Sample records for ONDAS MARINAS (water waves)
from WorldWideScience.org

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3

Condiciones oceanográficas durante la fase de relajación de un evento de surgencia invernal frente a Punta Lengua de Vaca, Coquimbo/ Oceanographic conditions during a relaxation phase of a winter upwelling event off Point Lengua de Vaca, Coquimbo

Moraga, Julio; Valdebenito, Eugenia; Rutllant, José
2001-01-01

Resumen en español RESUMEN. Entre el 10 y 17 de agosto de 1990 se efectuaron estaciones oceanográficas en el área frente al foco de surgencia de Punta Lengua de Vaca mediante CTD y botellas hasta 350 m de profundidad y una distancia de 12 millas náuticas de la costa (aproximadamente 22 km). Se analizan e interpretan, mediante perfiles T-S y estimaciones geostróficas, las características y dinámica de las aguas costeras y oceánicas en este período. Las observaciones comprendieron un (mas) período de relajación y posterior intensificación de los vientos favorables a la surgencia observados in situ mediante una estación meteorológica automática. La diferencia en el comportamiento de los campos de temperatura y salinidad en las estaciones próximas a la costa respecto de las oceánicas se explica por la intrusión de masas de agua y la influencia de ondas internas de gravedad. Estimaciones geostróficas referidas a 300 db indican corrientes del orden de 10 cm*s-1 hacia el norte en los primeros 100 m y hacia el sur bajo esa profundidad, consistentes con un esquema clásico de surgencia costera. Se analiza además la influencia de la surgencia generada frente a Punta Lengua de Vaca en las bahías de Tongoy y Guanaquero, ubicadas al norte de ese foco Resumen en inglés ABSTRACT. Oceanographic stations in a 12 nm transect off the upwelling focus of Punta Lengua de Vaca and adyacent area were occupied using CTD and bottles to 350 m depth on August 10 to 17, 1990. The characteristics and dynamics of coastal and oceanic waters are analyzed and interpreted by means of T-S profiles and geostrophic speed estimates. The observational period coincided with a relaxation of the coastal wind followed by an upwelling-favorable wind event, as observe (mas) d "in situ" by an automatic metereological station. Differences of the temperature and salinity behavior at the coastal stations with respect to the oceanic ones are explained by intrusion of oceanic water masses and the influence of internal gravity waves. Geostrophic estimates relative to the 300 db level indicate northward currents of the order of 10 cm*s-1 in the first 100 m depth layer and southward ones under that level, consistent with the classical coastal upwelling scheme. The influence of the upwelling focus on the Tongoy and Guanaquero bays located north of Punta Lengua de Vaca is analyzed

Scientific Electronic Library Online (Spanish)

4

Origen del tsunami de mayo de 1960 en el Lago Nahuel Huapi, Patagonia: aplicación de técnicas batimétricas y sísmicas de alta resolución/ Origin of the tsunami of may 1960 in the Lake Nahuel Huapi, Patagonia: application of the high-resolution bathymetric and seismic techniques

Villarosa, Gustavo; Outes, Valeria; Gomez, Eduardo A.; Chapron, Emmanuel; Ariztegui, Daniel
2009-11-01

Resumen en español El tsunami ocurrido en el lago Nahuel Haupi, Patagonia Argentina, el 22 de Mayo de 1960, constituye el primer ejemplo de tsunami en lagos continentales en Argentina. La batimetría de detalle obtenida con sonar batimétrico por medición de fase (SBMF) y dos perfiles sísmicos de alta resolución junto con tres testigos sedimentarios cortos del lago permitieron vincular al tsunami con el gran movimiento sísmico conocido como el terremoto de Valdivia, el sismo más fuerte (mas) registrado instrumentalmente a escala global (Mw 9,5). El impacto de las ondas sísmicas provocó la movilización de grandes volúmenes de sedimentos lacustres del sustrato, especialmente por debajo de los 70-80 m de profundidad de agua. El fallo fue probablemente inducido por la presencia de una superficie de baja coherencia (tefra?) que funcionó como plano de deslizamiento posibilitando la remoción de sedimentos y conformando una megaturbidita en la parte más profunda. La movilización de estos materiales provocó el desplazamiento de un gran volumen de agua, originando el tsunami que golpeó las costas de Bariloche y destruyó el muelle de la ciudad. Resumen en inglés The tsunami recorded in the Lake Nahuel Huapi, Patagonia Argentina, on May 22, 1960 is the first example of a tsunami in a continental lake in Argentina. High-resolution bathymetry (SBMF), 2 high-resolution seismic profiles together with three short sedimentary cores allowed linking this tsunami to the 1960 earthquake of Valdivia, the strongest (Mw 9.5) ever instrumentally recorded earthquake. The impact of the seismic waves produced huge mass-failure below 70-80 m water (mas) depth. The failure was probably induced by the presence of a non-cohesive surface (tephra layer?) that acted as a sliding surface, and the mobilized material evolved into a mega turbidite in the deep basin. A large volume of water was displaced by the mobilization of these sediments producing a tsunami that hit the coasts of Bariloche and destroyed the harbor of the city.

Scientific Electronic Library Online (Spanish)

5

Dinámica submareal y condiciones ambientales de la ría Deseado, Santa Cruz/ Subtidal dynamics and environmental conditions of the Río Deseado estuary, Santa Cruz

Isla, F.; Iantanos, N.; Estrada, E.
2004-09-01

Resumen en español La geometría del estuario del río Deseado, las condiciones climáticas semiáridas y la morfología de los cañones labrados en volcanitas han contribuido al dominio del régimen macromareal en este sector de la costa patagónica. A su vez, los efectos de las corrientes de marea se acentúan debido al empobrecimiento en el caudal del río, que en función del valle que se observa en la actualidad, debió haber llevado un importante caudal alimentado por las aguas de fus (mas) ión de la masa de hielo que rellenaba la cuenca del lago Buenos Aires. Cuando los hielos dejaron libre el valle del río Baker, el lago comenzó a desaguar hacia el Pacífico, dejando casi seco al río Deseado, que sólo recibe los aportes de los ríos Pinturas y Fénix Grande. La atenuación de la marea se reconoce en la gradación de los sedimentos de fondo: gravas en Puerto Deseado, arenas en la bahía Uruguay y fangos en la bahía Concordia. Las formas de fondo reconocidas como sonografías destacan megaóndulas bidimensionales orientadas según el flujo en el sector de isla de los Pájaros, y ondas de arena orientadas según el reflujo que se ubicaron a mayor profundidad hacia el interior de este sector de acumulación. Los registros de sonar lateral así como los muestreos de fondo confirmaron fondos planos arenosos con gravas en bahía Uruguay, y surcos erosivos (furrows) constituidos en fangos en el interior de la bahía Concordia. La mezcla de aguas marina y dulce se produce en Puesto El Paso mientras que en la bahía Concordia se dan los máximos de turbidez. Resumen en inglés The geometry of the Río Deseado estuary, the semiarid climatic conditions and the morphology of gorges carved into volcanic rocks contributed to the dominance of a macrotidal regime in this part of the Patagonian coast. In turn, the effects of tidal currents are increased due to the impoverishment of the Río Deseado discharge, whose valley used to drain the ice cover that occupied the Lago Buenos Aires basin. When the Río Backer valley became free of ice, the lake bega (mas) n to discharge to the Pacific Ocean. Since then, the Río Deseado has received only the supply of the Pinturas and Fénix Grande rivers. The decrease of the tidal action towards the headlands produces a grain-size segregation in the bottom sediments: gravel at Puerto Deseado, sand in Bahía Uruguay and mud in Bahía Concordia. Bedforms recognized in side-scan sonar records distinguished flood-oriented 2-D megaripples in the area of isla de los Pájaros, and ebb-oriented sand waves at a greater depth and some kilometres inland in the inlet of Bahía Uruguay. Sonographs and bottom samples confirmed flat beds composed of sands with gravel in Bahía Uruguay and furrows eroded in muds in Bahía Concordia. Water mixing (marine and freshwater) occurs in Puesto El Paso while turbidity maximum was measured in Bahía Concordia.

Scientific Electronic Library Online (Spanish)

6

Water Vapor around Sgr B2

Cernicharo, José; Goicoechea, Javier R.; Pardo Carrión, Juan Ramón; Asensio Ramos, Andrés
2006-01-10

Digital.CSIC (Spain)

7

Water Stress and Chlorosis Detection in Crop Canopies with AHS Thermal Imagery and CASI and ROSIS Hyperspectral Sensors: Implications on Yield

Zarco-Tejada, Pablo J.; Sepulcre-Cantó, G.; Pérez-Priego, O.; Sobrino, J. A.; Jiménez-Muñoz, J. C.; Berjón, A.; Martín Muñoz, Antonio Pedro; González, R.
2005-01-01

Digital.CSIC (Spain)

8

Warm Water Vapor around Sagittarius B2

Cernicharo, José; Goicoechea, Javier R.; Pardo Carrión, Juan Ramón; Asensio Ramos, Andrés
2006-05-10

Digital.CSIC (Spain)

9

Underwater acoustic propagation model to simulate seismic oceanography experiments

Kormann, Jean; Cobo, Pedro; Ranz Guerra, Carlos

Communication presented at the 14th International Congress on Sound Vibration, Cairns, Australia, 9-12 July 2007. | Seismic reflection is a technique used for decades to profile the earth layering beneath the ocean with a high lateral and vertical resolution. In the other hand, oceanographers use pr...

DRIVER (Spanish)

11

The sea-floor morphology of a Mediterranean shelf fed by small rivers, northern Alboran Sea margin

Lobo, F. J.; Fernández-Salas, L. M.; Moreno, I.; Sanz, J. L.; Maldonado, Andrés
2006-10-09

Digital.CSIC (Spain)

12

The influence of ocean waves in shallow water problems

Kormann, Jean; Ranz Guerra, Carlos; Fernández, Alejandro

5 pages.-- Communication presented at ForumAcusticum 2005 Budapest: "Acoustics: Science and Technology for Knowledge Based Society and Healthy Environment" (Aug 29-Sep 2, 2005). | In this paper we present the influence of ocean waves in shallow water scenarios which have geometric dimensions of abou...

DRIVER (Spanish)

13

The influence of ocean waves in shallow water problems

Kormann, Jean; Ranz Guerra, Carlos; Fernández, Alejandro
2005-08-01

Digital.CSIC (Spain)

14

The contourite depositional system of the Gulf of Cádiz: A sedimentary model related to the bottom current activity of the Mediterranean outflow water and its interaction with the continental margin

Hernández-Molina, F. Javier; Llave, E; Stow, D. A. V.; García, M. C.; Somoza, Luis; Vázquez, Juan Tomas; Lobo, F. J.; Maestro, A.; Díaz del Río, V.; Leon, R.,; Medialdea, T.; Gardner, J
2006-01-01

Digital.CSIC (Spain)

15

Suspended sediment fluxes and transport processes in the Gulf of Lions submarine canyons. The role of storms and dense water cascading

Palanques, Albert; Durrieu de Madron, Xavier; Puig, Pere; Fabrés, Joan; Guillén, Jorge; Calafat, Antoni; Canals, Miquel; Heussner, Serge; Bonnin, Jerôme
2006-01-01

Digital.CSIC (Spain)

18

Storm-driven shelf-to-canyon suspended sediment transport at the southwestern Gulf of Lions

Palanques, Albert; Guillén, Jorge; Puig, Pere; Durrieu de Madron, Xavier
2008-08-30

Digital.CSIC (Spain)

19

Simulating Echo Responses from Arbitrary-Geometry Targets Using Mode Conversion Approach

Buiochi, Flávio; Martínez Graullera, Óscar; Gómez-Ullate Alvear, Luis; Montero de Espinosa Freijo, Francisco
2008-01-01

Digital.CSIC (Spain)

21

Sedimentary processes in the Wilkes Land margin: a record of the Cenozoic East Antarctic Ice Sheet evolution

Donda, F.; Brancolini, G.; O'Brien, P.E.; De Santis, L.; Escutia, Carlota
2007-01-01

Digital.CSIC (Spain)

22

Sediment transport processes from the topset to the foreset of a crenulated clinoform (Adriatic Sea)

Puig, Pere; Ogston, Andrea S.; Guillén, Jorge; Fain, A. M. V.; Palanques, Albert
2007-02-01

Digital.CSIC (Spain)

23

Sediment dynamics during wet and dry storm events on the Têt inner shelf (SW Gulf of Lions)

Guillén, Jorge; Bourrin, F.; Palanques, Albert; Durrieu de Madron, Xavier; Puig, Pere; Buscail, R.
2006-01-01

Digital.CSIC (Spain)

24

Reforming of ethanol in a microwave surface-wave plasma discharge

Yanguas-Gil, Alejandro.; Hueso, J. L.; Cotrino, José; Caballero, A.; González-Elipe, Agustín R.
2004-11-01

Digital.CSIC (Spain)

26

Projects of the Royal Observatory of Belgium (ROB) at the Lanzarote Geodynamical Laboratory (LGL)

Ruymbeke, M. van; Somerhausen, André; Ducarme, B.; Vieira, Ricardo; Arnoso, José; Vélez, Emilio
2001-01-01

Digital.CSIC (Spain)

27

Procesos geológicos e intensidad macrosísmica Inqua del sismo de Pisco del 15/08/2007, Perú/ Geological process and INQUA macro-seismic intensity scale of Pisco earthquake 15/08/2007, Perú

Zavala, Bilberto; Hermanns, Reginald; Valderrama, Patricio; Costa, Carlos; Rosado, Malena
2009-12-01

Resumen en español El 15 de agosto de 2007 las ciudades de Pisco, Ica, Chincha y Cañete, ubicadas entre 140 y 300 km al sur de la capital peruana, fueron afectadas por un sismo de magnitud 7,9 (Mw). Los reportes finales del Instituto Nacional de Defensa Civil indicaron la ocurrencia de 519 muertes y entre 655 y 679 viviendas afectadas. Fueron severamente dañadas ciudades como Pisco, San Clemente y Tambo de Mora, áreas agrícolas en los valles de Pisco y Cañete y varios tramos de la carr (mas) etera panamericana sur. Lugares turísticos en la Reserva Nacional de Paracas fueron destruidos, vías de penetración a la sierra de Ica, Huancavelica y Lima fueron bloqueadas, y poblaciones asentadas sobre depósitos de antiguos deslizamientos sufrieron daños (Laraos, Chocos, Huangascar, Tantará). Balnearios, caletas y muelles artesanales en la zona litoral, áreas agrícolas y algunas granjas avícolas sufrieron los efectos de un tsunami. Procesos geológicos cosísmicos y postsísmicos responsables de los daños, ocurrieron en un radio de 200 km del epicentro. Deformaciones superficiales asociadas a licuación y expansión lateral se presentaron en las planicies y valles aluviales costeros, afectando sedimentitas terciarias y depósitos recientes, con niveles freáticos superficiales. Movimientos en masa (caída de rocas, derrumbes y deslizamientos), ocurrieron entre 32 y 198 km del epicentro, con volúmenes acumulados de 14.750 m³ (costa) y 9.585 m³ (sierra). Olas de tsunami post-sismo, alcanzaron un run up de hasta 10 m (playa Yumaque) y hasta 2 km de inundación (playa Lagunillas), en la Reserva Nacional de Paracas. La descripción geológica y geomorfológica de estos procesos, indicaron que el sismo de Pisco alcanzó un grado entre VII y VIII utilizando la escala de intensidad macrosísmica INQUA. Resumen en inglés In August 15th, 2007 the cities of Pisco, Ica, Chincha and Cañete, located south of the Peruvian capital city, were affected for a mayor earthquake (7.9 Mw). The final report from the National Institute of Civil Defense totaled 519 casualties and 655 to 679 damaged houses. Cities like Pisco, San Clemente and Tambo de Mora were severely affected, as well as agricultural areas in Pisco and Cañete valleys. The Panamericana highway was considerablely affected. In the Nation (mas) al Reserve Paracas many tourist places were destroyed and many secondary roads that connect the coastal area with the high part of the Andes (Ica, Huancavelica and Lima) were blocked due to rock falls. Small towns in the Andes placed on ancient landslide deposits were damaged (Laraos, Chocos, Huangascar, Tantará). Seaside resorts, creeks and small docks in the coastal area and some chicken farms were affected by the tsunami. Coseismic and postseismic geological processes were responsible for the damage in a 200 km radius from the epicenter. Ground deformation and lateral spreading happened in Tertiary sediments due to a shallow of the ground water table. Mass movements (rock fall, collapsing and landslides) are located between 32 and 198 km from the epicenter, with accumulated volumes of 14,750 m³ (Coastal area) and 9, 585 m³ (Andes area). The tsunami waves got 10 m of run up (Yumaque beach) and up to 2 km of flooding at the beach zone (Lagunillas beach) in the National Reserve of Paracas. The geological and geomorphological descriptions of this process determine that that the Pisco earthquake reached a VII and VIII grade on the INQUA macro-seismic intensity scale.

Scientific Electronic Library Online (Spanish)

28

Probing nonstandard neutrino interactions with supernova neutrinos

Esteban-Pretel, Andreu; Tomàs, Ricard; Valle, José W. F.
2007-09-10

Digital.CSIC (Spain)

31
34

Nonlinear ultrasonic waves in water-air mixtures

Vanhille, Christian; Campos-Pozuelo, Cleofé

Communication presented at: Acoustics '08 (Paris, France, June 29-July 4, 2008), comprising: 5th Forum Acusticum, 155th ASA Meeting, 9e Congrès Français d'Acoustique, 7th European Conference on Noise Control (Euronoise), 9th European Conference on Underwater Acoustics (ECUA).-- Book of abstracts pub...

DRIVER (Spanish)

35

Nonlinear ultrasonic waves in water-air mixtures

Vanhille, Christian; Campos-Pozuelo, Cleofé
2008-07-01

Digital.CSIC (Spain)

37

New analysis of a 50 years tide gauge record at Cananéia (SP-Brazil) with the VAV tidal analyisis program

Ducarme, B.; Venedikov, A. P.; Mesquita, A. R. de; Sampaio França, C. A.; Costa, D. S.; Blitzkow, D.; Vieira, Ricardo; Freitas, S. R. C.
2007-01-01

Digital.CSIC (Spain)

38

Morphometric analysis and genetic implications of pro-deltaic sea-floor undulations in the northern Alboran Sea margin, western Mediterranean Basin

Fernández-Salas, L. M.; Lobo, F. J.; Sanz, J. L.; Díaz del Río, V.; García, M. C.; Moreno, I.
2007-09-06

Digital.CSIC (Spain)

41

Measurement of hydrodynamic and environmental variables in Morrocoy, Venezuela/ Medición de variables hidrodinámicas y ambientales en Morrocoy, Venezuela

Solana S, Pedro; Castellanos, Bartolo; Nalesso, Mauro
2004-08-01

Resumen en español Se presentan los resultados de las mediciones de niveles del mar, profundidad del mar, corrientes tridimensionales realizadas en diversos lugares del Parque Nacional Morrocoy, oleaje y temperatura en el fondo del mar, así como resultados de mediciones de velocidad y dirección del viento, temperatura ambiental y precipitación acaecida desde mayo 2000 hasta marzo de 2002. El análisis de los registros de corrientes en gran parte del Parque muestra velocidades de corrient (mas) e de poca magnitud y dominada por la corriente de marea que interactúa con el sistema costero. La marea está definida como mixta, predominantemente diurna, con un rango de poca amplitud. La temporada de lluvias esta localizada entre los meses de junio a diciembre. Las temperaturas medias mensuales alcanzan su mínimo en los meses de enero y febrero, mientras que la velocidad media del viento es de 4.4 m/s con dirección dominante E-ESE. Resumen en inglés The results of measurements of sea level, water depth, three dimensional currents in several locations of the Morrocoy National Park, water waves and bottom temperature, as well as records of wind velocities and direction, air temperature and rainfall, during the period between May 2000 and March 2002, are shown. The analysis of the records of currents shows low intensity and dominated by the tide that interacts with the coastal system. The tide is defined as mixed, predo (mas) minantly diurnal, with low amplitude. The rainfall season is located between the months of June and December. The monthly average air temperature reaches their minimum during the months of January and February, whereas the mean wind velocity is 4.4 m/s with a dominant direction of E-ESE.

Scientific Electronic Library Online (Spanish)

43

Lee region of Gran Canaria

Barton, Eric D.; Basterretxea, Gotzon; Flament, Pierre; Gay Mitchelson-Jacob, E.; Jones, Bethan; Arístegui, Javier; Herrera, Félix
2000-07-01

Digital.CSIC (Spain)

46

Geomorphology of the Galicia Bank Region (NW Iberian Peninsula)

Ercilla, Gemma; Somoza, Luis; Vázquez, Juan T.; Estrada, Ferrán; Casas, David; [ERGAP Project and Cruise Team]
2008-01-01

Digital.CSIC (Spain)

47

Generación de frecuencias de referencia para la calibración de sistemas WDM en comunicaciones ópticas

Corredera Guillén, Pedro; Martín López, Sonia; Carrasco Sanz, Ana
2007-06-01

Digital.CSIC (Spain)

48

From the determination of sea emissivity to the retrieval of salinity: recent contributions to the SMOS mission from the UPC and ICM

Camps, Adriano; Font, Jordi; Vall-llossera, Marco; Villarino, R.; Gabarró, Carolina; Enrique, L.; Miranda, J.; Corbella, I.; Duffo, N.; Torres, F.; Blanch, S.; Aguasca, A.; Sabia, Roberto
2006-08-01

Digital.CSIC (Spain)

49

Evaluación de hidrogeles para aplicaciones agroforestales/ Evaluating hydrogels for agriforestry applications

Barón Cortés, Andrés; Barrera Ramírez, Ingrid Xiomara; Boada Eslava, Luis Francisco; Rodríguez Niño, Gerardo
2007-12-01

Resumen en español Con hidrogeles sintetizados por medio de la técnica de polimerización en suspensión inversa (PSI), compuestos por acrilamida y acrilato de potasio entrecruzados con N, N’ metilen-bis-acrilamida y que presentan diferentes comportamientos desde el punto de vista de capacidad y velocidad de hinchamiento, módulo elástico y propiedades de liberación, se estudia la modificación de las propiedades hidráulicas de un suelo tipo franco arcilloso realizando curvas de retenc (mas) ión de humedad, empleando ollas de presión de plato cerámico, y se desarrollan montajes para evaluar la modificación en la retención de los mismos, ante condiciones de dosificación prolongada e instantánea de agua de irrigación. Adicionalmente, se realizan cultivos de acacia y rábano en fase vivero en suelos acondicionados con diferentes hidrogeles, en el primer cultivo se evalúa el retraso en la marchitez de la especie y en el segundo la diferencia en crecimiento; simultáneamente para los cultivos, se hace el seguimiento del contenido de humedad in situ del suelo con respecto al tiempo. Se logra un método para la medición del módulo elástico y las propiedades de liberación y se establece un modelo para predecir el comportamiento de los hidrogeles en el suelo con el conocimiento de sus propiedades básicas en el estado libre. Finalmente, los resultados muestran la bondad del uso de hidrogeles en estas aplicaciones: hay mayor facilidad de liberación y retención de agua aprovechable por el suelo, retraso notable del marchitamiento en condiciones hostiles, y es mayor el crecimiento de las especies, entre otros beneficios, además se establecen pautas para definir las características del hidrogel más adecuado dependiendo de la aplicación deseada y se realiza una proyección hacia la disminución del consumo de agua para el mantenimiento de un cultivo. Resumen en inglés Hydrogels synthesised by inverse suspension polymerisation (ISP) technique consisting of acrylamide and potassium acrylate interlinked with N, N’ methylene-bis-acrylamide and presenting different behaviour in terms of rooting ability and speed, elastic module and release properties were studied. Markedly clayey soil properties were modified by drawing up moisture-retention curves using ceramic plate pressure waves and developing montages for evaluating modifications made (mas) to their retention, regarding prolonged and instantaneous irrigation-water dosage conditions. Acacia and radish crops were grown in nursery phase in soil conditioned with different hydrogels. Delayed specie withering was simultaneously evaluated in the first crop and difference in growth in the second one. Follow-up of in situ soil moisture content was also evaluated over a fixed period of time. A method was achieved for measuring elastic module and release properties and model was established for predicting hydrogel behaviour in soil having known basic properties in free state. The results revealed the usefulness of hydrogels in such applications: greater facility in usable water release and retention by soil, notable delay in withering in hostile conditions and greater growth of species. Guidelines were also established for defining the characteristics of hydrogel more adequately, depending on the desired application and a projection was made concerning reducing water consumption for maintaining a particular crop.

Scientific Electronic Library Online (Spanish)

50

Estructuras de deformación (¿sismitas?) en la Formación Río Negro, provincia de Río Negro, Argentina

Schillizzi, Roberto; Luna, Liliana; Falco, Juan Ignacio
2010-07-01

Resumen en español A Las estructuras de deformación (ED) en sedimentos blandos comprenden las alteraciones que se producen casi simultáneamente con la sedimentación. Estos procesos se hallan en relación directa con las características internas de los materiales sedimentarios y de los factores externos que actúan sobre ellos. Sus resultados incluyen deformaciones como inyecciones, fracturas, volcanes y laminaciones convolutas que afectan total o parcialmente la estratificación. Los se (mas) dimentos blandos deformados por sismos se incluyen bajo la denominación general de sismitas (seismites). Como objetivo de esta investigación se plantea reconocer, por primera vez, estructuras de deformación ubicadas en la Formación Río Negro presentes en el sector norte del Golfo San Matías, en inmediaciones del Faro Río Negro. La metodología empleada consistió en el reconocimiento y descripción de las estructuras, para lo cual se extrajeron muestras para determinar granulometría, mineralogía y contenido de materia orgánica. Se fotografiaron los distintos sectores con deformaciones con el fin de establecer modelos comparativos. El sector estudiado, de 4 km de extensión, se ubica entre el faro de Río Negro y el inicio del Banco Verde y morfológicamente corresponde a un frente acantilado con orientación ENE-OSO. En él se determinaron las siguientes ED: a- de carga simple, pseudonódulos contiguos y aislados, y estructuras complejas; b- de escape de fluidos y c- estructuras de deslizamiento basal y por presión dirigida. El origen de las deformaciones se debe a las características de las sedimentitas y a los procesos que las afectan tales como los efectos por carga, escapes de fluidos y las presiones dirigidas. Como origen de estos procesos se señalan: la presión de la columna litológica, las olas de tormentas y los terremotos. Por los rasgos hallados las deformaciones del litoral rionegrino tendrían un origen sísmico, proceso ocurrido en un único evento durante el ciclo Andino cuyos inicios se fijan hace aproximadamente 45 Ma. Por otra parte sus techos y bases no se hallan asociados a otros procesos de deformación y sus espesores no exceden el metro de potencia. Además se hallan acotadas a la zona de transición entre los miembros medio y superior de la Formación Río Negro descansando en algunos casos sobre arcilitas y en otros sobre limolitas, originadas en un paleorelieve de interdunas. Resumen en inglés Soft-sediment deformation structures (SSD) are alterations produced almost simultaneously with sedimentation. They are directly related to internal characteristics of sedimentary materials as well as to external factors acting on them. Results derived from such alterations are evidenced as injections, fractures, volcanoes and convolute laminations, among other forms, affecting stratification either totally or partially. Soft-sediment deformation structures resulting from (mas) seisms are known as seismites. The present study aims at determining for the first time the presence of SSD structures in the Río Negro Formation, located in the northern area of San Matías Gulf, near Río Negro Lighthouse, Argentina (Fig. 1). To this end, structures were firstly identified and further described. Samples were subsequently collected for the determination of grain-size, mineralogy and organic matter content. Photographs of the different sectors evidencing deformations were taken in order to determine further comparative models. Morphology in the study area is associated to cliffs with vertical, fractured fronts and with an average height of 70 m in whose base torn-down blocks are accumulated. The geological structure of the study area is related to the Cuenca del Colorado and the Comarca Nordpatagónica, whose basement is mainly composed of Paleozoic and Mesozoic crystalline rocks. The sedimentary tertiary cover from the Miocene-Pliocene is represented by light-blue sandstones of the Río Negro Formation (Andreis, 1965). This unit was formed in an aeolian environment with intercalations of clay-silt shallow lagoons and a marine episode located in the mid area of the Río Negro Formation. At the top of the Río Negro Formation there are Pleistocene-Holocene sedimentites having a thickness of up to 5 m. Within the local structural framework of our study area there are fractures with a NE-SW and a NW-SE direction, which are related with fractures N55º, N90º and N350º azimuth located in the abrasion platform. According to Dzulinsky and Walton (1965), Lowe (1975), Brencley and Newall (1977), Clauss (1993), van Loon (2002), Owen (2003), Neuwerth et al. (2006), Alfaro et al. (2006), Montenat et al. (2007), among others (Table 1), and, taking into account the geometry of deformations, laboratory reconstructions and field observations from our study area, it can be concluded that the classifications of SSD structures tend to establish morphologic and genetic systematizations. The following characteristics were identified in our study area: limited deformations among stratigraphic horizons; a lateral continuity of SSD structures at considerable distances; and a confinement between non-deformed strata and its lithological association with psamitic-pelitic sediments. The study area, which is 4 km long and is located between Río Negro Lighthouse and the beginning of Banco Verde, is from the morphological point of view, a cliffed front with an ENE-WSW orientation. Different types of SSD structures were identified in this area. For example, from the morphological point of view and according to the loading mechanisms observed, simple-load structures (Fig. 2), attached and detached pseudonodules (Figs. 3, 4 and 5) and complex structures (Fig. 6) were identified. Furthermore, from the genetic point of view and according to the intrusion processes observed in soft sediments, water-scape structures (Fig. 7) and plate- or fountain-like deformations (Fig. 8) were found. From the genetic point of view, and based on the collapse and pressure mechanisms observed, basal slumping (Fig. 9) and directed-pressure structures (Fig. 11) were also found. The above-mentioned SSD structures were analyzed and interpreted following Strachan´s model (2002) (Fig. 10) and Laird´s model (1968) (Fig. 12). The origin of SSD structures depends on the characteristics of sedimentites and on the mechanisms that produce them. In the study area, the materials susceptible to deformation come from an interdune environment that is characterized by granulometric variations derived from the fluctuating and restrictive climatic conditions (Cojan and Thiry, 1992) that typify the Río Negro Formation. Fine-grained materials having low cohesion and poor sorting such as the sediments of deformed strata (Fig. 13) produced SSD structures as a result of high pore pressure and liquefaction effects (Tsuchida and Hayashi, 1971; Obermeier, 1996). Grain packing with a porous value as that allows intercommunication among grains and saturated material, is also crucial to the formation of SSD structures. The mineralogic content of deformed levels is composed of i) quartz, chalcedony, orthose, plagioclase, pyroxenes and biotite, opaques (magnetite and ilmenite, autigenic pyrite) in crystalline aggregates; ii) undetermined Fe oxides; and iii) colorless and light-brown unaltered volcanic glass shards, clays identified as smectite-illite interstratified and scarce kaolinite. Grains are mainly subangular and, to a lesser extent, sub-round and round. The surface of the majority of grains in the study area was found clean and with some marks. The percentage of CaCO3 was found to vary from 0.5 to 3% and that of total organic carbon (TOC) was found to reach 1.5%. Deformations may be produced as a result of load deformation mechanisms, fluid escape, basal slumping or pressure-directed displacements. Due to load deformation mechanisms, structures are linked to gravity-related movements occurring during the initial stages of deposition. For these deformations to occur, grain-size at the overlaying levels should be thicker than at the underlying levels, for example, sandstones rather than silstones or claystones. These deformations are related to water saturation at the deformed level (fluidization-liquefaction). Therefore, deformation mechanisms, which involve both expulsion and rotation of fragments as well as fluid escape, are characterized by the action of lithostatic pressure which produces movement (deformation) and by the action of the underlying sedimentary levels. Deformations may also result from a fluid escape mechanism, i.e., from a mechanism associated to i) the spatial arrangement of grains (packing), ii) their shape, iii) their tendency to inequigranularity, and iv) the communication among macro- and micro- pores as well as the high or low sinuosity connection among themselves (Net and Limarino, 2000). Further requirements for deformations to occur include particular thixotrophic conditions, especially the presence of colloids among grains. The rupture of unions of particles either by hitting or by shearing is, among others, a cause which produces an unbalance between hydrostatic pressure and lithostatic pressure. If the latter is altered, the energetic unbalance makes fine sediments flow among the weakly lithified sandstones whose extrusion will occur via both vertical and horizontal pore ducts (Lopez Gamundi, 1986; Clauss, 1993). Basal slumping produces deformations that are associated not only to soft sediments deposited in natural slopes but also to interbedded sand- and mud-levels. Layers tend to have a prismatic-shaped geometry whose materials are under ductile-to-fragile conditions, in which antique layers support younger ones. Once horizontality is affected, movement, which is marked by a rupture of the original slope, begins. The lower levels are expected to transport the upper ones without affecting the original succession of layers. At the delay of movement derived from the compressive effect of the displacement front, fluids extrude forming cones or cut dikes (Fig. 10). Several deformations of this type initiate movement as result of differences in the hydrostatic gradient (Strachan, 2002). Deformations may be also produced as a result of pressure-directed displacements which are conditioned by the compaction level, thickness and ability of materials to deform. Thus, deformations occur because the original level is saturated in water as a result of the ductile behavior of materials (Bracco et al., 2005). Laird (1968) claims that SSD structures should meet some of the following requirements to be considered of seismic origin: slightly curved strata walls and floors to follow the original stratification and interruption of continuity of the stratum that is marked by a scar in which the sedimentary fillings keep their characteristics both above and below stratification. There could be rotated sediment clasts below the discontinuity as a result of a thrust-induced drag of the upper sedimentary packing. These processes could be, in turn, triggered either by the charge or pressure of the lithologic column, storm waves and seismicity. Storm-wave impact may also produce deformation in soft sediments. Nonetheless, no high energy structures such as cross-beddings or tsunami-type chaotic sedimentation were observed in our study area. Noteworthingly, for stormwave-derived liquefaction to occur, waves should reach magnitudes higher than 6 m (Alfaro et al., 2002), this being a phenomenon that was not recorded in our study area. Taken together, findings from the present study indicate that SSD structures in our study area are seismic alterations that occurred in an event during the Andean cycle whose beginnings are traced approximately 45 My ago. The fact that i) both the roofs and bottoms of these structures are not associated to other processes of deformation, ii) their thickness does not exceed one meter, and iii) they are confined to a transitional area between the middle and top members of the Río Negro Formation, lying in some cases on claystones and in some other cases, on siltstones, originated in an interdune paleorelief, confirms their seismic origin.

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51

Episodic meteorological and nutrient-load events as drivers of coastal planktonic ecosystem dynamics: a time-series analysis

Guadayol, Òscar; Peters, Francesc; Marrasé, Cèlia; Gasol, Josep M.; Roldán, Cristina; Berdalet, Elisa; Massana, Ramon; Sabata, Anna
2009-04-17

Digital.CSIC (Spain)

55

Contrasting styles of the Holocene highstand sedimentation and sediment dispersal systems in the northern shelf of the Gulf of Cadiz

Lobo, F. J.; Sánchez, R.; González-Álvarez, R.; Dias, J. M. A.; Hernández-Molina, F. Javier; Fernández-Salas, L. M.; Díaz del Río, V.
2004-03-01

Digital.CSIC (Spain)

56

Contourites in the Galicia bank (NW Iberian Atlantic)

Casas, David; Iglesias, Jorge; Vázquez, Juan T.; Somoza, Luis; León, Ricardo; Medialdea, Teresa; Juan, Carmen; García, Marga
2011-01-18

Digital.CSIC (Spain)

57

Comparison of the performance of net radiation calculation models

Kjaersgaard, Jeppe Hvelplund; Cuenca, Richard Henry; Martínez-Cob, Antonio; Gavilán Zafra, Pedro; Plauborg, F. L.; Mollerup, M.; Hansen, S.
2009-09-01

Digital.CSIC (Spain)

58

Chlorophyll increase due to internal waves in the shelf-break of Gran Canaria Island (Canary Islands)

Sangrà, P.; Basterretxea, Gotzon; Pelegrí, Josep Lluís; Arístegui, Javier
2001-01-01

Digital.CSIC (Spain)

59

Catchment soil moisture and rainfall characteristics as determinant factors for discharge/suspended sediment hysteretic loops in a small headwater catchment in the Spanish pyrenees

Seeger, M.; Errea, M. P.; Beguería, Santiago; Arnáez-Vadillo, J.; Martí Bono, Carlos Enrique; García-Ruiz, José María
2004-03-01

Digital.CSIC (Spain)

60

Caracterización de suelos con métodos geofísicos en La Guaira, Macuto, Caraballeda y Tanaguarena, estado Vargas, Venezuela/ Characterization of soils with geophysical methods in La Guaira, Macuto, Caraballeda and Tanaguarena, Vargas state, Venezuela

Romero, M; Cragno, A; Schmitz, M; Ambrosio, R
2006-03-01

Resumen en español El estado Vargas es considerada una zona con elevada amenaza sísmica, la cual quedó evidenciada por los daños ocurridos en 1967 a raíz del sismo de Caracas. Adicionalmente, en diciembre de 1999, tras prolongadas lluvias caídas durante todo el mes, se generaron numerosos derrumbes, deslizamientos y flujos torrenciales. Para conocer las características del subsuelo, como espesores de sedimentos y la estructura interna, se aplicaron los métodos geofísicos de sísmica (mas) de refracción, gravimetría y  mediciones de ruido ambiental en los conos aluviales entre La Guaira y Tanaguarena. Del estudio de las ondas de corte se determinó que los sedimentos en los conos están distribuidos básicamente en tres capas, la primera con velocidades entre 200 y 400  m/s hasta un máximo de 50 m de profundidad, la segunda entre 400 y 600 m/s hasta  90 de de profundidad y la tercera entre 600 y 750 m/s, sin alcanzar el basamento. De las ondas P se obtuvo que el nivel freático se encuentro entre los 5 y 10 m de profundidad. La profundidad máxima del basamento rocoso, reportada por estudios previos, se ubica en la costa de Caraballeda a 450 m de profundidad. En Macuto, las profundidades máximas son cercanas a los 290 m en el cono El Cojo, y cercanas a los 180 m en Punta de Mulatos en la Guaira. El buzamiento del basamento rocoso, estimado con base en los modelos gravimétricos, esta en el orden de los 17° a 21° hacia el norte en toda el área de estudio. Los valores del período fundamental de vibración del suelo, basados en mediciones de ruido ambiental, se ubican entre 0,9-1,8 segundos para las zonas de los conos aluviales. Resumen en inglés The Vargas state is considered a region with an elevated seismic hazard, which was evidenced by the damage caused by the 1967 Caracas earthquake. Additionally, in December 1999, many landslides and mudflows occurred due to intensive and persisting rainfall. In order to investigate the subsoil characteristics and the internal structure of the sediments, geophysical methods as seismic refraction studies, gravimetric measurements and ambient noise measurements were applied i (mas) n the alluvial fans between La Guaira and Tanaguarena. From the analysis of S-waves, we determined three layers in the fans, the first one with velocities between 200 and 400 m/s down to a maximum depth of 50 m, the second one between 400 and 600 m/s down to 90 m in depth and the third one between 600 and 750 m/s, without reaching the basement. From the P-waves we derived a shallow water level at 5-10 m in depth. The maximum bedrock depth, derived from earlier studies, is about 450 m at Caraballeda. In Macuto the bedrock depth is about 290 m in the El Cojo fan and around 180 m in depth in the Punta Mulatos in La Guaira fan. Based on the gravimetric models, the bedrock is inclined between 17° to 21° towards the north in the whole study area. The predominant periods of soil vibration, derived from ambient noise measurements, range generally between 0.9 and 1.8 s for the alluvial fans.

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62

Acoustic propagation trough internal gravity waves using normal-mode

Kormann, Jean; Ranz Guerra, Carlos

4 pages, 8 figures.-- Contributed to: 33rd International Acoustical Conference (Strbske Pleso, Slovakia, Oct 4-6, 2006) | In this paper we will interest ourselves on acoustic propagation through internal waves. This type of waves is generally due to variations of density on time scales of a few hour...

DRIVER (Spanish)

64

A time-dependent approach to electron pumping in open quantum systems

Stefanucci, Gianluca; Kurth, S.; Rubio Secades, Ángel; Gross, E. K. U.
2008-02-29

Digital.CSIC (Spain)

65

A new noise detected in the ocean

Guerra, Ángel; Martinell, Xavier; González, Ángel F.; Vecchione, Michael; Gracia, Joaquín; Martinell, Jordi
2007-01-01

Digital.CSIC (Spain)

66

A Computational Method to Calculate the Longitudinal Wave Evolution Caused by Interfaces Between Isotropic Media

Buiochi, Flávio; Martínez Graullera, Óscar; Ullate, Luis G.; Montero de Espinosa Freijo, Francisco
2004-02-01

Digital.CSIC (Spain)