Browsing by Author "Prates, G."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Magma displacements under insular volcanic fields, applications to eruption forecasting: El Hierro, Canary Islands, 2011-2013Publication . Garcia, A.; Fernandez-Ros, A.; Berrocoso, M.; Marrero, J. M.; Prates, G.; De la Cruz-Reyna, S.; Ortiz, R.Significant deformations, followed by increased seismicity detected since 2011 July at El Hierro, Canary Islands, Spain, prompted the deployment of additional monitoring equipment. The climax of this unrest was a submarine eruption first detected on 2011 October 10, and located at about 2 km SW of La Restinga, southernmost village of El Hierro Island. The eruption ceased on 2012 March 5, after the volcanic tremor signals persistently weakened through 2012 February. However, the seismic activity did not end with the eruption, as several other seismic crises followed. The seismic episodes presented a characteristic pattern: over a few days the number and magnitude of seismic event increased persistently, culminating in seismic events severe enough to be felt all over the island. Those crises occurred in 2011 November, 2012 June and September, 2012 December to 2013 January and in 2013 March-April. In all cases the seismic unrest was preceded by significant deformations measured on the island's surface that continued during the whole episode. Analysis of the available GPS and seismic data suggests that several magma displacement processes occurred at depth from the beginning of the unrest. The first main magma movement or 'injection' culminated with the 2011 October submarine eruption. A model combining the geometry of the magma injection process and the variations in seismic energy release has allowed successful forecasting of the new-vent opening.
- When agriculture rules over the territory: Drystone wallsPublication . Marçal Gonçalves, Marta; Pérez Cano, M. T.; Rosendahl, S.; Prates, G.; L. Villegas; I. Lombillo; H. Blanco; Y. BofillThe objectives of this paper are mainly the dissemination of knowledge about drystone walls, a “minor heritage”, and the awareness of its importance in the territory characterization. These objectives are achieved when this theme is disclosed and explained. Heritage is protected and appreciated only if it is understood. The expected practical impact is essentially related to the recognition of this type of heritage. The main methodology consists of bibliographical and iconography collection, field surveys and exchange of ideas with the local people. The approach is made from the point of view of how the practiced agriculture characterizes the territory, not only its structure, because is also necessary to know the local typologies of drystone walls to allow to characterize them. Some characteristics of drystone walls were discovered in this investigation, which are directly related to the territory where they are inserted. The following limitations were found: the gradual replacement of drystone walls with masonry walls; changes in the type of agriculture; the difficulty of finding masters who have the know-how about drystone walls; the recognition of this heritage by the local population; and the gradual local population diminution. Practical implications are an improved sense of belonging and identity as the knowledge and appreciation of this heritage increases the pride of the population which was verified in the field surveys. The originality of this paper is the object of study, the Parish of Cernache do Bonjardim, Portugal, since there are very few works about it, also with added value to the dissemination of this type of heritage and its potential exploitation and protection by local population. It is possible to renew theterritory of these walls and use it for touristic, educational and cultural purposes, encouraging the local economy.