR 15800 - Notice of Inventory Completion: U.S. Fish and Wildlife Service, Southwest Regional Office...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-16

... professional staff in consultation with the Hopi Tribe of Arizona; Pueblo of Acoma, New Mexico; Pueblo of Cochiti, New Mexico; Pueblo of Isleta, New Mexico; Pueblo of Jemez, New Mexico; Pueblo of Laguna, New Mexico; Pueblo of Nambe, New Mexico; Pueblo of Picuris, New Mexico; Pueblo of Pojoaque, New Mexico...

Contributions to the study of gasteromycetes of Puerto Rico

Treesearch

Angel M. Nieves-Rivera; D. Jean. Lodge; Orson K. Miller

1998-01-01

Battarrea stevenii and Tulostoma cf. meridionale, two cosmopolitan taxa are reported as new records for Puerto Rico. Both species were collected from the same disturbed subtropical dry forested area. A partial checklist of the taxa of macromycetes collected from Boquer*on Commonwealth- and Laguna Cartagena National Wildlife Refuges is also provided.

Simulation of flow in the upper North Coast Limestone Aquifer, Manati-Vega Baja area, Puerto Rico

USGS Publications Warehouse

Cherry, Gregory S.

2001-01-01

A two-dimensional computer ground-water model was constructed of the Manati-Vega Baja area to improve the understanding of the unconfined upper aquifer within the North Coast Province of Puerto Rico. The modeled area covers approximately 79 square miles within the municipios of Manati and Vega Baja and small portions of Vega Alta and Barceloneta. Steady-state two-dimensional ground-water simulations were correlated to conditions prior to construction of the Laguna Tortuguero outlet channel in 1940 and calibrated to the observed potentiometric surface in March 1995. At the regional scale, the unconfined Upper North Coast Limestone aquifer is a diffuse ground-water flow system through the Aguada and Aymamon limestone units. The calibrated model input parameters for aquifer recharge varied from 2 inches per year in coastal areas to 18 inches per year in the upland areas south of Manati and Vega Baja. The calibrated transmissivity values ranged from less than 500 feet squared per day in the upland areas near the southern boundary to 70,000 feet squared per day in the areas west of Vega Baja. Increased ground-water withdrawals from 1.0 cubic foot per second for 1940 conditions to 26.3 cubic feet per second in 1995, has reduced the natural ground-water discharge to springs and wetland areas, and induced additional recharge from the rivers. The most important regional drainage feature is Laguna Tortuguero, which is the major ground-water discharge body for the upper aquifer, and has a drainage area of approximately 17 square miles. The discharge to the sea from Laguna Tortuguero through the outlet channel has been measured on a bi-monthly basis since 1974. The outflow represents a combination of ground- and surface-water discharge over the drainage area. Hydrologic conditions, prior to construction of the Laguna Tortuguero outlet channel in 1943, can be considered natural conditions with minimal ground-water pumpage (1.0 cubic foot per second), and heads in the lagoon

Public Outreach of the South Texas Health Physic Society and Texas A&M University Nuclear Engineering Department

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berry, R. O.

In a cooperative effort of the members of the South Texas Chapter of the Heath Physics Society (STC-HPS) and the Texas A&M University Nuclear Engineering Department, great efforts have been made to reach out and provide educational opportunities to members of the general public, school age children, and specifically teachers. These efforts have taken the form of Science Teacher Workshops (STW), visits to schools all over the state of Texas, public forums, and many other educational arenas. A major motivational factor for these most recent efforts can be directly tied to the attempt of the State of Texas to sitemore » a low-level radioactive waste facility near Sierra Blanca in West Texas. When the State of Texas first proposed to site a low level radioactive waste site after the Low-Level Radioactive Waste Policy Act of 1980 was passed, many years of political struggle ensued. Finally, a site at Sierra Blanca in far West Texas was selected for study and characterization for a disposal site for waste generated in the Texas Compact states of Maine, Vermont and Texas. During this process, the outreach to and education of the local public became a paramount issue.« less

Characteristics of the Earth's orbit by observations of the setting Sun

NASA Astrophysics Data System (ADS)

Sclar, N.

2000-07-01

Measurements of the setting Sun were carried out over a period of 16 months at Aliso Pier in Laguna Beach, CA, USA. The measurements are treated with simple analyses to provide good estimates of the obliquity of the ecliptic, and the eccentricity, velocities and radii of the Earth's elliptical orbit about the Sun.

27 CFR 9.54 - Santa Ynez Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of the La Laguna and Sisquoc Land Grants with the Los Padres National Forest. (10) Then following the boundary of the Los Padres National Forest south, east, and south until it intersects with the eastern... Los Padres National Forest. (13) Then south and west following the boundary of the Los Padres National...

Procesos cuasi-moleculares en enanas blancas frías

NASA Astrophysics Data System (ADS)

Rohrmann, R. D.; Althaus, L. G.; Kepler, S. O.

We show that the radiation emitted by very cool white dwarf stars (Teff ~< 3000 K) with pure hydrogen atmospheres, is fully formed by radiative processes induced by atomic and molecular collisions. FULL TEXT IN SPANISH

47 CFR 73.202 - Table of Allotments.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Tecopa 288A, 291A Trona 247A Twentynine Palms 270A Wasco 224A Waterford 294A Westley *238A Willow Creek 253A, 258A Willows 292A Wofford Heights 251A COLORADO Akron 279C1 Arriba 240A Aspen 228A Blanca 249C2... Wardensville 239A White Sulphur Springs 227A WISCONSIN Ashland *275A Augusta *268C3 Boscobel 244C3 Crandon 276A...

Occurrence and fate of linear and branched alkylbenzenesulfonates and their metabolites in surface waters in the Philippines.

PubMed

Eichhorn, P; Flavier, M E; Paje, M L; Kneppe, T P

2001-03-26

Laguna de Bay in the Philippines is one of the largest freshwater lakes in Asia and is considered a primary source of drinking water, but also receives daily discharges of effluent from both domestic and industrial activities. Branched alkylbenzenesulfonates (ABS), which were banned in Europe and withdrawn from the market in the U.S. since the mid-1960s, but not in Southeast Asia, and linear alkylbenzenesulfonates (LAS) are anionic surfactants used in detergent formulations and are therefore main components of effluent discharges. The presence of both LAS and ABS in several water streams in the catchment area of Laguna de Bay was determined using liquid chromatography-mass spectrometry (LC-MS). The concentration levels of LAS (1.2-73 and 2.2-102 microg l(-1)) and ABS (1.1-75 and 1-66 microg l(-1)) in some tributaries of Laguna de Bay and its outlet (Pasig River) to Manila Bay were assessed in December 1999 and March 2000, respectively. The LAS/ABS ratio was calculated as an indication of the extent of the distribution and fate of these surfactants in the surface water. The nearer the location to the metropolitan area of Manila, the higher the levels of LAS and ABS detected in the waters. Moreover, the extent of biodegradation was investigated by monitoring their alkyl homologue distribution and the presence of sulfophenylcarboxylate (SPC) metabolites. Similarly, differences in the levels of SPC and the homologues were apparent at the different sampling points. Presumably, even the quite recalcitrant ABS form SPCs under the conditions present in Southeast Asia. Since wastewater treatment facilities are not well established in developing countries like the Philippines, the call for the use of environmentally friendly chemicals is of even higher significance.

Oldest Known Eucalyptus Macrofossils Are from South America

PubMed Central

Zamaloa, María C.; Nixon, Kevin C.; González, Cynthia C.; Wilf, Peter; Cúneo, N. Rubén; Johnson, Kirk R.

2011-01-01

The evolutionary history of Eucalyptus and the eucalypts, the larger clade of seven genera including Eucalyptus that today have a natural distribution almost exclusively in Australasia, is poorly documented from the fossil record. Little physical evidence exists bearing on the ancient geographical distributions or morphologies of plants within the clade. Herein, we introduce fossil material of Eucalyptus from the early Eocene (ca. 51.9 Ma) Laguna del Hunco paleoflora of Chubut Province, Argentina; specimens include multiple leaves, infructescences, and dispersed capsules, several flower buds, and a single flower. Morphological similarities that relate the fossils to extant eucalypts include leaf shape, venation, and epidermal oil glands; infructescence structure; valvate capsulate fruits; and operculate flower buds. The presence of a staminophore scar on the fruits links them to Eucalyptus, and the presence of a transverse scar on the flower buds indicates a relationship to Eucalyptus subgenus Symphyomyrtus. Phylogenetic analyses of morphological data alone and combined with aligned sequence data from a prior study including 16 extant eucalypts, one outgroup, and a terminal representing the fossils indicate that the fossils are nested within Eucalyptus. These are the only illustrated Eucalyptus fossils that are definitively Eocene in age, and the only conclusively identified extant or fossil eucalypts naturally occurring outside of Australasia and adjacent Mindanao. Thus, these fossils indicate that the evolution of the eucalypt group is not constrained to a single region. Moreover, they strengthen the taxonomic connections between the Laguna del Hunco paleoflora and extant subtropical and tropical Australasia, one of the three major ecologic-geographic elements of the Laguna del Hunco paleoflora. The age and affinities of the fossils also indicate that Eucalyptus subgenus Symphyomyrtus is older than previously supposed. Paleoecological data indicate that the

Conservation status of the buff-breasted sandpiper: Historic and contemporary distribution and abundance in south America

USGS Publications Warehouse

Lanctot, Richard B.; Blanco, D.E.; Dias, Rafael A.; Isacch, Juan P.; Gill, Verena A.; Almeida, Juliana B.; Delhey, Kaspar; Petracci, Pablo F.; Bencke, Glayson A.; Balbueno, Rodrigo A.

2002-01-01

We present historic and contemporary information on the distribution and abundance of Buff-breasted Sandpipers (Tryngites subruficollis) in South America. Historic information was collated from the literature, area ornithologists, and museums, whereas contemporary data were derived from surveys conducted throughout the main wintering range in Argentina, Uruguay, and Brazil during the austral summers of 1999 and 2001. Variable circular plot sampling was used to estimate population densities. During 1999, the highest concentration of Buff-breasted Sandpipers in Argentina was in southern Bahía Samborombón (General Lavalle District) and areas north of Mar Chiquita coastal lagoon. During 2001, the highest concentrations in Brazil were at Ilha da Torotama and Lagoa do Peixe National Park. During 1999 and 2001, the highest concentrations of Buff-breasted Sandpipers in Uruguay were found along three lagoons (Laguna de Rocha, Laguna de Castillos, and Laguna Garzón) bordering the Atlantic Ocean. Population densities (birds/ha) of Buff-breasted Sandpipers were 0.11 (95% C.I. = 0.04–0.31) in Argentina, 1.62 (0.67–3.93) in Brazil, and 1.08 (0.37–3.18) in Uruguay. High turnover rates at survey sites, due to the formation of large, mobile flocks, contributed to moderately large confidence intervals around our population density estimates. Nevertheless, compared with historic accounts of Buff-breasted Sandpipers, our survey data indicate the population size of this species has declined substantially since the late 1800s and contemporary information suggests the species has continued to decline during the past three decades. Buff-breasted Sandpipers were found almost exclusively in pasturelands and appear to depend heavily upon intensive grazing by livestock, which maintain suitable short grass conditions. We discuss the need for protection of critical areas and proper range management to ensure appropriate habitat remains available for the species, and provide suggestions

Oppression in Argentina: The Mataco Case. IWGIA Document No. 21.

ERIC Educational Resources Information Center

Rodriguez, Nemesio J.

The Mataco Indians are members of the Mataco-Mataguayo family which included several different groups that to some extent were related culturally speaking. According to the National Indigenous Census, there are 21,800 Mataco in Argentina today. The six Mataco settlements, situated in the land belt which extends from Pozo del Mortero to Laguna Yema…

Draft Genome Sequence of the Polyextremophilic Halorubrum sp. Strain AJ67, Isolated from Hyperarsenic Lakes in the Argentinian Puna.

PubMed

Burguener, Germán F; Maldonado, Marcos J; Revale, Santiago; Fernández Do Porto, Darío; Rascován, Nicolás; Vázquez, Martín; Farías, María Eugenia; Marti, Marcelo A; Turjanski, Adrián Gustavo

2014-02-06

Halorubrum sp. strain AJ67, an extreme halophilic UV-resistant archaeon, was isolated from Laguna Antofalla in the Argentinian Puna. The draft genome sequence suggests the presence of potent enzyme candidates that are essential for survival under multiple environmental extreme conditions, such as high UV radiation, elevated salinity, and the presence of critical arsenic concentrations.

The acoustic repertoire of bottlenose dolphins (Tursiops truncatus) from the southern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Bazua-Duran, Carmen

2005-04-01

Bottlenose dolphins live in a variety of habitats of the world's oceans using their acoustic repertoire to communicate and inspect their environment. This work investigates the acoustic repertoire of bottlenose dolphins that inhabit a coastal lagoon of the southern Gulf of Mexico, the Laguna de Terminos and how it may relate to the dolphins' general behavioral state and herd size, and to the general characteristics of the habitat, such as visibility, depth, and sea state. Preliminary results show that bottlenose dolphins produce by far more clicks than whistles in all behavioral states (feeding, resting, social, and travel) and herd sizes, which may correlate with the decreased visibility and shallow depth of the Laguna de Terminos. Additionally, silence was found during all behavioral states, but very seldom in herds of large size. These preliminary results suggest that bottlenose dolphins are choosing when and where to produce their phonations. Therefore, more detailed studies are needed to understand how these animals are using their acoustic sense to communicate and inspect their environment. [Work supported by CONACyT-Gobierno Edo. de Campeche and PAPIIT, UNAM.

First report of linear megaplasmids in the genus Micrococcus.

PubMed

Dib, Julian R; Wagenknecht, Martin; Hill, Russell T; Farías, María E; Meinhardt, Friedhelm

2010-01-01

High-altitude wetlands (above 4200m) in the northwest of Argentina are considered pristine and extreme environments. Micrococcus sp. A1, H5, and V7, isolated from such environments, were shown to contain linear megaplasmids, designated pLMA1, pLMH5, and pLMV7, respectively. As known from linear plasmids of other actinomycetes, all three plasmids were resistant to lambda exonuclease treatment, which is consistent with having terminal proteins covalently attached to their 5' DNA ends. Electrophoretic mobility, Southern analysis, and restriction endonuclease patterns revealed pLMA1 and pLMH5 being indistinguishable plasmids, even though they were found in different strains isolated from two distant wetlands - Laguna Azul and Laguna Huaca Huasi. Analysis of 16S rDNA sequences of Micrococcus sp. A1, H5, and V7 suggested a close relationship to Micrococcus luteus. Typing of isolates was performed using fingerprint patterns generated by BOX-PCR. Plasmid-deficient strains, generated from Micrococcus sp. A1, showed a significantly decreased resistance level for erythromycin. Copyright 2009 Elsevier Inc. All rights reserved.

Preliminary Geologic Map of the North-Central Part of the Alamosa 30' x 60' Quadrangle, Alamosa, Conejos and Costilla Counties, Colorado

USGS Publications Warehouse

Machette, Michael N.; Thompson, Ren A.; Brandt, Theodore R.

2008-01-01

This geologic map presents new polygon (geologic map unit contacts) and line (terrace and lacustrine spit/barrier bar) vector data for a map comprised of four 7.5' quadrangles in the north-central part of the Alamosa, Colorado, 30' x 60' quadrangle. The quadrangles include Baldy, Blanca, Blanca SE, and Lasauses. The map database, compiled at 1:50,000 scale from new 1:24,000-scale mapping, provides geologic coverage of an area of current hydrogeologic, tectonic, and stratigraphic interest. The mapped area is located primarily in Costilla County, but contains portions of Alamosa and Conejos Counties, and includes the town of Blanca in its northeastern part. The map area is mainly underlain by surficial geologic materials (fluvial and lacustrine deposits, and eolian sand), but Tertiary volcanic and volcaniclastic rocks crop out in the San Luis Hills, which are in the central and southern parts of the mapped area. The surficial geology of this area has never been mapped at any scale greater than 1:250,000 (broad reconnaissance), so this new map provides important data for ground-water assessments, engineering geology, and the Quaternary geologic history of the San Luis Basin. Newly discovered shoreline deposits are of particular interest (sands and gravels) that are associated with the high-water stand of Lake Alamosa, a Pliocene to middle Pleistocene lake that occupied the San Luis basin prior to its overflow and cutting of a river gorge through the San Luis Hills. After the lake drained, the Rio Grande system included Colorado drainages for the first time since the Miocene (>5.3 Ma). In addition, Servilleta Basalt, which forms the Basaltic Hills on the east margin of the map area, is dated at 3.79+or-0.17 Ma, consistent with its general age range of 3.67-4.84 Ma. This map provides new geologic information for better understanding ground-water flow paths in and adjacent to the Rio Grande system. The map abuts U.S. Geological Survey Open File Report 2005-1392 (a map of

Draft Genome Sequence of the Polyextremophilic Exiguobacterium sp. Strain S17, Isolated from Hyperarsenic Lakes in the Argentinian Puna.

PubMed

Ordoñez, Omar F; Lanzarotti, Esteban; Kurth, Daniel; Gorriti, Marta F; Revale, Santiago; Cortez, Néstor; Vazquez, Martin P; Farías, María E; Turjanski, Adrian G

2013-07-25

Exiguobacterium sp. strain S17 is a moderately halotolerant, arsenic-resistant bacterium that was isolated from Laguna Socompa stromatolites in the Argentinian Puna. The draft genome sequence suggests potent enzyme candidates that are essential for survival under multiple environmental extreme conditions, such as high levels of UV radiation, elevated salinity, and the presence of critical arsenic concentrations.

Sports Drove Silva to Teach Wellness

ERIC Educational Resources Information Center

Deschenie, Tina

2008-01-01

This article profiles teacher Leroy Silva (Laguna), 27, a.k.a. "Buster". Silva describes himself as an active guy who stays busy working out, playing basketball, softball, and more recently golf, soccer, and lacrosse. He teaches personal wellness and sports (not physical education), a job he began in 2006. Before that he was a trainer at…

Education for Rural Development: The Case of the UPCA/BNE Barrio Development School Project.

ERIC Educational Resources Information Center

Contado, Tito E.

The Barrio Development School, a 4-year action-research project which has been in operation for 2 years, is located at Masaya, Bay, Laguna, Philippines. Begun by the University of the Philippines, College of Agriculture, and the Board of National Education, it is a secondary school program for barrio youths who have decided to stay, live, and work…

A Multi-Scale Approach to Assess and Restore Ecosystems in a Watershed Context

DTIC Science & Technology

2013-09-01

Laguna Formation .. Mehrten Formation .. Metamorphic Rocks , Undifferentiated .. Modesto Formation. Upper Unit c=J North Merced Gravel .. Riverbank...distribution is unlimited. The US Army Engineer Research and Development Center (ERDC) solves the nation’s toughest engineering and environmental...watershed assessment procedure that can be used to evaluate existing ecological conditions as well as proposed changes. The approach employs indicators

Draft Genome Sequence of the Polyextremophilic Halorubrum sp. Strain AJ67, Isolated from Hyperarsenic Lakes in the Argentinian Puna

PubMed Central

Burguener, Germán F.; Maldonado, Marcos J.; Revale, Santiago; Fernández Do Porto, Darío; Rascován, Nicolás; Vázquez, Martín; Farías, María Eugenia; Marti, Marcelo A.

2014-01-01

Halorubrum sp. strain AJ67, an extreme halophilic UV-resistant archaeon, was isolated from Laguna Antofalla in the Argentinian Puna. The draft genome sequence suggests the presence of potent enzyme candidates that are essential for survival under multiple environmental extreme conditions, such as high UV radiation, elevated salinity, and the presence of critical arsenic concentrations. PMID:24503991

Geologic evaluation of remote sensing data, site 157, Awza-Borrego Desert, California

NASA Technical Reports Server (NTRS)

Wolfe, E. W.

1969-01-01

Remote sensing data were obtained at site 157 in May 1968 under mission 73 of the NASA aircraft program. The site is located in an area of high temperatures and extreme aridity immediately west of the Imperial Valley, Southern California. Site 157 is partially surrounded by pre-Cenozoic crystalline rocks exposed in the Fish Creek, Vallecito, and Tierra Blanca Mountains. The study area itself is underlain by more than 20,000 feet of sedimentary strata of late Cenozoic age.

Early recovery of subtropical dry forest in southwestern Puerto Rico

Treesearch

Peter L. Weaver

2011-01-01

Tree cover and species composition were surveyed in 1998, 2003, and 2010 after the elimination of grazing and fire on the lower 32 hectares of the Tinaja tract at Laguna Cartagena National Wildlife Refuge in south-western Puerto Rico. Surveys of the secondary subtropical dry forest showed that stems increased 3.9 times, trees 6.7 times, basal area 3.3 times, and...

Grandma's Wicker Sewing Basket: Untangling the Narrative Threads in Silko's "Ceremony"

ERIC Educational Resources Information Center

Beidler, Peter G.; Nelson, Robert M.

2004-01-01

Leslie Marmon Silko's "Ceremony" is a novel about a young man who returns to the Laguna Reservation in 1948, after horrifying experiences on the Pacific front in World War II. He comes home in a psychological mess after being released from a prisoner of war camp. An attempt is made to enable teachers to help first-time readers untangle the various…

Baja California, Mexico

NASA Technical Reports Server (NTRS)

1981-01-01

An interesting view down the axis of Baja California, Mexico (26.5N, 113.0W). At the center of the Scene is Laguna Ojo de Liebre (Bay of Whales) which is a breeding area for the Pacific Grey Whale. The Sea of Cortez, also known as the Gulf of California, is to the left and the Pacific Ocean is to the right.

Containment Area Aquaculture Program. Economics and Marketing of Aquaculture in Dredged Material Containment Areas

DTIC Science & Technology

1993-09-01

project shrimp farm and to use the information learned from the demonstration to examine the economic feasibility of aquaculture in dredged material...aquaculture within the USACE. The Containment Area Aquaculture Program (CAAP) was thus initiated in 1986, as a development of the Environmental ...company. The work of Mariquest was completed in 1989 by Cultured Seafood Group, Inc., Laguna Vista, TX. The

A Neural Network Based Workstation for Automated Cell Proliferation Analysis

DTIC Science & Technology

2001-10-25

work was supported by the Programa de Apoyo a Proyectos de Desarrollo e Investigacíon en Informática REDII 2000. We thank Blanca Itzel Taboada for...Meléndez1, G. Corkidi.2 1Centro de Instrumentos, UNAM. P.O. Box 70-186, México 04510, D.F. 2Instituto de Biotecnología, UNAM. P.O. Box 510-3, 62250...proliferation analysis, of cytological microscope images. The software of the system assists the expert biotechnologist during cell proliferation and

GT-9A - EARTH SKY - CENTRAL COASTAL AREA OF PERU

NASA Image and Video Library

1966-06-05

S66-38298 (5 June 1966) --- The central coastal area of Peru as seen from the Gemini-9A spacecraft during its 35th revolution of Earth. The body of water is the Pacific Ocean. The mountains are in the Cordillera Blanca range of the Andes. The 22,205-feet Huascaran is the highest peak in the area. The image was taken with a modified 70mm Hasselblad camera, using Eastman Kodak, Ektachrome MS (S.O. 217) color film Photo credit: NASA

U-Pb and K-Ar geochronology in Paleozoic and Mesozoic intrusive rocks of the Coastal Cordillera, Valparaiso, Chile

USGS Publications Warehouse

Gana, Paulina; Tosdal, Richard M.

1996-01-01

The U-Pb and K-Ar geochronology applied to intrusive rocks from the Coastal Batholith of Central Chile, demonstrates the existence of a basement block of the Mirasol Unit, with a crystallization age of 299??10 Ma, exposed in the northern block of the Melipilla Fault. The age of 214??1 Ma obtained in the 'Dioritas Gne??isicas de Cartagena Unit', indicates that a Late Triassic magmatism took place in this region; it coincides with the end of an extensive crustal melting period, proposed for northern Chile. The ages of the Jurassic plutonic units (Laguna Verde, Sauce, Pen??uelas and Limache) are restricted to the 156-161 Ma interval, showing in certain cases, inherited zircons from an unknown source. The difference between ages obtained using both chronological methods is a few million years, indicating that a short time passed between the crystallization and the cooling of the plutonic bodies, as well as a fast magmatic differentiation process. The Laguna Verde and Sauce Units, experienced a fast uplift, probably as a result of an extensional tectonic process in the magmatic arc, or induced by the magmatic pressure through fracture zones during Middle Jurassic.

Chemical composition of Argentinean propolis collected in extreme regions and its relation with antimicrobial and antioxidant activities.

PubMed

Vera, Nancy; Solorzano, Eliana; Ordoñez, Roxana; Maldonado, Luis; Bedascarrasbure, Enrique; Isla, María I

2011-06-01

This paper reveals, for the first time, the functional properties of propolis from an extreme region of Argentine (El Rincón, Province of Catamarca, Argentina), as well as the isolation and identification of bioactive compounds. The antioxidant activity was determined by the ABTS method and beta-carotene bleaching. The antibacterial activity was determined on methicillin resistant Staphylococcus aureus (MRSA) by the microdilution method and bioautographic assays. Twelve compounds were isolated and identified by NMR spectroscopy. The main bioactive compounds were 2',4'-dihydroxy-3'-methoxychalcone (3), 2',4'-dihydroxychalcone (9), 2',4',4-trihydroxy-6'- methoxychalcone (8), 5-hydroxy-4',7-dimethoxyflavone (4), 4',5-dihydroxy-3,7,8-trimethoxyflavone (10) and 7-hydroxy- 5,8-dimethoxyflavone (11). All compounds were active against clinical isolates (MIC50 10 microg/mL) and displayed antioxidant activity (SC50 values of 20 microg/mL). The MIC and SC50 values of the isolated compounds were lower than those obtained with crude propolis extracts, chloroform sub-extracts and isolated fractions.

Environmental Assessment for Public-Private Venture Housing, South Texas Region

DTIC Science & Technology

2001-12-01

Laguna Madre and was being used as an ornamental shrub. Small assemblages of live oak (Quercus virginiana) and redbay ( Persea borbonia) still exist...sapidus) and American oyster (Crassostrea virginica) are other common shellfish resources found in shallow coastal waters of the Coastal Bend (Case...possibility of finding ocelot or jaguarundi in or near NAS Corpus Christi. Recently delisted (64 Federal Register 46542-58; August 25, 1999), American

Epidemiology of Transfusion-Transmitted Infections Among Multi-Transfused Patients in Seven Hospitals in Peru

DTIC Science & Technology

2005-01-01

locate jcv Epidemiology of transfusion-transmitted infections among multi-transfused patients in seven hospitals in Peru 1 VA. Laguna-Torres a...and risk factors associated with TTIs among a sample of multi-transfused adult patients in Peru Study design: A cross- sectional multi-center study...was conducted across seven major hospitals in Peru fi’om February 2003 to September 2004 Self-reported behavior lntbrmatlon (medical procedures

New Contributions to Pseudonapomyza (Diptera: Agromyzidae) from Spain: Addition of Three New Species

PubMed Central

Gil-Ortiz, Ricardo; Martinez, Michel; Jiménez-Peydró, Ricardo

2010-01-01

The genus Pseudonapomyza (Diptera: Agromyzidae) includes the main leafminer pests for monocots. Three new species are described that were captured using Malaise traps in “Tinença de Benifassà”, “Font Roja” and “Lagunas de La Mata-Torrevieja” (Spain) Natural Parks: Pseudonapomyza curvata n. sp., P. longitata n. sp., and P. sicicornis n. sp. Systematics. Ecological data are discussed. PMID:21062209

WIDELink: A Bootstrapping Approach to Identifying, Modeling and Linking On-Line Data Sources

DTIC Science & Technology

2005-07-01

Mercedes Benz of Laguna Niguel — and collected on the order of 250 records from these sites. We normalized all data by lowercasing it. We then ran the...0.38 > [ mercedes , benz ] [47K] [5 . 0l v8] [ford] [21 , 3Digit] [4 . 3l v8] [mercury] [20 , 3Digit] [3 . 2l 6cyl] [lincoln] [2Digit , 3Digit] [3 . 2l

Geology, geochemistry, geochronology, and economic potential of Neogene volcanic rocks in the Laguna Pedernal and Salar de Aguas Calientes segments of the Archibarca lineament, northwest Argentina

NASA Astrophysics Data System (ADS)

Richards, J. P.; Jourdan, F.; Creaser, R. A.; Maldonado, G.; DuFrane, S. A.

2013-05-01

This study presents new geochemical, geochronological, isotopic, and mineralogical data, combined with new geological mapping for a 2400 km2 area of Neogene volcanic rocks in northwestern Argentina near the border with Chile, between 25°10‧S and 25°45‧S. The area covers the zone of intersection between the main axis of the Cordillera Occidental and a set of NW-SE-trending structures that form part of the transverse Archibarca lineament. This lineament has localized major ore deposits in Chile (e.g., the late Eocene La Escondida porphyry Cu deposit) and large volcanic centers such as the active Llullaillaco and Lastarría volcanoes on the border between Chile and Argentina, and the Neogene Archibarca, Antofalla, and Cerro Galán volcanoes in Argentina. Neogene volcanic rocks in the Laguna Pedernal and Salar de Aguas Calientes areas are mostly high-K calc-alkaline in composition, and range from basaltic andesites, through andesites and dacites, to rhyolites. Magmatic temperatures and oxidation states, estimated from mineral compositions, range from ~ 1000 °C and ∆FMQ ≈ 1.0-1.5 in andesites, to ~ 850 °C and ∆FMQ ≈ 1.5-2.0 in dacites and rhyolites. The oldest rocks consist of early-middle Miocene andesite-dacite plagioclase-pyroxene-phyric lava flows and ignimbrites, with 40Ar/39Ar ages ranging from 17.14 ± 0.10 Ma to 11.76 ± 0.27 Ma. Their major and trace element compositions are typical of the Andean Central Volcanic Zone, and show strong crustal contamination trends for highly incompatible elements such as Cs, Rb, Th, and U. These rocks are geochemically grouped as sub-suite 1. This widespread intermediate composition volcanism was followed in the middle-late Miocene by a period of more focused rhyodacitic flow-dome complex formation. These felsic rocks are characterized by less extreme enrichments in highly incompatible elements, and increasing depletion of heavy rare earth elements. These rocks are geochemically grouped as sub-suite 2. The

ON-SITE CAVITY LOCATION-SEISMIC PROFILING AT NEVADA TEST SITE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forbes, C.B.; Peterson, R.A.; Heald, C.L.

1961-10-25

Experimental seismic studies were conducted at the Nevada Test Site for the purpose of designing and evaluating the most promising seismic techniques for on-site inspection. Post-explosion seismic profiling was done in volcanic tuff in the vicinity of the Rainier and Blanca underground explosions. Pre-explosion seismic profiling was done over granitic rock outcrops in the Climax Stock area, and over tuff at proposed location for Linen and Orchid. Near surface velocity profiling techniques based on measurements of seismic time-distance curves gave evidence of disturbances in near surface rock velocities over the Rainier and Refer als0 to abstract 30187. Blanca sites. Thesemore » disturbances appear to be related to near surface fracturing and spallation effects resulting from the reflection of the original intense compression wave pulse at the near surface as a tension pulse. Large tuned seismometer arrays were used for horizontal seismic ranging in an attempt to record back-scattered'' or reflected seismic waves from subsurface cavities or zones of rock fracturing around the underground explosions. Some possible seismic events were recorded from the near vicinities of the Rainier and Blanca sites. However, many more similar events were recorded from numerous other locations, presumably originating from naturally occurring underground geological features. No means was found for discriminating between artificial and natural events recorded by horizontal seismic ranging, and the results were, therefore, not immediately useful for inspection purposes. It is concluded that in some instances near surface velocity profiling methods may provide a useful tool in verifying the presence of spalled zones above underground nuclear explosion sites. In the case of horizontal seismic ranging it appears that successful application would require development of satisfactory means for recognition of and discrimination against seismic responses to naturally occurring geological

A genome-wide perspective about the diversity and demographic history of seven Spanish goat breeds.

PubMed

Manunza, Arianna; Noce, Antonia; Serradilla, Juan Manuel; Goyache, Félix; Martínez, Amparo; Capote, Juan; Delgado, Juan Vicente; Jordana, Jordi; Muñoz, Eva; Molina, Antonio; Landi, Vincenzo; Pons, Agueda; Balteanu, Valentin; Traoré, Amadou; Vidilla, Montse; Sánchez-Rodríguez, Manuel; Sànchez, Armand; Cardoso, Tainã Figueiredo; Amills, Marcel

2016-07-25

The main goal of the current work was to infer the demographic history of seven Spanish goat breeds (Malagueña, Murciano-Granadina, Florida, Palmera, Mallorquina, Bermeya and Blanca de Rasquera) based on genome-wide diversity data generated with the Illumina Goat SNP50 BeadChip (population size, N = 176). Five additional populations from Europe (Saanen and Carpathian) and Africa (Tunisian, Djallonké and Sahel) were also included in this analysis (N = 80) for comparative purposes. Our results show that the genetic background of Spanish goats traces back mainly to European breeds although signs of North African admixture were detected in two Andalusian breeds (Malagueña and Murciano-Granadina). In general, observed and expected heterozygosities were quite similar across the seven Spanish goat breeds under analysis irrespective of their population size and conservation status. For the Mallorquina and Blanca de Rasquera breeds, which have suffered strong population declines during the past decades, we observed increased frequencies of large-sized (ROH), a finding that is consistent with recent inbreeding. In contrast, a substantial part of the genome of the Palmera goat breed comprised short ROH, which suggests a strong and ancient founder effect. Admixture with African goats, genetic drift and inbreeding have had different effects across the seven Spanish goat breeds analysed in the current work. This has generated distinct patterns of genome-wide diversity that provide new clues about the demographic history of these populations.

Populating the Semantic Web

DTIC Science & Technology

2004-07-01

Cars domain. We wrapped two used cars sites — Anaheim Lincoln Mer- cury and Mercedes Benz of Laguna Niguel — and collected on the order of 250 records...Make Mileage Engine < 1.31± 0.46 > < 2.38± 0.92 > < 3.83± 0.38 > [ mercedes , benz ] [47K] [5 . 0l v8] [ford] [21 , 3DIGIT] [4 . 3l v8] [mercury] [20

G-Proteins and Signal Transduction Annual Symposium (43rd), Held in Woods Hole, Massachusetts on September 6-9, 1989

DTIC Science & Technology

1989-12-31

Belgium. family of neurotransmitter receptors in Aplysia Neurons. V. 13 A G-protein, Gj 3, regulates a chloride channel in renal Brezina, S.S. Vogel...Cantiello, Department of Medicine, Columbia University, New York, C.R. Patenaude and D.A. Ausiello, Renal Unit, NY. Massachusetts General Hospital and...College of Medicine, Houston, TX. Dunham, Departments de Fisiologia , Universidad de la Laguna, Tenerife, Canary Islands, Spain, Department of 45. In vitro

Communist Insurgency in the Philippines

DTIC Science & Technology

1994-06-01

Philippines, the Filipinos had practiced self-government. They had a political and social organization known as the barangay or village which...Cabuyao and Santa Rosa in Laguna. The "Sakdalista" revolt was motivated by nationalistic yearning and desire for social reforms. These revolts were...Philippine Revolution, narrates the social condition in the Philippines then: But by the 1920s and 󈧢s, a great economic and social change had swept

Influenza and Other Respiratory Viruses in Three Central American Countries

DTIC Science & Technology

2010-01-01

de Seguridad Social, Tegucigalpa, Honduras. Correspondence: V. A. Laguna-Torres, US Naval Medical Research Center Detachment, 3230 Lima Pl, Washington...percentage of adult participants, we iden- tified viruses in 42% of ILI episodes.16 In two studies of children in Mexico , greater than 47% of ILI was...The University of Honduras, The Instituto Hondu- reño de Seguridad Social, Tegucigalpa, Honduras the Hospital de Santa Ana, El Salvador, and all

Delivery Time Variance Reduction in the Military Supply Chain

DTIC Science & Technology

2010-03-01

Donald Rumsfeld, designated “U.S. Transportation Command as the single Department of Defense Distribution Process Owner (DPO)” (USTRANSCOM, 2004...paragraphs explain OptQuest’s 54 functionality and capabilities as described by Laguna (1997) and Glover et al. (1999) as well as the OptQuest for ARENA...throughout the solution space ( Glover et al., 1999). Heuristics are strategies (in this case algorithms) that use different techniques and available

Toxocara (Nematoda: Ascaridida) and Other Soil-Transmitted Helminth Eggs Contaminating Soils in Selected Urban and Rural Areas in the Philippines

PubMed Central

Paller, Vachel Gay V.; de Chavez, Emmanuel Ryan C.

2014-01-01

The extent of contamination of soils with soil transmitted helminthes (STH) eggs, particularly Toxocara, was determined in selected urban and rural towns of Laguna, Philippines. Soil samples were collected from public schools, house yards, and empty lots. Results revealed that, of the 1480 soil samples collected, 460 (31%) were positive for STH eggs. Toxocara sp. was the most prevalent (77%), followed by Ascaris sp. (11%), hookworms/strongyles/free-living nematodes (7%), and Trichuris sp. (5%). Some soil physicochemical parameters were also determined and associated with Toxocara eggs prevalence and density in soil. Results revealed that Toxocara sp. eggs were most prevalent in less acidic, relatively high temperature and high moisture soil conditions. They were also prevalent in sandy, silty, and loamy soil textures but less prevalent in clayey. No significant differences were found between depth 1 (0–5 cm) and depth 2 (6–10 cm). This study revealed that Toxocara sp. eggs are ubiquitous and the extent of contamination in soils from the selected towns of Laguna is relatively high. Hence, the data generated in this study can be used in promoting public awareness, particularly for pet owners and local health officials, for effective prevention and control of this parasitosis. PMID:25383372

Re-Evaluating the Geological Evidence for Late Holocene Marine Incursion Events along the Guerrero Seismic Gap on the Pacific Coast of Mexico.

PubMed

Bianchette, Thomas A; McCloskey, Terrence A; Liu, Kam-Biu

2016-01-01

Despite the large number of tsunamis that impact Mexico's Pacific coast, stratigraphic studies focusing on geological impacts are scanty, making it difficult to assess the long-term risks for this vulnerable region. Surface samples and six cores were taken from Laguna Mitla near Acapulco to examine sedimentological and geochemical evidence for marine incursion events. Sediment cores collected from behind the beach barrier are dominated by intercalated layers of peat and inorganic sediments, mostly silt and clay, with little or no sand. Sand- and shell-rich clastic layers with high levels of sulfur, calcium, and strontium only occur adjacent to the relict beach ridge remnants near the center of the lagoon. With the exception of one thin fine sand layer, the absence of sand in the near-shore cores and the predominance of the terrigenous element titanium in the inorganic layers, evidently eroded from the surrounding hillslopes, suggests that these large-grained intervals do not represent episodic marine incursions, but rather were likely formed by the erosion and redeposition of older marine deposits derived from the beach ridge remnants when water levels were high. These results do not support the occurrence of a large tsunami event at Laguna Mitla during the Late Holocene.

The influence of local policy on contraceptive provision and use in three locales in the Philippines.

PubMed

Lee, Romeo B; Nacionales, Lourdes P; Pedroso, Luis

2009-11-01

The Philippines has a family planning programme, but modern contraceptive prevalence has been moderate. Among low-income women, fewer are using modern methods, resulting in a fertility rate among them of 5.9. This limited use is due to lack of consistent national and local government support for modern methods because of religious opposition. Following devolution of responsibility for health services to local government in 1991, three local leaders - in Laguna Province and the cities of Manila and Puerto Princesa - passed anti-modern contraceptive policies. This paper analyses the status and impact of these policies, using information from interviews with local government officials and family planning officers, published data and studies, and accounts in national newspapers. In Laguna Province and Puerto Princesa, the policies were ineffectually implemented or short-lived. The strictly-enforced Manila law, however, has severely disrupted the city's provision of free contraception to and method use by low-income women. The great majority of Filipinos (89%) approve of modern contraceptives. There is an urgent need to improve low-income women's access to modern contraceptives through itinerant and community-based distribution, especially in poor neighbourhoods in Manila, but also throughout the country. Strategies for increasing local government support for and provision of modern methods are also needed.

Re-Evaluating the Geological Evidence for Late Holocene Marine Incursion Events along the Guerrero Seismic Gap on the Pacific Coast of Mexico

PubMed Central

Bianchette, Thomas A.

2016-01-01

Despite the large number of tsunamis that impact Mexico’s Pacific coast, stratigraphic studies focusing on geological impacts are scanty, making it difficult to assess the long-term risks for this vulnerable region. Surface samples and six cores were taken from Laguna Mitla near Acapulco to examine sedimentological and geochemical evidence for marine incursion events. Sediment cores collected from behind the beach barrier are dominated by intercalated layers of peat and inorganic sediments, mostly silt and clay, with little or no sand. Sand- and shell-rich clastic layers with high levels of sulfur, calcium, and strontium only occur adjacent to the relict beach ridge remnants near the center of the lagoon. With the exception of one thin fine sand layer, the absence of sand in the near-shore cores and the predominance of the terrigenous element titanium in the inorganic layers, evidently eroded from the surrounding hillslopes, suggests that these large-grained intervals do not represent episodic marine incursions, but rather were likely formed by the erosion and redeposition of older marine deposits derived from the beach ridge remnants when water levels were high. These results do not support the occurrence of a large tsunami event at Laguna Mitla during the Late Holocene. PMID:27571270

Documentation Driven Software Development

DTIC Science & Technology

2010-06-01

Applications, Vol. 13, No. 1, March, 2006, pp. 28-38. 3. G. Jacoby, R. Marchany, Davis IV, “Using Battery Constraints Within Mobile Hosts To Improve Network ...2005. 2. Luqi, V. Berzins, William Roof, “Nautical Predictive Routing Protocol (NPRP) for the Dynamic Ad-Hoc Nautical Network (DANN)”, Monterey...Workshop 2005: realization of reliable systems on top of unreliable networked platforms, Laguna Beach, California, September, 2005. 3. B. Lewis, “The

Measuring the Behavior and Response to Sound of Beaked Whales Using Recording Tags

DTIC Science & Technology

2004-01-01

led by Alberto Brito of the University of La Laguna. His team of biology graduate students maintain a field station in the island of El Hierro ...in the Canary Island field site of El Hierro (Figs. 3, 4). In analyzing identification photos, the Italian group have confirmed sightings of several...specie. The exceptional sighting rate of both species in El Hierro makes this one of the densest coastal populations of beaked whales known

The Life and Times of MG Dennis E. Nolan, 1872-1956, The Army’s First G2.

DTIC Science & Technology

1998-01-01

Laguna de Bay, across Cavite Province to themselves in the last war, were divided into 25 Naic, on the west coast of the island of Luzon. 14R...reaching Indang , the next ing Adjutant General, First District, Department of town on the westerly route, the cavalry captured 62 Northern Luzon. While...pacifying Cavite Province, BG Theodore Roosevelt proclaimed the Filipino-Ameri- Schwann’s brigade swung south and did much the can War officially ended

Mössbauer studies on some Argentinian soil: Mollisols from Bahia Blanca

NASA Astrophysics Data System (ADS)

Saragovi, C.; Labenski, F.; Duhalde, S. M.; Acebal, S.; Venegas, R.

1994-12-01

Clay fractions of a Mollisol sample as is, treated with ammonium oxalate (AO), with dithionite-citrate-bicarbonate (DCB) and with dithionite-ethilene-diamine-tetraacetic acid (D-EDTA) methods, were studied. Illite-montmorillonites together with hematites, goethites and maghemites, all of the AI-substituted and with a wide range of sizes, were identified. It is found that the AO attack extracts little iron, whereas the other two attacks extract the magnetic signal. Furthermore, the DCB attack facilitates the reduction of the Fe3+ ions, while the D-EDTA method does not. Instead, this attack extracts more clay mineral Fe ions. A comparison with large grain soil samples is made.

Mineralogy and crystallization history of a highly differentiated REE-enriched hypabyssal rhyolite: Round Top laccolith, Trans-Pecos, Texas

NASA Astrophysics Data System (ADS)

O'Neill, L. Christine; Elliott, Brent A.; Kyle, J. Richard

2017-09-01

The Round Top hypabyssal rhyolite laccolith is a highly evolved magmatic system, enriched in incompatible elements including REE [Rare Earth Element(s)], U, Be, and F. The Round Top intrusion is part of a series of Paleogene intrusions emplaced as the Sierra Blanca Complex. These intrusions are situated within long-lived, complex tectonic regimes that have been subjected to regional compression and subduction, punctuated by extensional bimodal volcanism. The enrichment in the rhyolite that comprises Round Top is the result of the prolonged removal of compatible elements from the source magma chamber through the emplacement of earlier magmatic events. With the emplacement of each sequential laccolith, the F-rich source magma became more enriched in incompatible elements, with increasing HREE [Heavy Rare Earth Elements(s)] concentrations. The emplacement of Round Top as a laccolith (versus that of an extrusive rhyolitic flow) facilitated the retention of the volatile-rich vapor phase within the magma, forming ubiquitous REE-bearing minerals, mainly yttrofluorite and yttrocerite. The high temperature mineral-vapor phase alteration of the feldspar groundmass was essential to the formation of REE minerals, where the pervasive open pore space was occupied by the late-crystallizing minerals. These late-forming REE-bearing minerals also occur as crystals associated with other accessory and trace phases, as inclusions within other phases, along grain boundaries, and along fractures and within voids. The rhyolite at Round Top and other laccolith intrusions in the Sierra Blanca Complex represent a new sub-type of magmatic rare earth element hosting system.

Downstream effects of hydropower production on aquatic macroinvertebrate assemblages in two rivers in Costa Rica.

PubMed

Chaves-Ulloa, Ramsa; Umaña-Villalobos, Gerardo; Springer, Monika

2014-04-01

Despite the fact that little is known about the consequences of hydropower production in tropical areas, many large dams (> 15 m high) are currently under construction or consideration in the tropics. We researched the effects of large hydroelectric dams on aquatic macroinvertebrate assemblages in two Costa Rican rivers. We measured physicochemical characteristics and sampled aquatic macroinvertebrates from March 2003 to March 2004 in two dammed rivers, Peñas Blancas and San Lorenzo, as well as in the undammed Chachagua River. Sites above and below the dam had differences in their physicochemical variables, with wide variation and extreme values in variables measured below the dam in the San Lorenzo River. Sites below the dams had reduced water discharges, velocities, and depths when compared with sites above the dams, as well as higher temperatures and conductivity. Sites above dams were dominated by collector-gatherer-scrapers and habitat groups dominated by swimmer-clingers, while sites below dams had a more even representation of groups. In contrast, a comparison between two sites at different elevation in the undammed river maintained a similar assemblage composition. Tributaries might facilitate macroinvertebrate recovery above the turbine house, but the assemblage below the turbine house resembled the one below the dam. A massive sediment release event from the dam decreased the abundance per sample and macroinvertebrate taxa below the dam in the Peñas Blancas River. Our study illustrates the effects of hydropower production on neotropical rivers, highlighting the importance of using multiple measures of macroinvertebrate assemblage structure for assessing this type of environmental impact.

Examining Dynamical Processes of Tropical Mountain Hydroclimate, Particularly During the Wet Season, Through Integration of Autonomous Sensor Observations and Climate Modeling

NASA Astrophysics Data System (ADS)

Hellstrom, R. A.; Fernandez, A.; Mark, B. G.; Covert, J. M.

2016-12-01

Peru is facing imminent water resource issues as glaciers retreat and demand increases, yet limited observations and model resolution hamper understanding of hydrometerological processes on local to regional scales. Much of current global and regional climate studies neglect the meteorological forcing of lapse rates (LRs) and valley and slope wind dynamics on critical components of the Peruvian Andes' water-cycle, and herein we emphasize the wet season. In 2004 and 2005 we installed an autonomous sensor network (ASN) within the glacierized Llanganuco Valley, Cordillera Blanca (9°S), consisting of discrete, cost-effective, automatic temperature loggers located along the valley axis and anchored by two automatic weather stations. Comparisons of these embedded hydrometeorological measurements from the ASN and climate modeling by dynamical downscaling using the Weather Research and Forecasting model (WRF) elucidate distinct diurnal and seasonal characteristics of the mountain wind regime and LRs. Wind, temperature, humidity, and cloud simulations suggest that thermally driven up-valley and slope winds converging with easterly flow aloft enhance late afternoon and evening cloud development which helps explain nocturnal wet season precipitation maxima measured by the ASN. Furthermore, the extreme diurnal variability of along-valley-axis LR, and valley wind detected from ground observations and confirmed by dynamical downscaling demonstrate the importance of realistic scale parameterizations of the atmospheric boundary layer to improve regional climate model projections in mountainous regions. We are currently considering to use intermediate climate models such as ICAR to reduce computing cost and we continue to maintain the ASN in the Cordillera Blanca.

[The Ebro River and the Camino de Santiago].

PubMed

Cuchí de la Cuesta, Carlos

2003-01-01

Humans travel for many reasons; here we concentrate in pilgrimage and the role of the Ebro River as their means of transportation. The Camino de Santiago through the Ebro is linked to the devotion to Santa María del Pilar de Zaragoza, where according to the tradition appeared in flesh and body (January 2, 40, BC). Famous pilgrims are Luis VII of France, Lady Blanca, daughter of Carlos III. The Ebro's navigability allowed sustaining the fervor alive as it is proven by the many records found Catón, Estrabrón, Plinio, Avieno) describing its use for pilgrimage and commercial purposes.

The Hydraenidae of Cuba (Insecta: Coleoptera) III. Description of two new hygropetric species of Hydraena Kugelann.

PubMed

Deler-Hernández, Albert; Fikáček, Martin; Delgado, Juan A

2017-04-07

Two new species of the genus Hydraena Kugelann, 1794 collected from hygropetric habitats in eastern Cuba are described: Hydraena (Hydraenopsis) blancae sp. nov. from the Nipe-Sagua-Baracoa mountain range, and Hydraena (Hydraenopsis) matthiasi sp. nov. from the Sierra Maestra mountain range. Both species, especially the latter, are closely related to Hydraena (Hydraenopsis) franklyni Deler-Hernández & Delgado, 2012. Diagnostic characters for both new species are provided and illustrated; habitat information and distributional data are also included. An updated key to Cuban species of Hydraena is provided. With this study, the number of species of Hydraena known from Cuba raises to six.

Small-sized mesotheriines (Mesotheriidae, Notoungulata) from Northwestern Argentina: Systematic, chronological, and paleobiogeographic implications

NASA Astrophysics Data System (ADS)

Armella, M. A.; Nasif, N. L.; Cerdeño, E.

2018-04-01

The Neogene outcrops in Northwestern Argentina have provided many fossil mammals, particularly notoungulates. However, the fossil record of the early stages of the late Miocene is scarce. The present study describes two mesotheriine specimens from Las Arcas Formation (underlying the Chiquimil Formation dated at 9.14 ± 0.09 Ma; Catamarca Province) and Saladillo Formation (dated at 10 ± 0.3 Ma; Tucumán Province), represented by a left maxillary fragment with complete M1-3 and a right isolated M3, respectively. The main feature of these pieces is their small size, significantly smaller than that of the Miocene genera Eutypotherium, Typotheriopsis, and Pseudotypotherium, recorded in Argentina. In contrast, these mesotheriines are closer to specimens known from Bolivia. The comparative analysis allows us to refer the material herein described to Plesiotypotherium aff. P. achirense and Mesotheriinae indet., with all cautions inherent to the incompleteness of the material. In turn, the paleobiogeographic implication of these new records is approached. A relationship concerning phylogenetic aspects, size, temporal range, and distribution pattern is proposed, taking into account the small size of the studied material in a temporal context of medium to large-sized mesotheriines.

Fine-scale genetic structure in populations of the Chagas' disease vector Triatoma infestans (Hemiptera, Reduvidae).

PubMed

Pérez de Rosas, Alicia R; Segura, Elsa L; Fusco, Octavio; Guiñazú, Adolfo L Bareiro; García, Beatriz A

2013-03-01

Fine scale patterns of genetic structure and dispersal in Triatoma infestans populations from Argentina was analysed. A total of 314 insects from 22 domestic and peridomestic sites from the locality of San Martín (Capayán department, Catamarca province) were typed for 10 polymorphic microsatellite loci. The results confirm subdivision of T. infestans populations with restricted dispersal among sampling sites and suggest inbreeding and/or stratification within the different domestic and peridomestic structures. Spatial correlation analysis showed that the scale of structuring is approximately of 400 m, indicating that active dispersal would occur within this distance range. It was detected difference in scale of structuring among sexes, with females dispersing over greater distances than males. This study suggests that insecticide treatment and surveillance should be extended within a radius of 400 m around the infested area, which would help to reduce the probability of reinfestation by covering an area of active dispersal. The inferences made from fine-scale spatial genetic structure analyses of T. infestans populations has demonstrated to be important for community-wide control programs, providing a complementary approach to help improve vector control strategies.

Holocene Paleohydrology of the tropical andes from lake records

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbott, M. B., LLNL

Two century-scale time series in northern Bolivia constrain the ages of abrupt changes in the physical, geochemical, and biological characteristics of sediments obtained from lakes that formed during deglaciation from the late Pleistocene glacial maximum. The watersheds of Laguna Viscachani (16{degrees}12`S, 68{degrees}07`W, 3780m) and Lago Taypi Chaka Kkota (16{degrees}13`S, 68{degrees}21`W, 4300m), located on the eastern and western slopes of the Cordillera Real, respectively, contain small cirque glaciers. A high-resolution chronology of the lake sediments is provided by 23 AMS {sup 14}C dates of discrete macro-fossils. Late Pleistocene glaciers retreated rapidly, exposing the lake basins between 10,700 and 9700 {sup 14}Cmore » yr B.P. The sedimentary facies suggest that after 8900 {sup 14}C B.P. glaciers were absent from the watersheds and remained so during the middle Holocene. An increase in the precipitation-evaporation balance is indicated above unconformities dated to about 2300 {sup 14}C yr B.P. in both Lago Taypi Chaka Kkota and Laguna Viscachani. An abrupt increase in sediment accumulation rated after 1400 {sup 14}C yr B.P. signals the onset of Neoglaciation. A possible link exists between the observed millennial-scale shifts in the regional precipitation- evaporation balance and seasonal shifts in tropical insolation.« less

Statewide summary for Texas: Chapter B in Emergent wetlands status and trends in the northern Gulf of Mexico: 1950-2010

USGS Publications Warehouse

Handley, Lawrence R.; Spear, Kathryn A.; Gibeaut, Jim; Thatcher, Cindy A.

2014-01-01

The Texas coast (Figure 1) consists of complex and diverse ecosystems with a varying precipitation gradient. The northernmost portion of the coast, extending from Sabine Lake to Galveston Bay, is composed of salt, brackish, intermediate, and fresh marshes, with humid flatwoods inland (Moulton and others, 1997). Coastal prairies are found across the entire coast. From Galveston Bay to Corpus Christi Bay, rivers feed into large bays and estuarine ecosystems. Barrier islands and peninsulas exist along the coast from Galveston Bay to the Mexican border. The southernmost portion of the coast is composed of wind-tidal flats and the hypersaline Laguna Madre. The Laguna Madre lacks rivers and has little rainfall and restricted inlet access to the Gulf. Semiarid rangeland and irrigated agricultural land can be found inland.Approximately 6 million people live in Texas’ coastal counties (U.S. Census Bureau, 2010; Texas GLO, 2013). Seventy percent of the state’s industry and commerce occurs within 160.9 km (100 miles) of the coast (Moulton and others, 1997). Texas ports support 1.4 million jobs and generate $6.5 billion in tax revenues (Texas GLO, 2013). Chemical and petroleum production and marine commerce thrive on the Texas coast. Agriculture, grazing, commercial and recreational fishing, and recreation and tourism are strong industries along the coast and in adjacent areas; oil and gas production, agriculture, and tourism are the state’s three largest industries.

Tecuamburro Volcano, Guatemala: exploration geothermal gradient drilling and results

USGS Publications Warehouse

Goff, S.J.; Goff, F.; Janik, C.J.

1992-01-01

Results of geological, volcanological, hydrogeochemical, and geophysical field studies conducted in 1988 and 1989 at the Tecuamburro geothermal site, Guatemala, indicate that there is a substantial shallow heat source beneath the area of youngest volcanism. Gases from acid-sulfate springs near Laguna Ixpaco consistently yield maximum estimated subsurface temperatures of 300??C. To obtain information on subsurface temperatures and temperature gradients, stratigraphy, fracturing, hydrothermal alteration, and hydrothermal fluids, a geothermal gradient core hole (TCB-1) was drilled to 808 m low on the northern flank of the Tecuamburro Volcano complex. The hole is located 300 m south of a 300m-diameter phreatic crater. Laguna Ixpaco, dated at 2910 years. TCB-1 temperature logs do not indicate isothermal conditions at depth and the calculated thermal gradient from 500-800 m is 230??C/km. Bottom hole temperature is close to 240??C. Calculated heat flow values are around 350-400 mW/m2. Fluid-inclusion and secondary-alteration studies indicate that veins and secondary minerals were formed at temperatures equal to or slightly less than present temperatures; thus, the Tecuamburro geothermal system may still be heating up. The integration of results from the TCB-1 gradient core hole with results from field studies provides strong evidence that the Tecuamburro area holds great promise for geothermal resource development. ?? 1992.

A mobile detector for measurements of the atmospheric muon flux

NASA Astrophysics Data System (ADS)

Mitrica, B.; Brancus, I. M.; Margineanu, R.; Petcu, M.; Dima, M.; Sima, O.; Haungs, A.; Rebel, H.; Petre, M.; Toma, G.; Saftoiu, A.; Apostu, A.

2011-04-01

Measurements of the underground atmospheric muon flux are important in order to determine accurately the overburden in mwe (meter water equivalent) of an underground laboratory for appreciating which kind of experiments are feasible for that location. Slanic- Prohava is one of the 7 possible locations for the European large underground experiment LAGUNA (Large Apparatus studying Grand Unification and Neutrino Astrophysics). A mobile device consisting of 2 scintillator plates (≍0.9 m2, each) one above the other and measuring in coincidence, was set-up for determining the muon flux. The detector it is installed on a van which facilitates measurements on different positions at the surface or in the underground and it is in operation since autumn 2009. The measurements of muon fluxes presented in this contribution have been performed in the underground salt mine Slanic-Prahova, Romania, where IFIN-HH has built a low radiation level laboratory, and at the surface on different sites of Romania, at different elevations from 0 m a.s.l up to 655 m a.s.l. Based on our measurements we can say that Slanic site is a feasible location for LAGUNA in Unirea salt mine at a water equivalent depth of 600 mwe. The results have been compared with Monte-Carlo simulations performed with the simulation codes CORSIKA and MUSIC.

Air-to-air view of STS-26 Discovery, OV-103, launch from KSC

NASA Technical Reports Server (NTRS)

1988-01-01

Air-to-air view of STS-26 Discovery, Orbiter Vehicle (OV) 103, launch taken by T. Haydee Laguna, an airline passenger bound for Paradise Island in the Bahamas. She sent the photo of what she called 'the most beautiful sight this side of Heaven' to NASA along with a congratulatory letter. OV-103 is a small dot as it rises through the clouds from Kennedy Space Center Launch Complex (LC) pad 39B with a exhaust plume trailing behind it.

Bibliography of Publications Prior to July 1983 of the Coastal Engineering Research Center and the Beach Erosion Board.

DTIC Science & Technology

1984-03-01

and Laguna Madre , Texas, and the results of an office study of avatiabLe ,4. field data at the channel from construction in 1957 to 1975. GITI 13...E *.I.* M I SBU R E i , lE’, P J< 1:f W 0 RE * S ’ CH NOL!R:.I: I*IM E N I ; G OI. 0 M( R IPH I.(O ,0 G ;I COi-,S ; S MASA ’ i; S VT C; ;I :C 1::L

Publications | Argonne National Laboratory

Science.gov Websites

Carlo, F. De Carlo, Francesco De Graef, Marc de Jalon, Garcia De La Rosa, K. de Leon, P.A. Ignacio- de . Degenkolb, E. DeJongh, M. DeLisi, M. Delmont, T. O. DeLuca, C. Demas, N. Demchenko, Y. Demeshko, I. Demiguel , N. Kyrpides, Nikos La Joie, C. Labarta, J. LaBissoniere, D. Lacinski, L. Lacour, S. Laguna, I. Lai

Analytic Simulation of Tissue Damage from Penetrating Wounds to the Heart

DTIC Science & Technology

2006-12-01

Fragment Penetration – Sensitivity Study………. 141 I. Comparison of Long Rod versus Wedge Fragment Penetration into Gelatin…… 145 J. An Acoustic Model for...Penetrating Wounds to the Heart, MMVR 2005. See Appendix N. (2) El-Raheb, M., An Acoustic Model for Wave Propagation in a Weak Layer, JOURNAL OF APPLIED...An acoustic model for wave propagation in a weak layer” Michael El-Raheb ATK Mission Research, Laguna Hills, CA ATK MISSION RESEARCH W81XWH-04-C-0084

Geotechnical Data Inventory, Southern California Coastal Zone, Cape San Martin (Monterey County) to Mexican Border.

DTIC Science & Technology

1985-12-01

Adequate Several moderate to snail Santa Ynez Mts. sized creeks and streams The largest potential source for sediment is La Honda Canyon. Major drainage...Sized or Area Relative Size Sediment Rate Drainage Basin(s) Santa Ynez River (See note 5) Large 48,000 cu. yds./yr. Ref: 66 Honda Ck (See note 5) Small...Hematite- Ilmenite, Epidote. Ref: 4A Heavy Minerals* Ref: 56A Epidote Augite Hornblende Chlorite Opaques Los Angeles 9 6 23 12 33 Cliffs Laguna Beach "Coarse

Baja California, Mexico

NASA Technical Reports Server (NTRS)

1989-01-01

Sunglint on the surface of the Sea of Cortez near the island of Tiburon (28.5 N, 112.5W) reveals intricate patterns of internal waves under the placid surface. Mexico's state of Sonora and the Sonora Desert is on the mainland and the state of Baja California consists of the entire peninsula. The large bay on the Pacific side of Baja is Laguna Ojo de Libre (Bay of Whales) which is a breeding area for the Pacific Grey Whales.

Community-Based Education in San Juan La Laguna, Solola, Guatemala

ERIC Educational Resources Information Center

Abreo, Christina

2010-01-01

Indigenous education in Guatemala is currently undergoing a massive overhaul in the depth and breadth of its reach in Maya areas. Although much can be said about the re-evaluation and incorporation of indigenous culture, language and worldview into the schools' curricula, it is still failing to reach the country's adult population. As a result of…

The freezing level in the tropical Andes, Peru: An indicator for present and future glacier extents

NASA Astrophysics Data System (ADS)

Schauwecker, Simone; Rohrer, Mario; Huggel, Christian; Endries, Jason; Montoya, Nilton; Neukom, Raphael; Perry, Baker; Salzmann, Nadine; Schwarb, Manfred; Suarez, Wilson

2017-05-01

Along with air temperatures, the freezing level height (FLH) has risen over the last decades. The mass balance of tropical glaciers in Peru is highly sensitive to a rise in the FLH, mainly due to a decrease in accumulation and increase of energy for ablation caused by reduced albedo. Knowledge of future changes in the FLH is thus crucial to estimating changes in glacier extents. Since in situ data are scarce at altitudes where glaciers exist (above 4800 m above sea level (asl)), reliable FLH estimates must be derived from multiple data types. Here we assessed the FLHs and their spatiotemporal variability, as well as the related snow/rain transition in the two largest glacier-covered regions in Peru by combining data from two climate reanalysis products, Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar Bright Band data, Micro Rain Radar data, and meteorological ground station measurements. The mean annual FLH lies at 4900 and 5010 m asl, for the Cordillera Blanca and Vilcanota, respectively. During the wet season, the FLH in the Cordillera Vilcanota lies 150 m higher compared to the Cordillera Blanca, which is in line with the higher glacier terminus elevations. Coupled Model Intercomparison Project version 5 (CMIP5) climate model projections reveal that by the end of the 21st century, the FLH will rise by 230 m (±190 m) for Representative Concentration Pathway (RCP) 2.6 and 850 m (±390 m) for RCP8.5. Even under the most optimistic scenario, glaciers may continue shrinking considerably, assuming a close relation between FLH and glacier extents. Under the most pessimistic scenario, glaciers may only remain at the highest summits above approximately 5800 m asl.

Long term measurements of light absorbing particles on tropical glaciers

NASA Astrophysics Data System (ADS)

Schmitt, C. G.; Sanchez Rodriguez, W.; Arnott, W. P.; All, J.; Schwarz, J. P.

2016-12-01

We present results of six years of measurements of light absorbing particles (LAP) on glaciers of the Cordillera Blanca mountain range in Peru. Tropical glaciers are important sources of water for human consumption, agriculture, and hydroelectric power in the region. Regular measurements in the dry season show that light absorbing particle concentrations are generally low (equivalent to the absorption equivalent of 5-30 nanograms of black carbon per gram of snow) during non-El Nino years while values increase substantially during the recent El Nino. Two years of monthly measurements at two glaciers show that fresh snow LAP concentration are very low while LAP levels increase dramatically during snow-less periods.

Climate Change and Mountain Community Fire Management in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

All, J.; Medler, M.; Cole, R. J.; Arques, S.; Schmitt, C. G.

2014-12-01

In the central Andes of Peru, climate change is altering fire risk through changes in local meteorology and fuel loading. Greater moisture and favorable growing conditions are increasing vegetative productivity, which in turn increases fuel loads. This process is accentuated during El Nino events and potentially results in increased fire occurrence and frequency during relatively dry La Nina events. Park officials are concerned about the ramification of the changes on local ecology and tourist use of the resources. However, using a time-series of two different products from the MODIS Terra and Aqua platforms (Active Fire and Burned Area), TRMM 3B43 precipitation data, and Multivariate ENSO Index data we document fire occurrence and extent from 2000 to 2010 and our analysis indicates that fires are burning exclusively during winter months when there are no natural ignition sources. Globally, fire is used in conjunction with grazing to improve the regeneration and yield of grasses. During our interviews, locals claimed to only set fires in the buffer zone outside of the park, but our analysis indicates that the buffer zone rarely burns and that most fires begin within the park and only occasionally move into the buffer zones. Additionally, we determined that although this is small-scale fire activity every year, overall fire is having a very minor effect on local systems. The park service must develop programs to work with local grazing stakeholders to better limit the impacts of fire, while also address the negative perceptions from tourists in the future. In this instance, fire perception and fire reality are not the same and the challenge for resource managers is how to reconcile these two factors in order to more effectively manage the parklands.

Managing glacier related risks in the Chucchún Catchment, Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

Muñoz, Randy; Gonzáles, César; Price, Karen; Frey, Holger; Huggel, Christian; Cochachin, Alejo; García, Javier; Mesa, Luis

2015-04-01

On April 11 2010, the city of Carhuaz and settlements in the Chucchún Catchment (Ancash region, Peru) suffered the impact of a glacier lake outburst flood. An avalanche of rock and ice from the Mount Hualcán hit the glacier lake 513, triggering a glacial lake outburst flood (GLOF) of 1 million m3 which destroyed farmland and several infrastructures. Although there was no loss of human life, the event caused panic in the population. In consequence, the Municipality of Carhuaz prioritized GLOF-related risk management. The Glacier Project, funded by Swiss Agency for Development and Cooperation, and executed by CARE Peru and the University of Zurich, fosters the coordination among public institutions (Glaciological Unit of the National Water Authority, the Ministry of Environment and Municipality) and the population for risk management. In this contribution we present all components of the risk management strategy as well as the lessons learned during the implementation. Risk management involves managing both glacier hazard as well as the vulnerability of the population. In this framework a glaciological and geomorphological characterization of Mount Hualcán and lake 513 was perfomed in order to model past and potential future outburst floods and to assess the slope stability conditions. Based on three potential GLOF scenarios of different magnitudes, a hazard map was produced for the entire catchment, which served as the basis for the vulnerability and risk assessment as well as for the design and the implementation of an Early Warning System (EWS), including evacuation planning. The EWS consists of 4 components: 1) knowledge of risk, through hazard and vulnerability characterization; 2) monitoring and alert, through the installation of monitoring stations on lake 513 for detecting avalanches with geophones and cameras; 3) broadcasting and communications, through the implementation of communication protocols between the Municipality of Carhuaz and emergency institutions (police, health centers and schools) and also authorities at higher coordination levels (Regional Government and the National Emergency Operations Center) enabling rapid emergency care; and 4) Responsiveness, through strengthening and training of public and private institutions and local leaders that make up the Civil Defense Platforms, the development of Emergency Operations Plan, and continuous organization of simulations for the population. As result, the population is aware of the risks they face and knok how to respond in case of a lake outburst event. In addition, the results generated during studies related to the risk analysis are used for land management of the Municipality of Carhuaz. The successful implementation of this risk management strategy was only possible by combining comprehensively scientific and local knowledge. This EWS represents a pilot experience in Peru and the Andes, and contributes to relatively scarce international experience with GLOF EWS. An important lesson is that these processes require active leadership of local authorities and continuous learning by the population. The mere existence of technology does not ensure the success of the risk reduction measures; this can only be attained by the internalization of processes and by taking responsibility against the existing hazard by each resident, authority and institution.

Stratigraphy, Structure, and Geologic and Coastal Hazards in the Peñuelas to Salinas Area, Southern Puerto Rico: A Compendium of Published Literature

USGS Publications Warehouse

Rodríguez-Martínez, Jesús

2007-01-01

The Puerto Rico Electrical Power Authority has proposed construction of a pipeline to convey natural gas from the municipio of Pe?uelas to the Aguirre thermoelectric power plant in the municipio of Salinas in southern Puerto Rico. To ensure that the geologic conditions along the possible routes do not represent a threat to the physical integrity of the natural gas pipeline, and thus comply with State and Federal regulations, the Puerto Rico Electrical Power Authority requested the U.S. Geological Survey to provide a synthesis of published literature of the geology of the coastal plain in the Pe?uelas to Salinas area. The study area is located in part of the Southern Coastal Plain of Puerto Rico. In the area that extends from the municipio of Pe?uelas eastward to the Laguna de las Salinas at Ponce, a distance of about 5 miles, the study area is underlain by middle Tertiary carbonate units. Eastward from the Laguna de las Salinas to the pipeline terminus at the Aguirre power plant in Salinas, a distance of about 30 miles, the terrain is underlain by fan-delta deposits of Quaternary age. The carbonate units and the fan-delta deposits are underlain by early Tertiary and older-age volcaniclastics with subordinate sedimentary rocks and lavas. The Great Southern Puerto Rico Fault Zone is the principal geologic structural feature in southern Puerto Rico. At present, the Great Southern Puerto Rico Fault Zone is considered largely quiescent, although it apparently is associated with minor earthquakes. There is no evidence of terrestrial, late Quaternary faulting within the Pe?uelas to Salinas area. Seismic activity in this area mostly originates from extension zones of more distal shallow sources such as Mona Canyon to the northwest and the Anegada Trough northeast of the island of Puerto Rico. The magnitude of completeness of earthquakes in the study area ranges from 2.0 to 2.5. The seismic density for the southern coast including the study area is about 0.128 earthquakes

222Radon Concentration Measurements biased to Cerro Prieto Fault for Verify its Continuity to the Northwest of the Mexicali Valley.

NASA Astrophysics Data System (ADS)

Lazaro-Mancilla, O.; Lopez, D. L.; Reyes-Lopez, J. A.; Carreón-Diazconti, C.; Ramirez-Hernandez, J.

2009-05-01

The need to know the exact location in the field of the fault traces in Mexicali has been an important affair due that the topography in this valley is almost flat and fault traces are hidden by plow zone, for this reason, the southern and northern ends of the San Jacinto and Cerro Prieto fault zones, respectively, are not well defined beneath the thick sequence of late Holocene Lake Cahuilla deposits. The purpose of this study was to verify if Cerro Prieto fault is the continuation to the southeast of the San Jacinto Fault proposed by Hogan in 2002 who based his analysis on pre-agriculture geomorphy, relocation and analysis of regional microseismicity, and trench exposures from a paleoseismic site in Laguna Xochimilco, Mexicali. In this study, four radon (222Rn) profiles were carried out in the Mexicali Valley, first, to the SW-NE of Cerro Prieto Volcano, second, to the W-E along the highway Libramiento San Luis Río Colorado-Tecate, third, to the W-E of Laguna Xochimilco and fourth, to the W-E of the Colonia Progreso. The Radon results allow us to identify in the Cerro Prieto profile four regions where the values exceed 100 picocuries per liter (pCi/L), these regions can be associated to fault traces, one of them associated to the Cerro Prieto Fault (200 pCi/L) and other related with Michoacán de Ocampo Fault (450 pCi/L). The profile Libramiento San Luis Río Colorado-Tecate, show three regions above 100 pCi/L, two of them related to the same faults. In spite of the results of the Laguna Xochimilco, site used by Hogan (2002), the profile permit us observe three regions above the 100 pCi/L, but we can associate only one of the regions above this level to the Michoacán de Ocampo Fault, but none region to the Cerro Prieto Fault. Finally in spite of the Colonia Progreso is the shortest profile with only five stations, it shows one region with a value of 270 pCi/L that we can correlate with the Cerro Prieto Fault. The results of this study allow us to think in the

A Crustal Velocity Model for South Mexicali Valley, Baja California, México.

NASA Astrophysics Data System (ADS)

Ramirez, E.; Vidal-Villegas, A.; Stock, J. M.; Gonzalez-Fernandez, A.

2016-12-01

The northern Baja California region consists of two subregions of different geological features: the Peninsular Ranges of Baja California, of granitic composition, and the Mexicali Valley region, characterized by a series of sedimentary basins: the Laguna Salada and the Mexicali Valley. Due to the lack of an appropriate crust model for South Mexicali Valley, a refraction study was conducted. We installed 16 three-component short period stations (2 Hz) and one broadband station (100 s - 50 Hz). The stations, spaced 6 km along a refraction profile, recorded a blast performed in the southwest Arizona near the border with Sonora, Mexico. Records gathered were used to estimate a crust velocity structure model for South Mexicali Valley. The beginning of the profile is at San Luis Rio Colorado (SLRC), Sonora and its ending is at the middle of Sierra Juarez, Baja California. As a "reverse shot", for a 47 km section between SLRC and El Mayor Mountain, we used an aftershock M 3.4 of the 2010 M 7.2 El Mayor - Cucapah earthquake. Record sections show seismograms with impulsive P arrivals for nearby stations. The arrival Pn wave is observed at three stations located in Laguna Salada and Sierra Juarez. From the first arrivals of refractions and reflections of the P wave we performed direct modeling of travel times and relative amplitudes (normalized synthetic seismograms). Method based on asymptotic ray theory programed in the RAYINVR software (Zelt and Smith, 1992). We propose an average-three-layer velocity structure model: 2.9, 5.6 and 6.9 km/s, with thicknesses of 1.2, 4.4 and 9.6 km, respectively. Velocities of our model for the region under study are about 1 km/s higher than the model proposed by McMechan and Mooney (1984) for the Imperial Valley. The preliminary interpretation using the "reverse shot" indicates a crust of 15 km depth beneath the Mexicali Valley and 19 km under the El Mayor Mountain and Laguna Salada basin. On the eastern side of the El Mayor Mountain we

Long-Term Vegetation Dynamics in a Megadiverse Hotspot: The Ice-Age Record of a Pre-montane Forest of Central Ecuador.

PubMed

Montoya, Encarni; Keen, Hayley F; Luzuriaga, Carmen X; Gosling, William D

2018-01-01

Tropical ecosystems play a key role in many aspects of Earth system dynamics currently of global concern, including carbon sequestration and biodiversity. To accurately understand complex tropical systems it is necessary to parameterise key ecological aspects, such as rates of change (RoC), species turnover, dynamism, resilience, or stability. To obtain a long-term (>50 years) perspective on these ecological aspects we must turn to the fossil record. However, compared to temperate zones, collecting continuous sedimentary archives in the lowland tropics is often difficult due to the active landscape processes, with potentially frequent volcanic, tectonic, and/or fluvial events confounding sediment deposition, preservation, and recovery. Consequently, the nature, and drivers, of vegetation dynamics during the last glacial are barely known from many non-montane tropical landscapes. One of the first lowland Amazonian locations from which palaeoecological data were obtained was an outcrop near Mera (Ecuador). Mera was discovered, and analysed, by Paul Colinvaux in the 1980s, but his interpretation of the data as indicative of a forested glacial period were criticised based on the ecology and age control. Here we present new palaeoecological data from a lake located less than 10 km away from Mera. Sediment cores raised from Laguna Pindo (1250 masl; 1°27'S, 78°05'W) have been shown to span the late last glacial period [50-13 cal kyr BP (calibrated kiloyears before present)]. The palaeoecological information obtained from Laguna Pindo indicate that the region was characterised by a relatively stable plant community, formed by taxa nowadays common at both mid and high elevations. Miconia was the dominant taxon until around 30 cal kyr BP, when it was replaced by Hedyosmum , Asteraceae and Ilex among other taxa. Heat intolerant taxa including Podocarpus , Alnus , and Myrica peaked around the onset of the Last Glacial Maximum (c. 21 cal kyr BP). The results obtained from

Long-Term Vegetation Dynamics in a Megadiverse Hotspot: The Ice-Age Record of a Pre-montane Forest of Central Ecuador

PubMed Central

Montoya, Encarni; Keen, Hayley F.; Luzuriaga, Carmen X.; Gosling, William D.

2018-01-01

Tropical ecosystems play a key role in many aspects of Earth system dynamics currently of global concern, including carbon sequestration and biodiversity. To accurately understand complex tropical systems it is necessary to parameterise key ecological aspects, such as rates of change (RoC), species turnover, dynamism, resilience, or stability. To obtain a long-term (>50 years) perspective on these ecological aspects we must turn to the fossil record. However, compared to temperate zones, collecting continuous sedimentary archives in the lowland tropics is often difficult due to the active landscape processes, with potentially frequent volcanic, tectonic, and/or fluvial events confounding sediment deposition, preservation, and recovery. Consequently, the nature, and drivers, of vegetation dynamics during the last glacial are barely known from many non-montane tropical landscapes. One of the first lowland Amazonian locations from which palaeoecological data were obtained was an outcrop near Mera (Ecuador). Mera was discovered, and analysed, by Paul Colinvaux in the 1980s, but his interpretation of the data as indicative of a forested glacial period were criticised based on the ecology and age control. Here we present new palaeoecological data from a lake located less than 10 km away from Mera. Sediment cores raised from Laguna Pindo (1250 masl; 1°27′S, 78°05′W) have been shown to span the late last glacial period [50–13 cal kyr BP (calibrated kiloyears before present)]. The palaeoecological information obtained from Laguna Pindo indicate that the region was characterised by a relatively stable plant community, formed by taxa nowadays common at both mid and high elevations. Miconia was the dominant taxon until around 30 cal kyr BP, when it was replaced by Hedyosmum, Asteraceae and Ilex among other taxa. Heat intolerant taxa including Podocarpus, Alnus, and Myrica peaked around the onset of the Last Glacial Maximum (c. 21 cal kyr BP). The results obtained from

Carryover effects associated with winter location affect fitness, social status, and population dynamics in a long-distance migrant

USGS Publications Warehouse

Sedinger, James S.; Schamber, Jason L.; Ward, David H.; Nicolai, Christopher A.; Conant, Bruce

2011-01-01

We used observations of individually marked female black brant geese (Branta bernicla nigricans; brant) at three wintering lagoons on the Pacific coast of Baja California—Laguna San Ignacio (LSI), Laguna Ojo de Liebre (LOL), and Bahía San Quintín (BSQ)—and the Tutakoke River breeding colony in Alaska to assess hypotheses about carryover effects on breeding and distribution of individuals among wintering areas. We estimated transition probabilities from wintering locations to breeding and nonbreeding by using multistratum robust-design capture-mark-recapture models. We also examined the effect of breeding on migration to wintering areas to assess the hypothesis that individuals in family groups occupied higher-quality wintering locations. We used 4,538 unique female brant in our analysis of the relationship between winter location and breeding probability. All competitive models of breeding probability contained additive effects of wintering location and the 1997–1998 El Niño–Southern Oscillation (ENSO) event on probability of breeding. Probability of breeding in non-ENSO years was 0.98 ± 0.02, 0.68 ± 0.04, and 0.91 ± 0.11 for females wintering at BSQ, LOL, and LSI, respectively. After the 1997–1998 ENSO event, breeding probability was between 2% (BSQ) and 38% (LOL) lower than in other years. Individuals that bred had the highest probability of migrating the next fall to the wintering area producing the highest probability of breeding.

Lack of Microbial Diversity in an Extreme Mars Analog Setting: Poás Volcano, Costa Rica.

PubMed

Hynek, Brian M; Rogers, Karyn L; Antunovich, Monique; Avard, Geoffroy; Alvarado, Guillermo E

2018-04-24

The Poás volcano in Costa Rica has been studied as a Mars geochemical analog environment, since both the style of hydrothermal alteration present and the alteration mineralogy are consistent with Mars' relict hydrothermal systems. The site hosts an active volcano, with high-temperature fumaroles (up to 980°C) and an ultra-acidic lake. This lake, Laguna Caliente, is one of the most dynamic environments on Earth, with frequent phreatic eruptions, temperatures ranging from near-ambient to almost boiling, a pH range of -1 to 1.5, and a wide range of chemistries and redox potential. Martian acid-sulfate hydrothermal systems were likely similarly dynamic and equally challenging to life. The microbiology existing within Laguna Caliente was characterized for the first time, with sampling taking place in November, 2013. The diversity of the microbial community was surveyed via extraction of environmental DNA from fluid and sediment samples followed by Illumina sequencing of the 16S rRNA gene. The microbial diversity was limited to a single species of the bacterial genus Acidiphilium. This organism likely gets its energy from oxidation of reduced sulfur in the lake, including elemental sulfur. Given Mars' propensity for sulfur and acid-sulfate environments, this type of organism is of significant interest to the search for past or present life on the Red Planet. Key Words: Mars astrobiology-Acid-sulfate hydrothermal systems-Extremophiles-Acidic-High temperature-Acidiphilium bacteria. Astrobiology 18, xxx-xxx.

Succession in a microbial mat community - A Gaian perspective

NASA Technical Reports Server (NTRS)

Stolz, J. F.

1984-01-01

The contribution of prokaryotes to Gaian control systems is discussed. The survival of the Microcoleus-dominated stratified microbial community at Laguna Figueroa, after heavy rains flooded the evaporite flat with up to 3 m of water and deposited 5-10 cm of allocthonous sediment, demonstrates the resiliency of these communities to short-term perturbations while the microbial fossil record attests to their persistence over geologic time. It is shown that the great diversity of microbial species and their short generation time make them uniquely suited for Gaian mechanisms.

The diversity of Odonata and their endophytic ovipositions from the Upper Oligocene Fossillagerstätte of Rott (Rhineland, Germany)

PubMed Central

Petrulevičius, Julián F.; Wappler, Torsten; Nel, André; Rust, Jes

2011-01-01

Abstract A commented list of fossil Odonata from the Oligocene outcrop of Rott is given, together with descriptions of new traces of oviposition in plant tissues, very similar to ichnotaxa already known from the early Eocene Laguna del Hunco floras of Patagonia. The joint presences of odonatan larvae and traces of oviposition demonstrate the autochthony of these insects in the palaeolake of Rott, confirming the existence of a diverse and abundant aquatic entomofauna, a situation strikingly different to that in the contemporaneous Oligocene palaeolake of Céreste (France). PMID:22259267

Honduras: World Oil Report 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-08-01

This paper reports that after a lull last year, the Director General of Mines and Hydrocarbons the drilling is expected to resume this year with two onshore tests. Presumably, one of these will be a wildcat by Venezuela's Cambria Resources in the jungle area of the Mosquitia province along the Caribbean coast. Cambria Resources took over the Brus Laguna concession in this area from Bonavista Oil and Mining Corp. and finished a 348-mi seismic survey in 1989. Venezuela's PDVSA subsidiary, Maraven, also signed a deal in April to explore offshore this same area.

Sulphation of CaO-Based Sorbent Modified in CO2 Looping Cycles

NASA Astrophysics Data System (ADS)

Manovic, Vasilije; Anthony, Edward J.; Loncarevic, Davor

CaO-based looping cycles for CO2 capture at high temperatures are based on cyclical carbonation of CaO and regeneration of CaCO3. The main limitation of natural sorbents is the loss of carrying capacity with increasing numbers of reaction cycles, resulting in spent sorbent ballast. Use of spent sorbent from CO2 looping cycles for SO2 capture is a possible solution investigated in this study. Three limestones were investigated: Kelly Rock (Canada), La Blanca (Spain) and Katowice (Poland). Carbonation/calcination cycles were performed in a tube furnace with original limestones and samples thermally pretreated for different times (i.e., sintered). The spent sorbent samples were sulphated in a thermogravimetric analyzer. Changes in the resulting pore structure were then investigated using mercury porosimetry. Final conversions of both spent and pretreated sorbents after longer sulphation times were comparable or higher than those observed for the original sorbents. Maximum sulphation levels strongly depend on sorbent porosity and pore surface area. The shrinkage of sorbent particles during calcination/cycling resulted in a loss of sorbent porosity (≤48%), which corresponds to maximum sulphation levels ˜55% for spent Kelly Rock and Katowice. However, this is ˜10% higher than for the original samples. By contrast, La Blanca limestone had more pronounced particle shrinkage during pretreatment and cycling, leading to lower porosity, <35%, resulting in sulphation conversion of spent samples <30%, significantly lower than for the original sample (45%). These results showed that spent sorbent samples from CO2 looping cycles can be used as sorbents for SO2 retention if significant porosity loss does not occur during CO2 reaction cycles. For spent Kelly Rock and Katowice samples final conversions are determined by the total pore volume available for the bulky CaSO4 product.

Chemical profile of size-fractionated soils collected in a semiarid industrial area of Argentina

NASA Astrophysics Data System (ADS)

Morales Del Mastro, Anabella; Pereyra, Marcelo; Londonio, Agustín; Pereyra, Victoria; Rebagliati, Raúl Jiménez; Dawidowski, Laura; Gómez, Darío; Smichowski, Patricia

2014-12-01

A study was undertaken to assess the chemical profile of soil collected in Bahía Blanca (Argentina). In this industrial city, semiarid soils are affected by different industrial and agricultural activities, the presence of a saltpeter extraction facility, traffic and increasing urbanization. Sixteen soil samples (superficial and sub-superficial) were collected. Samples were sieved in two fractions (A < 37 μm, and 37 < B < 50 μm) before elemental analysis. Major, minor and trace elements namely, Al, As, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sb, Ti, V and Zn were determined by inductively coupled plasma optical emission spectrometry (ICP OES). Anions (Cl-, F-, SO42-) and cations (K+, Na+ and NH4+) were determined by high performance liquid chromatography (HPLC) after an aqueous extraction. As expected, crustal elements namely, Al, Ca, Fe, Mg and Ti exhibited the highest concentrations. Mean elemental concentration ranged from <0.3 μg g-1 (Sb) to 14.6 ± 0.6% (Ca). Ions concentrations in the soluble fraction measured at mg g-1 levels were in the order Cl- > Na+ ≅ SO42- > K+ > NO3-. Three indicators, namely, (i) coefficient of variation, (ii) coefficient of divergence and (iii) ratio of elemental concentration with respect to Ca were used to assess chemical, spatial and inter-profile variability. Chloride > Ca > Na+ > Mo > SO42-, dominated the variability indicating that these are key chemical markers for future assessment of crustal contribution to airborne particles in the area. The ratios Xi/Ca allowed discriminating the soil of the semi-arid region surrounding Bahía Blanca. The chemical profiles obtained in this study, particularly those of topsoil, will be a key input to characterize soil resuspension and its contribution to airborne particulate matter in a forthcoming receptor model analysis.

Ocean Model Impact Study for Coupled Hurricane Forecasting: An HFIP Initiative

NASA Astrophysics Data System (ADS)

Kim, H. S. S.; Halliwell, G. R., Jr.; Tallapragada, V.; Black, P. G.; Bond, N.; Chen, S.; Cione, J.; Cronin, M. F.; Ginis, I.; Liu, B.; Miller, L.; Jayne, S. R.; Sanabia, E.; Shay, L. K.; Uhlhorn, E.; Zhu, L.

2016-02-01

Established in 2009, the NOAA Hurricane Forecast Improvement Project (HFIP) is a ten-year project to promote accelerated improvements hurricane track and intensity forecasts (Gall et al. 2013). The Ocean Model Impact Tiger Team (OMITT) consisting of model developers and research scientists was formed as one of HFIP working groups in December 2014, to evaluate the impact of ocean coupling in tropical cyclone (TC) forecasts. The team investigated the ocean model impact in real cases for Category 3 Hurricane Edouard in 2014, using simulations and observations that were collected for different stages of the hurricane. Two Eastern North Pacific Hurricanes in 2015, Blanca and Dolores, are also of special interest. These two powerful Category 4 storms followed a similar track, however, they produced dramatically different ocean cooling, about 7.2oC for Hurricane Blanca but only about 2.7oC for Hurricane Dolores, and the corresponding intensity changes were negative 40 ms-1 and 20 ms-1, respectively. Two versions of operational HWRF and COAMPS-TC coupled prediction systems are employed in the study. These systems are configured to have 1D and 3D ocean dynamics coupled to the atmosphere. The ocean components are initialized separately with climatology, analysis and nowcast products to evaluate the impact of ocean initialization on hurricane forecasts. Real storm forecast experiments are being designed and performed with different levels of the ocean model complexity and various model configurations to study model sensitivity. In this talk, we report the OMITT activities conducted during the past year, present preliminary results of on-going investigation of air-sea interactions in the simulations, and discuss future plans toward improving coupled TC predictions. Gall, R., J. Franklin, F. Marks, E.N. Rappaport, and F. Toepfer, 2013: THE HURRICANE FORECAST IMPROVEMENT PROJECT. Bull. Amer. Meteor. Soc., 329-343.

Microseismicity Studies in Northern Baja California: General Results.

NASA Astrophysics Data System (ADS)

Frez, J.; Acosta, J.; Gonzalez, J.; Nava, F.; Suarez, F.

2005-12-01

Between 1997 and 2003, we installed local seismological networks in northern Baja California with digital, three-component, Reftek instruments, and with 100-125 Hz sampling. Each local network had from 15 to 40 stations over an area approximately of 50 x 50 km2. Surveys have been carried out for the Mexicali seismic zone and the Ojos Negros region (1997), the San Miguel fault system (1998), the Pacific coast between Tijuana and Ensenada (1999), the Agua Blanca and Vallecito fault systems (2001), the Sierra Juarez fault system (2002), and other smaller areas (2001 and 2003). These detailed microseismicity surveys are complemented with seismograms and arrival times from regional networks (RESNOM and SCSN). Selected locations presented here have errors (formal errors from HYPO71) less than 1 km. Phase reading errors are estimated at less than or about 0.03 s. Most of the activity is located between mapped fault traces, along alignments which do not follow the fault traces, and where tectonic alignments intersect. The results suggests an orthogonal pattern at various scales. Depth distributions generally have two maxima, one secondary maximum, at about 5 km; the other, located at 12-17 km. The Agua Blanca fault is essentially inactive for earthquakes with ML > 1.7. Most focal mechanisms are strike-slip with a minor normal component; the others are dominantly normal; the resulting pattern indicates a regional extensional regime for all the regions with an average NS azimuth for the P-axes. Fracture directions, obtained from directivity measurements, show orthogonal directions, one of which approximately coincides with the azimuth of mapped fault traces. These results indicate that the Pacific-North American interplate motion is not being entirely accommodated by the NW trending faults, but rather is creating a complex system of conjugate faults.

Evaluation of an early warning system for glacial lake outburst flood (GLOF) events in Huaraz, Peru

NASA Astrophysics Data System (ADS)

McKinney, D. C.; Somos-Valenzuela, M. A.

2014-12-01

People in Cordillera Blanca range in Peru have a long history dealing with natural disasters associated to high mountains; particularly Glacier Lakes Outburst Flood (GLOF). Examples in the Cordillera Blanca vary from a GLOF that occurred in 1941 that killed more than 5000 people in the city of Huaraz to recent events from Lake Artison Baja in 2012 and Lake 513 on 2010, which were not devastating thanks to safety systems previously installed in those lakes. However, glaciers continue melting leaving new lakes or changing the characteristics of lakes that were previously controlled making safety systems obsolete that worked successfully in the past protecting communities downstream. Lake Palcacocha has evolved from being safe after the installation of a safety system in 1970 to an imminent source of GLOF risk due to the expansion that has occurred during the last 40 years increasing from a volume of 500,000 to 17 million m3. In response to this risk the community in Huaraz is planning an Early Warning System (EWS) that will allow the population to mobilize to a safe area in case a GLOF occurs. In this work we present an adaptation of the LifeSIM model to calculate the benefits from such an EWS using 2007 census data and a FLO-2D flood simulation model. The outputs are the number of people in Huaraz that could lose their life due to a GLOF. Our results indicate that without an EWS around 19,773 people could lose their life; whereas, if an EWS is installed the number of victims reduces to 7344. Finally, if mobilization of the affected population is improved the value reduces to 2865. The results show the importance of the EWS as well as informing and training the population to how to react if a GLOF occurs.

Cryophenomena in the Cold Desert of Atacama

NASA Astrophysics Data System (ADS)

Buchroithner, Dr.; Trombotto, Dr.

2012-04-01

The study area of the Valle de Barrancas Blancas in the High Atacama Andes of Chile (68°39' W, 27°02' S), a kind of Patagonian "bajo sin salida", shows well preserved landforms resulting from a combination of slope, eolian, lacustrine/litoral, fluvial, glacial and periglacial regimes. They permit the reconstruction of geomorphological processes within this isolated catchment of approximately 160 km2. The mean annual air temperature varies between -2 and -4 °C and the precipitation is approximately 150 mm/a. Snowfall is frequent but the snow is quickly sublimated, redeposited and/or covered by cryosediments, i.e. mainly pumice pebbles. Water bodies present icings, even in summer. Regarding its climatic conditions the study area represents an extremely cold desertic region. Extremophile microfauna was also found. The area displays both in situ mountain permafrost and creeping permafrost. The active layer is 30 to 45 cm thick. It is a periglacial macro-environment where interdependent processes, and not only cryogenic processes but also erosion and eolian deposition and the action of fluvial washout mainly caused by precipitation, accumulation, retransportation/redeposition and melting of snow, play an important role. The cryogenic geomorphology of the Valle de Barrancas Blancas is varied and contains microforms such as patterned ground and microforms caused by cryoturbation, as well as mesoforms like rockglaciers and cryoplanation surfaces. Slopes are strongly affected by gelifluction. New cryoforms in South America and in the Southern Hemisphere like the Atacama Pingo (Pingo atacamensis) and Permafrosted Dunes ("Dunas heladas") were found. Intense niveo-eolian processes participate in the erosion of preexisting landforms, in the formation of subterraneous ice layers, and the retransportation/redeposition of snow and sediments. Studies of this periglacial environment are crucial for the understanding of Tundrean paleoenvironments and Martian conditions.

A new species of stygobitic freshwater crab of the genus Rodriguezia Bott, 1969 (Crustacea: Decapoda: Trichodactylidae) from Tabasco, Mexico.

PubMed

Alvarez, Fernando; Villalobos, JosÉ Luis

2018-02-07

A new species of freshwater crab of the family Trichodactylidae, genus Rodriguezia Bott, 1969 is described from Grutas de Agua Blanca in southern Tabasco, Mexico. Rodriguezia is a genus endemic to northern Chiapas and southern Tabasco, distributed over a small area of 70 km. Rodriguezia adani n. sp., the third species of the genus, occurs north of its two congeners, being stygobitic with obvious adaptations to cave life. It can be distinguished from R. villalobosi, an epigean species, by the absence of eyes, lack of pigmentation and elongation of the pereiopods; and from R. mensabak by having less elongated pereiopods relative to carapace breadth, an extremely reduced ocular peduncle, and a smaller adult size.

NSR&D FY15 Final Report. Modeling Mechanical, Thermal, and Chemical Effects of Impact

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Christopher Curtis; Ma, Xia; Zhang, Duan Zhong

2015-11-02

The main goal of this project is to develop a computer model that explains and predicts coupled mechanical, thermal and chemical responses of HE under impact and friction insults. The modeling effort is based on the LANL-developed CartaBlanca code, which is implemented with the dual domain material point (DDMP) method to calculate complex and coupled thermal, chemical and mechanical effects among fluids, solids and the transitions between the states. In FY 15, we have implemented the TEPLA material model for metal and performed preliminary can penetration simulation and begun to link with experiment. Currently, we are working on implementing amore » shock to detonation transition (SDT) model (SURF) and JWL equation of state.« less

Lipids of recently-deposited algal mats at Laguna Mormona, Baja California

NASA Technical Reports Server (NTRS)

Cardoso, J.; Brooks, P. W.; Eglinton, G.; Goodfellow, R.; Maxwell, J. R.; Philp, R. P.

1976-01-01

A preliminary survey of the lipid composition of the core of a recently deposited algal mat of a subtropical, hypersaline coastal pond is described. Two layers of the core were examined: the upper, 2-cm-thick layer, comprising the fresh algal mat of predominantly the blue-green species Microcoleus chthonoplastes, and the black anaerobic algal ooze at a depth of 10 cm. About 75% of the n-alkanes in the mat were accounted for by n-C17, with smaller amounts of higher homologues maximizing at n-C27. The ooze was characterized by a bimodal distribution with maxima at n-C17 and n-C27. The n-alkanoic acids distributions were similar to the corresponding n-alkane distributions. A marked decrease in the ratio of monounsaturated to saturated acids in the ooze relative to the mat was observed, which indicates a preferential removal of unsaturated components. Certain triterpenes of the hopane skeletal type were present in the mat and ooze. The presence of stanols and sterenes in the ooze with similar carbon number distributions suggests a relationship between them.

SRTM Colored Height and Shaded Relief: Laguna Mellquina, Andes Mountains, Argentina

NASA Image and Video Library

2001-06-14

This depiction of an area south of San Martin de Los Andes, Argentina, is the first Shuttle Radar Topography Mission SRTM view of the Andes Mountains, the tallest mountain chain in the western hemisphere.

Morphological and geochemical variations of Cyprideis (Ostracoda) from modern waters of the northern Neotropics.

PubMed

Meyer, J; Wrozyna, C; Gross, M; Leis, A; Piller, W E

2017-01-01

The variability of modern Cyprideis salebrosa and Cyprideis americana (Ostracoda) from the northern Neotropics were investigated in order to understand site specific influences on the isotopic composition of their valves (δ 18 O, δ 13 C) in comparison to their host water and to connect this to morphological features of their valves (valve size, nodosity). C. salebrosa was found in a stream (Shell Creek, Florida) and a slightly brackish lake (Laguna del Rincon, Dominican Republic; salinity <0.7 psu) while C. americana occurred in a coastal lake with polyhaline waters (Parrotee Pond, Jamaica; salinity: >20 psu). Valve size and position of nodes differed between the two species. A reverse temperature dependency have been considered to influence Shell length (seasonally in Shell Creek, summer: 1076 µm; winter: 1092 µm, supposedly permanently in Laguna del Rincon, 1035 µm). But, regarding the small dataset other factors could not be excluded to influence ostracod valve size. A decline of node frequency of C. salebrosa is mainly related to an increase in salinity. Isotopic values of ostracod valves reflect the trend in stable isotopes of their host water. Variations in Cyprideis salebrosa δ 18 O and δ 13 C values signify differences in their host water. Offsets of ostracod valves to a theoretical calcite precipitated in their host water with an uncertain time lag (+0.015 to +2.63 ‰) needs to be clarified. This study presents a contribution to the understanding of environmental influences on modern ostracod shell characters as basis for paleontological applications.

Molecular analysis of new isolates of Tomato leaf curl Philippines virus and an associated betasatellite occurring in the Philippines.

PubMed

Sharma, Pradeep; Matsuda, N; Bajet, N B; Ikegami, M

2011-02-01

Three new begomovirus isolates and one betasatellite were obtained from a tomato plant exhibiting leaf curl symptom in Laguna, the Philippines. Typical begomovirus DNA components representing the three isolates (PH01, PH02 and PH03) were cloned, and their full-length sequences were determined to be 2754 to 2746 nucleotides. The genome organizations of these isolates were similar to those of other Old World monopartite begomoviruses. The sequence data indicated that PH01 and PH02 were variants of strain B of the species Tomato leaf curl Philippines virus, while PH03 was a variant of strain A of the species Tomato leaf curl Philippines virus. These isolates were designated ToLCPV-B[PH:Lag1:06], ToLCPV-B[PH:Lag2:06], and ToLCPV-A[PH:Lag3:06], respectively. Phylogenetic analysis revealed that the present isolates form a separate monophyletic cluster with indigenous begomoviruses reported earlier in the Philippines. A betasatellite isolated from same sample belongs to the betasatellite species Tomato leaf curl Philippines betasatellite and designated Tomato leaf curl Philippines betasatellite-[Philippines:Laguna1:2006], ToLCPHB-[PH:Lag1:06]. When co-inoculated with this betasatellite, tomato leaf curl Philippines virus induced severe symptoms in N. benthamiana and Solanum lycopersicum plants. Using a PVX-mediated transient assay, we found that the C4 and C2 proteins of tomato leaf curl Philippines virus and the βC1 protein of ToLCPHB-[PH:Lag1:06] function as a suppressor of RNA silencing.

A Study of the Type II-Plateau Supernova SN 2014cx

NASA Astrophysics Data System (ADS)

Flatland, Kelsi; Leonard, Douglas Christopher; Williams, George Grant; Smith, Paul S.; Bilinski, Christopher; Dessart, Luc; Gonzalez, Luis; Hoffman, Jennifer L.; Huk, Leah; Milne, Peter; Smith, Nathan

2015-08-01

The type II-plateau (II-P) class of supernova is the most commonly observed type of core-collapse event, and yet the basic characteristics of this class are still being defined (e.g. Pejcha & Prieto 2015). Here we add to the growing sample of type II-P events with well-sampled data from observations of SN 2014cx. SN 2014cx was independently discovered on September 2, 2014 UT by Nakano et al. (2014; CBET 3963) and Holoien et al. (2014; ATEL 6436) in the nearby (d ~ 20.7 Mpc, Tully 1988) SBd galaxy NGC 337. It was classified as a young Type II supernova through spectra taken within a day of discovery at both optical (Nakano et al. 2014) and near-infrared (Morrell et al. 2014; ATEL 6442) wavelengths. Later (Andrews et al. 2015; ATEL 7084), it was photometrically determined to be specifically a type II-P supernova, indicating the core-collapse event of a progenitor that had a large hydrogen envelope (Pejcha & Prieto 2015). We initiated a photometric and spectropolarimetric campaign to follow SN 2014cx; over a five month period following the supernova's discovery, we obtained optical images using the 1-meter telescope at Mount Laguna Observatory as part of the MOunt LAguna SUpernova Survey (MOLASUS), and spectra as part of the SuperNova SpectroPOLarimetry project (SNSPOL). Here we present the initial analysis of the photometry and spectroscopy obtained as part of this campaign. We acknowledge support from NSF grants AST-1009571 and AST-1210311, under which part of this research was carried out.

A Study of the Type II-Plateau Supernova SN 2014cx

NASA Astrophysics Data System (ADS)

Flatland, Kelsi; Leonard, Douglas C.; Williams, Grant; Smith, Paul S.; Bilinski, Christopher; Gonzalez, Luis; Hoffman, Jennifer L.; Huk, Leah N.; Milne, Peter; Smith, Nathan; Supernova Spectropolarimetry Project

2016-06-01

The type II-plateau (II-P) class of supernova is the most commonly observed type of core-collapse event, and yet the basic characteristics of this class are still being defined (e.g. Pejcha & Prieto 2015). Here we add to the growing sample of type II-P events with well-sampled data from observations of SN 2014cx. SN 2014cx was independently discovered on September 2, 2014 UT by Nakano et al. (2014; CBET 3963) and Holoien et al. (2014; ATEL 6436) in the nearby (d ~ 20.7 Mpc, Tully 1988) SBd galaxy NGC 337. It was classified as a young Type II supernova through spectra taken within a day of discovery at both optical (Nakano et al. 2014) and near-infrared (Morrell et al. 2014; ATEL 6442) wavelengths. Later (Andrews et al. 2015; ATEL 7084), it was photometrically determined to be specifically a type II-P supernova, indicating the core-collapse event of a progenitor that had a large hydrogen envelope (Pejcha & Prieto 2015). We initiated a photometric and spectropolarimetric campaign to follow SN 2014cx; over a five month period following the supernova's discovery, we obtained optical images using the 1-meter telescope at Mount Laguna Observatory as part of the MOunt LAguna SUpernova Survey (MOLASUS), and spectra as part of the SuperNova SpectroPOLarimetry project (SNSPOL). Here we present the analysis of the photometry and spectroscopy obtained as part of this campaign. We acknowledge support from NSF grants AST-1009571 and AST-1210311, under which part of this research was carried out.

Patterns of mortality in a montane mixed-conifer forest in San Diego County, California.

PubMed

Freeman, Mary Pyott; Stow, Douglas A; An, Li

2017-10-01

We examine spatial patterns of conifer tree mortality and their changes over time for the montane mixed-conifer forests of San Diego County. These forest areas have recently experienced extensive tree mortality due to multiple factors. A spatial contextual image processing approach was utilized with high spatial resolution digital airborne imagery to map dead trees for the years 1997, 2000, 2002, and 2005 for three study areas: Palomar, Volcan, and Laguna mountains. Plot-based fieldwork was conducted to further assess mortality patterns. Mean mortality remained static from 1997 to 2002 (4, 2.2, and 4.2 trees/ha for Palomar, Volcan, and Laguna) and then increased by 2005 to 10.3, 9.7, and 5.2 trees/ha, respectively. The increase in mortality between 2002 and 2005 represents the temporal pattern of a discrete disturbance event, attributable to the 2002-2003 drought. Dead trees are significantly clustered for all dates, based on spatial cluster analysis, indicating that they form distinct groups, as opposed to spatially random single dead trees. Other tests indicate no directional shift or spread of mortality over time, but rather an increase in density. While general temporal and spatial mortality processes are uniform across all study areas, the plot-based species and quantity distribution of mortality, and diameter distributions of dead vs. living trees, vary by study area. The results of this study improve our understanding of stand- to landscape-level forest structure and dynamics, particularly by examining them from the multiple perspectives of field and remotely sensed data. © 2017 by the Ecological Society of America.

Earth Observations taken by Expedition 38 crewmember

NASA Image and Video Library

2014-01-21

ISS038-E-035123 (21 Jan. 2014) --- Apoyeque Volcano, Nicaragua is featured in this image photographed by an Expedition 38 crew member on the International Space Station. The Chiltepe Peninsula, highlighted in this photograph, extends into Lake Managua in west-central Nicaragua. The peninsula is formed from part of a large ignimbrite shield, a geologic structure created by deposition of primarily low density materials (such as pumice) ejected during violent, explosive eruptive activity. Ignimbrite deposits are most commonly emplaced during large pyroclastic flows - gravity-driven mixtures of rock, ash, and volcanic gases that can cover hundreds of kilometers at speeds of hundreds of kilometers per hour - with ignimbrite shields formed over geologic time by successive flows. The Apoyeque caldera, filled with a 2.8-kilometer-wide and 400-meter-deep lake, dominates the center of the peninsula. Geological evidence indicates that Apoyeque last erupted around 50 BCE (plus or minus 100 years). The Laguna Xiloa maar - a volcanic crater formed by the explosive interaction of magma and groundwater - is located immediately to the southeast of Apoyeque and is also filled with a lake. According to scientists, Laguna Xiloa last erupted approximately 6,100 years ago. More recently, a swarm of small earthquakes was detected near Apoyeque in 2012. These seismic swarms, when detected in volcanically active areas, may indicate movement of magma prior to an eruption. The capital city of Managua, not visible in the image, is located approximately 15 kilometers to the southeast of Apoyeque, while the town of Bosques de Xiloa is considerably closer (approximately four kilometers).

KSC-03pd1105

NASA Image and Video Library

2003-04-10

KENNEDY SPACE CENTER, FLA. -- David Mclaughlin, Prototype Lab technician at Kennedy Space Center, (center) poses with his Native American search team, the Laguna Firefighters from New Mexico, at the Hemphill site. Kennedy Space Center workers are participating in the Columbia Recovery efforts at the Lufkin (Texas) Command Center, four field sites in East Texas, and the Barksdale, La., hangar site. KSC is working with representatives from other NASA Centers and with those from a number of federal, state and local agencies in the recovery effort. KSC provides vehicle technical expertise in the field to identify, collect and return Shuttle hardware to KSC.

Aspilota-group (Hymenoptera: Braconidae: Alysiinae) diversity in Mediterranean Natural Parks of Spain

PubMed Central

Belokobylskij, Sergey A; Falcó-Garí, Jose Vicente; Jiménez-Peydró, Ricardo

2014-01-01

Abstract This work analyses the biodiversity of the Aspilota-group (Hymenoptera: Braconidae: Alysiinae) in three Mediterranean Natural parks: Natural Park of La Font Roja, Natural Park of Las Lagunas de la Mata-Torrevieja and Natural Park of La Tinença de Benifassà. Samples were carried out from April 2004 to December 2007. In total, 822 specimens, belonging to 52 species, were collected. Alpha, beta and gamma diversities were analysed, and the Tinença Park was proven to have higher diversity than the Font Roja and Torrevieja. Also, the structure of the Aspilota-group community was analysed. PMID:25197232

A nursing data base for initial patient assessment.

PubMed

Hartman, D; Knudson, J

1991-01-01

The introduction of nursing diagnoses at Saddleback Memorial Medical Center, Laguna Hills, CA, resulted in the nursing process becoming the basis for the documentation system. However, the medical model or body system remained the organizational structure for nursing data collection and narrative charting. The need for a model that would aid in identification and treatment of illness and not negatively affect the nursing process was the impetus behind the selection of Gordon's functional health patterns as the assessment format. These patterns provide a standard method for data collection and a holistic approach to assessment and diagnosis.

Analysis of organic matter in sediments and meteorites and paleochemical studies of extinct and contemporary life forms

NASA Technical Reports Server (NTRS)

Calvin, M.

1975-01-01

The insoluble organic materials present in the algal mats at Laguna Mormona, Baja California were studied. A series of six identical sediments collected from Mono lake which were stored under different conditions was investigated to see if any changes are observed in the lipid distribution patterns as a result of differences in sample storage conditions. Bacteria strains from Mono Lake sediments were cultured in bulk quantities and the sterol fractions from them were isolated and analyzed. Results add further support to the utility of the sterols as a chemotaxonomical tool in distinguishing and classifying these bacteria.

SUNLAB - The Project of a Polish Underground Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kisiel, J.; Dorda, J.; Konefall, A.

2010-11-24

The project of the first Polish underground laboratory SUNLAB, in the Polkowice-Sieroszowice copper mine, belonging to the KGHM Polska Miedz S.A. holding, is presented. Two stages of the project are foreseen: SUNLAB1 (a small laboratory in the salt layer exhibiting extremely low level of natural radioactivity) and SUNLAB2 (a big laboratory in the anhydrite layer, able to host the next generation liquid argon detector - GLACIER, which is considered within the LAGUNA FP7 project). The results of the natural radioactivity background measurements performed in the Polkowice-Sieroszowice salt cavern are also briefly summarized.

Recent Developments at the Accelerator Laboratory in Jyvaeskylae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trzaska, Wladyslaw Henryk

Recent developments at the Accelerator Laboratory in Jyvaeskylae are described. In addition to the existing K = 130 a new cyclotron has been added. It is capable of producing of high current proton and deuteron beams at 30 and 15 MeV correspondingly. It should be fully operational in 2010. A new development in Jyvaeskylae is the growing commitment to astroparticle physics. Jyvaeskylae took the main scientific responsibility for a new cosmic-ray experiment EMMA and has joined the LAGUNA project working on the design of the next generation of very large volume detectors for underground observatories.

Recent progress in Precambrian paleobiology

NASA Technical Reports Server (NTRS)

Schopf, J. W.

1986-01-01

Ongoing studies at UCLA include the following: (1) investigations in Archean and Proterozoic sequences of various locations; (2) laboratory and field studies of modern microbial biocoenoses (analogues of Precambrian microbial communities) especially those at Laguna Mormona, Baja California, Mexico; (3) development of new laboratory techniques for the separation and concentration of minute cellularly preserved fossils for isotopic and organic geochemical analyses; and (4) assembly of a computerized database for assessment of the timing and nature of major events occurring during Precambrian biotic evolution, and of the potential applicability of ancient microbiotas to problems of global biostratigraphy and biogeography.

SUNLAB-The Project of a Polish Underground Laboratory

NASA Astrophysics Data System (ADS)

Kisiel, J.; Budzanowski, M.; Chorowski, M.; Cygan, S.; Dorda, J.; Hanzel, S.; Harańczyk, M.; Horoszczak, L.; Januszewska, K.; Jaroń, L.; Konefalł, A.; Kozak, K.; Lankof, L.; Mania, S.; Markiewicz, A.; Markowski, P.; Mazur, J.; Mertuszka, P.; Mietelski, J. W.; Poliński, J.; Puchalska, M.; Pytel, W.; Raczyński, M.; Sadecki, Z.; Sadowski, A.; Ślizowski, J.; Sulej, R.; Szarska, M.; Szeglowski, T.; Tomankiewicz, E.; Urbańczyk, K.; Zalewska, A.

2010-11-01

The project of the first Polish underground laboratory SUNLAB, in the Polkowice-Sieroszowice copper mine, belonging to the KGHM Polska Miedź S.A. holding, is presented. Two stages of the project are foreseen: SUNLAB1 (a small laboratory in the salt layer exhibiting extremely low level of natural radioactivity) and SUNLAB2 (a big laboratory in the anhydrite layer, able to host the next generation liquid argon detector-GLACIER, which is considered within the LAGUNA FP7 project). The results of the natural radioactivity background measurements performed in the Polkowice-Sieroszowice salt cavern are also briefly summarized.

Groundwater-surface water interactions in a glacierized catchment and their influence on proglacial water supply

NASA Astrophysics Data System (ADS)

Gordon, R. P.; Lautz, L. K.; McKenzie, J. M.; Mark, B. G.

2012-12-01

The tropical glaciers of the Cordillera Blanca of Peru are retreating rapidly due to climate change, which threatens water resources for the quarter-million inhabitants of the upper Rio Santa river valley and many more downstream. Recent studies have shown that glacial melt supplies approximately half of dry season stream discharge in Cordillera Blanca valleys. The remainder of streamflow is supplied by groundwater stored in alpine meadows, moraines and talus slopes. In the future, when glacier loss has reduced the influence of melt water on streams, groundwater discharge will be the primary dry-season source of stream water for irrigation, municipalities, and hydropower in the Santa watershed. A better understanding of the dynamics of alpine groundwater, including sources and exchange fluxes, is therefore important for future planning in this region. Understanding these groundwater-surface water interactions is necessary for making accurate estimates of meltwater contributions to the hydrologic budget, and for our ability to make predictions about future water resources under deglaciating conditions. We combined measurements of groundwater-surface water exchange during the dry season with synoptic sampling of stream water and end-members in order to quantify the groundwater contributions to streamflow from an alpine meadow, debris fan, and moraine complex in a glacierized valley of the Cordillera Blanca. Using stream tracer-dilution techniques, we calculated channel water balances for 9 stream reaches of 100-200 m throughout the meadow and measured the discharge of glacial meltwater into debris fan and moraine units. We used vertical heat tracing to measure stream-groundwater exchange at 2-hour increments over 2 weeks in 13 stream locations in the meadow, debris fan, and moraine units. Channel water balance and heat tracing results show that, during the studied portion of the dry season, the stream loses water (2.5 l/s or ~25% of flow) to the subsurface in the

Landscape ecology of Trypanosoma cruzi in the southern Yucatan Peninsula.

PubMed

López-Cancino, Sury Antonio; Tun-Ku, Ezequiel; De la Cruz-Felix, Himmler Keynes; Ibarra-Cerdeña, Carlos Napoleón; Izeta-Alberdi, Amaia; Pech-May, Angélica; Mazariegos-Hidalgo, Carlos Jesús; Valdez-Tah, Alba; Ramsey, Janine M

2015-11-01

Landscape interactions of Trypanosoma cruzi (Tc) with Triatoma dimidiata (Td) depend on the presence and relative abundance of mammal hosts. This study analyzed a landscape adjacent to the Calakmul Biosphere Reserve, composed of conserved areas, crop and farming areas, and the human community of Zoh Laguna with reported Chagas disease cases. Sylvatic mammals of the Chiroptera, Rodentia, and Marsupialia orders were captured, and livestock and pets were sampled along with T. dimidiata in all habitats. Infection by T. cruzi was analyzed using mtDNA markers, while lineage and DTU was analyzed using the mini-exon. 303 sylvatic specimens were collected, corresponding to 19 species during the rainy season and 114 specimens of 18 species during dry season. Five bats Artibeus jamaicensis, Artibeus lituratus, Sturnira lilium, Sturnira ludovici, Dermanura phaeotis (Dp) and one rodent Heteromys gaumeri were collected in the three habitats. All but Dp, and including Carollia brevicauda and Myotis keaysi, were infected with predominately TcI in the sylvatic habitat and TcII in the ecotone. Sigmodon hispidus was the rodent with the highest prevalence of infection by T. cruzi I and II in ecotone and domestic habitats. Didelphis viginiana was infected only with TcI in both domestic and sylvatic habitats; the only two genotyped human cases were TcII. Two main clades of T. cruzi, lineages I (DTU Ia) and II (DTU VI), were found to be sympatric (all habitats and seasons) in the Zoh-Laguna landscape, suggesting that no species-specific interactions occur between the parasite and any mammal host, in any habitat. We have also found mixed infections of the two principal T. cruzi clades in individuals across modified habitats, particularly in livestock and pets, and in both haplogroups of T. dimidiata. Results are contradictory to the dilution hypothesis, although we did find that most resilient species had an important role as T. cruzi hosts. Our study detected some complex trends in

End to deficit of LPG. [Argentina] (in Spanish)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrich, V.

1980-03-01

In the Buenos Aires province of Argentina, Gas de Estado is constructing the future heart of the petrochemical complex, Bahia Blanca. The complex contains 2 absorption-refrigeration plants, a gas compressing plant, equipment maintenance shops and an important operations base for the Argentine truck gas pipelines. This will be the largest LPG plant in Latin America. The General Cerri plant, under construction, is located in an area of 40,000 sq m with new installations to extract ethane and higher hydrocarbons. The design optimizes the extraction of hydrocarbons from the natural gas and recovers 76% of the ethane. Selection of the processmore » resulted from an investigation that compared the system with processes that use water cooling and absorption with refrigerated oil.« less

Volatile components from mango (Mangifera indica L.) cultivars.

PubMed

Pino, Jorge A; Mesa, Judith; Muñoz, Yamilie; Martí, M Pilar; Marbot, Rolando

2005-03-23

The volatile components of 20 mango cultivars were investigated by means of simultaneous distillation-extraction, GC, and GC-MS. Three hundred and seventy-two compounds were identified, of which 180 were found for the first time in mango fruit. The total concentration of volatiles was approximately 18-123 mg/kg of fresh fruit. Terpene hydrocarbons were the major volatiles of all cultivars, the dominant terpenes being delta-3-carene (cvs. Haden, Manga amarilla, Macho, Manga blanca, San Diego, Manzano, Smith, Florida, Keitt, and Kent), limonene (cvs. Delicioso, Super Haden, Ordonez, Filipino, and La Paz), both terpenes (cv. Delicia), terpinolene (cvs. Obispo, Corazon, and Huevo de toro), and alpha-phellandrene (cv. Minin). Other qualitative and quantitative differences among the cultivars could be demonstrated.

Quantification by SEM-EDS in uncoated non-conducting samples

NASA Astrophysics Data System (ADS)

Galván Josa, V.; Castellano, G.; Bertolino, S. R.

2013-07-01

An approach to perform elemental quantitative analysis in a conventional scanning electron microscope with an energy dispersive spectrometer has been developed for non-conductive samples in which the conductive coating should be avoided. Charge accumulation effects, which basically decrease the energy of the primary beam, were taken into account by means of the Duane-Hunt limit. This value represents the maximum energy of the continuum X-ray spectrum, and is related to the effective energy of the incident electron beam. To validate the results obtained by this procedure, a non-conductive sample of known composition was quantified without conductive coating. Complementarily, changes in the X-ray spectrum due to charge accumulation effects were studied by Monte Carlo simulations, comparing relative characteristic intensities as a function of the incident energy. This methodology is exemplified here to obtain the chemical composition of white and reddish archaeological pigments belonging to the Ambato style of "Aguada" culture (Catamarca, Argentina 500-1100 AD). The results obtained in this work show that the quantification procedure taking into account the Duane-Hunt limit is suitable for this kind of samples. This approach may be recommended for the quantification of samples for which coating is not desirable, such as ancient artwork, forensic or archaeological samples, or when the coating element is also present in the sample.

Characterization of bacterial diversity associated with microbial mats, gypsum evaporites and carbonate microbialites in thalassic wetlands: Tebenquiche and La Brava, Salar de Atacama, Chile.

PubMed

Farías, M E; Contreras, M; Rasuk, M C; Kurth, D; Flores, M R; Poiré, D G; Novoa, F; Visscher, P T

2014-03-01

In this paper, we report the presence of sedimentary microbial ecosystems in wetlands of the Salar de Atacama. These laminated systems, which bind, trap and precipitate mineral include: microbial mats at Laguna Tebenquiche and Laguna La Brava, gypsum domes at Tebenquiche and carbonate microbialites at La Brava. Microbial diversity and key biogeochemical characteristics of both lakes (La Brava and Tebenquiche) and their various microbial ecosystems (non-lithifying mats, flat and domal microbialites) were determined. The composition and abundance of minerals ranged from trapped and bound halite in organic-rich non-lithifying mats to aragonite-dominated lithified flat microbialites and gypsum in lithified domal structures. Pyrosequencing of the V4 region of the 16s rDNA gene showed that Proteobacteria comprised a major phylum in all of the microbial ecosystems studied, with a marked lower abundance in the non-lithifying mats. A higher proportion of Bacteroidetes was present in Tebenquiche sediments compared to La Brava samples. The concentration of pigments, particularly that of Chlorophyll a, was higher in the Tebenquiche than in La Brava. Pigments typically associated with anoxygenic phototrophic bacteria were present in lower amounts. Organic-rich, non-lithifying microbial mats frequently formed snake-like, bulbous structures due to gas accumulation underneath the mat. We hypothesize that the lithified microbialites might have developed from these snake-like microbial mats following mineral precipitation in the surface layer, producing domes with endoevaporitic communities in Tebenquiche and carbonate platforms in La Brava. Whereas the potential role of microbes in carbonate platforms is well established, the contribution of endoevaporitic microbes to formation of gypsum domes needs further investigation.

Water-quality and ancillary data collected from the Arroyo Colorado near Rio Hondo, Texas, 2006

USGS Publications Warehouse

Roussel, Meghan C.; Canova, Michael G.; Asquith, William H.; Kiesling, Richard L.

2007-01-01

The Arroyo Colorado is in the lower Rio Grande Valley of southern Texas and extends from near Mission, Texas, eastward to the Laguna Madre estuarine and coastal marine system, which separates Padre Island from the Texas mainland. Streamflow in the Arroyo Colorado primarily is sustained by effluent from municipal wastewater-treatment plants along the stream banks. Since 1986, the tidal segment of the Arroyo Colorado from the port of Harlingen to the Laguna Madre has been designated by the State of Texas as an impaired water body because of low dissolved oxygen concentrations. Efforts to develop predictive water-quality models for the tidal segment of the Arroyo Colorado have been hampered by a lack of physical, biological, and biochemical data. Specifically, data on primary algal productivity, nutrient cycling, sediment deposition rates, and the relations between these processes and dissolved oxygen dynamics in the stream have been inadequate to support water-quality modeling efforts. The U.S. Geological Survey, in cooperation with the Texas Commission on Environmental Quality, did a study in 2006 to collect data associated with primary algal productivity, nutrient cycling, and dissolved oxygen dynamics in the tidal segment (2201) of the Arroyo Colorado near Rio Hondo. Specific objectives of the study were to (1) characterize water quality by measuring basic properties; (2) characterize the concentrations of carbon and nutrients, biochemical oxygen demand, total organic carbon, total suspended solids, and volatile suspended solids; (3) measure the seasonal differences of nutrient-dependent algal growth and algal production in the water column; (4) measure oxygen respiration or production rates; and (5) measure rates of sediment deposition.

Earth Observations taken by the Expedition 16 Crew

NASA Image and Video Library

2007-11-17

ISS016-E-010894 (17 Nov. 2007) --- Cosiguina Volcano, Nicaragua is featured in this image photographed by an Expedition 16 crewmember on the International Space Station. Three Central American countries (El Salvador, Honduras, and Nicaragua) include coastline along the Gulf of Fonseca that opens into the Pacific Ocean. The southern boundary of the Gulf is a peninsula formed by the Cosiguina volcano illustrated in this view. Cosiguina is a stratovolcano, typically tall cone-shaped structures formed by alternating layers of solidified lava and volcanic rocks (ash, pyroclastic flows, breccias) produced by explosive eruptions. The summit crater is filled with a lake (Laguna Cosiguina). The volcano last erupted in 1859, but its most famous activity occurred in 1835 when it produced the largest historical eruption in Nicaragua. Ash from the 1835 eruption has been found in Mexico, Costa Rica, and Jamaica. The volcano has been quiet since 1859, only an instant in terms of geological time. An earthquake swarm was measured near Cosiguina in 2002, indicating that tectonic forces are still active in the region although the volcano is somewhat isolated from the line of more recently active Central American volcanoes to the northwest and southeast. Intermittently observed gas bubbles in Laguna Cosiguina, and a hot spring along the eastern flank of the volcano are the only indicators of hydrothermal activity at the volcano. The fairly uniform vegetation cover (green) on the volcano's sides also attest to a general lack of gas emissions or "hot spots" on the 872 meter high cone, according to NASA scientists who study the photos downlinked from the orbital outpost.

Falcon Reservoir, Brownsville, TX, USA

NASA Image and Video Library

1991-08-11

STS043-151-043 (8 August 1991) --- The Rio Grande extends across the center of this photograph from Falcon Reservoir to its bulging delta, joining the Gulf of Mexico. Sediment brought down by the river is spread northward and southward by alongshore currents to form the barrier chain of Padre Island and its protected Laguna Madre Speckled agricultural land use patterns in the river valley contrast with range land northward from the white cloud, and with closed canopy forest on hills in Mexico. A Linhof camera with a 90mm lens, was used to expose the frame at 14:43 GMT, Aug. 8, 1991.

High plant diversity in Eocene South America: Evidence from Patagonia

USGS Publications Warehouse

Wilf, P.; Cuneo, N.R.; Johnson, K.R.; Hicks, J.F.; Wing, S.L.; Obradovich, J.D.

2003-01-01

Tropical South America has the highest plant diversity of any region today, but this richness is usually characterized as a geologically recent development (Neogene or Pleistocene). From caldera-lake beds exposed at Laguna del Hunco in Patagonia, Argentina, paleolatitude ~47oS, we report 102 leaf species. Radioisotopic and paleomagnetic analyses indicate that the flora was deposited 52 million years ago, the time of the early Eocene climatic optimum, when tropical plant taxa and warm, equable climates reached middle latitudes of both hemispheres. Adjusted for sample size, observed richness exceeds that of any other Eocene leaf flora, supporting an ancient history of high plant diversity in warm areas of South America.

Puerto Rico, humedales [Puerto Rico, wetlands

USGS Publications Warehouse

Adams, D. Briane; Hefner, John M.; Dopazo, Teresa

1999-01-01

descanso y la alimentación de cientos de aves migratorias en ruta entre Norte y Suramérica. Antes del drenaje de los humedales costeros para propósitos agrícolas, pantanos de agua dulce como los de la Laguna Cartagena, Laguna Guánica y Ciénaga El Anegado proveían hábitat a más de 1 00 especies de aves residentes y migratorias . Los humedales de las tierras altas del área central son el último refugio de la cotorra puertorriqueña, una especie en peligro de extinción. Aún los humedales del área metropolitana de San Juan (Laguna La Torrecilla, Torrecilla Baja, Laguna de Piñones hasta Punta Vacía Talega) proveen un hábitat excelente para la vida silvestre, mantienen criaderos de peces de alto valor económico y proveen recreación y oportunidades educativas a la población urbana.Treintiocho especies de vertebrados, moluscos y crustáceos, y 46 especies de aves, algunos raros o en peligro de extinción como la mariquita, el alcatraz, el pato dominicano, el pato silbón y la paloma cabeciblanca han sido observados en el área . También las playas asociadas con estos humedales urbanos proveen sitios de anidaje para las tortugas carey de concha y tinglar, ambas en peligro de extinción (Del Llano y otros, 1986).

Cosmic ray air shower characteristics in the framework of the parton-based Gribov-Regge model NEXUS

NASA Astrophysics Data System (ADS)

Bossard, G.; Drescher, H. J.; Kalmykov, N. N.; Ostapchenko, S.; Pavlov, A. I.; Pierog, T.; Vishnevskaya, E. A.; Werner, K.

2001-03-01

The purpose of this paper is twofold: first we want to introduce a new type of hadronic interaction model (NEXUS), which has a much more solid theoretical basis than, for example, presently used models such as QGSJET and VENUS, and ensures therefore a much more reliable extrapolation towards high energies. Secondly, we want to promote an extensive air shower (EAS) calculation scheme, based on cascade equations rather than explicit Monte Carlo simulations, which is very accurate in calculations of main EAS characteristics and extremely fast concerning computing time. We employ the NEXUS model to provide the necessary data on particle production in hadron-air collisions and present the average EAS characteristics for energies 1014-1017 eV. The experimental data of the CASA-BLANCA group are analyzed in the framework of the new model.

Estudio espectroscópico de la simbiótica CD-43o14304

NASA Astrophysics Data System (ADS)

García, L. G.; Brandi, E.; Ferrer, O. E.; Barbá, R.

En base a un monitoreo espectroscópico de estrellas simbióticas del hemisferio sur, realizado entre 1990 y 1997, se han reunido espectros en intermedia y alta resolución de la simbiótica CD-43o14304. Se trata de un sistema binario compuesto por una enana blanca y una gigante tipo K5 con un período orbital recientemente determinado, de 1448 días. Por primera vez se analiza el comportamiento espectral del objeto en un amplio rango espectral (3700-10000 Å) y en función de las fases orbitales observadas. Se interpretan las velocidades radiales de las emisiones y absorciones presentes y las variaciones en los perfiles estructurados de las líneas de Balmer y en el resto de las emisiones.

Extensive characterisation of bioactive phenolic constituents from globe artichoke (Cynara scolymus L.) by HPLC-DAD-ESI-QTOF-MS.

PubMed

Abu-Reidah, Ibrahim M; Arráez-Román, David; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

2013-12-01

The aim of this work was to characterise the phenolic compounds in artichoke (hearts) by using HPLC coupled to DAD-ESI-QTOF-MS, which proved useful in characterising 61 phenolic and other polar compounds. Notably, of the 61 compounds characterised, 34 new phenolic compounds with their isomers have been tentatively characterised in artichoke for the first time, namely: 3 hydroxybenzoic acids, 17 hydroxycinnamic acids, 4 lignans, 7 flavones, 2 flavonols, and 1 phenol derivative. Moreover, a total of 28 isomers of previously described phenolics have also been detected. The data compiled from the qualitative polyphenol characterisation indicate that the artichoke extract analysed (Blanca de Tudela variety) could be regarded as a bioactive functional food and also as a promising source of antioxidant phenolic compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evolución estelar en sistemas binarios

NASA Astrophysics Data System (ADS)

De Vito, M. A.; Benvenuto, O.

Definición y clasificación de sistemas binarios; descripción del comportamiento del sistema frente a la variación de su masa; binarias de rayos X; transferencia de masa en sistemas binarios masivos aplicado al posible esclarecimiento del progenitor azul de la supernova SN 1987A; comentario acerca de la evolución de enanas blancas de helio de baja masa y su conexión con los sistemas binarios; reseña del trabajo de Kippenhahn y Weigert sobre el cual está basado el código evolutivo desarrollado en la FCAG por el Dr. Benvenuto y sobre el cual se trabajará para poder incluir la evolución de una estrella con pérdida de masa perteneciente a un sistema binario.

Gas chromatography-mass spectrometry study of the essential oils of Schinus longifolia (Lindl.) speg., Schinus fasciculata (Griseb.) I. M. Johnst., and Schinus areira L.

PubMed

Murray, Ana P; Frontera, María A; Tomas, María A; Mulet, María C

2005-01-01

The essential oil composition from the aerial parts of three Anacardiaceae growing in Bahía Blanca, Argentina was studied by gas chromatography and gas chromatography-mass spectrometry. The essential oils of S. longifolia and S. fasciculata have been studied for the first time. The major constituents were alpha-pinene (46.5%), beta-pinene (15.1%) and alpha-phellandrene (10.1%) for S. longifolia and limonene (10.9%), beta-phellandrene (6.16%) and alpha-phellandrene (5.6%) for S. fasciculata. The major components of the essential oil of S. areira were limonene (28.6%), alpha-phellandrene (10.1%), sabinene (9.2%) and camphene (9.2%) differing from the literature data. The essential oils from S. areira and S. longifolia exhibited a high biotoxicity in a brine shrimp assay with Artemia persimilis.

New insights on the geological evolution of the continental margin of Southeastern Brazil derived from zircon and apatite (U-Th-Sm)/He and fission-track data

NASA Astrophysics Data System (ADS)

Krob, Florian; Stippich, Christian; Glasmacher, Ulrich A.; Hackspacher, Peter

2017-04-01

New insights on the geological evolution of the continental margin of Southeastern Brazil derived from zircon and apatite (U-Th-Sm)/He and fission-track data Krob, F.C.1, Stippich, C. 1, Glasmacher, U.A.1, Hackspacher, P.C.2 (1) Institute of Earth Sciences, Research Group Thermochronology and Archaeometry, Heidelberg University, INF 234, 69120, Heidelberg, Germany (2) Instituto de Geociências e Ciências Exatas, Universidade Estadual Paulista, Av. 24-A, 1515 Rio Claro, SP, 13506-900, Brazil Passive continental margins are important geoarchives related to mantle dynamics, the breakup of continents, lithospheric dynamics, and other processes. The main concern yields the quantifying long-term lithospheric evolution of the continental margin between São Paulo and Laguna in southeastern Brazil since the Neoproterozoic. We put special emphasis on the reactivation of old fracture zones running into the continent and their constrains on the landscape evolution. In this contribution, we represent already consisting thermochronological data attained by fission-track and (U-Th-Sm)/He analysis on apatites and zircons. The zircon fission-track ages range between 108.4 (15.0) and 539.9 (68.4) Ma, the zircon (U-Th-Sm)/He ages between 72.9 (5.8) and 427.6 (1.8) Ma whereas the apatite fission-track ages range between 40.0 (5.3) and 134.7 (8.0) Ma, and the apatite (U-Th-Sm)/He ages between 32.1 (1.52) and 92.0 (1.86) Ma. These thermochronological ages from metamorphic, sedimentary and intrusive rocks show six distinct blocks (Laguna, Florianópolis, Curitiba, Ilha Comprida, Peruibe and Santos) with different evolution cut by old fracture zones. Furthermore, models of time-temperature evolution illustrate the differences in Pre- to post-rift exhumation histories of these blocks. The presented data will provide an insight into the complex exhumation history of the continental margin based on the existing literature data on the evolution of the Paraná basin in Brazil and the latest

Hypothermic stunning of green sea turtles in a western Gulf of Mexico foraging habitat

PubMed Central

Tissot, Philippe E.; Streich, Mary M.; Walker, Jennifer Shelby; Rubio, Cynthia; Amos, Anthony F.; George, Jeffrey A.; Pasawicz, Michelle R.

2017-01-01

Texas waters provide one of the most important developmental and foraging habitats for juvenile green turtles (Chelonia mydas) in the western Gulf of Mexico, but hypothermic stunning is a significant threat and was the largest cause of green turtle strandings in Texas from 1980 through 2015; of the 8,107 green turtles found stranded, 4,529 (55.9%) were victims of hypothermic stunning. Additionally, during this time, 203 hypothermic stunned green turtles were found incidentally captured due to power plant water intake entrapment. Overall, 63.9% of 4,529 hypothermic stunned turtles were found alive, and 92.0% of those survived rehabilitation and were released. Numbers of green turtles recorded as stranded and as affected by hypothermic stunning increased over time, and were most numerous from 2007 through 2015. Large hypothermic stunning events (with more than 450 turtles documented) occurred during the winters of 2009–2010, 2010–2011, 2013–2014, and 2014–2015. Hypothermic stunning was documented between November and March, but peaked at various times depending on passage of severe weather systems. Hypothermic stunning occurred state-wide, but was most prevalent in South Texas, particularly the Laguna Madre. In the Laguna Madre, hypothermic stunning was associated with an abrupt drop in water temperatures strong northerly winds, and a threshold mean water temperature of 8.0°C predicted large turtle hypothermic stunning events. Knowledge of environmental parameters contributing to hypothermic stunning and the temporal and spatial distribution of turtles affected in the past, can aid with formulation of proactive, targeted search and rescue efforts that can ultimately save the lives of many affected individuals, and aid with recovery efforts for this bi-national stock. Such rescue efforts are required under the U.S. Endangered Species Act and respond to humanitarian concerns of the public. PMID:28306747

Diverse Responses to UV-B Radiation and Repair Mechanisms of Bacteria Isolated from High-Altitude Aquatic Environments▿

PubMed Central

Fernández Zenoff, V.; Siñeriz, F.; Farías, M. E.

2006-01-01

Acinetobacter johnsonii A2 isolated from the natural community of Laguna Azul (Andean Mountains at 4,560 m above sea level), Serratia marcescens MF42, Pseudomonas sp. strain MF8 isolated from the planktonic community, and Cytophaga sp. strain MF7 isolated from the benthic community from Laguna Pozuelos (Andean Puna at 3,600 m above sea level) were subjected to UV-B (3,931 J m−2) irradiation. In addition, a marine Pseudomonas putida strain, 2IDINH, and a second Acinetobacter johnsonii strain, ATCC 17909, were used as external controls. Resistance to UV-B and kinetic rates of light-dependent (UV-A [315 to 400 nm] and cool white light [400 to 700 nm]) and -independent reactivation following exposure were determined by measuring the survival (expressed as CFU) and accumulation of cyclobutane pyrimidine dimers (CPD). Significant differences in survival after UV-B irradiation were observed: Acinetobacter johnsonii A2, 48%; Acinetobacter johnsonii ATCC 17909, 20%; Pseudomonas sp. strain MF8, 40%; marine Pseudomonas putida strain 2IDINH, 12%; Cytophaga sp. strain MF7, 20%; and Serratia marcescens, 21%. Most bacteria exhibited little DNA damage (between 40 and 80 CPD/Mb), except for the benthic isolate Cytophaga sp. strain MF7 (400 CPD/Mb) and Acinetobacter johnsonii ATCC 17909 (160 CPD/Mb). The recovery strategies through dark and light repair were different in all strains. The most efficient in recovering were both Acinetobacter johnsonii A2 and Cytophaga sp. strain MF7; Serratia marcescens MF42 showed intermediate recovery, and in both Pseudomonas strains, recovery was essentially zero. The UV-B responses and recovery abilities of the different bacteria were consistent with the irradiation levels in their native environment. PMID:17056692

Late Pleistocene and Holocene Hydroclimate Variability in the Tropical Andes from Alpine Lake Sediments, Cordillera de Mérida, Venezuela

NASA Astrophysics Data System (ADS)

Larsen, D. J.; Abbott, M. B.; Polissar, P. J.

2014-12-01

The tropics play a major role in the global hydrologic cycle and changes to tropical rainfall patterns have critical implications for water resources and ecosystem dynamics over large geographic scales. In tropical South America, late Pleistocene and Holocene precipitation variability has been documented in geologic records and associated with numerous external and internal variables, including changes in summer insolation, South American summer monsoon strength, Pacific Ocean sea surface temperatures, continental moisture recycling, and other climate processes. However, there are few records from the northern hemisphere tropical Americas, a key region for understanding interhemispheric linkages and the drivers of tropical hydroclimate variability. Here, we present a ~13 ka record of coupled hydroclimate and environmental changes from Laguna Brava, a small (~0.07 km2), hydrologically closed lake basin situated at 2400 m asl in the Cordillera de Mérida, Venezuela. Sediment cores collected from varying water depths and proximity to shore are placed in a chronologic framework using radiocarbon ages from terrestrial macrofossils, and analyzed for a suite of physical, bulk geochemical, and stable isotopic parameters. Compound specific hydrogen isotope (D/H) measurements of terrestrial plant waxes (long-chain n-alkanes) show a sharp increase in the late Pleistocene, followed by a long-term trend toward more negative values that suggest a ~20‰ decrease in the D/H ratios of South American tropical precipitation during the Holocene. This pattern is consistent in sign and magnitude to other South American precipitation reconstructions from both hemispheres, indicating interhemispheric similarities in tropical hydroclimate variability. Superimposed on this continent-scale trend are changes in moisture balance and environmental conditions in the Venezuelan Andes. We reconstruct these parameters at Laguna Brava at multidecadal and centennial resolution and evaluate this

Hypothermic stunning of green sea turtles in a western Gulf of Mexico foraging habitat.

PubMed

Shaver, Donna J; Tissot, Philippe E; Streich, Mary M; Walker, Jennifer Shelby; Rubio, Cynthia; Amos, Anthony F; George, Jeffrey A; Pasawicz, Michelle R

2017-01-01

Texas waters provide one of the most important developmental and foraging habitats for juvenile green turtles (Chelonia mydas) in the western Gulf of Mexico, but hypothermic stunning is a significant threat and was the largest cause of green turtle strandings in Texas from 1980 through 2015; of the 8,107 green turtles found stranded, 4,529 (55.9%) were victims of hypothermic stunning. Additionally, during this time, 203 hypothermic stunned green turtles were found incidentally captured due to power plant water intake entrapment. Overall, 63.9% of 4,529 hypothermic stunned turtles were found alive, and 92.0% of those survived rehabilitation and were released. Numbers of green turtles recorded as stranded and as affected by hypothermic stunning increased over time, and were most numerous from 2007 through 2015. Large hypothermic stunning events (with more than 450 turtles documented) occurred during the winters of 2009-2010, 2010-2011, 2013-2014, and 2014-2015. Hypothermic stunning was documented between November and March, but peaked at various times depending on passage of severe weather systems. Hypothermic stunning occurred state-wide, but was most prevalent in South Texas, particularly the Laguna Madre. In the Laguna Madre, hypothermic stunning was associated with an abrupt drop in water temperatures strong northerly winds, and a threshold mean water temperature of 8.0°C predicted large turtle hypothermic stunning events. Knowledge of environmental parameters contributing to hypothermic stunning and the temporal and spatial distribution of turtles affected in the past, can aid with formulation of proactive, targeted search and rescue efforts that can ultimately save the lives of many affected individuals, and aid with recovery efforts for this bi-national stock. Such rescue efforts are required under the U.S. Endangered Species Act and respond to humanitarian concerns of the public.

A Multiproxy Approach to Unraveling Climate and Human Demography in the Peruvian Altiplano from a 5000 year Lake Sediment Core

NASA Astrophysics Data System (ADS)

Vaught-Mijares, R. M.; Hillman, A. L.; Abbott, M. B.; Werne, J. P.; Arkush, E.

2017-12-01

Drought and flood events are thought to have shaped the ways in which Andean societies have adapted to life in the Titicaca Basin region, particularly with regard to land use practices and settlement patterns. This study examines a small lake in the region, Laguna Orurillo. Water isotopes suggest that the lake primarily loses water through evaporation, making it hydrologically sensitive. In 2015, a 3.4 m overlapping sediment record was collected and inspected for evidence of shallow water facies and erosional unconformities to reconstruct paleohydrology. Sediment core chronology was established using 7 AMS radiocarbon dates and 210Pb dating and indicates that the core spans 5000 years. Additional sediment core measurements include magnetic susceptibility, bulk density, organic/carbonate content, and XRD. Results show a pronounced change in sediment composition from brittle, angular salt deposits to massive calcareous silt and clay around 5000 years BP. Multiple transitions from clay to sand show potential lake level depressions at 1540, 2090, and 2230, yr BP that are supported by a drastic increase in carbonate composition from 2760-1600 yr BP. Additional shallow-water periods may be reflected in the presence of rip-up clasts from 4000 to 3000 yr BP. These early interpretations align well with existing hydrologic records from Lake Titicaca. In order to develop a more detailed climate and land use record, isotope analyses of authigenic carbonate minerals using δ13C and δ18O and leaf waxes using δD are being developed. Ultimately, this record will be linked with records from nearby Lagunas Arapa and Umayo. Additional proxies for human population such as fecal 5β-stanols and proximal anthropologic surveys will be synthesized to contribute to a regional understanding of Holocene climate variability and human demography in the Peruvian Altiplano.

Xenarthra (Mammalia) from a new late Neogene fossiliferous locality in Northwestern Argentina

NASA Astrophysics Data System (ADS)

Zurita, Alfredo E.; Camacho, María; Miño-Boilini, Angel R.; Candela, Adriana M.; Cuadrelli, Francisco; Krmpotic, Cecilia M.; Solís, Natalia

2017-12-01

Northwestern Argentina contains one of the most complete continental late Neogene (ca. 9-2.58 Ma) fossiliferous sequences in South America, especially in the current territories of the Catamarca, Tucumán and Jujuy provinces. More precisely in Jujuy Province several localities bearing mainly fossil mammals have been reported at the Quebrada de Humahuaca in the Uquía, Maimará and Tilcara formations, in which the clade Xenarthra (Mammalia) is well-represented. In this scenario, the fossiliferous potential of other localities of Jujuy Province are less known, especially in those areas located at the northwest end of Argentina, bordering Bolivia in the Northern Puna. A new late Neogene fossiliferous locality near Calahoyo (3639 m.a.s.l), Jujuy Province, is here reported. The materials, belonging to Xenarthra, were exhumed from the base of the Tafna Formation which was deposited in a sedimentary basin by alluvial and/or fluvial currents, undergoing transitions of various lacustrine episodes. The taxa include the Tardigrada Pyramiodontherium bergi (Megatheriidae) and the Cingulata Eosclerocalyptus sp. (Glyptodontidae) and Macrochorobates chapalmalensis (Dasypodidae). From a biostratigraphic viewpoint, this assemblage suggests a Late Miocene-Pliocene age for the base of the Tafna Formation, and partially contradicts the supposed Plio-Pleistocene age of this unit. Finally, the new specimens here described indicate that Xenarthra were taxonomically and ecologically diverse during the late Neogene in the northwest end of Argentina, since they are represented by at least three main lineages (sloths, glyptodontids and armadillos).

Slow life histories in lizards living in the highlands of the Andes Mountains.

PubMed

Boretto, Jorgelina M; Cabezas-Cartes, Facundo; Ibargüengoytía, Nora R

2018-05-01

In the highlands of the Andes, lizards must balance precisely the allocation of energy for growth and reproduction to ensure their survival. We studied the individuals' age, growth rates, age at sexual maturity, and maximum life span of the viviparous lizard Phymaturus antofagastensis, endemic of cold and harsh environments at high altitudes in the Andes Mountains of Catamarca province, Argentina. We also estimated key life history parameters like reproductive effort, lifetime reproductive effort, net reproductive rate, and relative reproductive time in P. antofagastensis as well as in other Phymaturus to compare the interplay among growth, maintenance, and reproduction in species that live across a latitudinal and altitudinal gradient. We found that females and males of P. antofagastensis mature late in life, at 6-7 years old, respectively, and some individuals reached 20 years of age. Adult females showed higher specific growth rates than males and an adult life span of 9 years which, due to their biennial reproduction, results in an estimated production of only four litters in life. This species exhibits one of the highest lifetime reproductive efforts described for lizards. Our results indicate the existence of a tradeoff between the number of reproductive events throughout life and reproductive effort devoted to each event in Phymaturus, related to the phylogenetic group. The palluma group shows low reproductive effort but high number of reproductive events throughout their lives, whereas the patagonicus group shows high reproductive efforts in low number of reproductive events.

Influence of oregano essential oil on traditional Argentinean cheese elaboration: Effect on lactic starter cultures.

PubMed

Marcial, Guillermo E; Gerez, Carla L; de Kairuz, Martha Nuñez; Araoz, Victoria Coll; Schuff, Carola; de Valdez, Graciela Font

The aim of this work is to study the oregano essential oil (OEO) composition from Northwestern Argentinean regions and to evaluate its effect on the lactic starter cultures. The oregano used, Origanum vulgare var hirtum, was obtained from Andalgalá, Catamarca. The essential oil presented high amounts of α-terpinene (10%), γ-terpinene (15.1%), terpinen-4-ol (15.5%) and thymol (13.0%) as the main components. No negative effect on growth or metabolic activity of lactic acid bacteria Streptococcus thermophilus CRL 728 and CRL 813, Lactobacillus delbrueckii subsp. bulgaricus CRL 656 and CRL 468, and Lactococcus lactis subsp. lactis CRL 597 up to the maximum concentration (200μg/g) assayed was observed. No differences in the organoleptic characteristics of semi-hard cheeses flavored with oregano essential oil (200μg/g) and homemade cheeses flavored with oregano leaves were found. With respect to the microbiological quality of the products, neither enterobacteria nor mold and yeast were detected during ripening in essential-oil flavored cheese compared to control cheese (enterobacteria 2×10 3 UFC/g) and cheese flavored with oregano leaves (mold/yeast 4×10 4 CFU/g). Our results showed that the use of oregano essential oil and lactic starter culture considerably improved cheese quality. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Molecular phylogeography of the Chagas' disease vector Triatoma infestans in Argentina

PubMed Central

Pérez de Rosas, A R; Segura, E L; García, B A

2011-01-01

Triatoma infestans is the main vector of Chagas' disease in South America between latitudes 10°S and 46°S. A multilocus microsatellite data set of 836 individuals from 27 populations of T. infestans, from all its range of distribution in Argentina, was analyzed. Our results favor the hypothesis of two independent migration events of colonization in Argentina and secondary contacts. The majority of the populations of the western provinces of Catamarca, La Rioja, San Juan and the west of Cordoba province, had almost no shared ancestry with the rest of the populations analyzed. Probably those populations, belonging to localities close to the Andean region, could have been established by the dispersal line of T. infestans that would have arrived to Argentina through the Andes, whereas most of the rest of the populations analyzed may have derived from the dispersal line of T. infestans in non-Andean lowlands. Among them, those from the provinces of Formosa, Chaco, Santiago del Estero and Santa Fe shared different percentages of ancestry and presented lower degree of genetic differentiation. The migratory movement linked to regional economies and possibly associated with passive dispersal, would allow a higher genetic exchange among these populations of T. infestans. This study, using microsatellite markers, provides a new approach for evaluating the validity of the different hypotheses concerning the evolutionary history of this species. Two major lineages of T. infestans, an Andean and non-Andean, are suggested. PMID:21224874

Earth observations taken from Space Shuttle Columbia during STS-93 mission

NASA Image and Video Library

1999-07-23

STS093-704-087 (23-27 July 1999) --- This low angle, early morning shot over Chile was photographed from the Earth-orbiting Space Shuttle Columbia during the STS-93 mission. In the words of one of the scientists studying the STS-93 Earth imagery, Laguna Verde, in the Atacama Province of Chile (near the Argentine border), lies like a turquoise jewel among the stark black and white snow covered volcanic peaks of the High Andes. The ambient elevation in this part of the Andes is 16,000 feet (4,877 meters) with the highest local peak, Nevada Ojas de Salado (just to the right of the lake), reaching to 23,240 feet. (7084 meters.)

6. Credit USAF, April, 1945. Original in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Credit USAF, April, 1945. Original in the possession of Ken G. Oldfield, Laguna Hills, California. View looking west across North Base flightline of XP-80s Shooting Stars undergoing accelerated service tests. HANG-N-A hangars No. 1 (Building 4401) and No. 2 (Building 4402) appear at left of view, with runway control tower (T-65, or Building 4500) at far right. Flight operations offices were in T-42 (Building 4502) at base of control tower; this structure was not extant in 1995. In the background between the control tower and Building 4402 lies T-15, officer's quarters. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

SRTM Perspective of Colored Height and Shaded Relief Laguna Mellquina, Andes Mountains, Argentina

NASA Image and Video Library

2001-06-22

This depiction of an area south of San Martin de Los Andes, Argentina, is the first Shuttle Radar Topography Mission SRTMview of the Andes Mountains, the tallest mountain chain in the western hemisphere.

SRTM Perspective of Colored Height and Shaded Relief Laguna Mellquina, Andes Mountains, Argentina

NASA Technical Reports Server (NTRS)

2001-01-01

This depiction of an area south of San Martin de Los Andes, Argentina, is the first Shuttle Radar Topography Mission (SRTM)view of the Andes Mountains, the tallest mountain chain in the western hemisphere. This particular site does not include the higher Andes peaks, but it does include steep-sided valleys and other distinctive landforms carved by Pleistocene glaciers. Elevations here range from about 700 to 2,440 meters (2,300 to 8,000 feet). This region is very active tectonically and volcanically, and the landforms provide a record of the changes that have occurred over many thousands of years. Large lakes fill the broad mountain valleys, and the spectacular scenery here makes this area a popular resort destination for Argentinians.

Three visualization methods were combined to produce this image: shading, color coding of topographic height and a perspective view. The shade image was derived by computing topographic slope in the north-south direction. Northern slopes appear bright and southern slopes appear dark, as would be the case at noon at this latitude in the southern hemisphere. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow, red, and magenta, to white at the highest elevations. The perspective is toward the west, 20 degrees off horizontal with 2X vertical exaggeration. The back (west) edge of the data set forms a false skyline within the Andes Range.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission aboard Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: 55.0 x 37.2 kilometers ( 34.1 x 23.1 miles) Location: 40.4 deg. South lat., 71.3 deg. West lon. Orientation: West toward the top Image Data: Shaded and colored SRTM elevation model Date Acquired: February 2000

A remote sensing assessment of the impact of the 2010 Maule, Chile earthquake (Mw 8.8) on the volcanoes of the southern Andes

NASA Astrophysics Data System (ADS)

Pritchard, M. E.; Welch, M.; Jay, J.; Button, N.

2011-12-01

There are tantalizing, but controversial, indications that great earthquakes affect arc-wide volcanic activity. For example, analysis of historic eruptions at volcanoes of the southern Andes has shown that 3-4 eruptions were likely seismically triggered by Mw > 8 earthquakes in the Chile subduction zone -- particularly the 1906 and 1960 earthquakes (e.g., Watt et al., 2009). However, the 27 February 2010 Mw 8.8 Maule, Chile earthquake that ruptured the subduction zone between the 1960 and 1906 earthquakes does not appear to have triggered 3-4 volcanic eruptions in the same area in the 12 months after the event. In an effort to understand the relation between a large earthquake and volcanic unrest, we use a variety of satellite instruments to look for more subtle (i.e., not leading to eruption), but detectable change in thermal or deformation activity at the volcanoes of the southern Andes after the Maule earthquake and its aftershocks. For all of the volcanoes in the catalog of the Smithsonian Institution (approximately 80), we use nighttime MODIS and ASTER data to assess the thermal activity and ALOS InSAR data to characterize the surface deformation before and after the earthquake. The ALOS InSAR data are not ideal for detecting changes in deformation before and after the earthquake because of the small number of acquisitions in austral summer as well as ionospheric and tropospheric artifacts. We estimate that we could detect deformation > 5 cm/year. Similarly, the ASTER and MODIS data suffer respectively from poor temporal and spatial resolution of thermal anomalies. We update previous InSAR work that identified at least 8 areas of volcanic deformation in the southern Andes related to eruptive processes, subsidence of past lava flows, or surface uplift not associated with an eruption (Fournier et al., 2010). Of greatest interest are the two volcanic areas with the largest deformation signals between 2007-2008 (both > 15 cm/yr in the radar line of sight): Laguna

Geochronology of Quaternary glaciations from the tropical Cordillera Huayhuash, Peru

NASA Astrophysics Data System (ADS)

Hall, Sarah R.; Farber, Daniel L.; Ramage, Joan M.; Rodbell, Donald T.; Finkel, Robert C.; Smith, Jacqueline A.; Mark, Bryan G.; Kassel, Christopher

2009-12-01

The Cordillera Huayhuash in the central Peruvian Andes (10.3°S, 76.9°W) is an ideal mountain range in which to study regional climate through variations in paleoglacier extents. The range trends nearly north-south with modern glaciers confined to peaks >4800 m a.s.l. Geomorphology and geochronology in the nearby Cordillera Blanca and Junin Plain reveal that the Peruvian Andes preserve a detailed record of tropical glaciation. Here, we use ASTER imagery, aerial photographs, and GPS to map and date glacial features in both the western and eastern drainages of the Cordillera Huayhuash. We have used in situ produced cosmogenic 10Be concentrations in quartz bearing erratics on moraine crests and ice-polished bedrock surfaces to develop an exposure age chronology for Pleistocene glaciation within the range. We have also collected sediment cores from moraine-dammed lakes and bogs to provide limiting 14C ages for glacial deposits. In contrast to the ranges to the north and south, most glacial features within the Cordillera Huayhuash are Lateglacial in age, however we have identified features with ages that span ˜0.2 to ˜38 ka with moraine sets marking the onset of glacier retreat at ˜0.3 ka, ˜9-10 ka, ˜13-14 ka, ˜20-22 ka, and >26 ka. The range displays a pronounced east-west variation in maximum down-valley distance from the headwall of moraine crests with considerably longer paleoglaciers in the eastern drainages. Importantly, Lateglacial paleoglaciers reached a terminal elevation of ˜4000 m a.s.l. on both sides of the Cordillera Huayhuash; suggesting that temperature may have been a dominant factor in controlling the maximum glacier extent. We suggest that valley morphology, specifically valley slope, strongly influences down-valley distance to the maximum glacier extent and potential for moraine preservation. While regionally there is an extensive record of older (>50 ka) advances to the north (Cordillera Blanca) and to the south (Junin region), the apparent

Geochronology of Tropical Alpine Glaciations From the Cordillera Huayhuash, Peru

NASA Astrophysics Data System (ADS)

Hall, S. R.; Farber, D. L.; Rodbell, D. T.; Finkel, R. C.; Ramage, J. M.; Smith, J. A.; Mark, B. G.; Seltzer, G. O.

2004-12-01

The Cordillera Huayhuash of the Central Peruvian Andes (10.3° S, 76.9° W) is an ideal range to study regional climate signals and variations in paleo-ice volumes. Located between the Cordillera Blanca to the north and the Junin region to the south, the range trends nearly north-south with modern glaciers confined to the high peaks (>4800 m). Cross-cutting relationships, geomorphology, and correlation with surface exposure dated moraines in the nearby Cordillera Blanca suggest the region preserves a rich record of tropical glaciation. In order to determine the glacial chronology we mapped and dated glacial features of the Jahuacocha valley (which drains the western side of the range) and two eastern drainages, the Mitococha valley, and the Carhuacocha valley. At each locality we used ASTER data, aerial photographs, and GPS to map glacial features both within main valleys and tributaries. We sampled quartz-bearing erratics on moraine crests as well as ice-polished bedrock surfaces for exposure age dating using in situ produced cosmogenic 10Be and 26Al. In the Jahuacocha valley, the greatest ice extent reached an elevation of ˜4090m and moraine crest boulders yield and age of ˜11.2 ±0.6 ka suggesting a significant late Glacial ice advance or stillstand. A younger cluster of moraines exists ˜1 km up-valley at an elevation of ˜4100m. These moraines, dated at ˜8.0 ±1.0 ka, suggest an early Holocene advance. In the Mitococha valley, a young moraine and polished bedrock dated at ˜0.2 ka and ˜11.4 ±0.4 ka respectively span the late Glacial through recent. The late Glacial features of this eastern drainage occur at an elevation of ˜4100m while the recent events occur at an elevation of ˜4380m. Our preliminary results suggest that all three valleys experienced a very similar glacial history with minor differences likely due to the variations in valley morphology. Comparing the chronology of glaciation in the Cordillaera Huayhuash with that in regions to the

Groundwater, springs, and stream flow generation in an alpine meadow of a tropical glacierized catchment

NASA Astrophysics Data System (ADS)

Gordon, R.; Lautz, L. K.; McKenzie, J. M.; Mark, B. G.; Chavez, D.

2013-12-01

Melting tropical glaciers supply approximately half of dry season stream discharge in glacierized valleys of the Cordillera Blanca, Peru. The remainder of streamflow originates as groundwater stored in alpine meadows, moraines and talus slopes. A better understanding of the dynamics of alpine groundwater, including sources and contributions to streamflow, is important for making accurate estimates of glacial inputs to the hydrologic budget, and for our ability to make predictions about future water resources as glaciers retreat. Our field study, conducted during the dry season in the Llanganuco valley, focused on a 0.5-km2 alpine meadow complex at 4400 m elevation, which includes talus slopes, terminal moraines, and a debris fan. Two glacial lakes and springs throughout the complex feed a network of stream channels that flow across the meadow (~2 km total length). We combined tracer measurements of stream and spring discharge and groundwater-surface water exchange with synoptic sampling of water isotopic and geochemical composition, in order to characterize and quantify contributions to streamflow from different geomorphic features. Surface water inputs to the stream channels totaled 58 l/s, while the stream gained an additional 57 l/s from groundwater inputs. Water chemistry is primarily controlled by flowpath type (surface/subsurface) and length, as well as bedrock lithology, while stable water isotopic composition appears to be controlled by water source (glacial lake, meadow or deep groundwater). Stream water chemistry is most similar to meadow groundwater springs, but isotopic composition suggests that the majority of stream water, which issues from springs at the meadow/fan interface, is from the same glacial source as the up-gradient lake. Groundwater sampled from piezometers in confined meadow aquifers is unique in both chemistry and isotopic composition, but does not contribute a large percentage of stream water exiting this small meadow, as quantified by

Sexual size dimorphism, sex ratio and the relationship between seasonality and water quality in four species of Gordiida (Nematomorpha) from Catamarca, Argentina.

PubMed

Salas, L; De Villalobos, C; Zanca, F

2011-09-01

A total of 687 adult nematomorphs of four species of Gordiida: Chordodes brasiliensis (393 specimens), Noteochorododes cymatium (47 specimens), N. talensis (162 specimens) and Pseudochordodes dugesi (85 specimens) were collected during a period of 1 year from El Simbolar stream, Argentina. Free-living worms were abundant during autumn and spring, but their number decreased during winter and summer. Males were shorter and significantly more abundant than females. The presence of N. cymatium, N. talensis and P. dugesi was correlated with water temperature and these species were most abundant in winter and spring. The presence of C. brasiliensis was correlated with flow rate and pH; this species was more abundant in autumn and winter. These four species are sympatric.

"Her mouth is medicine": Beth Brant and Paula Gunn Allen's decolonizing queer erotics.

PubMed

Burford, Arianne

2013-01-01

This article asserts the need to recognize the complexity of the theoretical work of more lesbian Native American writers, focusing specifically Beth Brant (Bay of Quinte Mohawk) and Paula Gunn Allen (Laguna Pueblo). Their poetry and short stories provide a theoretically nuanced analysis of how heteronormativity is intertwined in and dependent on colonialism, and thus a methodology for Queer Theory that requires an understanding of it in relation to colonialism. They reject heteronormative Pocahontas fantasies about Native women, offering a lesbian-based tactic for decolonization through the expression of erotic desire. This article demonstrates the endless possibilities for fierce queer resistance, revolutionary change, and healing from the trauma of genocide and the accompanying colonialist heteropatriarchal disciplining of Native women's bodies.

The Search for Bright Variable Stars in Open Cluster NGC 6819.

NASA Astrophysics Data System (ADS)

Talamantes, Antonio; Sandquist, E. L.

2009-01-01

During this research period data was taken for seven nights at the 1m telescope at Mt. Laguna Observatory for the open cluster NGC 6819. For four of the nights data was taken using a V-band filter. For the three nights remaining nights the data was taken using an R-band filter. Photometry was done using the ISIS image subtraction package. Six new variable stars were located using these techniques. These variable types include a pulsating variable, five detached eclipsing binaries. Of the detached eclipsing binaries, three are near the cluster turnoff and two in the blue straggler region(and one of these has total eclipses). Nine previously known variables(six contact binaries, two detached eclipsing binaries and one near-contact binary) were also studied.

Bilateral Leydig cell tumor in a six-year-old intersex goat affected by Polled Intersex Syndrome.

PubMed

Monteagudo, L V; Arruga, M V; Bonafonte, J I; Ordás, M; Whyte, A; Gallego, M; Bascuas, J A; Sierra, I

2008-01-01

A 6-year-old, sterile, Blanca Celtibérica breed adult doe was referred to our faculty. The doe had external female genitalia, a short anogenital distance, and normally shaped udders. Masculinization signs in the head shape and male behavior were also noted at the time of referral. Genetic analysis demonstrated normal 2n = 60 XX karyotype and an absence of the sex-determining region Y (SRY). The animal was homozygous for a DNA deletion responsible for the Polled Intersex Syndrome (PIS). A uterus and 2 uterine horns were present at the postmortem examination. Gartner's ducts and degenerated Wolffian derivatives persisted. There were 2 intra-abdominal testicle-like structures, one of which consisted of epididymal and deferent ducts. An advanced Leydig cell tumor, resulting in almost total destruction of the intratesticular structures, was also observed. Leydig cell tumors usually produce testosterone. Thus, these histologic findings are compatible with the evident virilization.

Chalcones in bioactive Argentine propolis collected in arid environments.

PubMed

Solórzano, Eliana; Vera, Nancy; Cuello, Soledad; Ordoñez, Roxana; Zampini, Catiana; Maldonado, Luis; Bedascarrasbure, Enrique; Isla, María I

2012-07-01

The aim of this study was to assess the chemical and biological profile of propolis samples collected in arid environments of north-western Argentina. The samples were from two phytogeographical regions (Prepuna and Monte de Catamarca Province). Propolis ethanolic extracts (PEE) and chloroform (CHL), hexane (HEX) and aqueous (AQ) sub-extracts of samples from three regions (CAT-I; CAT-II and CAT-III) were obtained. All PEE exhibited antioxidant activity in the DPPH radical scavenging assay (SC50 values between 28 and 43 microg DW/mL). The CHL extract was the most active (SC50 values between 10 and 37 microg DW/mL). The antioxidant activity in the beta-carotene bleaching assays was more effective for PEE and CHL (IC50 values between 2 and 9 microg DW/mL, respectively). A similar pattern was observed for antibacterial activity. The highest inhibitory effect on the growth of human Gram-positive bacteria was observed for CHL-III and CHL-I (Monte region) with minimal inhibitory concentration values (MIC100) of 50 to 100 microg DW/mL. Nine compounds were identified by HPLC-PAD. Two of them (2', 4'- dihydroxychalcone and 2',4'- dihydroxy 3'-methoxychalcone) were found only in propolis samples from the Monte phytogeographical region. We consider that the Argentine arid region is appropriate to place hives in order to obtain propolis of excellent quality because the dominant life forms in that environment are shrubby species that produce resinous exudates with a high content of chalcones, flavones and flavonols.

Microbiological quality of Argentinian paprika.

PubMed

Melo González, María G; Romero, Stella M; Arjona, Mila; Larumbe, Ada G; Vaamonde, Graciela

The aim of this study was to evaluate the microbiological quality of paprika produced in Catamarca, Argentina. Microbiological analyses were carried out for the enumeration of total aerobic mesophilic bacteria, coliforms, yeasts and molds, and the detection of Salmonella in samples obtained from different local producers during three consecutive years. The mycobiota was identified paying special attention to the mycotoxigenic molds. Standard plate counts of aerobic mesophilic bacteria ranged from 2.7×10 5 to 3.7×10 7 CFU/g. Coliform counts ranged from <10 to 8.1×10 4 CFU/g. Salmonella was not detected in any of the samples tested. Fungal counts (including yeasts and molds) ranged between 2×10 2 and 1.9×10 5 CFU/g. These results showed a high level of microbial contamination, exceeding in several samples the maximum limits set in international food regulations. The study of the mycobiota demonstrated that Aspergillus was the predominant genus and Aspergillus niger (potential producer of ochratoxin A) the most frequently isolated species, followed by Aspergillus flavus (potential producer of aflatoxins). Other species of potential toxigenic fungi such as Aspergillus ochraceus, Aspergillus westerdijkiae, Penicillium chrysogenum, Penicillium crustosum, Penicillium commune, Penicillium expansum and Alternaria tenuissima species group were encountered as part of the mycobiota of the paprika samples indicating a risk of mycotoxin contamination. A. westerdijkiae was isolated for the first time in Argentina. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

2002 Airborne Geophysical Survey at Pueblo of Laguna Bombing Targets, New Mexico. Revision 3

DTIC Science & Technology

2005-10-01

conducted and results evaluated. The eight cesium magnetometers , GPS systems (positioning and attitude), fluxgate magnetometers , data recording...Accurate positioning requires a correction for this lag. Time lags between the magnetometers , fluxgate magnetometer , and GPS signals were measured by...between magnetometers and fluxgate ); An initial check flight after installation. Under the category of data QA/QC: An extensive test flight to

76 FR 24512 - Laguna Cartagena National Wildlife Refuge, Lajas, Puerto Rico; Draft Comprehensive Conservation...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-02

... enforcement officer. Alternative C (Wetland Restoration Emphasis) Under this alternative, we would concentrate... limited baseline biological information. Active habitat wetland management would be implemented by... National Wildlife Refuge. Alternative B (Wildlife Diversity and Habitat Restoration, Proposed) Under this...

CARBON AND NITROGEN ALLOCATION MODEL FOR THE SEAGRASS THALASSIA TESTUDUNUM IN LOWER LAGUNA MADRE

EPA Science Inventory

Inverse modeling methods are a powerful tool for understanding complex physiological relationships between seagrasses and their environment. The power of the method is a result of using ranges of data in a system of constraints to describe the biological system, in this case, t...

Offshore geology and geomorphology from Point Piedras Blancas to Pismo Beach, San Luis Obispo County, California

USGS Publications Warehouse

Watt, Janet Tilden; Johnson, Samuel Y.; Hartwell, Stephen R.; Roberts, Michelle

2015-01-01

Sea level was approximately 120 to 130 m lower during the Last Glacial Maximum (about 21 ka). This approximate depth corresponds to the modern shelf break, a lateral change from the gently dipping (0.8° to 1.0°) outer shelf to the slightly more steeply dipping (about 1.5° to 2.5°) upper slope in the central and northern parts of the map area. South of Point San Luis in San Luis Bay, deltaic deposits offshore of the mouth of the Santa Maria River (11 km south of the map area) have prograded across the shelf break and now form a continuous low-angle (about 0.8°) ramp that extends to water depths of more than 160 m. The shelf break defines the landward boundary of slope deposits. North of Estero Bay, the shelf break is characterized by a distinctly sharp slope break that is mapped as a landslide headscarp above landslide deposits. Multibeam imagery and seismic-reflection profiles across this part of the shelf break show evidence of slope failure, such as slumping, sliding, and soft-sediment deformation, along the entire length of the scarp. Notably, this shelf-break scarp corresponds to a west splay of the Hosgri Fault that dies out just north of the scarp, suggesting that faulting is controlling the location (and instability) of the shelf break in this area.

Managing the impact of climate change on the hydrology of the Gallocanta Basin, NE-Spain.

PubMed

Kuhn, Nikolaus J; Baumhauer, Roland; Schütt, Brigitta

2011-02-01

The Gallocanta Basin represents an environment highly sensitive to climate change. Over the past 60 years, the Laguna de Gallocanta, an ephemeral lake situated in the closed Gallocanta basin, experienced a sequence of wet and dry phases. The lake and its surrounding wetlands are one of only a few bird sanctuaries left in NE-Spain for grey cranes on their annual migration from Scandinavia to northern Africa. Understanding the impact of climate change on basin hydrology is therefore of utmost importance for the appropriate management of the bird sanctuary. Changes in lake level are only weakly linked to annual rainfall, with reaction times between hours and months after rainfall. Both the total amount of rainfall over the reaction period, as well as individual extreme events, affect lake level. In this study the characteristics and frequencies of daily, event, monthly and bi-monthly rainfall over the past 60 years were analysed. The results revealed a clear link between increased frequencies of high magnitude rainfall and phases of water filling in the Laguna de Gallocanta. In the middle of the 20th century, the absolute amount of rainfall appears to have been more important for lake level, while more recently the frequency of high magnitude rainfall has emerged as the dominant variable. In the Gallocanta Basin, climate change and the distinct and continuing land use change since Spain joined the EU in 1986 have created an environment that is in a more or less constant state of transition. This highlights two challenges faced by hydrologists and climatologists involved in developing water management tools for the Gallocanta Basin in particular, but also other areas with sensitive and rapidly changing environments. Hydrologists have to understand the processes and the spatial and temporal patterns of surface-climate interaction in a watershed to assess the impact of climate change on its hydrology. Climatologists, on the other hand, have to develop climate models

Paleotsunami deposits along the coast of Egypt correlate with historical earthquake records of eastern Mediterranean

NASA Astrophysics Data System (ADS)

Salama, Asem; Meghraoui, Mustapha; El Gabry, Mohamed; Maouche, Said; Hussein, Hesham; Korrat, Ibrahim

2017-04-01

Tsunami deposits are investigated along the Mediterranean coast of Egypt in the framework of the EC-Funded ASTARTE project (Assessment, Strategy And Risk Reduction for Tsunamis in Europe - FP7-ENV2013 6.4-3, Grant 603839) and the French-Egyptian IMHOTEP project. The study area located west of Alexandria is selected according to historical earthquakes and related inundation events as recorded in archives. Field investigations include: 1) Coastal geomorphology along estuaries, wedge-protected and dune-protected lagunas, and terrace-platforms as potential sites for paleotsunami and boulder records, and 2) Investigations of paleotsunamis deposits and their spatial distribution using trenching and coring. In addition of 10 trenches (1.5-m-depth) and 16 (1 to 2.5-m-depth) core descriptions with detailed logging and Xrays, data collection includes geochemical analysis, magnetic susceptibility and radiocarbon dating necessary for the identification of tsunamis records. In stratigraphic successions of low energy marine and alluvial deposits, mixed sand, gravel and broken shells are interpreted as catastrophic layers correlated with tsunami deposits. The two selected sites at Kefret Saber 32-km west of Marsa-Matruh city and 10 km northwest of El Alamein village are inner lagunas protected by 2 to 40-m-high dunes parallel to the shoreline. A total of 50 samples of organic deposits and charcoal fragments were collected from both sites, among which 20 samples have been dated. Dated charcoal in deposits above and below the catastrophic layers lead us to correlate them with the 24 June 1870 (Mw 7.5), 8 August 1303 (Mw 8) and 21 July 365 (Mw 8 - 8.5), major earthquakes that generated tsunamis with the inundation of Alexandria harbor. Major tsunamigenic seismic sources being along the Hellenic subduction zone and Cyprus arc, our study of paleotsunami deposits and their distribution along the Egyptian coast will help in a better constraint of the size and recurrence of tsunamis, and

The Instituto de Astrofísica de Canarias: 30 years of Research and Communication in Astronomy.

NASA Astrophysics Data System (ADS)

Del Puerto, Carmen; Rodriguez, Nayra; Rosenberg, Alfred; Beckman, John Etienne

2015-08-01

1985 was a year of inauguration for the Instituto de Astrofísica de Canarias (IAC). In that year its two observatories, the Observatorio del Roque de los Muchachos, on the island of La Palma, (where its 10.4m optical-NIR telescope vies with the world´s major instruments), and the Observatorio del Teide, on the island of Tenerife, as well as its headquarters in La Laguna, Tenerife, were all inaugurated. This young institution has rapidly become the leading research centre for astronomy in Spain and achieved research standards at a European and world level. The 30th anniversary celebrations this year give an opportunity to maximize its already very active outreach programmes. In February two shows, featuring IAC researchers, and with astronomical themes, were shown in the main theatre of the city of La Laguna, and during the year further entertainment, collaborating with Canarian musicians and artists, is planned. Two exhibitions have been designed combining the anniversary with celebrations of the International Year of Light: “Listen to the Universe”, in Tenerife, and “Thirty Journeys around the Sun”, in La Palma, which will be open to the public for most of the year. A new outreach magazine “Parallaxes” will be launched by the IAC, in both paper and digital editions, and will complement the current blog, and news websites of the institute, as well as its communications on Facebook and Twitter. Among the activities being organized in Tenerife will be the formal naming of traffic circles with names of the telescopes at the Observatories. In conjunction with the municipal wine cellars of the local city of Tegueste a new Canarian wine produced by innovative methods and with an astronomical motif on its label, is to be launched during the year. All of these activities are in addition to the somewhat more routine productions of videos on the research lines of the IAC, including exoplanets, solar stellar, and interstellar physics, galaxies, and cosmology.

Inventory of the freshwater fishes from a densely collected area in South America-a case study of the current knowledge of Neotropical fish diversity.

PubMed

Bertaco, Vinicius A; Ferrer, Juliano; Carvalho, Fernando R; Malabarba, Luiz R

2016-07-18

We herein analyse the history of the description of the freshwater fish fauna from three drainages in one of the most densely collected areas of Brazil, and possibly of South America, the Rio Grande do Sul State, southern Brazil. An updated inventory of the freshwater fish species from rio Uruguay (partial) in Brazil, Laguna dos Patos (complete) and rio Tramandaí basins (complete) is presented. We found the number of new species described in these drainages increased nearly 56% since 1981, reaching a total of 422 species, but even now 10% of this number still corresponds to undescribed species. This rate of species description suggests that previous estimates of the Neotropical fish fauna are low, and we predict a final number of Neotropical fishes larger than the largest prediction estimate (8,000 species), after other regions of South and Central Americas become densely sampled. We discuss and attempt to demonstrate that species diversity knowledge is historically and strictly related to collecting efforts. We also demonstrate that the ecoregions in eastern South America with the highest density of species per area correspond to the areas more densely sampled in collections, and this may represent a bias in such kinds of analyses. This uneven sampling in Brazilian regions is apparently associated with the uneven distribution of Zoological research centers in different regions of the country. Small-sized species represents an important source of new species, along with little explored regions or little explored habitats, sometimes associated with restricted range species, and species complexes that need revisionary work. In contrast to other Neotropical regions, Atheriniformes are relatively diverse, sharing the fifth place in species richness with Gymnotiformes, and there is a remarkably high number of species of Rivulidae. Eight species are endemic to the rio Tramandaí drainage, 68 to the Laguna dos Patos system, and 78 to the rio Uruguay drainage. Almost 10

Spatio-temporal evolution of the Tuxtla Volcanic Field

NASA Astrophysics Data System (ADS)

Kobs Nawotniak, S. E.; Espindola, J.; Godinez, L.

2010-12-01

Mapping of the Tuxtla Volcanic Field (TVF), located in Veracruz, Mexico, through the use of digital elevation models, aerial photography, and field confirmation has found 353 distinct cones, 4 large composite volcanoes, and 42 maars. Eruptive activity in the TVF began in the late Miocene, underwent a quiescent period approximately 2.6-0.8 Ma, and continues into historic times with the most recent eruption occurring at San Martín Tuxtla volcano in 1793. The covariance of the minimum cone separation in the TVF indicates that, despite the influence of clear vent alignments following regional faulting trends, the field as a whole is anticlustered. Dividing the cones by morphometric age shows that while the older cones have an anti-clustered distribution, the younger cones (<50 Ka) are clustered. The younger cones display a stronger spatial association with the Anegada fault than their predecessors, are more likely to form in aligned groups of similarly-sized cones, and are clustered in two areas: the area immediately surrounding San Martín Tuxtla and an area approximately 3 km east of Laguna Catemaco. These areas of concentrated volcanism roughly correspond to the locations of two gravity anomalies previously identified in the area. While the average height/width ratio is equal between the two clusters, the cones in the eastern group are significantly smaller than their counterparts in the western group. The maars of the TVF are mostly located within the younger volcanic series, west of Laguna Catemaco, and have an anticlustered distribution; many of the maars are evenly spaced along curved lines, where they are weakly grouped according to crater diameter. Results indicate volcanism TVF has undergone continued spatial restriction over time, concentrating in the western half of the TVF with the onset of the eruption of the younger volcanic series 0.8 Ma and further contracting along the principle fault system within the last 50 Ka.

Remote sensing capacity of Raman spectroscopy in identification of mineral and organic constituents

NASA Astrophysics Data System (ADS)

Chen, Bin; Stoker, Carol; Cabrol, Nathalie; McKay, Christopher P.

2007-09-01

We present design, integration and test results for a field Raman spectrometer science payload, integrated into the Mars Analog Research and Technology (MARTE) drilling platform. During the drilling operation, the subsurface Raman spectroscopy inspection system has obtained signatures of organic and mineral compositions. We also performed ground truth studies using both this field unit and a laboratory micro Raman spectrometer equipped with multiple laser excitation wavelengths on series of field samples including Mojave rocks, Laguna Verde salty sediment and Rio Tinto topsoil. We have evaluated laser excitation conditions and optical probe designs for further improvement. We have demonstrated promising potential for Raman spectroscopy as a non-destructive in situ, high throughput, subsurface detection technique, as well as a desirable active remote sensing tool for future planetary and space missions.

Design of Belief Propagation Based on FPGA for the Multistereo CAFADIS Camera

PubMed Central

Magdaleno, Eduardo; Lüke, Jonás Philipp; Rodríguez, Manuel; Rodríguez-Ramos, José Manuel

2010-01-01

In this paper we describe a fast, specialized hardware implementation of the belief propagation algorithm for the CAFADIS camera, a new plenoptic sensor patented by the University of La Laguna. This camera captures the lightfield of the scene and can be used to find out at which depth each pixel is in focus. The algorithm has been designed for FPGA devices using VHDL. We propose a parallel and pipeline architecture to implement the algorithm without external memory. Although the BRAM resources of the device increase considerably, we can maintain real-time restrictions by using extremely high-performance signal processing capability through parallelism and by accessing several memories simultaneously. The quantifying results with 16 bit precision have shown that performances are really close to the original Matlab programmed algorithm. PMID:22163404

Design of belief propagation based on FPGA for the multistereo CAFADIS camera.

PubMed

Magdaleno, Eduardo; Lüke, Jonás Philipp; Rodríguez, Manuel; Rodríguez-Ramos, José Manuel

2010-01-01

In this paper we describe a fast, specialized hardware implementation of the belief propagation algorithm for the CAFADIS camera, a new plenoptic sensor patented by the University of La Laguna. This camera captures the lightfield of the scene and can be used to find out at which depth each pixel is in focus. The algorithm has been designed for FPGA devices using VHDL. We propose a parallel and pipeline architecture to implement the algorithm without external memory. Although the BRAM resources of the device increase considerably, we can maintain real-time restrictions by using extremely high-performance signal processing capability through parallelism and by accessing several memories simultaneously. The quantifying results with 16 bit precision have shown that performances are really close to the original Matlab programmed algorithm.

Polymeric quantum mechanics and the zeros of the Riemann zeta function

NASA Astrophysics Data System (ADS)

Berra-Montiel, Jasel; Molgado, Alberto

We analyze the Berry-Keating model and the Sierra and Rodríguez-Laguna Hamiltonian within the polymeric quantization formalism. By using the polymer representation, we obtain for both models, the associated polymeric quantum Hamiltonians and the corresponding stationary wave functions. The self-adjointness condition provides a proper domain for the Hamiltonian operator and the energy spectrum, which turned out to be dependent on an introduced scale parameter. By performing a counting of semiclassical states, we prove that the polymer representation reproduces the smooth part of the Riemann-von Mangoldt formula, and also introduces a correction depending on the energy and the scale parameter. This may shed some light on the understanding of the fluctuation behavior of the zeros of the Riemann function from a purely quantum point of view.

The Road to 'Bonneville'

NASA Technical Reports Server (NTRS)

2004-01-01

This false-color panoramic camera composite traverse map depicts the Mars Exploration Rover Spirit's journey since landing at Gusev Crater, Mars. It was generated from three of the camera's different wavelength filters (750 nanometers, 530 nanometers and 480 nanometers). This map was created on the 65th martian day, or sol, of Spirit's mission, after Spirit had traveled 328 meters (1076 feet) from its lander to the rim of the crater dubbed 'Bonneville.' From this high point, Spirit was able to capture with its panoramic camera the entire rover traverse. The map points out major stops that Spirit made along the way, including features nicknamed 'Adirondack;' 'Stone Council;' 'Laguna Hollow;' and 'Humphrey.' Also highlighted is the landscape feature informally named 'Grissom Hill' and Spirit's landing site, the Columbia Memorial Station.

Meteorite, a rock from space: A planetarium adventure for children

NASA Astrophysics Data System (ADS)

Rodríguez Hidalgo, I.; Naveros Y Naveiras, R.; González Sánchez, O.

2008-06-01

At the Museum of the Science and the Cosmos (MCC, La Laguna, Tenerife) there is a small planetarium. All the different planetarium shows are carried out entirely by the Museum staff, from the original idea and the script to the final production. In February 2007, Meteorite, a rock from space, a new show, specifically for children, was released. The characters (astronomical bodies) are played by puppets, designed and manufactured for this occasion; the script has been carefully written, and introduces many astronomical concepts in the form of an entertaining tale, which encourages the children to participate by crying, counting, helping the characters - just like a traditional puppet show. The aim of this contribution is to review the different resources (some of them really innovative) used to create this programme, which offers plenty of future possibilities.

Arsenic in Water Resources of the Southern Pampa Plains, Argentina

PubMed Central

Paoloni, Juan D.; Sequeira, Mario E.; Espósito, Martín E.; Fiorentino, Carmen E.; Blanco, María del C.

2009-01-01

Confronted with the need for accessible sources of good quality water and in view of the fact that the threat to public health posed by arsenic occurs mainly through the ingestion of contaminated drinking water, the presence and distribution of arsenic was evaluated in the southern Pampa Plains of Bahía Blanca district in Argentina. The findings show variable concentrations of arsenic in a complex distribution pattern. Complementary information is provided on the behavior of the groundwater resource and its salinity in terms of dissolved ions. Groundwater is the most severely affected, 97% of the samples exceeding the guideline value for arsenic in drinking water as recommended by the WHO (Guidelines for Drinking Water Quality, 2004). and showing maximum concentrations of up to 0.30 mg/L. Informing those responsible for preventive medicine and alerting the community at large will facilitate measures to mitigate exposure and ensure the safety of drinking water. PMID:19936127

Comparative Study of Phenolic Profile, Antioxidant Capacity, and Color-composition Relation of Roselle Cultivars with Contrasting Pigmentation.

PubMed

Camelo-Méndez, Gustavo A; Jara-Palacios, M José; Escudero-Gilete, M Luisa; Gordillo, Belén; Hernanz, Dolores; Paredes-López, Octavio; Vanegas-Espinoza, Pablo E; Del Villar-Martínez, Alma A; Heredia, Francisco J

2016-03-01

Roselle is a plant that accumulates anthocyanins significantly, hence its importance as food coloring and as a source of antioxidant compounds for human health. This study was aimed to determine phenolic composition and antioxidant capacity of methanolic extracts, and beverages obtained from native roselle cultivars in Mexico (Negra, Sudan, Rosa and Blanca) with different degrees of pigmentation, and to establish the color-composition relationship. Chromatographic methods were used to determine phenolic compounds: flavanols, flavonols, benzoic, hibiscus and phenolic acids as well as two main anthocyanins (cyanidin 3-sambubioside and delphinidin 3-sambubioside). The antioxidant capacity was evaluated by ABTS and FRAP assays. Tristimulus colorimetry showed to be a useful technique to determine the color-composition relationship, leading to equations that allowed to predict anthocyanin content of roselle (R > 0.84). Also, a stepwise linear discriminant analysis (SLDA) was developed in order to classify roselle cultivars. The obtained mathematical model could be an important tool to be used in colorimetric characterization of functional compounds used in food processing.

El contexto de la familia y el vecindario en la salud de los ancianos del estudio EPESE hispano

PubMed Central

Reyes-Ortiz, Carlos A.; Camacho, María E.; Eschbach, Karl; Markides, Kyriakos S.

2014-01-01

RESUMEN En este artículo se discute el papel de la familia y el vecindario en la salud de los ancianos méjico-americanos del estudio EPESE (Established Populations for Epidemiologic Studies of the Elderly) hispano. La paradoja epidemiológica consiste en que, a pesar de estar en desventaja socioeconómica, los ancianos hispanos tienen mortalidad relativamente menor que los ancianos de raza blanca. Esto es especialmente cierto cuando el anciano vive en los vecindarios donde hay un porcentaje alto de méjico-americanos. La familia también juega un papel importante en estos ancianos al disminuir el riesgo de institucionalización o de morbilidad. Asimismo, el estrés originado en problemas económicos o al depender económicamente de la familia, habiendo inmigrado en edades tardías, puede sobrepasar la capacidad de amortiguamiento del estrés y afectar la salud del anciano méjico-americano. PMID:25190897

Geological Survey investigations in the U12e.05 tunnel, Nevada Test Site

USGS Publications Warehouse

Diment, William H.; Wilmarth, V.R.; Houser, F.N.; Dickey, D.D.; Hinrichs, E.N.; Botinelly, T.; Wilcox, R.E.; Byers, F.M.

1959-01-01

The U12e.05 tunnel, one of two laterals from the main U12e tunnel, trends west and connects with the main tunnel about U960 feet from the portal (fig. 2). The U12e.05 tunnel was driven for the nuclear test, code name Blanca, which took place on October 30, 1958. Before the explosion, the tunnel was 8 feet high and 8 to 9 feet wide and consisted of 990 feet of workings, a shot chamber, and an alcove (fig. 2). The original shot chamber, at the west end of the tunnel, was 19 feet long, 10 feet wide, and 15 feet high. The vertical and minimum cover over the original shot chamber are 1,150 and 950 feet, respectively. After detonation of the nuclear device in the test, code named Logan, in the U12e.02 tunnel on October 15, 1958, the U12e.05 tunnel, locally, was damaged severely.

Distribution and human health risk assessment of PAHs in four fish species from a SW Atlantic estuary.

PubMed

Oliva, Ana L; La Colla, Noelia S; Arias, Andrés H; Blasina, Gabriela E; Lopez Cazorla, Andrea; Marcovecchio, Jorge E

2017-08-01

The aim of this study is to assess-for the first time-the concentration of the 16 polycyclic aromatic hydrocarbons (PAHs) in the muscle tissues of four fish species (Micropogonias furnieri, Cynoscion guatucupa, Ramnogaster arcuata, and Mustelus schmitti) from Bahía Blanca estuary, Argentina and to evaluate their sources, distribution, and the human health risks implicated. Considering the four species under study, mean total PAH concentrations showed the following decreasing accumulation trend: M. schmitti, R. arcuata, C. guatucupa, and M. furnieri. Low molecular weight PAHs, such as naphthalene and phenanthrene, were generally predominant, displaying properties of PAH mixtures generated from petrogenic pollution. Of the four fish species analyzed, M. furnieri was the only one that did not raise any human consumption warning. In the case of the other species, exceeding values were found above the safety human consumption guidelines. Nevertheless, the screening criteria for carcinogenic PAHs proposed by the USEPA indicated a good quality status for these fish species.

Age and extent of the Ilopango TBJ Tephra inferred from a Holocene chronostratigraphic reference section, Lago De Yojoa, Honduras

USGS Publications Warehouse

Mehringer, P.J.; Sarna-Wojcicki, A. M.; Wollwage, L.K.; Sheets, P.

2005-01-01

Eruption of central El Salvador's Ilopango Volcano early in the first millennium A.D. caused death, cultural devastation, and exodus of southern Mesoamericans. It also left a time-stratigraphic marker in western El Salvador and adjacent Guatemala - the Ilopango Tierra Blanca Joven, or TBJ tephra. Mineral suites and major element abundances identify a silicic volcanic ash in cores from Lago de Yojoa, Honduras, as Ilopango TBJ. This extends its reported range more than 150 km to the northeast. Analyses of glass from the TBJ tephra from the Chalchuapa archaeological site, El Salvador, and from Lago de Yojoa, Honduras, establish the first major element reference fingerprint for the TBJ tephra. The Lago de Yojoa cores also hold two previously undated trachyandesitic tephra layers originating from the nearby Lake Yojoa Volcanic Field. One fell shortly before 11,000 14C yr B.P. and the other about 8600 14C yr B.P. ?? 2004 University of Washington. All rights reserved.

Biostratigraphic implications of the first Eocene land-mammal fauna from the North American coastal plain

NASA Astrophysics Data System (ADS)

Westgate, James W.

1988-11-01

A newly discovered vertebrate fossil assemblage, the Casa Blanca local fauna, comes from the Laredo Formation, Claiborne Group, of Webb County, Texas, and is the first reported Eocene land-mammal fauna from the coastal plain of North America. The mammalian fauna is correlated with the Serendipity and Candelaria local faunas of west Texas, the Uinta C faunas of the Rocky Mountains, the Santiago Formation local fauna of southern California, and the Swift Current Creek local fauna of Saskatchewan. The vertebrate-bearing deposit lies about 32 m above a horizon containing the marine gastropod Turritella cortezi, which ranges from east Texas to northeast Mexico in the lower half of the Cook Mountain and Laredo Formations and is a guide fossil to the Hurricane Lentil in the Cook Mountain Formation. Nannoplankton found in these middle Eocene formations belong to the upper half of Nannoplankton Zone I6 and allow correlation with European beds of late Lutetian to early Bartonian age.

Digital Data from the Great Sand Dunes and Poncha Springs Aeromagnetic Surveys, South-Central Colorado

USGS Publications Warehouse

Drenth, B.J.; Grauch, V.J.S.; Bankey, Viki; New Sense Geophysics, Ltd.

2009-01-01

This report contains digital data, image files, and text files describing data formats and survey procedures for two high-resolution aeromagnetic surveys in south-central Colorado: one in the eastern San Luis Valley, Alamosa and Saguache Counties, and the other in the southern Upper Arkansas Valley, Chaffee County. In the San Luis Valley, the Great Sand Dunes survey covers a large part of Great Sand Dunes National Park and Preserve and extends south along the mountain front to the foot of Mount Blanca. In the Upper Arkansas Valley, the Poncha Springs survey covers the town of Poncha Springs and vicinity. The digital files include grids, images, and flight-line data. Several derivative products from these data are also presented as grids and images, including two grids of reduced-to-pole aeromagnetic data and data continued to a reference surface. Images are presented in various formats and are intended to be used as input to geographic information systems, standard graphics software, or map plotting packages.

Recognition on space photographs of structural elements of Baja California

NASA Technical Reports Server (NTRS)

Hamilton, W.

1971-01-01

Gemini and Apollo photographs provide illustrations of known structural features of the peninsula and some structures not recognized previously. An apparent transform relationship between strike-slip and normal faulting is illustrated by the overlapping vertical photographs of northern Baja California. The active Agua Blanca right-lateral strike-slip fault trends east-southeastward to end at the north end of the Valle San Felipe and Valle Chico. The uplands of the high Sierra San Pedro Martir are a low-relief surface deformed by young faults, monoclines, and warps, which mostly produce west-facing steps and slopes; the topography is basically structural. The Sierra Cucapas of northeasternmost Baja California and the Colorado River delta of northwesternmost Sonora are broken by northwest-trending strike-slip faults. A strike-slip fault is inferred to trend northward obliquely from near Cabo San Lucas to La Paz, thence offshore until it comes ashore again as the Bahia Concepcion strike-slip fault.

Different types of degradable vectors from low-molecular-weight polycation-functionalized poly(aspartic acid) for efficient gene delivery.

PubMed

Dou, X B; Hu, Y; Zhao, N N; Xu, F J

2014-03-01

Poly(aspartic acid) (PAsp) has been employed as the potential backbone for the preparation of efficient gene carriers, due to its low cytotoxicity, good biodegradability and excellent biocompatibility. In this work, the degradable linear or star-shaped PBLA was first prepared via ring-opining polymerization of β-benzyl-L-aspartate N-carboxy anhydride (BLA-NCA) initiated by ethylenediamine (ED) or ED-functionalized cyclodextrin cores. Then, PBLA was functionalized via aminolysis reaction with low-molecular-weight poly(2-(dimethylamino)ethyl methacrylate) with one terminal primary amine group (PDMAEMA-NH2), followed by addition of excess ED or ethanolamine (EA) to complete the aminolysis process. The obtained different types of cationic PAsp-based vectors including linear or star PAsp-PDM-NH2 and PAsp-PDM-OH exhibited good condensation capability and degradability, benefiting gene delivery process. In comparison with gold standard polyethylenimine (PEI, ∼ 25 kDa), the cationic PAsp-based vectors, particularly star-shaped ones, exhibited much better transfection performances. Copyright © 2013 Elsevier Ltd. All rights reserved.

Associational Patterns of Scavenger Beetles to Decomposition Stages.

PubMed

Zanetti, Noelia I; Visciarelli, Elena C; Centeno, Nestor D

2015-07-01

Beetles associated with carrion play an important role in recycling organic matter in an ecosystem. Four experiments on decomposition, one per season, were conducted in a semirural area in Bahía Blanca, Argentina. Melyridae are reported for the first time of forensic interest. Apart from adults and larvae of Scarabaeidae, thirteen species and two genera of other coleopteran families are new forensic records in Argentina. Diversity, abundance, and species composition of beetles showed differences between stages and seasons. Our results differed from other studies conducted in temperate regions. Four guilds and succession patterns were established in relation to decomposition stages and seasons. Dermestidae (necrophages) predominated in winter during the decomposition process; Staphylinidae (necrophiles) in Fresh and Bloat stages during spring, summer, and autumn; and Histeridae (necrophiles) and Cleridae (omnivores) in the following stages during those seasons. Finally, coleopteran activity, diversity and abundance, and decomposition rate change with biogeoclimatic characteristics, which is of significance in forensics. © 2015 American Academy of Forensic Sciences.

Increasing the Knowledge of Stratification in Shallow Coastal Environments

NASA Astrophysics Data System (ADS)

Ojo, T.; Bonner, J.; Hodges, B.; Maidment, D.; Montagna, P.; Minsker, B.

2006-12-01

A testbed has been established using Corpus Christi Bay as an environmental field facility to study the phenomenon of hypoxia that has been observed to develop at certain periods during the year. Stratification affects vertical turbulent mixing of heat, momentum and mass (or constituents) within the water column, in turn influencing the transport of material. The mixing threshold is dependent on the value of the Richardson Number, Ri with inhibition due to stratification occurring at low values (< 0.25) and complete vertical mixing occurring at high values (> 0.25) of Ri. Corpus Christi Bay with average depth of ~3 m is the largest among a system of five bays has been known to stratify due to inflows of hypersaline water (up to 50 psu) from adjoining bays, the Laguna Madre and Oso Bay. Laguna Madre is separated from the Gulf of Mexico by a barrier island and becomes hypersaline because of the imbalance between inflow of freshwater and bay evaporation. Hypersalinity also occurs in Oso Bay due to anthropogenic forcing from a power plant that draws 400 MGD of cooling water from the upper Laguna Madre, discharging waste water into Oso Bay. Several wastewater treatment plants also discharge directly into Oso Bay or its tributary streams. The objective of this study is to develop a methodology for prescribing a set of parameters required for modeling and characterization of hypoxia in this shallow wind-driven bay. The extent to which Ri is dependent on external forcing at the surface boundary was measured using our fully instrumented sensor platforms. Each sensor platform includes sensors for synchronic near-surface meteorological (wind velocity, barometric pressure, air temperature) and water column oceanographic (current, water temperature, conductivity, particle size distribution, particulate concentration, dissolved oxygen, nutrient) variables. These were measured using fixed and mobile vertical profiling sensor platforms. A 2D hydrodynamic model was initially

Revised Geologic Map of the Fort Garland Quadrangle, Costilla County, Colorado

USGS Publications Warehouse

Wallace, Alan R.; Machette, Michael N.

2008-01-01

The map area includes Fort Garland, Colo., and the surrounding area, which is primarily rural. Fort Garland was established in 1858 to protect settlers in the San Luis Valley, then part of the Territory of New Mexico. East of the town are the Garland mesas (basalt-covered tablelands), which are uplifted as horsts with the Central Sangre de Cristo fault zone. The map also includes the northern part of the Culebra graben, a deep structural basin that extends from south of San Luis (as the Sanchez graben) to near Blanca, about 8 km west of Fort Garland. The oldest rocks exposed in the map area are early Proterozic basement rocks (granites in Ikes Creek block) that occupy an intermediate structural position between the strongly uplifted Blanca Peak block and the Culebra graben. The basement rocks are overlain by Oligocene volcanic and volcaniclastic rocks of unknown origin. The volcanic rocks were buried by a thick sequence of basin-fill deposits of the Santa Fe Group as the Rio Grande rift formed about 25 million years ago. The Servilleta Basalt, a regional series of 3.7?4.8 Ma old flood basalts, was deposited within sediment, and locally provides a basis for dividing the group into upper and lower parts. Landslide deposits and colluvium that rest on sediments of the Santa Fe Group cover the steep margins of the mesas. Exposures of the sediment beneath the basalt and within the low foothills east of the Central Sangre de Cristo fault zone are comprised of siltstones, sandstones, and minor fluvial conglomerates. Most of the low ground surrounding the mesas and in the graben is covered by surficial deposits of Quaternary age. The alluvial deposits are subdivided into three Pleistocene-age units and three Holocene-age units. The oldest Pleistocene gravel (unit Qao) is preserved as isolated remnants that cap high surfaces north and east of Fort Garland. The primary geologic hazards in the map area are from earthquakes, landslides, and localized flooding. The Central

A geochemical study of the winonaites: Evidence for limited partial melting and constraints on the precursor composition

NASA Astrophysics Data System (ADS)

Hunt, Alison C.; Benedix, Gretchen K.; Hammond, Samantha J.; Bland, Philip A.; Rehkämper, Mark; Kreissig, Katharina; Strekopytov, Stanislav

2017-02-01

The winonaites are primitive achondrites which are associated with the IAB iron meteorites. Textural evidence implies heating to at least the Fe, Ni-FeS cotectic, but previous geochemical studies are ambiguous about the extent of silicate melting in these samples. Oxygen isotope evidence indicates that the precursor material may be related to the carbonaceous chondrites. Here we analysed a suite of winonaites for modal mineralogy and bulk major- and trace-element chemistry in order to assess the extent of thermal processing as well as constrain the precursor composition of the winonaite-IAB parent asteroid. Modal mineralogy and geochemical data are presented for eight winonaites. Textural analysis reveals that, for our sub-set of samples, all except the most primitive winonaite (Northwest Africa 1463) reached the Fe, Ni-FeS cotectic. However, only one (Tierra Blanca) shows geochemical evidence for silicate melting processes. Tierra Blanca is interpreted as a residue of small-degree silicate melting. Our sample of Winona shows geochemical evidence for extensive terrestrial weathering. All other winonaites studied here (Fortuna, Queen Alexander Range 94535, Hammadah al Hamra 193, Pontlyfni and NWA 1463) have chondritic major-element ratios and flat CI-normalised bulk rare-earth element patterns, suggesting that most of the winonaites did not reach the silicate melting temperature. The majority of winonaites were therefore heated to a narrow temperature range of between ∼1220 (the Fe, Ni-FeS cotectic temperature) and ∼1370 K (the basaltic partial melting temperature). Silicate inclusions in the IAB irons demonstrate partial melting did occur in some parts of the parent body (Ruzicka and Hutson, 2010), thereby implying heterogeneous heat distribution within this asteroid. Together, this indicates that melting was the result of internal heating by short-lived radionuclides. The brecciated nature of the winonaites suggests that the parent body was later disrupted by

Glacier Runoff and Human Vulnerability to Climate Change: The Case of Export Agriculture in Peru (Invited)

NASA Astrophysics Data System (ADS)

Carey, M.

2013-12-01

There is growing concern about the effects of climate change and ensuing glacier shrinkage on water supplies for mountain communities worldwide. The issue is only becoming more complex as researchers seek to quantify glacier contributions to streamflow and to pinpoint when and how much glacier runoff will likely change as a result of future climate change and glacier variation. Additionally, some researchers are beginning to recognize the importance of understanding the human dimensions of glacier retreat to identify which social groups (stakeholders) use glacier runoff and how much they use, as well as what socio-environmental forces affect both water supplies and water use. This presentation examines these societal aspects of glacier runoff to analyze human vulnerability to hydrological changes in Peru's Santa River watershed below the most glaciated tropical mountain range in the world, the Cordillera Blanca. Specifically, it focuses on the billion-dollar export-oriented agricultural industry within the Chavimochic irrigation project, which uses Santa River water to irrigate approximately 80,000 hectares in the coastal desert region. Since the 1980s, Santa River water has allowed Chavimochic to sustain a major export economy, provide jobs in the agro-industry and related services, stimulate human migration, enhance or alter livelihoods, generate hydroelectricity, supply drinking water, and shape urban growth and land use practices. All of these variables are dependent on glacier meltwater from the Cordillera Blanca, especially during the dry season when glaciers provide most of the Santa River's water. In short, hundreds of thousands of people have come to depend on glacier runoff, thus revealing their high level of vulnerability to hydrological fluctuations in a glacier-fed watershed. What's more, people worldwide rely on the asparagus, avocados, and artichokes grown with glacier runoff. Consequently, the export-oriented agriculture, through the "virtual water

Implementation of new tools in molecular epidemiology studies of Echinococcus granulosus sensu lato in South America.

PubMed

Avila, Héctor G; Santos, Guilherme B; Cucher, Marcela A; Macchiaroli, Natalia; Pérez, Matías G; Baldi, Germán; Jensen, Oscar; Pérez, Verónica; López, Raúl; Negro, Perla; Scialfa, Exequiel; Zaha, Arnaldo; Ferreira, Henrique B; Rosenzvit, Mara; Kamenetzky, Laura

2017-06-01

The aim of this work was to determine Echinococcus granulosus sensu lato species and genotypes in intermediate and definitive hosts and in human isolates from endemic regions of Argentina and Brazil including those where no molecular data is available by a combination of classical and alternative molecular tools. A total of 227 samples were isolated from humans, natural intermediate and definitive hosts. Amplification of cytochrome c oxidase subunit I gene fragment was performed and a combination of AluI digestion assay, High Resolution Melting analysis (HRM) assay and DNA sequencing was implemented for Echinococcus species/genotype determination. E. granulosus sensu stricto (G1) was found in sheep (n=35), cattle (n=67) and dogs (n=5); E. ortleppi (G5) in humans (n=3) and cattle (n=108); E. canadensis (G6) in humans (n=2) and E. canadensis (G7) in pigs (n=7). We reported for the first time the presence of E. ortleppi (G5) and E. canadensis (G6) in humans from San Juan and Catamarca Argentinean provinces and E. canadensis (G7) in pigs from Cordoba Argentinean province. In this work, we widened molecular epidemiology studies of E. granulosus s. l. in South America by analyzing several isolates from definitive and intermediate hosts, including humans from endemic regions were such information was scarce or unavailable. The presence of different species/genotypes in the same region and host species reinforce the need of rapid and specific techniques for accurate determination of Echinococcus species such as the ones proposed in this work. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of the Consequences of a Cistern Truck Accident While Transporting Dangerous Substances through a Tunnel.

PubMed

Malecha, Ziemowit M; Poliski, Jarosaw; Chorowski, Maciej

2017-12-01

The transportation of dangerous substances by truck carriers harbors important safety issues in both road and mine tunnels. Even though traffic conditions in road and mine tunnels are different, the potential geometric and hydrodynamic similarities can lead to similar effects from the uncontrolled leakage of the dangerous material. This work was motivated by the design study of the LAGUNA-LBNO (Large Apparatus studying Grand Unification and Neutrino Astrophysics and Long Baseline Neutrino Oscillations) project. The considered neutrino detector requires a huge amount of liquid argon, which must be transported down the tunnel. The present work focuses on the estimation of the most credible incident and the resulting consequences in the case of a truck accident in the tunnel. The approach and tools used in the present work are generic and can be adapted to other similar situations. © 2017 Society for Risk Analysis.

First Record of Culex (Microculex) daumastocampa (Diptera: Culicidae) in Mexico, with Notes on Cx. rejector and Cx. imitator.

PubMed

Ortega-Morales, A; Garza-Hernández, J A; González-Álvarez, V H; Hernández-Triana, L M; Rodríguez-Pérez, M A

2018-03-08

Culex (Microculex) daumastocampa Dyar & Knab was originally described by Dyar and Knab (Proc US Nat Mus 35:53-70, 1908) from larvae collected at axils of bromeliads in Port San Felipe, Panama. Culex daumastocampa is found in Colombia, Venezuela, Panama, Suriname, Costa Rica, Nicaragua, Guatemala, and Mexico, although its presence had not been reported suggesting its northernmost distribution. In Mexico, the subgenus Microculex had included Cx. rejector Dyar and Knab, and Cx. imitator Theobald. However, after that collection specimens were re-examined along with other specimens collected during 2016 in Chiapas (all specimens are available in the Culicidae Collection of the Universidad Autonoma Agraria Antonio Narro Unidad Laguna [UAAAN-UL], Mexico). Culex daumastocampa is now reported for the first time in Mexico, Cx. rejector for Chiapas, and Cx. imitator removed from the checklist of previous reports as to be present in Mexico.

Paleoenvironmental and Paleoecological Reconstruction of the Ancient Maya Port Site of Vista Alegre, Quintana Roo, Mexico

NASA Astrophysics Data System (ADS)

Rissolo, D.; Jaijel, R.; Glover, J. B.; Goodman, B.; Beddows, P. A.; Carter, A.; Smith, D.

2013-12-01

Ancient Maya ports along the largely unstudied northeast coast of the Yucatan Peninsula once supported a network of trade routes linking people, goods, and ideas from across Mesoamerica. The Costa Escondida Project has focused on the interrelationships between the ancient Maya and their dynamic coastal environment along the shores of the Laguna Holbox. Central to our interdisciplinary efforts is a paleoenvironmental and paleoecological reconstruction of the key port of Vista Alegre - a low-lying island surrounded by a complex mosaic of costal ecosystems, sedimentological facies, and hydrological conditions. Geoarchaeological field methods, such as sediment coring, have made possible multiproxy analyses that enable us to better understand sea level fluctuations and the morphology of the shoreline and harboring locations over time, as well as changes in ecosystem biodiversity, which would have presented the maritime Maya with unique challenges and opportunities.

ALARA development in Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez, M.A.M.

1995-03-01

Even though the ALARA philosophy was formally implemented in the early 1980`s, to some extent, ALARA considerations already had been incorporated into the design of most commercial equipment and facilities based on experience and engineering development. In Mexico, the design of medical and industrial facilities were based on international recommendations containing those considerations. With the construction of Laguna Verde Nuclear Power Station, formal ALARA groups were created to review some parts of its design, and to prepare the ALARA Program and related procedures necessary for its commercial operation. This paper begins with a brief historical description of ALARA development inmore » Mexico, and then goes on to discuss our regulatory frame in Radiation Protection, some aspects of the ALARA Program, efforts in controlling and reducing of sources of radiation, and finally, future perspectives in the ALARA field.« less

[Macrophytes from some high Andean lakes of Ecuador and their low potential as bioindicators of eutrophication].

PubMed

Kiersch, Benjamin; Mühleck, Ralf; Gunkel, Günter

2004-12-01

The occurrence of macrophyte in three high Andean lakes of Ecuador, Lago San Pablo, Laguna La Mica and Lago Cuicocha was recorded in 5-9 transects per lake. The first two lakes are eutrophic, the third is an extremely oligotrophic caldera lake. The dominant species in eutrophic lakes are Ceratophyllum demersum, Myriophyllum quitense, Polamogeton illinoensis, P. striatus and Elodea matthewsii. In the oligotrophic lake P. pectinatus, P. illinoensis, and the Characeae Chara rusbyana, Ch. globularis and Nitella acuminata occur. The maximum depth of the macrophyte's presence can be used as an indicator of the trophic state, ranging from about 5 m in Mica to 35 m in Cuicocha. The bioindication value of the macrophyte species in these high Andean lakes is low, because few species occur and because some of them are not specific to environmental conditions.

75 FR 2477 - Plan Development for Kiowa, Rita Blanca, Black Kettle and McClellan Creek National Grasslands...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-15

..., No. 183, p. 54363. That notice also requested review on the CER, the Ecological Sustainability Report... Ecological Sustainability Report (ESR) that was completed in August, 2008 will continue to be used as a... Socio-economic Sustainability Report that was completed in August 2008 is not affected by the change in...

77 FR 51044 - Laguna Cartagena National Wildlife Refuge, PR; Final Comprehensive Conservation Plan and Finding...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-23

... plants, haying, research studies, wildlife surveying and monitoring, scientific collections, and camping... interest, including West Indian whistling ducks and kestrels. Under this alternative, specific activities...