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What can lithics tell us about hominin technology's 'primordial soup'? An origin of stone knapping via the emulation of Mother Nature
Get PDFThe use of stone hammers to produce sharp stone flakes—knapping—is thought to represent a significant stage in hominin technological evolution because it facilitated the exploitation of novel resources, including meat obtained from medium-to-large-sized vertebrates. The invention of knapping may have occurred via an additive (i.e., cumulative) process that combined several innovative stages. Here, we propose that one of these stages was the hominin use of ‘naturaliths,’ which we define as naturally produced sharp stone fragments that could be used as cutting tools. Based on a review of the literature and our own research, we first suggest that the ‘typical’ view, namely that sharp-edged stones are seldom produced by nonprimate processes, is likely incorrect. Instead, naturaliths can be, and are being, endlessly produced in a wide range of settings and thus may occur on the landscape in far greater numbers than archaeologists currently understand or acknowledge. We then explore the potential role this ‘naturalith prevalence’ may have played in the origin of hominin stone knapping. Our hypothesis suggests that the origin of knapping was not a ‘Eureka!’ moment whereby hominins first made a sharp flake by intention or by accident and then sought something to cut, but instead was an emulative process by hominins aiming to reproduce the sharp tools furnished by mother nature and already in demand. We conclude with a discussion of several corollaries our proposal prompts, and several avenues of future research that can support or question our proposal
A polar oceans shipping information system
No full textGlobally, ships above a certain tonnage, as well as an increasing number of smaller vessels, rely on
the AIS (Automatic Identification System) to safely navigate around other vessels, which are typically
the only dynamically moving surface obstacles in most oceans. In the polar seas however, there are
additional challenges due to the dynamic nature of icebergs and sea ice. While satellite technology
has improved spatiotemporal coverage and sophistication, local observation remains invaluable for
navigating ice infested waters. An analogous system to AIS, tailored for the polar oceans, could
enhance safety by providing additional knowledge of the ice a ship is sailing through. This system
could function as a distributed communication network, which integrates data on key environmental
parameters collected from all vessels operating in polar regions which then can be used with remote
sensing products to improve situational awareness for all maritime traffic. We propose that an
international initiative to develop such a system could be pursued through a collaborative research
program utilizing national polar research vessels
Tree nursery environments and their effect on early trait variation
Get PDFDespite the major role of nurseries in raising young plants and trees prior to transplantation, not enough is known about how the nursery climate impacts the growth and development of plants from germination through to maturity. It is important for forestry practitioners to understand the effect that different nursery environments may have on early stage growth as these may exceed differences due to genetic variation and can confound the use of early stage traits for selection. Here, a replicated progeny-provenance experiment of the economically and ecologically important species Scots pine (Pinus sylvestris L.) was established in three environmentally distinct nurseries in Scotland and traits including survival, growth, form, and phenology were measured. Temperature variation and photoperiod were the only uncontrolled environmental variables during this period, and their effect on measured traits was found to be significant among nurseries from the first growing season onwards. Trait interactions were not consistent between nurseries, indicating that the effectiveness of using proxy traits to select for desirable characteristics may depend on the environment in which the trees are grown. This study is the first in a series that will examine trait variation in Scots pine from seedlings to mature trees and highlights the importance of carefully considering and accounting for the nursery environment when growing trees for subsequent transplantation
Soil species sensitivity distributions for terrestrial risk assessment of silver nanomaterials: the influence of nanomaterial characteristics and soil type
Get PDFSilver nanomaterials (AgNMs) are released into the soil through various anthropogenic activities, including as biocides and in biosolid amendments. There is an abundance of toxicity data available for AgNMs and soil organisms, yet the assessment of their ecological risk and the influence of NM characteristics and exposure conditions on AgNM hazard in soils are not well elucidated. In this study, available soil ecotoxicology data for AgNMs and other Ag forms were collated from literature into a database. Using this database, species sensitivity distributions (SSDs) for soil biota were constructed. From these SSDs we calculated hazard concentrations for 50% of species (HC 50 ) that would allow us to robustly compare effects on soil organisms soil or liquid media and to assess relationships to NM properties (coating) and major soil properties. For all AgNMs, the calculated HC 50 value was 3.09 (1.74–5.21) mg kg −1 for studies conducted with soil dwelling species in soils and 0.70 (0.32–1.64) mg L −1 for liquid exposures. In comparison, the HC 50 value for Ag salt (silver nitrate, AgNO 3 ) was 2.74 (1.22–5.23) mg kg −1 for soil and 0.01 (0.01–0.03) mg L −1 for liquid-based exposures. At a detailed level, the Ag salt was more toxic than the NMs across most soil species and endpoints. Further analyses indicated that both NM surface coating and soil type influence AgNM toxicity. In soil exposures SSDs indicated similar effects across differently coated NM forms, however, in liquid-based assays both uncoated and PVP-coated AgNMs were more toxic to soil tested organisms than citrate-coated AgNMs. Soil cation exchange capacity (CEC) and organic carbon (OC) also influenced AgNM toxicity, with AgNMs being more toxic in soils with higher CEC and lower OC. Our study provides a data resource of toxicity data for soil species and the first hazard thresholds for risk assessment of AgNMs in soils and provides new insights into the factors driving AgNM hazard for soils species
Submerged bedrock shore platforms, Orkney Islands, UK: A new record of significant, though chronologically uncertain sea-level change and coastal erosion
Get PDFReconstructions of sea level change in NW Europe are primarily based on records of relative sea level (RSL) recovered from terrestrial environments, above modern sea level. This deficit in marine-based records results from the highly limited number of sea level indicators observed in modern submarine settings, as well as the often-limited absolute chronology information available. This sampling bias introduces significant uncertainty in former RSL predictions, negatively impacting efforts to accurately model ice-sheet histories and isostatic response. Here we present new seabed mapping data (i.e. high-resolution multibeam bathymetry) from northern Scotland to address this data gap. Encircling the Orkney Islands we identify an exceptional sequence of submerged terraces ranging from -5 to -95 m below modern sea level, carved in bedrock. We interpret these bedrock terraces as relict shore platforms, based on their spatial distribution and a range of geomorphological characteristics. Shore platform development was linked to contemporaneous landward coastline erosion and cliff formation, and each landform pair (i.e. terrace = shore platform and accompanying seacliff / escarpment) likely represents a single sea-level stillstand event of considerable duration (possibly millennia). These wide and well-preserved shore platforms attest to formation during multiple, separate periods of RSL stillstand, and we estimate that 5–7 RSL stillstands are recorded offshore Orkney. We discuss their potential age – spanning more than the last glacial cycle (i.e. Middle - Late Pleistocene) – and explore the wider implications for Quaternary coastal erosion and sea-level change in the region. This study shows how marine geological data and geomorphological analysis can be used to identify palaeo-sea-level indicators within a glacio-isostatically complex region. Despite a current lack of absolute chronological constraint, we believe these observations may provide crucial information towards understanding sea level change within the NW European region
Modeling the Internal Redistribution of Earth's Proton Radiation Belt by Interplanetary Shocks
Get PDFA large proton belt enhancement occurred on 24 March 1991 following an interplanetary shockthat impacted the dayside magnetopause at ∼03:40 UT. Its formation was measured by the proton telescopeaboard CRRES and attributed to the injection and inward transport of solar energetic particles (SEPs) by anazimuthally propagating electric field pulse induced by the shock's compression of the magnetosphere. This ledto an increase in the flux of high energy (>25 MeV) protons by several orders of magnitude at L ≈ 2.5 which hasbeen well‐studied. However, a flux enhancement by up to one order of magnitude was also seen in 1–20 MeVprotons at L ≈ 2. Protons in this energy range pose a hazard to orbiting spacecraft as a major contributor to solarcell nonionizing dose. The 1–20 MeV enhancement cannot be explained by the inward transport of a solarproton source, because a newly injected source population at the required energy would have a drift velocity toolow to interact with the pulse. Instead, we hypothesize that the 1–20 MeV enhancement was caused by theredistribution of radiation belt protons to different drift shells by the pulse. To test this hypothesis, we apply anovel method to predict the change in phase space density during a shock event which utilizes reverse‐timeparticle tracing simulations. Our results show that the 1–20 MeV enhancement can be accounted for by internalredistribution as hypothesized. We thus identify a new mechanism for proton belt enhancements that does notdepend on a SEP source and present a way to model it
The foraging distribution and habitat use of chick-rearing snow petrels from two colonies in Dronning Maud Land, Antarctica
Get PDFThe polar sea-ice zones are highly productive and seasonal habitats that support large populations of vertebrate predators. In the Antarctic, snow petrels ( Pagodroma nivea ) are regarded as highly ice-dependant, yet knowledge of their habitat use and foraging distribution during the breeding period comes largely from ship-based observations. Snow petrels show sexual size dimorphism, and previous studies have demonstrated a degree of sexual segregation in habitat use in East Antarctica during the incubation period. Here, we characterise the movements, behaviour and habitat use of foraging snow petrels using bird movement and remotely sensed environmental data. We tracked snow petrels from two colonies in Dronning Maud Land, East Antarctica during early chick rearing in January to February 2022, a period of unusually rapid sea-ice retreat in the region. During the chick-rearing period, mean foraging range was c. 395 km and did not differ between the sexes. However, we found some evidence of differing habitat use between the sexes: males foraged more in areas of higher sea-ice concentration and over the continental shelf, while females utilized deeper waters and lower sea-ice concentrations. Sexes also diverged in their behavioural responses to both sea ice and depths, with males more likely to switch to foraging in areas of higher sea-ice concentrations than females and females more likely to switch to foraging in deeper waters than males. Although both sexes were more likely to forage at higher sea-ice concentrations, they also used areas with little or no sea ice. This contrasts with previous studies and may have been due to the unusual paucity of sea-ice cover during our tracking period
Hydrological summary for the United Kingdom: May 2025
Get PDFThe monthly summary of hydrological conditions in the United Kingdom is compiled as part of the National Hydrological Monitoring Programme (a joint UKCEH and BGS enterprise). The report features contemporary data for rainfall, river flow, reservoir and groundwater levels in the form of maps and graphs. A commentary is provided on the status of the nation’s water resources and any notable hydrological events during the month. The National River Flow and National Groundwater Level Archives help provide an historical context for these contemporary assessments. Financial support for the production of the Hydrological Summaries is provided by Defra, the Environment Agency, the Scottish Environment Protection Agency, the Rivers Agency in Northern Ireland and the Office of Water Services
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