Aspects of Termination II and MIS 5 as Recorded at the West Spitsbergen Margin

IMAGES V cores MD99-2303 (77°31.18N, 08°23.98W: 2277m water depth) and MD99-2304 ((77°37.26N, 09°56.90W: 1315m water depth) provide high resolution information about high latitude climate variability during Termination II and MIS 5. Here we report a study of stable isotopes, ice rafted debris and magnetic properties in these cores with a detailed focus on Termination II and MIS 5. The cores are located underneath the west Spitsbergen current, thereby reflecting changes in the distribution and strength of Atlantic Water flowing into the northern part of the Nordic Seas. During Termination II, flickering conditions occur as the insolation starts to increase, before a final abrupt response is seen as the insolation reaches interglacial values. The new glacial inception is seen as an almost instantaneous response to the large insolation fall during MIS 5.5, with an extremely rapid transition from full interglacial to glacial conditions. Throughout the rest of MIS 5 we observe somewhat less expressed but still clear responses to the subsequent insolation changes. The sites are under main influence of the Svalbard-Barents Sea Ice Sheet, but the Scandinavian Ice Sheet does to some extent also affect the observed variability. Relatively large-scale ice dynamical changes of short duration occur repeatedly. These are particularly well expressed in ice rafted debris records, indicating frequent instability of the surrounding ice sheets, superimposed on the insolation induced variability. This high frequency variability indicates that feedback mechanisms with a shorter response time than the orbital forcing is of major importance at driving high latitude paleoclimate variability.