The Kasei Valles, Mars: a unified record of episodic channel flows and ancient ocean levels

There is widespread evidence across Mars of past flows in major channel systems as well as more than one palaeo ocean level. However, evidence for the timing of channel flows and ocean levels is based on geographically diverse sources with a limited number of dates, making reconstructions of palaeo flows and ocean levels patchy. Here, based on high-resolution topography, image analysis and crater statistics, we have dated 35 different surfaces in Kasei Valles, that are predominantly found within erosional units enabling us to reconstruct a fascinating timeline of episodic flooding events (ranging from 3.7 to 3.6 Ga to ca. 2.0 Ga) interacting with changing ocean/base levels. The temporal correlation of the different surfaces indicates five periods of channel flows driving the evolution of Kasei Valles, in conjunction with the development of (at least) two ocean levels. Furthermore, our results imply that such ocean rose in elevation (ca. 1000 m) between ca. 3.6 Ga and 3.2 Ga and soon afterwards disappeared, thereby indicating a complex ancient Martian hydrosphere capable of supporting a vast ocean, with an active hydrological cycle stretching into the Amazonian

Composed Index for the Evaluation of Energy Security in Power Systems within the Frame of Energy Transitions—The Case of Latin America and the Caribbean

Energy transitions are transforming energy systems around the globe. Such a shift has caused the power system to become a critical piece of infrastructure for the economic development of every nation on the planet. Therefore, guaranteeing its security is crucial, not only for energy purposes but also as a part of a national security strategy. This paper presents a multidimensional index developed to assess energy security of electrical systems in the long term. This tool, named the Power System Security Index (PSIx), which has been previously used for the evaluation of a country in two different time frames, is applied to evaluate the member countries of the Latin American Energy Organization, located within the Latin America and the Caribbean region, to measure its performance on energy security. Mixed results were obtained from the analysis, with clear top performers in the region such as Argentina, while there are others with broad areas of opportunity, as is the case of Hait

Knickpoints in Martian channels indicate past ocean levels

On Mars, the presence of extensive networks of sinuous valleys and large channels provides evidence for a wetter and warmer environment where liquid water was more abundant than it is at present. We undertook an analysis of all major channel systems on Mars and detected sharp changes in elevation along the river long profiles associated with steep headwall theatre-like valleys and terraces left downstream by channel incision. These breaks in channel longitudinal slope, headwalls and terraces exhibit a striking resemblance with terrestrial fluvial features, commonly termed 'knickpoints'. On Earth, such knickpoints can be formed by more resistant bedrock or where changes in channel base-level have initiated erosion that migrates upstream (such as tectonic uplift or sea level change). We observed common elevations of Martian knickpoints in eleven separate channel systems draining into the Martian Northern lowlands. Numerical modeling showed that the common elevations of some of these knickpoints were not random. As the knickpoints are spread across the planet, we suggest that these Martian knickpoints were formed in response to a common base level or ocean level rather than local lithology. Thus, they potentially represent a record of past ocean levels and channel activity on Mars

Interactions between barrier islands and backbarrier marshes affect island system response to sea level rise: Insights from a coupled model

Interactions between backbarrier marshes and barrier islands will likely play an important role in determining how low-lying coastal systems respond to sea level rise and changes in storminess in the future. To assess the role of couplings between marshes and barrier islands under changing conditions, we develop and apply a coupled barrier island-marsh model (GEOMBEST+) to assess the impact of overwash deposition on backbarrier marsh morphology and of marsh morphology on rates of island migration. Our model results suggest that backbarrier marsh width is in a constant state of change until either the backbarrier basin becomes completely filled or backbarrier marsh deposits have completely eroded away. Results also suggest that overwash deposition is an important source of sediment, which allows existing narrow marshes to be maintained in a long-lasting alternate state (similar to 500m wide in the Virginia Barrier Islands) within a range of conditions under which they would otherwise disappear. The existence of a narrow marsh state is supported by observations of backbarrier marshes along the eastern shore of Virginia. Additional results suggest that marshes reduce accommodation in the backbarrier bay, which, in turn, decreases island migration rate. As climate change results in sea level rise, and the increased potential for intense hurricanes resulting in overwash, it is likely that these couplings will become increasingly important in determining future system behavior

L’escola rural. CRA El Trescaire

Dissetenes Jornades de Foment de la Investigació de la FCHS (Any 2012)Ens ha semblat oportú ampliar el concepte d'educació al món rural. En aquest sentit, hem recollit unes pautes que vénen en un llibre editat pel MRP el títol del qual és del tot significatiu: Treballar a l'escola rural ¿Treballar a l'escola rural? ¡Treballar a l'escola rural! Si pensem que possiblement aquest siga el nostre primer destí com a mestres el títol podria ser: Treballar a l'escola rural(m'ha tocat una escola rural) ¿Treballar a l'escola rural?(¡ufh no tinc ni idea que es fa aquí!) ¡Treballar a l'escola rural! (ja estic treballant en una escola rural, ¡és genial!) En aquest llibre figuren algunes de les funcions i objectius fonamentals de l’educació al mon rural, nosaltres mitjançant el nostre treball d’investigació en volgut fer una primera aproximació a aquest mon tan proper i necessari per la futura tasca com docents.We thought it appropriate to extend the concept of education in rural areas. In this regard, we have collected some guidelines that come in a book published by MRP whose title is quite significant: Working at the rural school ¿Work mean? ¡Working in the rural school! If you think this may be our first destination as Masters title could be: Working at the rural school (I have had a rural school) ¿Work mean? (¡Ufh I have no idea what is done here!) ¡Working in the rural school! (I'm working in a rural school, ¡is great!) In this book are some of the fundamental objectives and functions education in rural areas, we work with our research wanted to make a first approach to this world as next and necessary for future work as teachers