1,721,099 research outputs found
Workshop em Ciencias da Terra e do Espaço
No full textO Workshop em Ciências da Terra e do Espaço faz parte integral do Programa Doutoral em Ciências da Terra e do Espaço da Universidade de Évora. Este evento procura promover não só o estudo de assuntos nesta área do conhecimento, mas sobretudo desenvolver capacidades de aprendizagem autónoma, segundo as metodologias utilizadas no meio científico. A participação dos alunos, e em particular dos doutorandos, nos congressos nacionais e internacionais é fundamental. O objectivo deste encontro é a divulgação e discussão da investigação em Ciências da Terra, da Atmosfera, e do Espaço para promover a fusão de conhecimentos e metodologias. Também é objectivo do encontro encorajar os jovens investigadores no desenvolvimento das suas ideias e projetos na Universidade de Évora. As comunicações estão relacionados com os temas da investigação em curso e são apresentadas pelos doutorandos envolvidos em projetos de investigação e dissertações de doutoramento.
O Workshop em Ciências da Terra e do Espaço tem os seguintes objetivos:
• Permitir que os estudantes tomem contacto com trabalhos de investigação na área da Terra, da Atmosfera e do Espaço;
• Desenvolver capacidades para construção do conhecimento científico mediante a utilização de metodologias que promovam a pesquisa, discussão e debate de
temas específicos;
• Proporcionar a produção de elementos de divulgação (relatórios, artigos, comunicações) mediante a aplicação das regras aceites em meio académico;
• Dar aplicação às metodologias científicas abordadas em diferentes domínios das Ciências da Terra, da Atmosfera e do Espaço
VIAGEM AO INTERIOR DA TERRA
No full textMais de 200.000 terramotos são registados e localizados à escala mundial cada ano. A monitorização
sísmica à escala global, regional e local fornece informação que permite compreender a ocorrência
dos sismos e, portanto, permite cartografar as regiões de alto e baixo risco sísmico. Densificação de
redes sísmicas e técnicas avançadas da análise sísmica facilitaram a descoberta do até então
desconhecidos fenómenos sísmicos (sismos lentos, ruptura sísmicas múltiplas e, velocidade de
ruptura supersónica), que vieram iluminar a física dos terramotos. A monitorização sísmica
permanente, portanto, fornece informações fundamentais para um melhor conhecimento do interior
da Terra e para a avaliação do risco sísmico e a engenharia sísmica
Physics of Seismo-Electromagnetic Phenomena: Twenty Years After
No full textThis paper presents a work that aims to study seismo-electromagnetic phenomena in the Western Part of the Eurasia-Nubia Plate Boundary. This region has a significant tectonic activity combined with relatively low electromagnetic noise levels, rendering high quality seismo-electromagnetic measurements possible. An overview of the topic is made and future perspectives are presented
Seismicity of Azores and Geodynamic implications
No full textOver the past thirty years, several seismological studies have been carried out in the Azores region in
order to characterize the geodynamic complexity of this region. In this work, we summarize these
studies and highlight their main conclusions. The analysis of the focal mechanisms of large
earthquakes reveals that there are two zones in the Azores, namely, zones I and II, with different
stress pattern and strain rates. In zone I, which is located between 30º W and 27º W, faulting motion
corresponds to a left-lateral strike slip with horizontal E-W compression and N-S extension and a
strain rate of 6.7 mm/yr. In zone II, which is located between 27º W and 23º W, the seismic moment
tensor indicates normal faulting with horizontal NE-SW extension and a strain rate of 3.1 mm/yr.
Special Focus on Advances in Symbolic and Numeric Computation IV
No full textThis Special Focus on Advances in Symbolic and Numeric Computation IV of Mathematics in Computer Science (MCS) edited by Amélia Loja, Mourad Bezzeghoud, Joaquim Infante Barbosa and José Alberto Rodrigues is organized in connection with the 5th International Conference on Numerical and Symbolic Computation: Developments and Applications, and it is devoted to publishing relevant results on the development and/or applications of numerical and symbolic computational methods in Mathematics, Applied Sciences and Engineering.
Original research papers and insightful survey manuscripts addressing all aspects of numerical and symbolic computation are welcome.
Topics and areas of interest for this special focus include, but are not limited to
- integrated numerical and/or symbolic computation,
- integrated graphical and/or analytical computation,
- image processing,
- symbolic computation and didactical tools,
- modeling and optimization,
- systems identification and control,
- evolutionary algorithms,
- computational intelligence,
- fuzzy systems,
- computational mathematics,
- computational engineering,
- computational physics and chemistry,
- computational economics, management and planning,
- health and biomedical computing applications,
- design and implementation of algorithms and software tools.SYMCOMP202
Riscos Tecnológicos e Naturais e a sua Prevenção
No full textTema 1 - água um agente transformador
Tema 2 - riscos sísmicos e vulcânicos
Tema 3 - clima, fenómenos extremos e alterações climáticas
Tema 4 – riscos tecnológicos e efeitos da actividade humano na saúd
Proceedings of the 12th International Workshop on Nonlinear Dynamics of Electronic Systems (NDES 2004)
Get PDFNONLINEAR DYNAMICS OF ELECTRONIC SYSTEMS 2004 (NDES 2004) is the twelfth in a series of international specialist workshops on Nonlinear Dynamics of Electronics Systems, since 1993, when the first NDES workshop took place in Dresden. Since then, the NDES has steadily increased its impact in the scientific community, becoming a truly international event, the largest of its kind in Europe.
In 2004, the workshop brought together specialists in engineering and applied sciences, in physics and geophysics and in mathematics, in order to provide an opportunity to meet in a low-cost informal setting to address new theoretical and practical results, novel analysis and design methods in nonlinear dynamic systems and circuits and to discuss open problems in nonlinear science in general.
NDES2004 has been organized and hosted by the Centro de Geofísica de Évora (Centre of Geophysics of Évora) of the University of Évora, Portugal. Évora is, since 1986, a UNESCO World Heritage Site.
This book of proceedings contains all accepted papers, distributed among the following subjects: Circuit systems, Chaos, Stability and Control, Nonlinear Time Series Analysis, Chaos in Earth Sciences, Econophysics and Econometrics, Biological Systems and Synchronization.
We are very grateful to the following sponsors: Fundação Eugénio de Almeida, Fundação Calouste Gulbenkian, Fundação para a Ciência e a Tecnologia, Câmara Municipal de Évora, Banco Espírito Santo, CARMIM – Reguengos de Monsaraz and Universidade de Évora.
We are also very grateful to the invited speakers for contributing to NDES2004 and for meeting our deadlines.
We express our warm thanks to all the technicians that enthusiastically collaborated to make this event a pleasant reality; in particular we would like to mention the contribution of Luis Almas (University of Évora).
Finally we also thank all participants for their contributions and for coming. We wish all a very productive and enjoyable stay in Évora!
Évora, April 15, 2004 The Editor
TWO DECADES OF EARTH SCIENCE RESEARCH
Get PDFIn 2012, the Évora Geophysics Centre (CGE) celebrates 20 years of activity. In
these two decades, the national scientific system underwent a profound
transformation, new organizational structures appeared, and participation in
structures and international networks, and scientific integration reached very high
levels. The national scientific environment is now more qualified and competitive;
however the available funding per researcher became scarcer.
Currently the CGE team includes 67 full members, and is organized in two
main Lines of Research: (1) Atmosphere and Hydrosphere, (ii) Solid Earth. The first one
comprises the centers of activity: Meteorology & Climate, Water, Environment, & Surface
Processes, and Energy & Flow Structures, while the latter is composed of the centers of
activity: Active Tectonics & Risks, Lithosphere, Mantle & Geological Resources, and
Heritage & Archeometry.
The time of maturity has come for GCE as a research unit, with a growth
trajectory that was not always linear; however it has been progressive with respect to
scientific quality, organizational structure, and the scientific and training outputs that
were made available to the community.
It is also the time to reflect on the past and to define future strategies. This
debate is carried out within the evolving framework in which the CGE develops its
activity. Actually, CGE faces new challenges on the times ahead. At the national
level new rules of public funding have been announced, which are expected to
increase competition for national funding, together with a strong pressure to make
networking among the teams for the use of the available facilities. At the
international level, CGE is challenged to collaborate with national and international
teams to get access to the new European funding program HORIZON 2020.
The workshop “Two Decades of Earth Science Research” was held at the
University of Évora, on 23 November 2012, as the closure of the Program of
Celebrations, which spanned over the year of 2012. For this workshop we invited
national and international key figures as "keynote speakers", and other colleagues,
which with us will reflect on the evolution of Earth Sciences, Atmosphere and
Hydrosphere, and the national and European science on these two decades. With
this initiative we will also make our contribution to the community for the analysis
of this framework and define new directions for the scientific activity
Seismicity and Ground Motion Simulations of the SW Iberia Margin
Get PDFIn this study, we focus on the region between Gorringe Bank and the Horseshoe Fault located in the SW Iberia margin, which is believed to be the site of the great 1755 earthquake. We model ground motions using an extended source located near the Horseshoe scarp to generate synthetic waveforms using a wave propagation code, based on the finite-difference method. We compare the simulated waveforms using a 3-D velocity model down to the Moho discontinuity with a simple 1-D layered mod- el. The radiated wave field is very sensitive to the velocity model and a small number of source parameters; in particular, the rupture directivity. The rupture directivity (controlled by the rupture initiation location), the strike direction and the fault di- mensions are critical to the azimuthal distribution of the maximum amplitude oscilla- tions. We show that the use of a stratified 1-D model is inappropriate in SW Iberia, where sources are located in the oceanic domain and receivers in the continental do- main. The crustal structure varies dramatically along the ray paths, with large-scale heterogeneities of low or high velocities. Moreover, combined with the geometric li- mitations inherent to the region, a strong trade-off between several parameters is of- ten observed; this is particularly critical when studying moderate magnitude earth- quakes (M< 6), which constitute the bulk of the seismic catalogue in SW Iberia
A possible radio anomaly observed on the occasion of the MW=6.0 earthquake occurred in Dodecanese islands at the end of January 2020
Get PDFSince 2009, several VLF/LF radio receivers have been installed throughout Europe in order to realize a European radio network for studying the radio precursors of earthquakes, called the INFREP network. The current network has nine VLF/LF receiving stations, two in Romania and Greece, one in Italy, Austria, Portugal, Cyprus, and Serbia. The receivers can measure with 1 min sampling rate the intensity of 10 radio signals in the band VLF (10-50 kHz) and LF (150-300 kHz). The scope of existing transmitters is manifold, e.g. they are used for radio broadcast (LF), for radio- navigation or time signals and mainly for military purposes in the VLF range. At the end of January 2020 an intense seismic crisis occurred in Dodecanese Islands; the main event (Mw= 6.0) occurred on January 30. This seismic activity occurred in the "sensitive" area of the INFREP network. The analysis of the data collected by INFREP receivers has revealed clear anomalies in three VLF signals appearing some days before the main earthquake. The anomalies appear in the trends collected by the Cyprus receiver and the epicenter is inside the 5th Fresnel ellipses defined by transmitters- receiver. Here we report the data analysis and we present in detail the anomalies. The possibility that they are precursors of the quoted earthquake seems significant.
Biagi, P.F., Colella, R., Schiavulli, L., Ermini, A., Boudjada, M., Eichelberger, H., Schwingenschuh, K., Katzis, K., Contadakis, M.E., Skeberis, C., Moldovan, I.A. and Bezzeghoud, M. (2019) The INFREP Network: Present Situation and Recent Results. Open Journal of Earthquake Research,8, 101-115. https://doi.org/10.4236/ojer.2019.8200
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