El Cronicón Cordubense de Fernando de Salmerón.

Sin resume

El Cronicón Cordubense de Fernando de Salmerón.

Sin resume

Un nuevo significado del topónimo España

Durante la Edad Media, muchos cronistas y notarios de ios reinos cristianos de la Península ibérica solían emplear el topónimo Híspanla o España con dos significados diferentes, refiriéndose a veces a la Península entera, con sus islas adyacentes, y a veces al al-Andalus, es decir, a la región peninsular dominada por los musulmanes. Fue el Padre Flórez el primero en observar esta curiosa costumbre lingüística, y después varios historiadores la han analizado o la han tomado como base para especulaciones metahistóricas. Hoy por hoy, el mejor estudio se encuentra en las páginas que le dedicó al asunto el profesor J.A. Maravall hace un cuarto de siglo en su magistral libro sobre el concepto de España en la Edad Media

Extension and stress during continental breakup: seismic anisotropy of the crust in Northern Afar

Studies that attempt to simulate continental rifting and subsequent breakup require detailed knowledge of crustal stresses, however observational constraints from continental rifts are lacking. In addition, a knowledge of the stress field around active volcanoes can be used to detect sub-surface changes to the volcanic system. Here we use shear wave splitting to measure the seismic anisotropy of the crust in Northern Afar, a region of active, magma-rich continental breakup. We combine shear wave splitting tomography with modelling of gravitational and magmatic induced stresses to propose a model for crustal stress and strain across the rift. Results show that at the Ethiopian Plateau, seismic anisotropy is consistently oriented N–S. Seismic anisotropy within the rift is generally oriented NNW–SSE, with the exception of regions north and south of the Danakil Depression where seismic anisotropy is rift-perpendicular. These results suggest that the crust at the rift axis is characterized by rift-aligned structures and melt inclusions, consistent with a focusing of tectonic extension at the rift axis. In contrast, we show that at regions within the rift where extension rate is minimal the seismic anisotropy is best explained by the gravitationally induced stress field originating from variations in crustal thickness. Seismic anisotropy away from the rift is controlled by a combination of inherited crustal structures and gravitationally induced extension whereas at the Dabbahu region we show that the stress field changes orientation in response to magmatic intrusions. Our proposed model provides a benchmark of crustal stress in Northern Afar which will aid the monitoring of volcanic hazard. In addition we show that gravitational forces play a key role in measurements of seismic anisotropy, and must be considered in future studies. We demonstrate that during the final stages of continental rifting the stress field at the rift axis is primarily controlled by tectonic extension, but that gravitational forces and magmatic intrusions can play a key role in the orientation of the stress field

Multiple benefits of blue-green infrastructure and the reduction of environmental risks: case study of ecosystem services provided by a SUDS pond

This paper gives an account of multiple benefits provided by Granton SUDS pond and discusses their relevance to the alleviation of environmental, economic and social risks. The pond was established in 2005 and is situated in a park, close to a supermarket and a college. It has an area of approximately 2600 m2 and a hydrographic survey carried out as part of this research provided an estimate for the pond’s volume of 1904 m3 for the normal operating conditions. However, during flooded conditions (also observed during this research) the pond’s volume increases to circa 2545 m3. The pond has considerable biodiversity value and an important amenity function. The locality is enjoyed daily by many visitors and is particularly popular with joggers, dog walkers and families. Modelling of the pond’s catchment was undertaken using the hydrodynamic model CityCAT coupled with the hydrological model SHETRAN. Changes in water discharge from the pond were simulated using the time series of precipitation and air temperature data obtained from the Scottish Environment Protection Agency (SEPA). The discharge is higher in winter, which determines shorter retention times. That has implications for the observed dynamics of the hydrobiological community, with higher risk of cyanobacterial development in the summer. However, according to the ICP MS analysis of water chemistry, the observed planktonic community and the biological water quality estimated by macroinvertebrate sampling, are all broadly similar to those in other ponds. CityCAT results show that the presence of the pond delays and reduces the peak discharge after extreme precipitation events, with reductions being greater for smaller events. This study contributes to accumulating evidence of interlinkages among hydrology, ecology, biogeochemistry and biological water quality at the SUDS ponds sites, thus underlying the need for a comprehensive simultaneous consideration of their subsystems. These aspects are indispensable for reducing the risk of negative environmental effects and vital for planning future urban developments and nature-based solutions, as well as for the management of existing SUDS assets