Holocene Mg/Ca, alkenones, and light stable isotope measurements on the outer North Iceland shelf, sediment core MD99-2269

We present new Holocene century to millennial-scale proxies for the well-dated piston core MD99-2269 from Húnaflóadjúp on the North Iceland Shelf. The core is located in 365 mwd and lies close to the fluctuating boundary between Atlantic and Arctic/Polar waters. The proxies are: alkenone-based SST°C, and Mg/Ca SST°C estimates and stable d13C and d18O values on planktonic and benthic foraminifera. The data were converted to 60 yr equi-spaced time-series. Significant trends in the data were extracted using Singular Spectrum Analysis and these accounted for between 50% and 70% of the variance. A comparison between these data with previously published climate proxies from MD99-2269 was carried out on a data set which consisted of 14-variable data set covering the interval 400-9200 cal yr BP at 100 yr time steps. This analysis indicated that the 1st two PC axes accounted for 57% of the variability with high loadings clustering primarily into "nutrient" and "temperature" proxies. Clustering on the 100 yr time-series indicated major changes in environment at ~6350 and ~3450 cal yr BP, which define early, mid- and late Holocene climatic intervals. We argue that a pervasive freshwater cap during the early Holocene resulted in warm SST°s, a stratified water column, and a depleted nutrient supply. The loss of the freshwater layer in the mid-Holocene resulted in high carbonate production, and the late Holocene/neoglacial interval was marked by significantly more variable sea surface conditions.

Location and ages of terrestrial peatlands located on continental shelves and in coastal sediments

This synthesis dataset contains records of freshwater peat and lake sediments from continental shelves and coastal areas. Information included is site location (when available), thickness and description of terrestrial sediments as well as underlying and overlying sediments, dates (when available), and references.

(Table 1) Age determination of composite sediment record LO09-14

A sediment core from Reykjanes Ridge has been studied at 10- to 50-year time resolution to document variability of Holocene surface water conditions in the western North Atlantic and to evaluate effects of Holocene ice-rafting episodes. Diatom assemblages are converted to quantitative sea surface temperatures (SST) using three different transfer functions. Spectral and scale-space methods are also applied on the records to explore variability at different timescales. Diatom assemblage and SST records clearly show that decaying remnants of the Laurentide ice sheet strongly influenced early Holocene climate in the western North Atlantic. This overrode the predominance of Milankovitch forcing, which played a key role in the development of Holocene climate in the eastern North Atlantic and Nordic Seas. Superimposed on general Holocene climate change is high-frequency SST variability on the order of 1°-3°C. The record also documents climatic oscillations with 600- to 1000-, ~1500-, and 2500-year periodicities, with a time-dependent dominance of different periodicities through the Holocene; a clear change in variability occurred about 5 ka BP. The SST record also provides evidence for Holocene cooling events (HCE) that, in some cases, correlate to documented southward intrusions of ice into the North Atlantic.

(Table 1) Age determination of Barents Sea sediment cores

he separate roles of oceanic heat advection and orbital forcing on influencing early Holocene temperature variability in the eastern Nordic Seas is investigated. The effect of changing orbital forcing on the ocean temperatures is tested using the 1DICE model, and the 1DICE results are compared with new and previously published temperature reconstructions from a transect of five cores located underneath the pathway of Atlantic water, from the Faroe-Shetland Channel in the south to the Barents Sea in the north. The stronger early Holocene summer insolation at high northern latitudes increased the summer mixed layer temperatures, however, ocean temperatures underneath the summer mixed layer did not increase significantly. The absolute maximum in summer mixed layer temperatures occurred between 9 and 6 ka BP, representing the Holocene Thermal Maximum in the eastern Nordic Seas. In contrast, maximum in northward oceanic heat transport through the Norwegian Atlantic Current occurred approximately 10 ka BP. The maximum in oceanic heat transport at 10 ka BP occurred due to a major reorganization of the Atlantic Ocean circulation, entailing strong and deep rejuvenation of the Atlantic Meridional Overturning Circulation, combined with changes in the North Atlantic gyre dynamic causing enhanced transport of heat and salt into the Nordic Seas.

Las enfermedades crónicas como prioridad de la vigilancia de la salud pública en España

En la actualidad, la vigilancia epidemiológica sigue centrada, en España, en las enfermedades transmisibles incluidas en la lista de enfermedades de declaración obligatoria. Sin embargo, el patrón epidemiológico que dominó hasta las últimas décadas del siglo XX ha cambiado. Las enfermedades infecciosas, que eran las principales causas de morbimortalidad, han dado paso a un predominio de las enfermedades crónicas. En este sentido, se ha avanzado en la redacción y la aprobación de normativa específica sobre vigilancia de la salud pública. No obstante, tenemos pendiente el desarrollo de esta normativa que, entre otros puntos, recoge el mandato de organizar la vigilancia de las enfermedades no transmisibles en España. El objetivo de este trabajo es describir algunas características a tener en cuenta para desarrollar un sistema nacional de vigilancia de la salud pública vinculado a las estrategias ya existentes para la prevención y el control de las enfermedades crónicas.

Aspectos arábigo-andaluces en la producción literaria de Antonio Gala

La presencia de una sociedad musulmana en la Península Ibérica desde el siglo VIII al XVII, es decir desde la conquista árabe hasta la expulsión de los moriscos, convierte a los musulmanes inevitablemente en tema literario. Ya desde los más primitivos textos épicos aparecen los musulmanes de al-Ándalus no sólo como antagonistas de los héroes sino desarrollando otras funciones literarias como sucede en el Cantar del Mio Cid o de los Infantes de Lara. Incluso surgen en la lejanía los sarracenos de al-Ándalus, en los trovadores catalanes en lengua occitana. Y en el siglo XV, se convierten casi en un género literario en la literatura de Castilla: se convierten en los moros imaginarios de los romances fronterizos, es la morofilia literaria, es el moro de Granada el que entra en la literatura. La idealización del moro de Granada por parte de la literatura castellana es un hecho sorprendente, porque es contemporánea primero de una cruenta guerra, la de Granada, en los romances fronterizos, y de la rebelión morisca y del enfrentamiento ideológico cristiano-morisco después, al pasar el tema, casi intacto, al Siglo de Oro, fenómeno que resumió brillantemente Emilio García Gómez en sus estudios de Ibn Zamrak como: «Jamás tan brillante puente de plata fue tendido a enemigo que huye» El fenómeno no tiene todavía una explicación satisfactoria, porque no puede ser un simple recurso psicológico, como quiere Juan Goytisolo, que otros enemigos vencidos tuvo España y no los idealizó, ni tampoco se podría suponer que es una literatura de protesta, de una contestación a la política nacional como quieren otros autores. Creemos que, en primer lugar, la maurofilia es esencialmente estética y no ética, y en segundo lugar, que arranca de tiempos anteriores a los conflictos abiertos bélicos e ideológicos -la idealización del «moro de Granada» ya se produce en la Crónica de Alfonso XI de 1344...

Beso de espía, desde el paredón : hace 75 años fusilaron a Mata Hari

Fondo Margaritainés Restrepo