Ánchel Belmonte

Hydrological change in Southern Europe responding to increasing North Atlantic overturning during Greenland Stadial 1

Significance This study presents robust evidence of two hydrological phases within the Greenland Stadial 1 (GS-1) cold event (12.8−11.7 ka B.P.) in Southern Europe. We present a well-dated high-resolution speleothem record (Seso Cave, Central Pyrenees) where temperature and hydrological signals are independently reconstructed. Detailed interpretation of stable isotopes and trace elements allow characterizing a first dry period followed, after 12,500 y before 2000 A.D., by more humid conditions. Our findings point to the resumption of the Atlantic overturning circulation as the main mechanism behind the hydrological response in Europe during this mid–GS-1 transition. The second phase, cold in Greenland but humid in Western Europe, represents a new paradigm in the well-established model of dry, cold stadials during the last glacial period. Greenland Stadial 1 (GS-1) was the last of a long series of severe cooling episodes in the Northern Hemisphere during the last glacial period. Numerous North Atlantic and European records reveal the intense environmental impact of that stadial, whose origin is attributed to an intense weakening of the Atlantic Meridional Overturning Circulation in response to freshening of the North Atlantic. Recent high-resolution studies of European lakes revealed a mid–GS-1 transition in the climatic regimes. The geographical extension of such atmospheric changes and their potential coupling with ocean dynamics still remains unclear. Here we use a subdecadally resolved stalagmite record from the Northern Iberian Peninsula to further investigate the timing and forcing of this transition. A solid interpretation of the environmental changes detected in this new, accurately dated, stalagmite record is based on a parallel cave monitoring exercise. This record reveals a gradual transition from dry to wet conditions starting at 12,500 y before 2000 A.D. in parallel to a progressive warming of the subtropical Atlantic Ocean. The observed atmospheric changes are proposed to be led by a progressive resumption of the North Atlantic convection and highlight the complex regional signature of GS-1, very distinctive from previous stadial events.

Speleothem formation in Northeastern Iberian Peninsula under the influence of different climatic conditions over last glacial cycles

Speleothem growing is closely linked to warm climates with a positive hydrological balance. Mild temperatures and hydrological availability are conditions that tend to stimulate soil CO 2 production due to denser vegetation cover and higher microbial activity. In such situations, waters enriched with dissolved carbonate are common and can infiltrate in the karstic system. This study compiles 158 dates from 34 speleothems collected in nine caves in the Northeastern Iberia to distinguish the time intervals with speleothem formation. A clear connection of speleothem growth and interglacial periods is established but

Ice Caves in Spain

Abstract In Spain there are at least 156 ice caves inventoried in the Pyrenees, Cantabrian Mountains, and Teide. In the Pyrenees there are ice caves in at least seven different massifs and in the Cantabrian Mountains are concentrated mainly in the Picos de Europa. In eight ice caves there have been applied techniques such as endoclimatic survey, geochronology, CCC analysis, mapping, ice structure, mass balances, TLS surveys, orthothermography and GPR surveys from the last 8 years. The ice volume has a significant interannual variation together with a regressive trend during the last decades, and the ice has ages ranging from centuries to a few millennia. In Spain Ice there are all kinds of possible ice caves, from the static to the dynamic, with metamorphic and congelation ice. Due to their risk of disappearance in the short medium term, it is very important to understand the ice cave systems and their past dynamics.