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This work presents unprecedented, high-resolution palaeomagnetic data from the sedimentary record of Lake Levinson-Lessing, the deepest lake in northern central Siberia. Palaeomagnetic analyses were carried out on 730 discrete samples from the upper 38 m of the 46 m long core Co1401, which was recovered from the central part of the lake. Alternating field demagnetization experiments were carried out to obtain the characteristic remanent demagnetization. The relative palaeointensity is determined using the magnetic susceptibility, the anhysteretic remanent magnetization, and the isothermal remanent magnetization for normalization of the partial natural remanent magnetization. The chronology of Co1401 derives from correlation of the relative palaeointensity of 642 discrete samples with the GLOPIS-75 reference curve, accelerated mass spectrometer radiocarbon ages, and optically stimulated luminescence dating. This study focuses on the part > 10 ka but also presents preliminary results for the younger part of the core. The record includes the geomagnetic excursions Laschamps and Mono Lake and resolves sufficient geomagnetic features to establish a chronology that continuously covers the last ∼ 62 kyr. The results reveal continuous sedimentation at high rates between 45 and 95 cm kyr−1. The low variability of the magnetic record compared to datasets of reference records with lower sedimentation rates may be due to a smoothing effect associated with the lock-in depths. Because Co1401 was cored without core segment overlap the horizontal component of the characteristic remanent magnetization can only be used with caution. Nevertheless, the magnetic record of Co1401 is exceptional as it is the only high-resolution record of relative palaeointensity and palaeosecular variations from the Arctic tangent cylinder going back to ∼ 62 ka.

The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012–2014 HSPDP coring campaign.

Lake Ohrid (Macedonia, Albania) is thought to be more than 1.2 million years old and host more than 300 endemic species. As a target of the International Continental scientific Drilling Program (ICDP), a successful deep drilling campaign was carried out within the scope of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in 2013. Here, we present lithological, sedimentological, and (bio-)geochemical data from the upper 247.8 m composite depth of the overall 569 m long DEEP site sediment succession from the central part of the lake. According to an age model, which is based on 11 tephra layers (first-order tie points) and on tuning of bio-geochemical proxy data to orbital parameters (second-order tie points), the analyzed sediment sequence covers the last 637 kyr. The DEEP site sediment succession consists of hemipelagic sediments, which are interspersed by several tephra layers and infrequent, thin (< 5 cm) mass wasting deposits. The hemipelagic sediments can be classified into three different lithotypes. Lithotype 1 and 2 deposits comprise calcareous and slightly calcareous silty clay and are predominantly attributed to interglacial periods with high primary productivity in the lake during summer and reduced mixing during winter. The data suggest that high ion and nutrient concentrations in the lake water promoted calcite precipitation and diatom growth in the epilimnion during MIS15, 13, and 5. Following a strong primary productivity, highest interglacial temperatures can be reported for marine isotope stages (MIS) 11 and 5, whereas MIS15, 13, 9, and 7 were comparably cooler. Lithotype 3 deposits consist of clastic, silty clayey material and predominantly represent glacial periods with low primary productivity during summer and longer and intensified mixing during winter. The data imply that the most severe glacial conditions at Lake Ohrid persisted during MIS16, 12, 10, and 6, whereas somewhat warmer temperatures can be inferred for MIS14, 8, 4, and 2. Interglacial-like conditions occurred during parts of MIS14 and 8.

The marine habitat beneath Antarctica's ice shelves spans ∼1.6 million km 2 , and life in this vast and extreme environment is among Earth's least accessible, least disturbed and least known, yet likely to be impacted by climate-forced warming and environmental change. Although competition among biota is a fundamental structuring force of ecological communities, hence ecosystem functions and services, nothing was known of competition for resources under ice shelves, until this study. Boreholes drilled through a ∼ 200 m thick ice shelf enabled collections of novel sub-ice-shelf seabed sediment which contained fragments of biogenic substrata rich in encrusting (lithophilic) macrobenthos, principally bryozoans - a globally-ubiquitous phylum sensitive to environmental change. Analysis of sub-glacial biogenic substrata, by stereo microscopy, provided first evidence of spatial contest competition, enabling generation of a new range of competition measures for the sub-ice-shelf benthic space. Measures were compared with those of global open-water datasets traversing polar, temperate and tropical latitudes (and encompassing both hemispheres). Spatial competition in sub-ice-shelf samples was found to be higher in intensity and severity than all other global means. The likelihood of sub-ice-shelf competition being intraspecific was three times lower than for open-sea polar continental shelf areas, and competition complexity, in terms of the number of different types of competitor pairings, was two-fold higher. As posited for an enduring disturbance minimum, a specific bryozoan clade was especially competitively dominant in sub-ice-shelf samples compared with both contemporary and fossil assemblage records. Overall, spatial competition under an Antarctic ice shelf, as characterised by bryozoan interactions, was strikingly different from that of open-sea polar continental shelf sites, and more closely resembled tropical and temperate latitudes. This study represents the first analysis of sub-ice-shelf macrobenthic spatial competition and provides a new ecological baseline for exploring, monitoring and comparing ecosystem response to environmental change in a warming world., Competing Interests: Declaration of competing interest The authors declare no competing interest., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Where polar ice sheets meet the coast, they can flow into the sea as floating ice shelves. The seabed underneath is in complete darkness, and may be Earth's least known surface habitat. Few taxa there have been fully identified to named species (see Supplemental information) - remarkable for a habitat spanning nearly 1.6 million km 2 . Glimpses of life there have come from cameras dropped through 10 boreholes, mainly at the three largest Antarctic ice shelves - the Ross (McMurdo), Filchner-Ronne and Amery. Pioneering studies of life under boreholes found distinct morphotypes of perhaps >50 species. Here, we report remarkable growth and persistence over thousands of years of benthic faunal species collected in 2018 from the seabed under the Ekström Ice Shelf (EIS), Weddell Sea., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)