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Around 8150 BP, the Storegga tsunami struck North-west Europe. The size of this wave has led many to assume that it had a devastating impact upon contemporaneous Mesolithic communities, including the final inundation of Doggerland, the now submerged Mesolithic North Sea landscape. Here, the authors present the first evidence of the tsunami from the southern North Sea, and suggest that traditional notions of a catastrophically destructive event may need rethinking. In providing a more nuanced interpretation by incorporating the role of local topographic variation within the study of the Storegga event, we are better placed to understand the impact of such dramatic occurrences and their larger significance in settlement studies.

Holocene relative shore level (RSL) changes and Stone Age palaeogeography of Hiiumaa Island are reconstructed using airborne LiDARelevation data, sedimentological and archaeological proxies as well ...

This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (ERC funded project No. 670518 LOST FRONTIERS, https://europa.eu/european-union/index_en, https://lostfrontiers.teamapp.com/). The project gratefully acknowledges the support of the Estonian Research Council (https://www.etag.ee/en/estonian-research-council/, Grant number: PUTJD829). PGS (https://www.pgs.com/) is acknowledged through provision of data used in this paper under license CA-BRAD-001-2017. Doggerland was a landmass occupying an area currently covered by the North Sea until marine inundation took place during the mid-Holocene, ultimately separating the British landmass from the rest of Europe. The Storegga Event, which triggered a tsunami reflected in sediment deposits in the northern North Sea, northeast coastlines of the British Isles and across the North Atlantic, was a major event during this transgressive phase. The spatial extent of the Storegga tsunami however remains unconfirmed as, to date, no direct evidence for the event has been recovered from the southern North Sea. We present evidence of a tsunami deposit in the southern North Sea at the head of a palaeo-river system that has been identified using seismic survey. The evidence, based on lithostratigraphy, geochemical signatures, macro and microfossils and sedimentary ancient DNA (sedaDNA), supported by optical stimulated luminescence (OSL) and radiocarbon dating, suggests that these deposits were a result of the tsunami. Seismic identification of this stratum and analysis of adjacent cores showed diminished traces of the tsunami which was largely removed by subsequent erosional processes. Our results confirm previous modelling of the impact of the tsunami within this area of the southern North Sea, and also indicate that these effects were temporary, localized, and mitigated by the dense woodland and topography of the area. We conclude that clear physical remnants of the wave in these areas are likely to be restricted to now buried, palaeo-inland basins and incised river valley systems. Publisher PDF

During the late glacial and early Holocene, vast areas of dry land stretched from the British Isles to continental Europe over what is now the southern part of the North Sea. Whilst it is known that this landscape was inhabited, little is known about the cultures that lived there and the surrounding environment. This study focuses on the Brown Bank area, between the UK and Dutch coasts, with its significant 25 km long and 10-15 m high ridge on the seabed which has provided many Mesolithic ex-situ finds. However, all of these finds have been recovered serendipitously due to commercial fishing and dredging, and thus the landscape and sedimentary context of these archaeological finds is unclear.The goal of this study is to map the terrestrial features in the Brown Bank area and reconstruct the palaeolandscape and its inundation to determine the potential locations from which this archaeological material derives, and potentially locate Mesolithic settlement sites. The project uses high-resolution parametric echosounder surveys in a dense survey network to record the area and facilitate later targeted dredging and vibro-core sampling.The seismic surveys revealed a pre-marine inundation landscape with fluvial channels eroded into post glacial sediments. A peat layer was located on the top of the banks of the channels where it continues laterally hundreds of metres. Radiocarbon dating of the top part of the peat layer, just below the transgressive deposits gave ages around 10.2-9.9 cal ka BP. Palaeogeographic reconstructions based on the mapped terrestrial features and the available relative sea level change data suggest that the final inundation of the area happened c. 1000 years later. Where dredging was carried out in areas of interest, primarily where the early Holocene surface outcropped onto the seabed, a large number of blocks of peat with pieces of wood and other macrofossils were recovered, suggesting a good potential for preservation of possible archaeological material and possible locations of origin for the serendipitous finds made by fishermen.We conclude that this study provides new insights into the palaeogeography and the timing of the inundation of the Brown Bank area and gives the landscape context to the potential Mesolithic habitation of this part of the southern North Sea.

Doggerland was a land mass occupying an area currently covered by the North Sea until marine inundation took place during the mid-Holocene, ultimately separating the British land mass from the rest of Europe. The Storegga Slide, which triggered a tsunami reflected in sediment deposits in the Northern North Sea, North East coastlines of the British Isles and across the North Atlantic, was a major event during this transgressive phase. The spatial extent of the Storegga tsunami however remains unconfirmed because to date no direct evidence for the event has been recovered from the southern North Sea. We present evidence that Storegga associated deposits occur in the southern North Sea. Palaeo-river systems have been identified using seismic survey in the southwestern North Sea and sedimentary cores extracted to track the Mid Holocene inundation. At the head of one palaeo-river system near the Outer Dowsing Deep, theSouthern River, we observed an abrupt and catastrophic inundation stratum. Based on lithostratigraphic, macro and microfossils and sedimentary ancient DNA (sedaDNA) evidence, supported by optical stimulation luminescence (OSL) and radiocarbon dating, we conclude these deposits were a result of the Storegga event. Seismic identification of this stratum to adjacent cores indicated diminished traces of the tsunami, largely removed by subsequent erosional processes. Our results demonstrate the catastrophic impact of Storegga within this area of the Southern North Sea, but indicate that these effects were temporary and likely localized and mitigated by the dense woodland and topography of the area. We conclude clear physical remnants of the wave are likely to be restricted to inland basins and incised river valley systems.

Report, according to the EU Floods Directive (2007/60/EC) with insurance purposes was completed in Estonia, 2016. The output of this work fulfilled the Directive targets to produce the flood maps of inland water bodies, with return periods of 2, 5, 10, 25, 50, 100, 200, 500 and 1000 years. The flood maps were created in ArcMap10.2.2 and ArcHydro environments, based on data of absolute maximum water levels (WLs) of Estonian state hydrological network. Created 834 flood maps based on data of 152 gauging stations: flood maps of 37 fluvial water systems and 8 standing water bodies. The flood heights with corresponding return periods were obtained from probability analysis of WLs data. Obtained results illustrate that the higher risk for the floods is expected at intersections of branching streams in Low-Estonia and upland margins of High Estonia. Before completion of the report, the existing flood maps covered only a small fraction of Estonia, i.e., territory of 17 cities only. Developed by us the flood map creation tool, is simple, allows modelling and visualising both the flood heights and corresponding overflows of watercourses over the whole country. However, the outcome depends on the availability of hydrological data and the quality of digital elevation models.

Tonisson, H.; Suursaar, U.; Kont, A.; Muru, M.; Rivis, R.; Rosentau, A.; Tamura, T., and Vilumaa, K., 2018. Rhythmic patterns of coastal formations as signs of past climate fluctuations on uplifting coasts of Estonia, the Baltic Sea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 611–615. Coconut Creek (Florida), ISSN 0749-0208. On uplifting and tideless Baltic Sea Coasts in Estonia, a number of elevated mid to late Holocene beach ridge systems with rhythmic patterns are identified. Such uplifted coastal formations serve as archives of past variations in sea level and climate, as well as extreme events. Luminescence dating and interpretation of airborne LiDAR elevation data were used to identify the main formation mechanisms of such beach ridge systems. More extensive (up to 100–150 ridges) and clearer ridge patterns were found on faster emerging (up...

Relative sea level (RSL) changes and the palaeogeography of a Neolithic hunter-fisher-gatherer settlement site on the former shore of the Gulf of Finland in the city centre of Tallinn were reconstructed by implementing GIS in landscape modelling based on archaeological, sedimentary and shore displacement data. AMS radiocarbon dating of mammal bones from the cultural layer suggests the existence of the hunter-fisher-gatherer settlement around 5.1–4.8 cal. ka BP on a seaward inclining sandy beach of Tallinn palaeo-bay c. 100 m from the Litorina Sea shoreline and at about 2.4 m above the coeval sea level. The shoreline passed the study site at about 5.8 cal. ka BP and retreated towards northeast with an average speed of 13 m per century, while the RSL lowered by c. 2.5 mm annually. Combining radiocarbon dates of terrestrial and marine mammal bones from the Neolithic cultural layer, a marine reservoir effect of 35014C years for the brackish-water Baltic Sea was calculated. By using high-resolution archaeological data in combination with RSL and other geological proxies, we demonstrate new possibilities to reconstruct the palaeoenvironment of deeply buried coastal settlement sites and to predict a possible continuation of the cultural layer in heavily built-up areas.

Vilumaa, K.; Tonisson, H.; Sugita, S.; Buynevich, I.V.; Kont, A.; Muru, M.; Preusser, F.; Bjursater, S.; Vaasma, T.; Vandel, E.; Molodkov, A., and Jarvelill, J.I., 2016. Past extreme events recorded in the internal architecture of coastal formations in the Baltic Sea region. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 775–779. Coconut Creek (Florida), ISSN 0749-0208. The postglacial uplift and transgressive-regressive phases of the Baltic Sea have affected the formation and displacement of sandy accumulation forms in the region. The dune-ridge complexes preserve a geological record of past sea-level fluctuations, coastal evolution, and extreme events, and offer insights into major driving mechanisms. This study aims to improve methodologies for identifying different storm signatures in coastal deposits using examples from Estonia and ...

Tonisson, H.; Suursaar, U.; Alari, V.; Muru, M.; Rivis, R.; Kont, A.; and Viitak, M., 2016. Measurement and model simulations of hydrodynamic parameters, observations of coastal changes and experiments with indicator sediments to analyse the impact of storm St. Jude in October, 2013. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 1257 - 1261. Coconut Creek (Florida), ISSN 0749-0208. The aim of the study is to analyse the meteorological parameters, hydrodynamic conditions and coastal changes caused by a severe European storm referred to as St. Jude (Christian). It crossed the Baltic Sea on 27–29 October 2013. At Cape Kelba in the west Estonian archipelago, wave parameters were measured by RDCP and simulated by two wave models. Shoreline and topographic changes were recorded before and after the storm by RTK-GPS device. Simultaneous experi...

Different post-IR Infrared Stimulated Luminescence (IRSL) approaches are applied to sediments from a Holocene coastal foredune sequence on Ruhnu Island in the eastern Baltic Sea. The comparison of D e-values and ages determined by the different approaches is complimented by fading and bleaching experiments. The fading experiments imply strong fading of IRSL (50°C) signals and no fading of any of the post-IR IRSL signals, but this is not confirmed by the determined D e-values. In fact, post-IR IRSL (150°C) D e-values agree within errors with those calculated for IRSL (50°C). From the bleaching experiments it is inferred that the higher values observed for post-IR IRSL at more elevated stimulation temperatures (225°C/290°C) are likely related to either thermal transfer and/or slow-to-bleach components within the signal. For the dating of the Holocene foredune sequence of Ruhnu Island, the post-IR IRSL (150°C) approach is preferred and these agree with the limited independent age control available from radiocarbon dating. Accordingly, the sequence formed between ca. 7.0 ka and 2.5 ka ago.

Morphogenesis and inner structure of the Holocene foredune plain in the Narva -Joesuu area, eastern Gulf of Finland were studied using the optically stimulated luminescence dating, ground penetrating radar study and interpretation of airborne LIDAR elevation data . The results show that the Narva-Joesuu foredune plain consists of c. 100 parallel coastal foredune ridges built of well - sorted fine sand underlain by gently (~7o) sea ward-dipping sandy beach deposits. The distal part of the plain which consists of at least 15 ridges, was formed during the regressive phase of the Ancylus Lake/early Litorina Sea , serving as a barrier for the lagoon behind it. A larger portion of ridges, with an average progradation rate 0.26 m a –1 , was formed in the conditions of falling relative sea level during the Litorina regression and has been separated from the older foredune succession by a hiatus related to the Litorina transgression at 8.5-7.3 cal. ka BP. In the highest central part of the plain the foredune growth was interrupted by foredune instability and a re-blowing episode dated to 5.4±0.9 ka BP which may correlate with a larger regional cooling at 5.8-5.1 cal. ka BP in the North Atlantic and central Europe . During the last 3000 years, the foredune progradation rate decreased to 0.17 m a –1 , most probably because of decelerated land-uplift and increased human impact due to coastal protection.

Based on geological and archaeological proxies from NW Russia and NE Estonia and on GIS-based modelling, shore displacement during the Stone Age in the Narva-Luga Klint Bay area in the eastern Gulf of Finland was reconstructed. The reconstructed shore displacement curve displays three regressive phases in the Baltic Sea history, interrupted by the rapid Ancylus Lake and Litorina Sea transgressions c. 10.9–10.2 cal. ka BP and c. 8.5–7.3 cal. ka BP, respectively. During the Ancylus transgression the lake level rose 9 m at an average rate of about 13 mm per year, while during the Litorina transgression the sea level rose 8 m at an average rate of about 7 mm per year. The results show that the highest shoreline of Ancylus Lake at an altitude of 8–17 m a.s.l. was formed c. 10.2 cal. ka BP and that of the Litorina Sea at an altitude of 6–14 m a.s.l., c. 7.3 cal. ka BP. The oldest traces of human activity dated to 8.5–7.9 cal. ka BP are associated with the palaeo-Narva River in the period of low water level in the Baltic basin at the beginning of the Litorina Sea transgression. The coastal settlement associated with the Litorina Sea lagoon, presently represented by 33 Stone Age sites, developed in the area c. 7.1 cal. ka BP and existed there for more than 2000 years. Transformation from the coastal settlement back to the river settlement indicates a change from a fishing-and-hunting economy to farming and animal husbandry c. 4.4 cal. ka BP, coinciding with the time of the overgrowing of the lagoon in the Narva-Luga Klint Bay area.