Sea surface temperature reconstruction for the middle Pleistocene from sediment core MD03-2699

Past sea surface water conditions of the western Iberian Margin were reconstructed based on biomarker analyses of a marine deep sea core MD03-2699 from the Estremadura Spur north off Lisbon, providing new insights into orbital and suborbital-scale climate variability between marine isotope stage (MIS) 15 to MIS 9 (580 to 300 ka). We use biomarker-based proxy records such as the alkenone unsaturated index to estimate sea surface temperature (SST), the total alkenone concentration to reconstruct phytoplankton productivity, and terrestrial biomarkers to evaluate the continental input. The results extend the existing biomarker record, namely the SST for the Iberian Margin, back to the sixth climatic cycle (580 ka). A general trend of stable interglacials contrasts with glacial periods and glacial inceptions which are marked by high-frequency variability. Thus, several short-lived climatic coolings were identified by large SST decreases, the occurrence of ice-rafted detritus and high percentages of the tetraunsaturated alkenone C 37:4. Some of these events were extremely cold and similar in their general trends to the well-known Heinrich events of the last glaciation. We identified eight Heinrich-type events between 580 and 300 ka. The general deglaciation pattern detected between MIS 15 and MIS 9 is similar in their general trends to that characterizing the more recent climatic cycles, i.e., marked by two coolings separated by a short warming episode which may reflect the southward, northward, and southward migration of the Polar Front.

AUTO-RUINS. Thinks about automobile into the contemporary landscape

The article analyses the evolution of the representation of the automobile inserted in the natural and urban environment in the Contemporary Art, from the appearance of the first cars in the beginning of the 20th century until the present day. The text compares the diverse attitudes and analysis of some representative artists who have used the image of the machine in general and the car in particular in their aesthetic discourse, using as a conductive thread the metaphor of the life cycle (birth, growth, feeding, reproduction and death). It deals with the discovery, the development and the coexistence between human and the automobile and its interpretation as a basic element of the artistic work. The text connects the image of the automobile located in the contemporary industrial landscape utilizing the artist references who have integrated the car in their work inside the natural or artificial environment characteristic of each moment. At the same time, the article goes deeply into the relationship of romantic ruin and natural landscape and the evolution of the industrial and architectural modern environment, through the work of the artists who has used the car as an inhabitant of the landscape.