Sea surafce temperature reconstruction for sediment core SU81-18

Reconstructing the impact of Heinrich events outside the main belt of ice rafting is crucial to understanding the underlying causes of these abrupt climatic events. A high-resolution study of a marine sediment core from the Iberian margin demonstrates that this midlatitude area was strongly affected both by cooling and advection of low-salinity arctic water masses during the last three Heinrich events. These paleoclimatic time series reveal the internal complexity of each of the last three Heinrich events and illustrate the value of parallel studies of the organic and inorganic fractions of the sediments.

Dinoflagellate cysts counts of sediment core MD95-2042

Dinoflagellate cysts were analysed from IMAGES core MD952042 (37°48?N; 10°01?W) retrieved from the Tagus Abyssal Plain. Previous results of stable isotope and magnetic susceptibility measurements as well as of planktonic foraminiferal temperature reconstruction from this core, suggest the occurrence of "Heinrich-like events" (i.e. large ice-sheet decay) during Marine Isotopic Stage 5 (MIS 5). Dinoflagellate assemblages of this time period have revealed six dinocyst events that are characterised by peaks in Bitectatodinium tepikiense percentages. These events occur synchronously with "Heinrich-like events" previously identified. They are coeval with major retreats of the forest on land, indicating, therefore, drastic changes in the regional climate. However, results from the Ice-Rafted Detritus (IRD) analysis of the >150 ?m lithic fraction shows that MIS 5 of MD952042 has only recorded one significant input of iceberg discharge, located at the MIS 6/MIS 5 transition. It seems therefore that it is the only event that could be called a "true Heinrich event".