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The late Holocene tsunami in the Shetland Islands (UK) identified in Loch Flugarth, north Mainland
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Tsunami deposits around the North Sea basin are needed to assess the long-term hazard of tsunamis. Here, we present sedimentary evidence of the youngest tsunami on the Shetland Islands from Loch Flugarth, a coastal lake on northern Mainland. Three gravity cores show organic-rich background sedimentation with many sub-centimetre-scale sand layers, reflecting recurring storm overwash and a sediment source limited to the active beach and uppermost subtidal zone. A basal 13-cm-thick sand layer, dated to 426–787 cal. a CE based on 14C, 137Cs and Bayesian age–depth modelling, was found in all cores. High-resolution grain-size analysis identified four normally graded or massive sublayers with inversely graded traction carpets at the base of two sublayers. A thin organic-rich ‘mud’ drape and a ‘mud’ cap cover the two uppermost sublayers, which also contain small rip-up clasts. Grain-size distributions show a difference between the basal sand layer and the coarser and better sorted storm layers above. Multivariate statistical analysis of X-ray fluorescence core scanning data also distinguishes both sand units: Zr, Fe and Ti dominate the thick basal sand, while the thin storm layers are high in K and Si. Enriched Zr and Ti in the basal sand layer, in combination with increased magnetic susceptibility, may be related to higher heavy mineral content reflecting an additional marine sediment source below the storm-wave base that is activated by a tsunami. Based on reinterpretation of chronological data from two different published sites and the chronostratigraphy of the present study, the tsunami seems to date to c. 1400 cal. a BP. Although the source of the tsunami remains unclear, the lack of evidence for this event outside of the Shetland Islands suggests that it had a local source and was smaller than the older Storegga tsunami (8.15 cal. ka BP), which affected most of the North Sea basin.
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RBINS Staff Publications 2024
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The Late Neolithic Michelsberg culture – just ramparts and ditches? A supraregional comparison of agricultural and environmental data
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The archaeobotanical state of research from sites of the Michelsberg and the Bischheim culture (5th/4th millenium BC) in France, Belgium, southern Netherlands and Germany has been compiled and discussed in the context of archaeological, climatological and biological data. Compared with Bischheim and the Middle Neolithic the farmers of the Michelsberg culture had a reduced crop spectrum with emphasis on cereal growing. It is still under debate, from where the tetraploid wheat has been introduced. Possibly the growing of oil/fibre plants was abandoned by the Michelsberg farmers. Interestingly the same reduced crop spectrum is found somewhat later in the distribution area of the Funnelbeaker culture as well as in the Neolithic sites of Great Britain and Ireland. Climatic causes are not likely for this phenomenon. Instead, zoologial and botanical results point to an agricultural system with more emphasis on stock farming, which might have been based on a cultural decision.
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RBINS Staff Publications
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The life cycle of the ancient asexual ostracod Darwinula stevensoni (Brady & Robertson, 1870) (Crustacea, Ostracoda) in a temperate pond
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RBINS Staff Publications
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The life history of Mytilocypris henricae (CHAPMAN) (Crustacea, Ostracoda) in Lake Bathurst (N.S.W.)
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RBINS Staff Publications
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The life-cycle of the ancient asexual ostracod Darwinula stevensoni (Brady & Robertson, 1870) (Crustacea, Ostracoda) in a temporated pond
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RBINS Staff Publications
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The link between microbial diversity and nitrogen cycling in marine sediments is modulated by macrofaunal bioturbation
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Objectives : The marine benthic nitrogen cycle is affected by both the presence and activity of macrofauna and the diversity of N-cycling microbes. However, integrated research simultaneously investigating macrofauna, microbes and N-cycling is lacking. We investigated spatio-temporal patterns in microbial community composition and diversity, macrofaunal abundance and their sediment reworking activity, and N-cycling in seven subtidal stations in the Southern North Sea. Spatio-Temporal Patterns of the Microbial Communities : Our results indicated that bacteria (total and beta-AOB) showed more spatio-temporal variation than archaea (total and AOA) as sedimentation of organic matter and the subsequent changes in the environment had a stronger impact on their community composition and diversity indices in our study area. However, spatio-temporal patterns of total bacterial and beta-AOB communities were different and related to the availability of ammonium for the autotrophic beta-AOB. Highest bacterial richness and diversity were observed in June at the timing of the phytoplankton bloom deposition, while richness of beta-AOB as well as AOA peaked in September. Total archaeal community showed no temporal variation in diversity indices. Macrofauna, Microbes and the Benthic N-Cycle : Distance based linear models revealed that, independent from the effect of grain size and the quality and quantity of sediment organic matter, nitrification and N-mineralization were affected by respectively the diversity of metabolically active beta-AOB and AOA, and the total bacteria, near the sediment-water interface. Separate models demonstrated a significant and independent effect of macrofaunal activities on community composition and richness of total bacteria, and diversity indices of metabolically active AOA. Diversity of beta-AOB was significantly affected by macrofaunal abundance. Our results support the link between microbial biodiversity and ecosystem functioning in marine sediments, and provided broad correlative support for the hypothesis that this relationship is modulated by macrofaunal activity. We hypothesized that the latter effect can be explained by their bioturbating and bio-irrigating activities, increasing the spatial complexity of the biogeochemical environment.
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No RBINS Staff publications
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The link between microbial diversity and nitrogen cycling in marine sediments is modulated by macrofaunal bioturbation
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RBINS Staff Publications
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The lithostratigraphy of the Lower Devonian formations of the Eisleck (Northern Luxembourg). Comparison with their Belgian lateral equivalents.
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The Eisleck region forms the northern third of the territory of the Grand-Duchy of Luxembourg and also represents the southeastern part of the Ardennes. The underground is made up of detrital rocks (shales and sandstones) of lower Devonian age folded during the Variscan orogeny. They have undergone strong diagenesis reaching up to weak metamorphism. In order to allow modern geological mapping of this area, a lithostratigraphical framework is proposed. Seven formations are considered and their lithological characteristics, thicknesses and paleogeographical settings are described. References to their paleontological content are also mentioned. Comparisons with their Belgian lateral equivalents are drawn in order to facilitate the cross-border comprehension of geological maps.
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RBINS Staff Publications 2017
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The littoral sea cucumber (Echinodermata: Holothuroidea) fauna of Guam re-assessed
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RBINS Staff Publications
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The lobed-lipped species of Haplochromis (Teleostei, Cichlidae) from Lake Edward, two instead of one
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RBINS Staff Publications 2019
