Geofísica

Climate changes have been considered an essential factor controlling the shaping of the recent alluvial landscapes in central Amazonia, with implications for explaining the biogeographic patterns in the region. This landscape is characterized by wide floodplains and various terrace levels at different elevations. A set of older terraces with ages between 50 and >200 ka occupy the higher portions of central Amazonia, whereas multiple terraces next to floodplains occur at lower elevations and display ages of a few thousand years.

Despite representing one of the largest cratons on Earth, the early geological evolution of the Amazonia Craton remains poorly known due to relatively poor exposure and because younger metamorphic and tectonic events have obscured initial information. In this study, we investigated the sedimentary archives of the Carajás Basin to unravel the early geological evolution of the southeastern Amazonia Craton. The Carajás Basin contains sedimentary rocks that were deposited throughout a long period spanning more than one billion years from the Mesoarchean to the Paleoproterozoic.

Technical information about deep foundations of built structures may in some cases be unavailable or incomplete due to the lack of construction documentation and electronic media in which the reports are stored. This problem is particularly relevant for telecommunication towers constructed two-to-three decades ago but still under operation and subject to new loading demands from expanding networks. Nondestructive evaluation with geophysical methods has been applied to determine the depth to the bottom of deep foundations, a key parameter to evaluate their bearing capacity and settlements.

Technical information about deep foundations of built structures may in some cases be unavailable or incomplete due to the lack of construction documentation and electronic media in which the reports are stored. This problem is particularly relevant for telecommunication towers constructed two-to-three decades ago but still under operation and subject to new loading demands from expanding networks. Nondestructive evaluation with geophysical methods has been applied to determine the depth to the bottom of deep foundations, a key parameter to evaluate their bearing capacity and settlements.

Explosive volcanism and oceanic crust generation are key aspects to understanding the break-up history of the Rodinia. Its impact on the extreme glaciations of the Cryogenian was marked by ocean chemistry fluctuations in these times, which are still poorly known and preserved in western Gondwana.

We used thermomechanical numerical models to simulate the formation and evolution of divergent continental margins since continental rifting, taking into account surface processes of erosion of the continental escarpment. We found that the degree of crust–mantle coupling, the magnitude and extent of erosion of the coastal landscape, and the preexistence of weakness zones in the continental crust are important elements that control the reactivation of faults along divergent margins during the postrift phase.

A Rede Sismográfica Brasileira (RSBR) está em operação desde 2009, sendo atualmente composta por um conjunto de quase 100 estações sismográficas banda-larga, com capacidade de transmissão de dados em tempo real. O monitoramento automático de ocorrências de eventos sísmicos é realizado através do software SeisComP, com poucas modificações em seus parâmetros originais de detecção e localização. Mais de 90% dos eventos no catálogo sísmico da RSBR são detectados manualmente por analistas, em rotinas diárias de análises dos sismogramas.

Os métodos geofísicos da eletrorresistividade (ER), radar de penetração no solo (GPR) e eletromagnético no domínio do tempo (TDEM) foram empregados nesta pesquisa visando caracterizar um depósito de areia em uma Mineração de Pequena Escala (MPE) localizada no município de Leme, São Paulo. A área de estudo está localizada na borda leste da Bacia do Paraná, onde a areia usada, principalmente, na construção civil é extraída da Formação Piramboia.

O aumento da geração de resíduos sólidos urbanos, observado ao longo dos anos, tem suscitado discussões importantes a respeito da forma como eles são dispostos. Quando realizados em lixões e aterros controlados, a contaminação de solos e águas subterrâneas torna-se provável. Quando dispostos em aterros sanitários, um projeto adequado às normas vigentes e monitoramento constante pode evitar a ocorrência de problemas ambientais.