Programa de Pós-Graduação em Geofísica - CPGF/IG
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2355
O Programa de Pós-Graduação em Geofísica da UFPA (CPGF) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA). Foi o segundo no Brasil a formar recursos humanos em Geofísica em nível de pós-graduação stricto sensu. Criado em 1972, funcionou até 1992 junto com os Cursos de Pós-Graduação em Geoquímica e Geologia.
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Item Acesso aberto (Open Access) Aplicação de sísmica de alta resolução em ambiente estuarino amazônico, na investigação de estruturas neotectônicas(Universidade Federal do Pará, 2015-02-27) CORRÊA, Alberto Jacques Ribeiro; PINHEIRO, Roberto Vizeu Lima; http://lattes.cnpq.br/3251836412904734; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471Seismic methods of high resolutions have been intensely used on the mapping of the Quaternary, investigation of sedimentary processes, and others. The study area is located in the north region of the state of Pará, between the parallels 1° S and 2° S and the meridians 50.5° and 48.25°, the research being carried out in the submerged areas bordering the Marajó Island in its east and the southeast part, comprising the Bay of Marajó, the mouth of the Tocantins River and Pará River. The high resolution seismic employed in this region aims to tectonic investigation by using the data collected by the acoustic profiler SB-512I from Edgetech, and from these data to identify structural shapes, fractures, subsidence or elevations ruled by tectonism. From the analysis of the seismic data obtained in the study area, nine features were identified interpreted as tectonic occurrences. Due the specificities of equipment and geological characteristics of the region, possible areas of tectonic faults were not detected at great depths by the equipment used, however, they were found in areas where tectonic forces occurred with sufficient intensity to cause visible faults in the mapped pseudo-sections.Item Acesso aberto (Open Access) Avaliação do modelo hidrodinâmico SMC: uma aplicação na Costa Norte Brasileira(Universidade Federal do Pará, 2016-05-24) MOTA, Fabíola Cardoso da; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471Coastal environments are highly dynamic because of complex processes that occur in the transition between the ocean and the continent. Climate changes induce changes in the coastal zone that cause decline in economic, environmental and subsistence values. The integrated coastal zone management is a continuous and dynamic process, in which decisions should be taken in order to sustainable development and protection of resources of coastal and marine areas. The main goal of integrated coastal zone management is to improve the life quality of human communities that are dependent of coastal resources, taking into account the maintenance of biological diversity and ecosystems productivity. The coastal modelling system called SMC Brazil was introduced in Brazil by the Ministry of Environment in order to standardize the modeling throughout the coastal zone of the country. This study aims to implement the model SMCBrasil in North Coast of Brazil (Princesa beach- Algodoal Island), evaluate it and analyze the hydrodynamic answers, in order to know more about coastal processes that govern this region. In order to understand the processes in the study area, the methodology consisted in collect in situ data to know about the intensity of coastal parameters. 6 cases were created in the model to represent the wave theories (Linear, Stokes and Composite) and sediment transport (Bailard and Soulsby) for two moments of tide: low tide and high tide. Two mesh grids were created in the study area, and one entry point that would fit better to it and the conditions limits of the model was chosen. The propagated waves by the composed theory represented the study area in question more than the others, and the simulated sediment transport simulated by Soulsby theory suffered less interference of interpolation than the Bailard, since it considers the bed transport and suspension. The simulated cases in this study were based on boundary conditions that more often occur on the study area, so the results can be used as a basin to understanding how the coastal processes occur in it in general way.Item Acesso aberto (Open Access) Características hidrodinâmicas da plataforma interna do nordeste paraense(Universidade Federal do Pará, 2014-08-28) ALVES, Alex Costa; BÉRGAMO, Alessandro Luvizon; http://lattes.cnpq.br/9711842025835463This study aims to characterize the hydrodynamics of the continental shelf near the northeast coast of Pará state of in adjacent points to the municipalities of Salinópolis and Marapanim. The choice of the period of data acquisition took into account the contribution of the Tocantins River, which has a higher discharge during the month of April and lower discharge during September. Data were collected at two anchored stations on September 11, 2013 and April 25, 2014, both of 25 hours duration. Each as obtained data were not only hydrodynamic (longitudinal component of current) and hydrographic data (temperature, salinity and density), it was possible to calculate the transport of mass and volume. The observations were performed using a couple of acoustic Doppler current profilers and salinity, temperature and pressure data recorders. The data processing included filtering by moving averages and interpolation to analyze the results in dimensionless depth. The hydrographic results revealed a possible influence of continental drainage during the acquisition period. The comparison between water currents and wind during the experiments showed that the influence of the wind was not relevant in the circulation. The transport calculations indicate a circulation predominantly influenced by tide and freshwater contributions.Item Acesso aberto (Open Access) Caracterização física do estuário do rio Mojuim em São Caetano de Odivelas - PA(Universidade Federal do Pará, 2015-02-25) ROCHA, Adriano Santos da; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471The present study has as objective describe the hydrodynamics, hydrologic and morphological aspects, of estuary of Mojuim River, it is localized in São Caetano de Odivelas city –PA (Salgado Paraense),it is analyzing the variations that happen according sea cycle seasonality (rain regime).The hydrologic and hydrodynamics data was collected in two seasonal period in 2014:March,it corresponds to rainy period (~500 mm)and September, it corresponds to dry period (~100 mm),both during tide of syzygy. The bathymetric survey happened only in the rainy period and it was realized with an echo sounder in a sampling grid with 116 spaced cross profile of 200m.In the estuarine channel,it was defined a section where it was realized profiles of strength measurement and current intensity and output, with ADCP, and in three fixed stations,right bank (RB), center(C),and left bank (LB)it was realized collections of conductivity and turbidity with a CDT and an OBS, in the water column. The pattern of tidal and the salinity they were also obtained with a pressure sensor and conductivity fixed in the LB during 56 days in the rainy period and 57 days in dry ones. The estuarine is shallow (4,5 m of average depth) and it is restrained by a regime of semidiurnal macrotidals. During a tidal cycle the salinity increases in the floods and decreases in the ebb tide in both seasonal periods. Turbidity increases in the floods and it decreases in the ebb tide of the rain period and the value measured in the center (C) is double found in the banks. In the dry period, the salinity was higher to rainy period (average 20 and 8, respectively) .This estuarine presents well mixed; it is vertically homogeneous in the rainy period and highly stratified in the dry. The flood flows occur predominantly at the center section, while the ebb flows predominate in the RB, in the two situations the highest intensity of the current occurs in the rainy season. The estuary is an importer in the two periods, however, more entering in the rainy period (resulting transport of 95,87 m³/s) .These data correspond to the first information on the hydrological and hydrodynamics characteristics of the estuary and they can support further studies in the region.Item Acesso aberto (Open Access) Caracterização hidrodinâmica do Furo da Laura (Rio Guajará-mirim), Amazônia Oriental(Universidade Federal do Pará, 2014-12-01) FERNANDES, Aldo Rafael Pascoal; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471Preserve our coastal and estuarine environments are of great importance to local and regional development, as these environments are located most cities and serve as a cradle for several specimens, despite these environments gather information and know their characteristic and seasonal patterns are important aspects. In this context, Laura hole (Rio Guajará-Mirim), transitional estuarine environment and important role in the economic and social framework for coastal communities, cities and surroundings, serves as one of the main routes of fishing inputs to the state. The Hole Laura is a water body adjacent to Marajó Bay, has two connections to the same and is under their direct influence, is located at coordinates UTM 22M, 796169-830035 W and S 9880864-9916228 through it were held three oceanographic, dry season (October 2013), the rainy season (February 2014) and dry (August 2014), this important stream with use of equipment for measurement of geophysical parameters in the region bathymetry, hydrodynamic, tide variation and salinity. There was in possession of these parameters the hydrodynamic behavior, classification and tidal range, phase difference between ebb and flood, salinity trend in the stream in response to the Marajó Bay, besides the identification of morphological features characteristics and seasonal analysis these changes in the collection of sections 1 and 2 pre-established, as well as mapping and preparation of a bathymetric map of the study area.Item Acesso aberto (Open Access) Métodos de processamento de sísmica rasa em fundos submersos no baixo curso do rio Amazonas(Universidade Federal do Pará, 2014-12-02) WATANABE, Fábio Kiyoshi; PINHEIRO, Roberto Vizeu Lima; http://lattes.cnpq.br/3251836412904734; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471The study area is located on northeast region of Pará state, it includes the Pará river, Tocantins river’s outfall and Marajó bay. The study is restricted to Amazon estuarine complex, characterized by coastal lowland regions which have been formed during the Holocene marine transgression which flooded vales of rivers. This work aims to improve the knowledge about the shallow seismic methods in the Amazon, specifically on tributary rivers, applying the X-STAR 3200-XS system. The work’s focus is to enable ways to process the information from this geophysical acquisition system, little used in the region, applying methods of treatment in seismic profiles where it’s possible to perceive the horizontal continuity’s distribution and a better morphological identification, besides that is also important locate the depth of acoustic basement. This work intents to present a methodological proposal to investigate the sedimentary unconsolidated covers deposited in submerged areas of different amazonian environments. From these data a processing flow in the region will be made to explain some aspects, related mainly to its limiters, besides more suitable criteria to a better data acquisition.Item Acesso aberto (Open Access) Modelagem hidrodinâmica 2DH no furo de Laura - Nordeste Paraense(Universidade Federal do Pará, 2016-05-23) LOPES, Matheus Santiago; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471The estuarine environments are widely studied over the past decades due to its social, environmental and economic importance. For example, the strategies to contain oil spill are based on hydrodynamic modeling research. The application of numerical models to predict and analyze circulation patterns inside coastal water bodies is growing in the country. In northern Brazil the use of those models is still experimental. In this work was used the software SisBaHia to implement, calibrate and validate a hydrodynamic model to the water body “furo da Laura” (FL), located on Guajara-Mirin river, on the coastal region of northeastern Pará. The model was calibrated with previous data about surface elevation and current speed collected in three periods: dry season of 2013, rainy season of 2014 and dry season of 2014. The flood and ebb tide flow occurs simultaneously in two entrances that the FL presents. The goal was to locate the barotropic convergence and its seasonal variation. It was simulated one month during the rainy season (February) and one month during the dry season (August). It was simulated a lagrangian transport with particles released in Sol bay with an analysis of its horizontal dispersion. The convergence sites were found nearby the south entrance of the FL and the divergence sites have a spatial variation due the tide cycle. The particles released in the Sol bay tend to leave the modeling domain and don’t penetrate the FL, but they contribute with the erosion and sedimentation process that occurs in coast of the Colares Island.Item Acesso aberto (Open Access) Modelagem hidrodinâmica aplicada ao estuário amazônico: uma abordagem em malha flexível(Universidade Federal do Pará, 2014-08-19) BORBA, Thaís Angélica da Costa; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471Amazonian Estuary is a very complex system due to its large number of water bodies; it also encompasses four of the 20 largest rivers of world. Several hydrodynamic models have been applied on this system, but its complexity on shape makes difficult the grid definition when curvilinear grid is used. This research aimed the implementation of hydrodynamic model on this, based in flexible mesh grid that is easier to define on this kind of systems than curvilinear grids, and analyze the hydrodynamic patterns within this estuary. The methodology is based on the use of D-Flow in which a flexible mesh can be defined. The model domain encompasses the low course of Amazon River, Tapajós River, Xingu River, Tocantins River, Guajará Bay, Marajó Bay, Breves Strait and Pará River as well as the flood plain area and the adjacent continental shelf. The model presents a quite good calibration values for tidal signal as well as discharge since the Pearson's correlation coefficient presented values bigger than 0.95 for both and rmse presented values smaller than 5% for the former and 15% for the latter. The model also performed well on representation of several scenarios that represented extreme conditions regarding tide and discharge sources of Amazonian Estuary and it showed expected patterns by comparison with in situ data.Item Acesso aberto (Open Access) Modelagem matemática do sistema estuarino dos rios Mojuim e Mocajuba (Pará-BR)(Universidade Federal do Pará, 2016-02-29) SANTOS, Arthur Souza dos; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471The estuaries of Mojuim and Mocajuba rivers are located in the eastern sector of the Amazon Coastal Zone and represent a peculiar and complex environment. They are connected by several channels and are receive influence of the Bay of Marajó and the Atlantic Ocean. The following research aims to implement a hydrodynamic model based on a flexible grid on the of Mojuim and Mocajuba rivers estuarine system; and to analyze the hydrological and hydrodynamic characteristics of the upper estuary of these rivers. The methodology involves the use of D-Flow Flexible Mesh pack a get simulate hydrodynamics patterns into the domain that covers the Mojuim Mocajuba rivers, the canals connecting these rivers, part of the mouth of the Bay of Marajó and the adjacent tidal flats. It was also performed an "in situ" systematic data collection, in which parameters of flow, salinity, turbidity and water level were analyzed during a tidal cycle in sites located at the upper estuary of Mojuim and Mocajuba rivers. In the Mojuim river two seasonal campaigns were made in two different sites and in the Mocajuba river only one campaign were made in the rainy season, however, a tide station was installed in this location that operated for 25 weeks. Part of the sample data were used as input to the hydrodynamic model. The upper estuary of Mocajuba river presented a macrotidal regime with maximum height of 5.8m recorded. In the Mojuim river, a gradual attenuation of the tidal wave is noticeable and, in the collection point and in the upper estuary a one-way flow discharge during the rainy season was observed. A different hydrodynamic pattern between the two rivers was also observed, with ebb speed more intense than floods and their hydrological properties directly influenced by the tide fluctuation. Finally a hydrodynamic model in flexible grid was implemented and calibrated in the researched area, where initial and boundary conditions were assigned, as well as adjustments to the border forcing. The model generated a good representation of the estuary conditions, showing acceptable tidal and hydrodynamic pattern when compared with the "in situ" measurement, once the error between the measured data and modeled data related to the water level were less than 5%, and errors related to transportation are lower than 15%.Item Acesso aberto (Open Access) Utilização da sísmica de reflexão rasa no estudo da morfodinâmica de rios na região amazônica(Universidade Federal do Pará, 2014-09-29) FURTADO, Camila da Cunha; VIZEU, Roberto; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471The main idea of this research is identify and characterize morphodynamic phenomena present on the lay of the Pará river and foz of the Tocantins river, this area comprises from the Bocas bay unto east portion of the Marajó island. It is a region where exists scarcity of information and data about constitution and morphology of the lay, there is necessity to search new knowledge. Sediment samples from the bottom of the river were collected with the assistance of a Van Veen sampler, 181 (one hundred eighty-one) samples submitted to macroscopic analysis aiming to identify the type of material which composes the bottom. With the data of hydrodynamic modeled assistance was possible to connect the patterns of bottom forms with the sort of sediment which composes the lay and the prevailing hydrodynamic in the local. Based on the seismic data, was possible to identify and map the sonographic patterns in 15 types of echoes, classified in four categories. The less frequent echo types are the ones which present very irregular lays and little or no acoustic signal penetration. Specially the C1 type characterized by diffraction hyperbolas presence and the D1 type which treat responses arising from large deposits of sediments, found just in two forms of acoustic. The most significant bottom forms were identified on the stretch where the Canaticu river flows to Pará river where the principal canal width decreases from 8km to 4km in upper depth to 20m. The adhibition geophysical methods (acoustics), by the use of the Sub-Bottom profiler SB-0512, enable the knowing of the bottom forms, as well as its dimensions that those submerged forms show over the studied region. The way how this region’s lay sets itself and the dimensions that those corps reach can affect the sailing on some river’s stretch, as well as it can affect future civilian building. Therefore, this work opens ways to future more appropriate investigations on the issues mentioned above.