Description: The Plio-Pleistocene intensification of Northern Hemisphere continental ice-sheet development is known to have profoundly affected the global climate system. Evidence for early continental glaciation is preserved in sediments throughout the North Atlantic Ocean, where ice-rafted detritus (IRD) layers attest to the calving of sediment-loaded icebergs from circum-Atlantic ice sheets. So far, Early-Pleistocene IRD deposition has been attributed to the presence of high-latitudinal ice sheets, whereas the existence and extent of ice accumulation in more temperate, mid-latitudinal regions remains enigmatic. Here we present results from the multiproxy provenance analysis of a unique, Pleistocene-Holocene IRD sequence from the Irish NE Atlantic continental margin. There, the Challenger coral carbonate mound (IODP Expedition 307 site U1317) preserved an Early-Pleistocene record of 16 distinctive IRD events, deposited between ca 2.6 and 1.7 Ma. Strong and complex IRD signals are also identified during the mid-Pleistocene climate transition (ca 1.2 to 0.65 Ma) and throughout the Middle-Late Pleistocene interval. Radiogenic isotope source-fingerprinting, in combination with coarse lithic component analysis, indicates a dominant sediment source in the nearby British-Irish Isles, even for the oldest, Early-Pleistocene IRD deposits. Hence, our findings demonstrate, for the first time, repeated and substantial (i.e. marine-terminating) ice accumulation on the British-Irish Isles since the beginning of the Pleistocene. Contemporaneous expansion of both high- and mid-latitudinal ice sheets in the North Atlantic region is therefore implied at the onset of the Pleistocene. Moreover, it suggests the recurrent establishment of (climatically) favourable conditions for ice sheet inception, growth and instability in mid-latitudinal regions, even in the earliest stages of Northern Hemisphere glacial expansion and in an obliquity-driven climate system.

Description: As an update to the Northeast Greenland - Digital Bathymetric Compilation (https://doi.pangaea.de/10.1594/PANGAEA.849313), the updated digital bathymetric model (DBM) for the Northeast Greenland (NEG) continental shelf (74°N - 81°N) contains new original bathymetry data for the Northeast Greenland continental shelf, specifically in front of the 79 North Glacier, recorded during R/V Polarstern expedition PS100. This work was supported in part through the Deutsche Forschungsgemeinschaft (DFG) within the Special Priority Program (SPP) 1889 "Regional Sea Level Change and Society" (grant OGreen79), the German Federal Ministry for Education and Research (BMBF) within the GROCE project (Grant 03F0778A), and the NERC project "Greenland in a warmer climate: What controls the advance & retreat of the NE Greenland Ice Stream" (Grant NE/N011228/1).