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7th International Congress of the Brazilian Geophysical Society
- Conference date: 28 Oct 2001 - 31 Oct 2001
- Location: Salvador, Bahia, Brazil
- Published: 28 October 2001
61 - 80 of 465 results
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Estatística Básica Com Grandezas Do Clima De Ondas Da Bacia De Campos
More LessEste trabalho apresenta alguns resultados do estudo do
Clima de Ondas da Bacia de Campos: Fundamentos e
Análise dos Dados (Seixas, 2001). Os resultados constituem
a base para o entendimento das características do
clima desta região ou de qualquer outra.
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Estudos Geofísicos Integrados No Lixão De Cuiabá, Mt, Brasil – Resultados Preliminares
One of the major concerns in geoenvironmental
projects is the soil and water contamination caused by
the waste disposal. The geophysical methods applied
are a good way to get some information required in a
site characterization program. This work shows some
results obtained through resistivity, EM inductive and
GPR surveys in the search of informations about the
impact caused by a waste disposal area in Cuiabá,
State of Mato Grosso, Brazil.
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Five Years Of Ozone Measurements At La Paz, Bolivia
Authors Francesco Zaratti, Ricardo N. Forno and Eduardo R. PalenqueWe present main results of a 5 years ozone
measurements program at La Paz, Bolivia, where
a Brewer spectrophotometer is in operation since
July 1996. We also show interesting comparisons
with “overpassing” satellite data, taken by the
TOMS (Total Ozone Mapping Spectrophotometer).
Finally, results of an ozone sonde
campaign, carried out in order to explore a
possibly ozone anomaly over the Andean
Highland, are reported.
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Groundwater And Contaminated Land Geophysics: Pressing Problems And The Way Forward
By Max A. MejuEnvironmental geophysics is enjoying rapid growth in
the present socio-political climate of increasing
awareness of the effect of man’s past activities on the
environment. It deals with pressing issues attracting
public attention ranging from local-scale fluid-rock
changes to large-scale climatic changes caused by
natural processes and anthropogenic activities.
Realistic multi-dimensional imaging of contaminated
land, understanding fluid-rock interactions, optimal
data integration and remote prediction of flow and
subsoil composition are the pressing scientific issues
at the present time. Some suggestions are offered in
this paper for handling these challenging problems.
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Imageamento Elétrico 2-D Aplicado À Avaliação Ambiental De Posto De Combustíveis
More LessAn study including geoelectrical
methods, drilling and chemical water analysis
was carried out in an area to determine the
extent of oil contamination in groundwater.
Resistivity method was applied using a high
resolution 2-D electrical imaging technique.
The origin of a well defined high
resistivity anomaly was proved to be due a
hydrocarbon contamination at the top of the
saturated zone, showing the importance of the
geophysical technique to this kind of problem.
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Investigações Geofísicas Na Avaliação De Risco Geológico Em Áreas Cársticas Urbanas - Exemplos Da Região Metropolitana De Curitiba , Pr, Brasil
Authors Marcio J. Silva, Augustinho Rigoti, Eduardo de Mio and Fernando Santos CorrêaColapsos e acomodações da superfície são comuns
em terrenos calcários e têm geralmente pequena
importância quando ocorrem em áreas não povoadas,
mas podem ser desastrosos quando ocorrem em áreas
urbanas. Nos municípios localizados ao norte de
Curitiba, região objeto do presente estudo, já foram
registradas muitas ocorrências deste tipo de fenômeno
mas, felizmente, sem conseqüências desastrosas até o
momento. Contudo, o risco existe, é real. É muito
importante poder-se contar com técnicas de
reconhecimento de subsuperfície para demarcar as
áreas de maior risco ou investigar as condições em
áreas onde ocorrem grandes concentrações de pessoas
como escolas e outros locais que causam
aglomerações. Investigações diretas, com furos de
sondagem, são muito caras para serem utilizadas
sistematicamente. Por outro lado, métodos geofísicos
podem auxiliar muito neste reconhecimento, com
vantagens de custo e rapidez.
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Levantamento Geofiísico No Depósito De Lixo De Bangu Na Zona Oeste Da Cidade Do Rio De Janeiro
Authors Alexandre C. Monteiro and Rozanda G. da S. CostaThere is a program of decontamination of Guanabara bay in Rio de Janeiro state, Brazil. The Sarapuí river which has its estuary on this bay, pass by the east boundary of the waste disposal studied by this work.
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Método Eletromagnético Indutivo E Gpr Aplicados À Detecção De Contaminação Do Solo E Água Subterrânea Por Resíduos Industriais
Authors Wagner França Aquino and Marco Antonio B. BotelhoIn the study presented, geophysical surveys were
applied in the assessment of soil and groundwater
contamination of an abandoned industrial area, where
the hazardous wastes were infiltrated directly into the
soil. The proposed goals were to detect and map the
presence of the contaminants on the subsurface
through the use of frequency domain electromagnetic
method (FDEM) and ground penetrating radar (GPR).
The FDEM method was carried out to obtain apparent
electrical conductivity of the terrain in different
investigated depths, what allowed to map contaminant
plume related to the inorganic compounds
disseminated in the soil and dissolved in the
groundwater. The GPR data provided the imaging of
the contaminants present in the vadose and saturated
zones, besides to confirm the indications of the
contamination flow as pointed by the FDEM survey.
Also, it was verified that the low frequency antenna
(25MHz) is able tool to determine the extension of the
inorganic contamination plume.
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Modelagem De Pseudo-Seções De Resistividade E Polarizabilidade Aparentes – Estudo Em Uma Área De Disposição De Resíduos Urbanos
More LessThis work shows the results of quantitative
interpretations of pseudosections of resistivity and
apparent polarity. These pseudosections were
obtained using the electric profiling , in dipole-dipole
arrangement, at a sanitary landfill near the city of Rio
Claro, São Paulo. The modeled pseudosections, using
algorithm based on finite element numerical modeling
methods, permitted the determination of the limits
and depths of the waste pile and the surrounding
zone contaminated by percolation of leachate derived
from the landfill.
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Programa Pax-Vóbis
More LessThe Program PAX-VÓBIS, proposed by the Department
of Geophysics of University Federal of Pará
(UFPA) to the municipal government of Belém, has 4
new objectives to exercise of Geophysics: 1) environmental
studies of cemetery of Tapanã, 2) monitoring
Bengui cemetery, 3) revision of the law of implantation
of cemiteries, 4) course about study impacts
of cemiteries with geophysics. The project was
demanded by the City hall, due to the repercussion
obtained with the use of Geophysics in the investigation
of cemeteries, that helped in the decision of the
definitive closing of Bengui cemetery due to the inappropriate
groundwater level in the region. The Program
PAX-VÓBIS was hampered by the cut of resources
because of the new law of fiscal responsability.
But nevertheless the first results already obtained
with electroresistivity proved again that the Geophysics
can give a very important contribution in the
study of cemeteries.
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Prospecção Do Contaminante (Bhc) Através Da Eletrorresistividade
Authors Eduardo Moraes and Patricia GrazinoliThis paper presents a case study in which the
Resistivity method was used at a site known as
Cidade dos Meninos, in the Municipality of Duque de
Caxias, Rio de Janeiro, where the subsoil was
contaminated by an organochlorine pesticide called
HCH – Hexaclorocyclehexane, and by metabolites. A
comparison between preliminary evaluation of this
method and the Ground Penetrating Radar (GPR) has
been presented elsewhere (Grazinoli et al., 1999). The
contamination occurred by the disposal of a great
quantity of HCH directly above the soil, without any
protection. The Resistivity survey was carried out in
order to help the determination of the site
stratigraphy, and the detection of contamination
processes that were taking place. Detailed geological
and hydrogeological informations, as well as Ground
Penetrating Radar (GPR) data were used to help the
interpretation (Barreto, 1998; Grazinoli, 1997).
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Tópicos Sobre Metodologias Passíveis Para A Determinação Do Pé Do Talude Continental Conforme A Convenção Das Nações Unidas Sobre O Direito Do Mar
More LessThis work aims at presenting some topics about the methodology employed by Brazil in order to determine
the foot of the continental slope and another one that would be developed from stratigraphical studies for the
same intention in accordance to United Nations Convention on the Law of the Sea (UNCLOS). Just to
exemplify, the method was applied in the Brazilian Southern Margin. The Brazilian’s methodology was
developed as established on 76 article, line b, UNCLOS: “…the foot of continental slope (FCS) is the point of
the maximum change in gradient in its base”. In the same area were carried out data from core samples and
their results may be considered as an alternative method to FCS determination, in terms of: “In the absence of
evidence in contrary, ….”, as establishes the same convention. When both results were plotted, it could be
noticed that Brazilian’s methodological results presents a reasonable coherence and consistence, and even,
may not be considered “aggressive” in terms of territorial demands.
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Utilização Integrada De Métodos Elétricos E Do Gpr Na Análise Ambiental Do Aterro Sanitário De Jundiaí – Sp
This paper reports the results of a geophysical
research in the waste disposal located at Jundiaí-SP.
This site is typified by waste cells, which have
significant quantities of material above the water
table. The main objectives were: to characterize the
structure of the waste disposal in subsurface, to
determine the depth of the water table, the direction
of the groundwater flow and to map the
contamination plume. Vertical electrical sounding
(VES), electrical profiling and ground penetrating
radar (GPR) were used in an integrated way. Based
on the VES resistivity values, it was possible to
identify the contaminants in the sediments and the
depth to the water table. The results of the electrical
profiling integrated to the GPR allowed for the
mapping of conductivity lateral variation, with higher
condutivity zones interpreted as more contaminated
sites or fractured zones in the bedrock. As a final
product, a potentiometric map indicates the
preferential groundwater flow.
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Valores De Resistividade Elétrica Em Um Latossolo Do Distrito Federal
The electrical resistivity geophysical method
is fairly used in geological and groundwater studies,
as well as environmental monitoring activities. This
method has high sensibility for moisture variations,
and in the soils, this kind of variation can be
correlated with structural and textural aspects.
Therefore, seems to be possible to use electrical
resistivity measurements to estimate variations in
physical properties of soils. In this work, electrical
resistivity measurements were used for evaluate the
lateral variation of texture in a latosoil. The study area
is located at Distrito Federal, in the central region of Brazil.
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Aplicação De Gpr (Ground Penetrating Radar) Como Ferramenta No Diagnóstico Ambiental Em Área Industrial
This paper presents the results of an investigation carried out by the Universidade Federal do Rio de Janeiro (UFRJ) with the cooperation of the Petroflex Indústria e Comércio S.A., a petrochemical industry. This research is part of the company Social Project (2000-2005), titled: “Conheça seu Manguezal” (Knowing your mangrove). The company is located on the borders of the Guanabara Bay, Rio de Janeiro State, Brazil. In the study, Geophysical survey was applied in two areas located within the industrial park in order to identify solid waste contamination (rubber and plastic and metal brass). It was used the Ground Penetrating Radar (GPR) technique with equipment RAMAC/MALA, which provides high resolution images of the underground. The study area consists of clay landfills on clay and sands deposited in marine conditions, which are presently contaminated by brackish water.
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Avaliação Do Potencial Arqueológico Da Pedra Da Gávea: “Desmistificando Um Mito Com O Auxílio Do Gpr”
A ocorrência de vazios rochosos, comumente
chamado de cavernas, está condicionada à ação
geológica no tempo em formações específicas
(calcárea por exemplo) e/ou à atividade humana.
Através da observação geológica direta e de
procedimentos de investigações indiretas (geofísica),
verificou–se a impossibilidade da ocorrência destas
estruturas no maciço rochoso da Pedra da Gávea. Um
levantamento do tipo reflexão, com seis linhas de
caminhamento foi suficiente para constatar a
inexistência de contrastes de propriedades elétricas.
Um total de aproximadamente 850 m3 de rocha sólida
foi investigado.
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Avaliação Do Radar De Penetração No Solo (Gpr) Em Uma Investigação Do Subsolo
Authors Patricia L. Grazinoli and Henrique Lorenzo CimadevilaThis paper presents a stratigraphy study carried out
with the Ground Penetrating Radar (GPR). This study
was made at the construction site of a building in the
campus of the Federal University of Rio de Janeiro.
The site was investigated by conventional percussion
borings (SPT - Standard Penetration Test), and the
two methods were evaluated for the capacity to detect
the interfaces between different layers, in particular
the soil-rock interface. In the GPR investigation three
antennae were used: 50, 100 and 200 MHz. The
penetration of the GPR method was restricted by the
presence of a fill layer, about 3m thick, and by the
possibility that the pore-water contains salt. The data
obtained with the various antennae, after processing,
revealed the most relevant ground features, the data
obtained with the 50 MHz antenna being specially
revealing with respect to the soil-rock interface.
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Emprego Do Gpr Na Investigação Morfológica Dos Solos Dos Tabuleiros Costeiros No Litoral Norte Do Estado Da Bahia
More LessExperimental employ of Ground-penetrating radar to
investigation of tablelands of north coastal at Bahia, Brazil
Nine profiles were studied along a catena developed
on Barreiras Group sediments, in Fazenda Rio Negro,
Entre Rios town (Bahia - Brasil). It was used, besides
the analysis traditionally maid, the search
electromagnetic through GPR - Ground-penetrating
radar. The objective of such a study was it of
analyzing the level of answer of that tool in the
acquisition of information about the features that
happen in the underground, by means of comparisons
of the radargramas and pedologic descriptions
obtained in the area. The used equipment was a
Geophysical Survey model, with antenna of 80 MHz.
The results of the radargramas indicate that the
antenna maid is not the ideal for risings that demand
larger detail of the most superficial layers, up to 1,0
depth meter. For the deepest layers it showed an
excellent answer, mainly in the investigation in the
occurrence of hardened layers, as the hardpan. The
radargrametric analysis confirmed the existence of a
process of transformation in Podzoils, that happens
accompanied by the hardpan and fragipan in depth.
Index terms: soil prospection, Ground-penetrating
radar, soil genesis, coastal tablelands, Barreiras Group.
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Gpr Technique Applied To Mineral Exploration Of Geodes In Basalts: Agate Geode Deposits (Rs, Brazil)
Authors Angelo M. Hirakata and Adelir José StriederThe agate geode deposits occurring in the Salto do
Jacuí Mining District (RS, Brazil) are considered to
be the world largest ones. They are hosted in
tholeiitic basalts of Serra Geral Fm. (Paraná Flood
Basalts). The agate geodes occur in highly vesiculated
basalts, that are variably weathered. Agate geodes
vary in size from 0,10 to 1,0 m, but usually show a
mean diameter in the range of 0,25 – 0,40 m. Agate
geodes are often completely massive, fulfilled by
chalcedony, or by chalcedony and quartz. GPR
technique was applied agate geode exploration.
Key words: GPR technique, agate geodes, basalts,
mineral exploration, geophysic
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Gpr Technique Applied To Mineral Exploration Of Geodes In Basalts: Amethyst Geode Deposits (Rs, Brazil)
More LessGeodes in basalts are not simply a void problem. The
amethyst geodes are hosted by a massive, poorly
fractured basalt. Amethyst geodes range from 0,1 to
1,0 m in diameter, and are variably filled with
different paragenesis. GPR technique does permit
imaging amethyst geodes and other structural features
based on contrasting electrical properties of materials.
GPR imaging resolution, penetration and wave
propagation image features depend on EM wave
frequency. High frequency EM wave (800 and 1000
MHz) has low penetration and high resolution, and
they are suitable for amethyst geode detection, even
the reflection and diffraction pattern produced. Low
frequency EM imaging (250 MHz) imaging for
amethyst geode can display reflection and diffraction
pattern similar to that defined for high frequency
ones, but can also image fracture systems crosscutting
host basalts. These radargrams patterns can be used
mainly for amethyst exploration and extraction planning.
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