Last Interglacial transgression rates and high stand duration in the near-field Eemian North Sea

The sea-level history of the Eemian transgression and high stand in the Southern North Sea (The Netherlands), first described by Zagwijn (1983), features in many Last Interglacial sea-level and GIA studies. The reconstruction is based on sedimentary contacts in coastal deposits (transgressed tidal-mud buried peat beds, regressed peat-covered tidal flat tops). The location of the area and the rates of transgression that are experienced indicates a relation with deglaciation history of the nearby Scandinavian Ice Sheet, notably its southwestern sector. The relative dating of the sequence of Eemian index-points comes from pollen palynology and is well-established. This sea-level history spans some 1000-2000 years of last rapid transgression (relative sea level rise of some 30 meters), some 6000-5000 years of high stand (sea level stays within a few meters) and then ends with a sea-level fall, in tandem with climatic deterioration. These durations follow from the correlation of the pollen zones to varved sequences in the NW Germany (classic sites Bispingen and Quakenbrück, newer sites in the Eifel: ELSA, Sirocko et al. 2005). The highstand duration in the Scandinavian near field is about half as short as the far field + intermediate field high-stand as established with U/Th dating of fossil reefs in the tropical seas of all oceans (e.g. Medina-Elizalde 2013). The absolute timing assigned to the Eemian transgression and high-stand, varies greatly between studies. Some authors correlate the shape of regional sea-level curve to the global benthic δ18O signal and have recording of transgression start as early as 130-128 ka and sea-level fall begin at 123-121 ka (e.g. Kopp et al. 2009). Other authors correlate onset of temperate conditions as testified by pollen, equating sites off Iberia (going back to Sánchez-Goñi et al. 1999) and in the Mediterranean to those at the latitude of the North Sea, arriving at a recording onset of c.124 ka and high stand ending c.117 ka. Further authors would have it start and stop a few 1000 years later than that, implying that temperate conditions in the North Sea set on later than in Southern Europe, lagging to a stronger degree than into the Holocene. New data and analysis (Sier et al. in review) from the central Netherlands will be presented and supports a relatively late onset (c.121 ka). Lines of reasoning include palaeomagnetic cor¬relations (onset Blake event), the NEEM record and EDML1 time scale, the ELSA record. To further evaluate these findings, checking if the Eemian near-field postglacial GIA could lag the δ18O signal too, we connect to Scandinavia (e.g. Bauch & Erlenkeuser 2008). The earlier the Eemian near-field transgression starts, the earlier into the Last Interglacial had this ice sheet lost most of its mass (or GIA response between the two glaciations would be very different, which is unlikely). The later the transgression starts, the longer some ice-mass survived. This has implications for roles attributed to other ice-sheets. A comparison of the (ocean marine) deglaciation history of Scandinavia for Termination II and Termination I, and the rates of postglacial sea-level rise recorded in the Eemian and Holocene will be presented