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Scientific diving (SD) is defined as any diving activity that applies scientific procedures to produce subsidies for studies and technical works in underwater environments. The first report of an underwater scientific study in Brazil dates to the 19th century, in the Abrolhos reefs. Currently, in Brazil, scientific diving has been performed in various areas, from shallow coastal regions to remote and sometimes hard-to-reach places, such as oceanic islands, flooded caves, and icy areas like Antarctica. However, the regulation of SD in Brazil still lacks more concrete actions towards an effective and efficient self-regulation that offers physical safety to practitioners and institutional safeguards for organizations that use it in their research projects. Thus, this article aims to contribute to a better understanding of this critical issue in Brazil and to serve as a reference and incentive for the training of professionals and the development of these activities in the country. It includes: 1) a historical review of SD; 2) a diagnosis of the training and application of SD in Brazil; 3) the evolution of marine sciences in Brazil from the perspective of SD; 4) a review of the use of environmental assessment and underwater conservation techniques in oceans and internal waters; 5) an analysis of the evolution of scientific diver training in Brazil, including a diagnosis on training; 6) the history and updates of the rules, regulations, and safety of SD. Given all the potential of diving combined with specific techniques for research, monitoring, and marine and limnic science in Brazil, we aim to understand the evolution of scientific diving teaching and to outline perspectives in the country, as it is crucial for the training of qualified scientists capable of performing these underwater tasks. Finally, we present future plans for the development of this activity in Brazil from the point of view of research and the labor market. [ABSTRACT FROM AUTHOR]

Machado, A.A. and Calliari, L.J., 2016. Synoptic systems generators of extreme wind in southern Brazil: atmospheric conditions and consequences in the coastal zone. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 1182 - 1186. Coconut Creek (Florida), ISSN 0749-0208. The coast of Rio Grande do Sul (RS), southern Brazil, suffers a seasonal variation due to the dynamics associated with the frequency and intensity of storms. These storms are mostly associated with high intensity extratropical cyclones that generate wind waves which can change a beach profile from its maximum accretion state to complete erosion during a period that can vary from few hours to a few days. Using the Generalized Pareto Distribution, we observe that the 0.01 probability density value of all the wind speed values studied was 17 ms−1. Analyzing the storms that generate extreme winds (ie ≥ 17 m s−1), an increase in the number of extreme events to the coast of RS was observed over the past 66 years (1948-2013). The increase in the frequency of extreme events of wind, will modify and increase flooding, storm surge, and erosion along the coast. It was observed that the main weather systems generating strong winds to the shore of the RS are extratropical cyclones, which are mainly formed between parallels 30°S to 40°S, with two preferred trajectories, east and southeast, generating both erosion and storm surges. The majority of extratropical cyclones presentend propagation velocities between 20-40 km h−1 (61.97%). The months with the highest number of extreme events were June (22), followed by October (16). The consequences of storms in RS coast were: erosion of 45 m3m−1, storm surge of 1.88 m, wind speed of 26.21 m s−1 and significant wave height of 8.79 m. [ABSTRACT FROM AUTHOR]

A new mixed turbidite-contourite system is described in the northern Campos Basin, southeastern Brazilian margin. This system is developed in a middle slope setting, and was formed through non-synchronous interaction between the turbidity current and a contour current in the same stratigraphic interval (Miocene). Depositional cycles were differentiated based on diagnostic seismic features. Seismic attributes, seismic facies, and isochron maps were used to identify alternating cycles of downslope and alongslope processes in the study area, along with the intermediate stage with features from both processes (mixed system). Seismic units were then associated with the dominant type of current. Alongslope current activity can be distinguished from the downslope current based on its acoustic characteristics (mainly low root-mean-square (RMS) amplitude values), internal architecture (clinoforms), and external geometry pattern (alongslope trend). On the other hand, downslope gravity currents develop deposits with high-amplitude or chaotic seismic facies, usually higher values of RMS amplitude, channel or channel-lobe features, erosive surfaces, and a basinward depositional trend. The first and oldest seismic unit (S1) was interpreted as a dominantly alongslope system, with vertical aggrading sigmoidal clinoforms and high-frequency, low-amplitude reflections commonly associated with fine-grained sedimentary deposits, typical of a plastered drift, along with a basinward mass transport deposit (MTD) from previous drift instability. Seismic unit S2 represents the intermediate stage where both gravity-driven and along-slope currents act asynchronously. Its is refered to as a mixed turbidite-contourite sequence that shows high-amplitude sediment waves migrating upslope and a moat feature that is carved in its upslope front. The interfingering between high- and low-amplitude reflectors, distal chaotic facies, together with sediment waves and a channel moat, points to a sand-rich deposit reworked by northward-flowing contour currents. Seismic units S3 and S4 show downslope features with chaotic facies (S3) and paleochannels with coarse basal lag deposits (high RMS amplitude values) (S4). In S4, a series of long-lived submarine channels formed. Last, seismic unit S5, referred to as the second plastered drift sequence, is marked by low-amplitude clinoforms that thin basinward. At the seafloor, submarine channel banks (formed at S4) covered by fine sediment deposits (from S5) show asymmetrical features with a slight northward depositional trend, indicating a northward-flowing bottom current, as the deposits are known to pile up in a downcurrent trend. Important information on the paleocurrents' direction was also made based on the final deposits display (e.g. terraces, sediment waves, paleochannels). Research on alternating dominant processes and transitional stages or mixed depositional systems, with both turbidites and contour currents, may provide a better understanding of deep-water depositional processes. Because these processes do not always fit previous depositional models that are mainly described for synchronous systems, new insights on cyclic non-synchronous mixed systems can improve our understanding of how mixed systems are organized through time and space. Being able to determine which were the dominant processes that controlled the sedimentation by indicating periods where the margin was mostly submitted to sediment transfer from continent to the basin and periods where the oceanic currents prevailed by redistributing sediments along the isobaths and replacing the axis of downslope transfer conduits. Setting new models on cyclic deposits and intermediate stages can have a future economic impact on potential hydrocarbon reservoir architecture. • A new description of a non-synchronous Mixed Turbidite-Contourite System. • Alternated and cyclic deposits of down-slope and along-slope processes with a transitional stage of flow interaction. • Dominant flow depositional systems identification based on seismic response. • How mixed systems are organized through time and space. [ABSTRACT FROM AUTHOR]