Sea-level change

Ancient slipways are spread throughout the Aegean coastline, constitute an important part of Greek naval history and maritime tradition, and provide valuable evidence of the relative sea level (rsl) change from the period of their construction and use since their function required them to be situated at the water's edge. Geoarchaeological surveys of rsl changes in several coastal sites either revealed unknown slipways or offered some fresh insights into the functional features of sites previously published. The slipways here presented, albeit covering a wide chronological range from the Classical period to Modern times, follow similar construction and functional principles. The contemporary measured depths of the seaward end of the rock-cut sloping floors are interpolated into the curves of the rsl rise for the Aegean and allow us to conclude that slipways are good sea level indicators and suggest their functional height with an uncertainty not exceeding the tidal range.

We present a sequence-stratigraphically based reappraisal of sea-level variations for the Paleogene, Neogene, and early Quaternary Periods (66.0-1.5 Ma) that is bio-chronostratigraphically controlled and then fine-tuned through oxygen-isotopic (δ 18 O) calibrations, with a higher-frequency, mostly isotopically-calibrated curve for the last 1.5 m.y. of the Quaternary Period. Depositional sequences that form the basis of sea-level curves are largely third-order cycles (~0.5-2.5 m.y. in duration) for the Paleogene-Neogene interval and fourth-and fifth-order cycles (~400-100 k.y.) for the Quaternary. The availability of better resolved, astronomically tuned Cenozoic chronostratigraphy and new sequence-stratigraphic studies in the past three decades makes this update timely. In this major revision, the ages of the depositional surfaces (i.e., sequence boundaries and maximum flooding surfaces, which form the basis of the sea-level curves) have been calibrated to marine benthic foraminiferal oxygen-isotopic data, thereby improving their chronologic precision. The amplitudes of sea-level highs and lows have been re-evaluated based on global averaging of stratigraphic estimates, aided by isotopic data, where we also discuss the many inherent issues that reduce the efficacy of both methodologies. The global-mean data suggest that the shorter-term highs and lows are extremely variable during the Cenozoic Era, ranging from ~150 to a few tens of meters of change. Refined ages of the sequence boundaries and the resultant durations of third-order sequences imply their strong linkage to the long period modulations of the obliquity and eccentricity cycles and, thus, to climatic variations.

We examine the Holocene environmental changes in a wet dune slack of the Portuguese coast, Poço do Barbarroxa de Baixo. Lithology, organic matter, biological proxies and high-resolution chronology provide estimations of sediment accumulation rates and changes in environmental conditions in relation to sea-level change and climate variability during the Holocene. Results show that the wet dune slack was formed 7.5 cal. ka BP, contemporaneous with the last stages of the rapid sea-level rise. This depositional environment formed under frequent freshwater flooding and water ponding that allowed the development and post-mortem accumulation of abundant plant remains. The wetland evolved into mostly palustrine conditions over the next 2000 years, until a phase of stabilization in relative sea-level rise, when sedimentation rates slowed down to 0.04 mm yr−1, between 5.3 and 2.5 cal. ka BP. Later, about 0.8 cal. ka BP, high-energy events, likely due to enhanced storminess and more frequent o...

Lake Victoria ecosystem has undergone major ecological changes in the recent decades. Sedimentary diatom analysis and Fe/Mn determined by Energy Dispersive X-ray Fluorescence (EDXRF) have provided phytoplankton (diatom) productivity and the resultant anoxia (Fe/Mn) in Lake Victoria at Napoleon Gulf during the late Holocene (1778 cal yr BP (calibrated years before present) to 2008 AD) with radiocarbon dates determined using Accelerator Mass Spectrometry standard method. The results showed that increased total diatom counts in Napoleon Gulf during the late Holocene correspond with increased Fe/Mn ratio (anoxia) in some of the profiles and not in others and in most cases those that correspond correlate very well with increased eutrophication from nitrate input (Total Nitrogen, TN). Therefore slightly increased anoxia not related to increased diatom productivity was recorded in Lake Victoria at Napoleon Gulf from the period 1778 to 1135 cal yr BP. There was slightly increased diatom productivity at Napoleon Gulf from the period 857 to 758 cal yr BP but it did not increase anoxia in the lake. The period 415 cal yr BP to 2008 AD recorded increased anoxia at Napoleon Gulf related to high diatom productivity especially from 415 to 390 cal yr BP and 191 cal yr BP to 2008 AD.

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Lake Victoria ecosystem has undergone major ecological changes in the recent decades. Sedimentary diatom analysis and Fe/Mn determined by Energy Dispersive X-ray Fluorescence (EDXRF) have provided phytoplankton (diatom) productivity and the resultant anoxia (Fe/Mn) in Lake Victoria at Napoleon Gulf during the late Holocene (1778 cal yr BP (calibrated years before present) to 2008 AD) with radiocarbon dates determined using Accelerator Mass Spectrometry standard method. The results showed that increased total diatom counts in Napoleon Gulf during the late Holocene correspond with increased Fe/Mn ratio (anoxia) in some of the profiles and not in others and in most cases those that correspond correlate very well with increased eutrophication from nitrate input (Total Nitrogen, TN). Therefore slightly increased anoxia not related to increased diatom productivity was recorded in Lake Victoria at Napoleon Gulf from the period 1778 to 1135 cal yr BP. There was slightly increased diatom productivity at Napoleon Gulf from the period 857 to 758 cal yr BP but it did not increase anoxia in the lake. The period 415 cal yr BP to 2008 AD recorded increased anoxia at Napoleon Gulf related to high diatom productivity especially from 415 to 390 cal yr BP and 191 cal yr BP to 2008 AD.

Integrated Ocean Drilling Program (IODP) Expedition 325 cored submerged reefs along the shelf edge of the Great Barrier Reef (GBR) to study sea-level and environmental changes and their impacts on reef communities and reef growth since the Last Glacial Maximum (LGM). Previous work defined five reef sequences (Reef 1

Lithostratigraphic and diatom analysis of core samples from 10 raised lake basins from an inner (Lyngen) and outer (Vanna) coastal area of Troms, northem Norway, was made in order to reconstruct relative sea-level change during the Holocene and Late Weichselian. A variety of facies types and facies sequences, controlled primarily by sea-level change and inftuenced also by climatic factors, is recognized. Main facies types are: (I) Marine (mud and sand), (Il) Transitional (laminated gyttja or gyttja and silt), (Ill) Lacustrine (gyttjajplant detritus), and (IV) Mixed (gyttja, mud and sand/gravel). Laminated transitional facies li, in nearly all cases, is interpreted as having formed under meromictic limnic conditions following basin isolation from the sea, whereas heterolithic mixed facies IV forms usually under littoral inftuence during ingression. Sea-level displacement curves are constructed for Lyngen and Vanna based on radiocarbon-dated isolation and ingression contacts, elevation/inferred-age data for prominent raised shorelines, and other data,. The evidence suggests that the Tapes transgression at Lyngen had a minimum amplitude of 2-3 m and peaked at ca. 7000 BP. Average rates of pre-Tapes (before 8500 BP) and post-Tapes (after 6000 BP) regression are approximately 15 and 3 mm/year respectively at Lyngen, and lO and 1.5 mm/year respectively at Vanna.

A detailed examination of transgressions and regressions that occurred during the Thanetian (58.7-55.8 Ma) may provide an important constraint on the global palaeoenvironment. Seven tectonically "stable" regions (the eastern Russian Platform, Northwestern Europe, Northwestern Africa, Northeastern Africa, the Arabian Platform, the northern Gulf of Mexico, and Southern Australia), represent exceptional records of transgressiveregressive (T-R) cyclicity. Their chronostratigraphic frameworks are sufficiently well constrained to permit accurate correlation. Surprisingly, except for a generally regressive trend occurring in the late Thanetian, no common T-R cycles can be delineated, which indicates an absence of global-scale T-R cyclicity during the Thanetian. Furthermore, we find no clear correspondence between documented T-R patterns and previously reported eustatic changes. We suggest that a warm climate and an absence of major glaciations in the earlymiddle Thanetian, coupled with only slow eustatic change expected from tectonic processes, stabilized Thanetian eustatic sea level. Regional subsidence or uplift, possibly generated by mantle flow in the form of dynamic topography, governed transgressions and regressions locally and resulted in an inconsistency between T-R cycles in different parts of the globe. The late Thanetian regressive episode, which preceded the Paleocene-Eocene Thermal Maximum, may be linked to an advance of glaciation.

Observations of relative sea-level change and local deglaciation in western Scotland provide critical constraints for modelling glacio-isostatic rebound in northern Britain over the last 18 000 years. The longest records come from Skye, Arisaig and Knapdale with a shorter, Holocene, record from Kintail. Biostratigraphic (diatom, pollen, dinoflagellate, foraminifera and thecamoebian), lithological and radiocarbon analyses provide age and elevation parameters for each sea-level index point. All four sites reveal relative sea-level change that is highly non-monotonic in time as the local vertical component of glacio-isostatic rebound and eustasy (or global meltwater influx) dominate at different periods.

Diatoms in surface sediments from a data set of 27 brackish lakes and nine fjords in Jutland, Denmark (range 0.2 – 31 g·L–1 total dissolved solids (TDS)), were analysed using multivariate methods to determine response to measured parameters (depth, total phosphorus (TP), total nitrogen (TN), TN/TP, salinity, water body type). Water body type, salinity, depth and TP together explained 25.3% of the variation in the diatom data and were all independently significant predictors. A diatom–salinity model (r2jack = 0.887, root mean square error of prediction = 0.246 log salinity, g·L–1) was developed from the 36 sample training set and applied to fossil diatom assemblages in three sediment cores from the east Vejlerne wetland, Denmark, a nature reserve created after the damming of an embayment of the polyhaline Limfjord (~26 g·L–1 TDS) in the late 19th century. The diatom–inferred salinity reconstructions reflect the known salinity history of the Limfjord and the freshwater–subsaline Vejle...

Lake isolation studies provide the most reliable method for reconstructing the shore displacement history of the areas affected by postglacial isostatic land uplift. Due to the slow uplift rate and the presence of numerous lakes, the Finnish south coast is one of the key areas for investigating the Litorina transgression and subsequent shore displacement history of the Baltic. To reconstruct the relative sea-level dynamics during the late Holocene, three small lakes from the critical altitudes were analysed concerning their diatom, sulphate-sulphur, and sodium stratigraphies and loss-on-ignition values. Comparisons of the records indicate that the availability of nutrients significantly influenced the diatom-floristic patterns during the lake isolation. In particular, the mass occurrence of Fragilaria spp. seems to be associated with high values of sulphate-sulphur and sodium during and after isolation. On the basis of the new and old data, a shore displacement curve for the 30 m Litorina isobase is compiled. This indicates that since the clear Litorina transgression at 7500-6500 14 C BP, no transgressions have taken place but that the shore displacement in the area has been a stable process. The occurrence of a number of raised shore formations between the altitude of the major Litorina shore and the present sea level in south Finland can be attributed to the erosion of soft soil layers by the high-energy wave action on the exposed shore sections.

Observations of relative sea-level change and local deglaciation in western Scotland provide critical constraints for modelling glacio-isostatic rebound in northern Britain over the last 18 000 years. The longest records come from Skye, Arisaig and Knapdale with a shorter, Holocene, record from Kintail. Biostratigraphic (diatom, pollen, dinoflagellate, foraminifera and thecamoebian), lithological and radiocarbon analyses provide age and elevation parameters for each sea-level index point. All four sites reveal relative sea-level change that is highly non-monotonic in time as the local vertical component of glacio-isostatic rebound and eustasy (or global meltwater influx) dominate at different periods.

We analyzed diatoms, lithology, and stable isotopes in a sediment core from the Ciénaga Grande de Santa Marta lagoon to reveal the history of late Holocene relative sea level rise and the ontogeny of the lagoon on the Caribbean coast of Colombia. At ~5300 cal. yr BP, the area was characterized by shallow, freshwater ponds that were prone to seasonal flooding. From ~4250 to ~2060 cal. yr BP, these ponds became brackish as relative sea level began to rise, and since ~2060 cal. yr BP, marine conditions have prevailed. In addition to tracking relative sea level rise, we also investigated periods of greater and lesser precipitation during times of brackish and marine conditions, respectively, as indicated by diatom-inferred changes in water salinity and shifts in the source of sediment organic matter. Comparisons with other regional paleoenvironmental records suggest that humid climate conditions prevailed in the Caribbean until about 4000 cal. yr BP. After that time, climate became more...

This paper focuses on the palaeogeographic development of the Rhine-Meuse river mouth (the Netherlands) in the early-middle Holocene. During the Holocene transgression, an area of 800 km2 transformed from valley to estuary within 200 years (8.5-8.3 ka BP: sea-level jump; Hijma and Cohen, subm.). Initially, overbank deposition started to increase (fluvial onlap of lowstand system tract) accompanied by widespread peat formation. The transition to the transgressive system tract (transgressive surface) is diachronous, but mainly ...

Geologie en Mijnbouw 77: 247–262, 1999. © 1999 Kluwer Academic Publishers. Printed in the Netherlands. ... Sea level, climate change and coastal evolution in Morar, northwest Scotland ∗ ... Ian Shennan1, Michael Tooley2, Frances Green1, Jim Innes1, Kevin Kennington3, ...

We reconstructed late Holocene fluctuations of Kluane Lake in Yukon Territory from variations in bulk physical properties and carbon and nitrogen elemental and isotopic abundances in nine sediment cores. Fluctuations of Kluane Lake in the past were controlled by changes in climate and glaciers, which affected inflow of Slims and Duke rivers, the two largest sources of water flowing into the lake. Kluane Lake fluctuated within a narrow range, at levels about 25 m below the present datum, from about 5000 to 1300 cal yr BP. Low lake levels during this interval are probably due to southerly drainage of Kluane Lake to the Pacific Ocean, opposite the present northerly drainage to Bering Sea. Slims River, which today is the largest contributor of water to Kluane Lake, only rarely flowed into the lake during the period 5000 to 1300 cal yr BP. The lake rose 7-12 m between 1300 and 900 cal yr BP, reached its present level around AD 1650, and within a few decades had risen an additional 12 m. Shortly thereafter, the lake established a northern outlet and fell to near its present level.

Integrated Ocean Drilling Program (IODP) Expedition 325 cored submerged reefs along the shelf edge of the Great Barrier Reef (GBR) to study sea-level and environmental changes and their impacts on reef communities and reef growth since the Last Glacial Maximum (LGM). Previous work defined five reef sequences (Reef 1-5) that span the last 30,000 years. Here we examined the variation in coralgal assemblages and their paleoenvironmental settings in late glacial to deglacial sequences from 23 holes cored seaward of the modern GBR in water depths from 46 to 131 m along four transects at three localities: Hydrographers Passage (HYD-01C and HYD-02A), Noggin Pass (NOG-01B), and Ribbon Reef (RIB-02A). We identified three coralline algal assemblages and eight coral assemblages indicating a broad range of reef settings from the shallow reef crest (0-5 m) to the deep forereef slope (>20 m). We document in detail for the first time the distribution and composition of reef communities that grew in the GBR during the LGM from 22,000-19,000 years ago. They included coral taxa that are major reef builders today: Isopora, Acropora gr. humilis, Dipsastraea gr. pallida, Porites, and Montipora. Prior to the fall in sea level to the maximum extent of the LGM, late glacial reef communities developed more proximally (landward) to the modern GBR along the shelf edge. Their distribution and composition reflect influences of the older Pleistocene basement depth and possible terrigenous sediment inputs. Post-LGM deglacial reef growth was vigorous in proximal sites and characterized by the accretion of a very shallow high-energy coralgal assemblage composed of medium to robustly branching Acropora, including A. gr. humilis, and thick algal crusts of Porolithon gr. onkodes associated with vermetid gastropods. More distally, reef growth was variably impacted by terrigenous input following deglacial reflooding of antecedent reef terraces. The coralgal succession and sedimentary facies in Noggin Pass indicate that an early drowning trend was linked to increased turbidity that was likely controlled by shelf morphology (narrow shelf, steep slope) and/or proximity to a paleo-river mouth. The deglacial succession in Ribbon Reef lacks typical shallow-water indicators, which may reflect influences of the particularly steep slope of the northern GBR shelf edge on reef zonation. A major sealevel jump at the onset of the Younger Dryas displaced reef habitats further upslope, forming a barrier reef system mainly composed of robustly branching acroporids distinct from the more distal sites. Our results highlight the importance of sedimentation and shelf morphology in addition to relative sea-level changes in controlling variations in reef community over centennial to millennial timescales.

The aim of this paper is to evaluate the compatibility between the Holocene relative sea-level (RSL) curves proposed for the Brazilian littoral and mangrove dynamics along a fluvial valley in the state of southern Bahia. This was done integrating geomorphological, sedimentological, palynological, and stable isotopic data from two cores collected at the mouth of the Jucuruçu River and at a site 23 km inland, near the city of Prado, northeastern Brazil. Core PR07, sampled from a fluvial plain at about 4.5±1 m above the RSL, reveals mangrove pollen (5–20%) and estuarine/terrestrial organic matter (δ13C=~–25‰, C/N=7.3–67) between 4.5 m (~7400 cal yr BP) and 1.75 m depth (~5350 cal yr BP). Core PR11, sampled from a mangrove tidal flat, also revealed mangrove pollen taxa (5-28%) since 660 cal yr BP. Core PR07 indicated absence of mangrove pollen and increase of sedimentary organic matter sourced from terrestrial C3 plants (δ13C=~–27‰, C/N=22–159) during the last 5350 cal yr BP. Probably, ...

Palaeoecological investigations, involving pollen analysis, dendrochronology, and radiocarbon dating of bog-pine, provide the basis for reconstruction of vegetation dynamics, landscape development, and human impact in two contrasting parts of lowland northern Connemara, western Ireland, namely Ballydoo and Derryeighter in the east, and Renvyle/Letterfrack/Cleggan at the Atlantic coast some 40 km to the west. The history of Scots pine (Pinus sylvestris) is traced in detail. Standout features include the dominant role the tree played from the early Holocene onwards and especially at Ballydoo, its ability to grow on peat surfaces (so-called pine flush) over the course of several millennia during the mid-Holocene (centred on c. 5 ka), and its demise in a three-step fashion to become regionally extinct at c. 2.3 ka. The factors influencing these developments, including climate change, are discussed. Another natural phenomenon, namely the spread of blanket bog, is shown to be an on-going ...

We examine the Holocene environmental changes in a wet dune slack of the Portuguese coast, Poço do Barbarroxa de Baixo. Lithology, organic matter, biological proxies and high-resolution chronology provide estimations of sediment accumulation rates and changes in environmental conditions in relation to sea-level change and climate variability during the Holocene. Results show that the wet dune slack was formed 7.5 cal. ka BP, contemporaneous with the last stages of the rapid sea-level rise. This depositional environment formed under frequent freshwater flooding and water ponding that allowed the development and post-mortem accumulation of abundant plant remains. The wetland evolved into mostly palustrine conditions over the next 2000 years, until a phase of stabilization in relative sea-level rise, when sedimentation rates slowed down to 0.04 mm yr −1 , between 5.3 and 2.5 cal. ka BP. Later, about 0.8 cal. ka BP, high-energy events, likely due to enhanced storminess and more frequent onshore winds, caused the collapse of the foredune above the wetlands' seaward margin. The delicate balance between hydrology (controlled by sea-level rise and climate change), sediment supply and storminess modulates the habitat's resilience and ecological stability. This underpins the relevance of integrating past records in coastal wet dune slacks management in a scenario of constant adaptation processes.

Dep. of Earth and Planetary Sc., Nagoya Univ., Geocoastal Research Group, Univ. of Sydney, Dep. de Estrat. y Paleont., Univ. de Granada, Inst. of Geol. and Paleont., Tohoku Univ., Dep. of Ecol. & Evol. Bio., Univ. of California, AORI, Univ. of Tokyo, ANSTO, Inst. for Env. Res., Australia, Res. Sch. of Earth Sc., Austral. Nation. Univ., Lamont-Doherty Earth Observatory, USA, School of GeoSciences, Univ. of Edinburgh

The urbanised peat-rich coastal-deltaic plain of the Netherlands is severely subsiding due to human-induced phreatic groundwater level lowering, as this causes peat layers to compress and oxidise. To determine the potential susceptibility of this area to future subsidence by peat compression and oxidation, the effects of lowering present-day phreatic groundwater levels were quantitatively evaluated using a subsidence model. Input were a 3D geological subsurface voxel-model, modelled phreatic groundwater levels, and functions for peat compression and oxidation. Phreatic groundwater levels were lowered by 0.25 and 0.5m, and the resulting peat compression and oxidation over periods of 15 and 30 years were determined. The model area comprised the major cities Amsterdam and Rotterdam, and their surrounding agricultural lands.The results revealed that for these scenarios agricultural areas may subside between 0.3 and 0.8m; potential subsidence in Amsterdam and Rotterdam is considerably lo...

Micro x-ray fluorescence (µXRF) core scanning is capable of measuring the elemental composition of lake sediment at sub-millimetre resolution, but bioturbation and physical mixing may degrade environmental signals at such fine scales. The aim of this research is to determine the maximum possible resolution at which meaningful environmental signals may be reconstructed from lake sediments using this method. Sediment from a coastal lake in the Outer Hebrides, Scotland, has been analysed using calibrated element measurements to reconstruct storminess since AD 200. We find that a Ca/K ratio in lake-core sediments reflects the presence of fine calcium carbonate shell fragments, a constituent of sand in the catchment that is washed and blown into the lake. Variations in this ratio are significantly correlated with instrumental records of precipitation and low pressures, suggesting it is a proxy for storminess. Furthermore, identification of a c. 60-year cycle supports a climatic influence...

Ice-core (Dansgaard et al. 1993; Johnsen et al. 2001; NGRIP members 2004) and marine sediment records (Bond et al. 1992; Moreno et al. 2004; Rasmussen & Thomsen 2004) spanning the last glacial cycle provide compelling evidence of multiple reorganizations of the climatic system triggered by changes thought to originate in the North Atlantic region (Broecker et al. 1992; Clark et al. 2002). Sudden shifts in air temperature from a cool climate to interstadial values, known as Dansgaard-Oeschger events (DO), have been active most notably during Marine Isotope Stage (MIS) 3. Abrupt and large in amplitude, DO cycles operated on a millennial to centennial time scale and are best expressed in the North Atlantic region

Sediment cores from three sites along the east-coast of Sweden, northwestern Baltic Proper, have been studied with respect to lithologies, geochemistry, and diatom assemblages to trace and date early human impact with emphasis on nutrient discharge. The three sites Bråviken, Himmerfjärden, and Ådfjärden, have been impacted to various degree during the last millennia by multiple stressors like excessive nutrient discharge and hazardous substances, leading to coastal hypoxia, eutrophication, and pollution. These stressors are mainly caused by drivers in the drainage area as increased human population, changed land use, and point sources as industries and a sewage treatment plant. Even though their detailed history differs, the results show similar general patterns for all three sites. We find no evidence in our data from the coastal zone supporting the hypothesis that the extensive areal distribution of hypoxia in the open Baltic Sea during the Medieval Climate Anomaly was caused by human impact. Timing of the onset of man-made eutrophication, as identified from δ 15 N and changes in diatom composition, differs between the three sites, reflecting the site specific geography and local environmental histories of these areas. The onset of eutrophication dates to ∼1800 CE in Bråviken and Himmerfjärden areas, and to ∼1900 CE in the less urban area of Ådfjärden. We conclude that the recorded environmental changes during the last centuries are unique in a thousand year perspective.

Reference total nitrogen (TN) concentrations for the Gårdsfj€ arden estuary in the central Bothnian Sea, which receives discharge from an industrial point-source, have been estimated from diatom assemblages using a transfer function. Sedimentological and diatom evidence imply a good ecological status before 1920 with an assemblage dominated by benthic taxa indicating excellent water transparency, high diatom species richness and less organic sedimentation resulting in homogeneous well oxygenated sediments. A change in the diatom assemblage starts between 1920 and 1935 when the species richness declines and the proportion of planktic taxa increases. Increased organic carbon sedimentation after 1920 led to hypoxic bottom waters, and the preservation of laminae in the sediments. The trend in the reconstructed TN-values agrees with the history of the discharge from the mill, reaching maximum impact during the high discharge between 1945 and 1990. The background condition for TN in Gårdsfj€ arden is 260e300 mg L À1 , reconstructed until 1920.

Paralia sulcata is a diatom commonly found in both the plankton and benthos of coastal environments. This species is heavily silicified and thus preserves well in sedimentary records, making it a potentially useful paleoindicator species. However, its tychopelagic nature and association with a wide range of environmental conditions have made detailed paleoecological interpretations complicated. The abundance and size of P. sulcata varies in sediments along the Swedish west coast. While most cells have diameters from 12 to 18 lm, cells greater than 20 lm can constitute over 50% of the population. High-resolution stratigraphies in sediment cores from two Swedish fjords reveal changes in the abundance and valve diameter of P. sulcata over a 200 year time span. Paralia sulcata is abundant in non-laminated sediment sequences. Cells with large diameters (>20 lm) are however more common in laminated sections. The connections between environmental parameters and P. sulcata abundance and size were further investigated from surface sediments along the Swedish west coast. Multivariate analyses highlight the importance of surface water properties and water column stability in the abundance and size distribution of P. sulcata along the coast. Water columns that are vertically mixed have more upwelling of nutrient-rich, high salinity water to the surface; and these conditions result in large populations of small-sized P. sulcata. In contrast, stratified water columns with low surface water salinity and low phosphorus concentrations show reduced quantities of P. sulcata, but a higher percentage of cells greater than 20 lm. These results help clarify the potential of P. sulcata as a paleoindicator species in coastal environments.

Throughout the last century~ the Swedish coasts have been exposed to climatic variation and human influence, and this has altered the biota in some areas. Diatoms and silicoflagellates in a periodically-laminatedsediment core from Kolj6 Fjord (Swedish west coast) were examined to assess recent changes in the microalgal community. The most notable changes in the plankton occurred at the beginning of a long period of water column stratification in the fjord that extended from 1930 to 1980. The planktonic flora changed from a community dominated by Bacte~*osira bathyornphala and Thalassionerna nitzschioides during the 1800s to a community dominated by De~ouula coufervacea, T. nitzschioMes, and Thalassiosira spp. after 1930. Silicoflageflates were more abundant after 1940. Planktonic variations corresponded to oscillations in climate, hydrography, and weather, which determine water colnnln stability in the fjord. The tychopelagic species, Pardia sulca~, was more abundant in unlaminated sections of the core, indicating preference for a vertically mixed water colnnln. No direct effects of increased nutrient loading on the plankton could be established. Epiphytic diatoms show a period of decline from the 1950s to 1990s. This trend probably follows a shift in the macroalgal community to less-suitable host species. To what extent this pattern has been influenced or reinforced by humans cannot be determined at the present time. The results from Kolj6 Fjord, in particular the exploration of meteorological andphysical oceanographic influences on algal dynamics~ emphasize the importance of distinguishing between natural and humaninduced changes in the environment.

Integrated Ocean Drilling Program (IODP) Expedition 325, designed to investigate the fossil reefs on the shelf edge of the Great Barrier Reef, was the fourth expedition to utilize a mission-specific platform and was conducted by the European Consortium for Ocean Research Drilling (ECORD) Science Operator (ESO). The objectives of Expedition 325 were to establish the course of sea level change, define sea-surface temperature variations, and analyze the impact of these environmental changes on reef growth and geometry for the region over the period of 20-10 ka. To meet these objectives, a succession of fossil reef structures preserved on the shelf edge seaward of the modern barrier reef were cored from a dynamically positioned vessel in February-April 2010. A total of 34 boreholes across 17 sites were cored in depths ranging from 42.27 to 167.14 meters below sea level (lowest astronomical tide taken from corrected EM300 multibeam bathymetry data). Borehole logging operations in four boreholes provided continuous geophysical information about the drilled strata. The cores were described during the Onshore Science Party (OSP) at the IODP Bremen Core Repository (Germany) in July 2010, where minimum and some standard measurements were made. Preliminary postcruise dating of core catcher samples and initial observations of the cores made during the OSP confirm that coral reef material ranging in age from >30,000 to 9,000 calendar years before present (years before 1950 AD) was recovered during Expedition 325. Further postcruise research on samples taken during the OSP is expected to fulfill the objectives of the expedition.

The major reef-building coral genus Acropora has never been recorded, living or fossil, from the Marquesas Islands in the central Pacific Ocean, which are characterized by limited modern reef formations. During the ''Musorstom 9'' cruise in 1997, investigations of marine platforms representing drowned reef systems revealed for the first time the presence of two Acropora species as fossils at seven Marquesas islands. The predominant species was Acropora valida, which was widespread in the archipelago and dated between 7.4 and 48.6 ka, providing evidence of an earlier Pacific distribution pattern broader than previously observed. It is proposed that disappearance of Acropora after 7.4 ka was linked to climatic events probably ENSO events controlling the distribution of corals and coral reefs in the eastern Pacific without excluding alternatively the effects of an increase in sea-level rise.

Several lines of evidence concur to explain the climatic #uctuations that occurred in the central region of Argentina during the last millennium. The investigation was advanced in two ways: on the one hand, a geographic model was elaborated; and on the other, a temporal sequence for various climatic situations was developed. During the last 1000 yr, two signi"cant events related to global changes occurred: the Medieval Warm Period (MWP) and the Little Ice Age (LIA). The Medieval Warm Period was characterized by a humid and warm climate in the plains and recession of the Andean glaciers. In contrast, during the Little Ice Age the plains had temperate, semi-arid to arid climates, and Andean glaciers advanced. In the western region, the #uvial-lacustrine systems were more extensive during cold events (LIA) and contracted during warm events (MWP). In contrast, in the eastern region the #uvial-lacustrine systems showed a diminution during cold events and increased their extent during warm episodes. During the LIA, the occurrence of two cold pulses separated by an intermediate period has been established. The "rst cold pulse extended from the beginning of the XV century to the end of the XVI century; the second cold pulse (the main one) began at the beginning of the XVIII century and lasted until the beginning of the XIX century. Both cold pulses can be related to the SpoK rer and Maunder Minimums respectively. These climatic changes modi"ed the landforms, in#uenced the vegetation distribution and were one of the main factors for control of human activities during the last 1000 yr.

This study takes a comprehensive approach to characterizing the isolation sequence of Heimerdalsvatnet, a coastal lake in the Lofoten Islands, northern Norway. We use established methods and explore new techniques to assess changes in marine influence. Bathymetric and sub-bottom profiles were acquired to examine basin-wide sedimentation and a 5.8 m sediment core spanning the last 7800 cal yr BP was analyzed. We measured magnetic susceptibility, bulk organic matter properties, molecular biomarkers, diatom assemblages, and elemental profiles acquired by scanning X-ray fluorescence. These characteristics of the sediment reflect detailed changes in salinity and water column conditions as the lake was progressively isolated. Three distinct litho/chemo-stratigraphic units represent a restricted marine phase (7800-6500 cal yr BP), a transitional phase characterized by intermittent marine influence (6500-4900 cal yr BP), and complete isolation and freshwater sedimentation (4900 cal yr BP to present). Although there are uncertainties in the estimate of the threshold elevation of the lake, the timing of these phases generally corresponds with previous interpretations of the local relative sea-level history. This record captures sea-level regression following the Tapes transgression and supports the interpretation of a subsequent sea-level stillstand, dated in Heimerdalsvatnet from 6500 to 4900 cal yr BP.

The main motivation for Integrated Ocean Drilling Program Expedition 310 to the Tahitian Archipelago was the assumption that the last deglacial sea-level rise is precisely recorded in the coral reefs of this far-field site. The Tahitian deglacial succession typically consists of coral framework subsequently encrusted by coralline algae and microbialites. The high abundance of microbialites is uncommon for shallow-water coral reefs, and the environmental conditions favouring their development are still poorly understood. Microbioerosion patterns in the three principal framework components (corals, coralline algae, microbialites) are studied with respect to relative light availability during coral growth and subsequent encrustation, in order to constrain the palaeobathymetry and the relative timing of the encrustation. Unexpectedly for a tropical, light-flooded setting, ichnotaxa typical for the deep-euphotic to dysphotic zone dominate. The key ichnotaxa for the shallow euphotic zone are scarce in the analysed sample set, and are restricted to the base of the deglacial succession, thus reflecting the deglacial sea-level rise. At the base of the deglacial reef succession, the ichnocoenoses present in the corals indicate shallower bathymetries than those in the encrusting microbialites. This is in agreement with radiocarbon data that indicate a time gap of more than 600 years between coral death and microbialite formation. At the top of the deglacial reef succession, in contrast, the microbioerosion patterns in the three framework components indicate a uniform palaeobathymetry, and radiocarbon ages imply that encrustation took place shortly after coral demise. An enigma arises from the fact that the ichnocoenoses imply photic conditions that appear very deep for zooxanthellate coral growth. During the deglacial sea-level rise increased nutrients and fluvial influx may have led to (seasonal?) eutrophication, condensing the photic zonation. This would have exerted stress on the coral ecosystem and played a significant role in initiating microbialite development. h Coral reefs, DP hunter, Expedition 310, last deglacial sea-level rise, microbioerosion, microendoliths, microbialites, palaeobathymetry, Tahiti sea-level.

The recent discovery of one of the earliest Mesolithic occupation sites in northern Britain, at Howick on the Northumberland coast, in association with multiperiod archaeological evidence nearby, highlights the importance of UK coastal settings as focii of human occupation through the Holocene. Environmental evidence from a nearby river valley (8.15 m of sediment ranging in age from about 12 000 cal. BP to the present) records local and regional environmental change. Twenty-four radiocarbon dates based on plant macrofossils provide a strong chronological framework. Calcareous microfossil assemblages (foraminifera, ostracods) have been recovered from the fine-grained sediments, recording a change from marine through to brackish and eventually freshwater conditions between about 8200 and 6500 cal. BP. A preliminary pollen study of the core has permitted a reconstruction of the regional vegetation as it responded to climatic amelioration and human influence upon the landscape. Radiocarbon dating and sedimentological evidence indicates a major hiatus between approximately 11 000 and 8000 years BP (including the period of Mesolithic occupation), represented by a 30 cm layer of coarse sands and sandstone pebbles, probably the result of a significant high-energy event dated to about 8300 cal. BP. Although not a typical tsunami deposit, the age and context suggests that this may be associated with the Storegga Slide event, already well-documented along the eastern coast of Scotland. The sedimentary and biological remains at Howick record environmental change over much of the Holocene and are compared with other environmental change records from the region to provide an environmental framework for the archaeology of this coastline.

Ocean acidification by atmospheric carbon dioxide has increased almost continuously since the last glacial maximum (LGM), 21 000 years ago. It is expected to impair tropical reef development, but effects on reefs at the present day and in the recent past have proved difficult to evaluate. We present evidence that acidification has already significantly reduced the formation of calcified bacterial crusts in tropical reefs. Unlike major reef builders such as coralline algae and corals that more closely control their calcification, bacterial calcification is very sensitive to ambient changes in carbonate chemistry. Bacterial crusts in reef cavities have declined in thickness over the past 14 000 years with largest reduction occurring 12 000-10 000 years ago. We interpret this as an early effect of deglacial ocean acidification on reef calcification and infer that similar crusts were likely to have been thicker when seawater carbonate saturation was increased during earlier glacial intervals, and thinner during interglacials. These changes in crust thickness could have substantially affected reef development over glacial cycles, as rigid crusts significantly strengthen framework and their reduction would have increased the susceptibility of reefs to biological and physical erosion. Bacterial crust decline reveals previously unrecognized millennial-scale acidification effects on tropical reefs. This directs attention to the role of crusts in reef formation and the ability of bioinduced calcification to reflect changes in seawater chemistry. It also provides a long-term context for assessing anticipated anthropogenic effects.

Integrated Ocean Drilling Program (IODP) Expedition 325, designed to investigate the fossil reefs on the shelf edge of the Great Barrier Reef, was the fourth expedition to utilize a mission-specific platform and was conducted by the European Consortium for Ocean Research Drilling (ECORD) Science Operator (ESO). The objectives of Expedition 325 were to establish the course of sea level change, define sea-surface temperature variations, and analyze the impact of these environmental changes on reef growth and geometry for the region over the period of 20-10 ka. To meet these objectives, a succession of fossil reef structures preserved on the shelf edge seaward of the modern barrier reef were cored from a dynamically positioned vessel in February-April 2010. A total of 34 boreholes across 17 sites were cored in depths ranging from 42.27 to 167.14 meters below sea level (lowest astronomical tide taken from corrected EM300 multibeam bathymetry data). Borehole logging operations in four boreholes provided continuous geophysical information about the drilled strata. The cores were described during the Onshore Science Party (OSP) at the IODP Bremen Core Repository (Germany) in July 2010, where minimum and some standard measurements were made. Preliminary postcruise dating of core catcher samples and initial observations of the cores made during the OSP confirm that coral reef material ranging in age from >30,000 to 9,000 calendar years before present (years before 1950 AD) was recovered during Expedition 325. Further postcruise research on samples taken during the OSP is expected to fulfill the objectives of the expedition.

Synchronized demographic and behavioral patterns among distinct populations is a well-known, natural phenomenon. Intriguingly, similar patterns of synchrony occur among prehistoric human populations. However, the drivers of synchronous human ecodynamics are not well understood. Addressing this issue, we review the role of environmental variability in causing human demographic and adaptive responses. As a case study, we explore human ecodynamics of coastal hunter-gatherers in Holocene northern Europe, comparing population, economic, and environmental dynamics in two separate areas (northern Norway and western Finland). Population trends are reconstructed using temporal frequency distributions of radiocarbon-dated and shoreline-dated archaeological sites. These are correlated to regional environmental proxies and proxies for maritime resource use. The results demonstrate remarkably synchronous patterns across population trajectories, marine resource exploitation, settlement pattern, a...

A digital elevation model describing topography, tide elevation and inundation degree and frequency of a mangrove forest in North Brazil is discussed in relation to existing phosphate and physicochemical data in waters of an adjacent tidal creek. Due to smooth topography, an increase of 20 cm in tidal height above average neap tides increases flooded area from about 50 to 80%. Analysis of the relationship between microtopography, tidal height and flooding rate showed that in the upper 60 cm of the mangrove forest, increases of 20 cm in topographical height resulted in a doubling of the inundation frequency. This can be particularly relevant for the analysis of nutrient mobilization and vegetation structure of infrequently inundated wetlands. Throughout the year, low-tide phosphate in creek water was inversely proportional to the maximum area flooded during high tide, this correlation being higher during the dry season. Similarly, the inverse relationship between flooded areas and low-tide / hightide pH ratios was highly significant during the dry season and the beginning of the rainy season. Although the high correlations obtained are based on data pairs obtained at high and low tide, it has to clarified whether the association between inundation degree and creek water pH is relevant for the stability of P compounds in sediment on the short scale of a tidal cycle.

Coral reefs have grown continuously during the Last 24 ka on the island of Espiritu Santo (Vanuatu, SouthWest Pacific) in a setting characterized by frequent tectonic uplifts related to subduction of the Australia plate beneath the Vanuatu Island arc. Sedimentological and geochemical studies of two neighbouring areas having much different mean uplift rates and environmental settings provides an opportunity to analyze the environmental factors that promoted the widespread development of microbialite crusts from about 24 to 6 ka B.P. Nutrient supplies, and probably the rapidity of the sea level rise, are critical to an explanation of the distinctive distribution of microbialites in reef cores. Nutrient flux has been related to terrigenous fluxes in the Tasmaloum reef system that fringed the southwest uplifting coast of Espiritu Santo and possibly to upwelling in the Urélapa sequence that was isolated from the main island during its growth. A peak in microbialite abundance occurred between 16 and 10 ka B.P., a time window characterized by increasing erosional processes and/or more intense upwelling during a very rapid rise in sea-level.

Rising sea levels due to climate change can have severe consequences for coastal populations and ecosystems all around the world. Understanding and projecting sea-level rise is especially important for low-lying countries such as the Netherlands. It is of specific interest for vulnerable ecological and morphodynamic regions, such as the Wadden Sea UNESCO World Heritage region.Here we provide an overview of sea-level projections for the 21st century for the Wadden Sea region and a condensed review of the scientific data, understanding and uncertainties underpinning the projections. The sea-level projections are formulated in the framework of the geological history of the Wadden Sea region and are based on the regional sea-level projections published in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5). These IPCC AR5 projections are compared against updates derived from more recent literature and evaluated for the Wadden Sea region. The projectio...

Integrated archaeological and paleoenvironmental investigations provide long-term perspectives on human–environment interactions. In the North Atlantic region, early human settlements were established in marginal agricultural environments and were susceptible to various environmental stressors. The Lofoten Islands have had an important role in the history of this region, particularly during the Iron Age, when Lofoten developed from pioneering agricultural settlements to a prominent node of power and trade under Viking chieftains. Iron Age
developments in Lofoten were concurrent with significant natural environmental changes, including variations in climate and sea level. However, there has not been a comprehensive investigation of their influence on early settlements. The purpose of the study is to review Iron
Age cultural developments in Lofoten using published archaeological data and paleoenvironmental records of past climate and sea-level change, and to present specific examples of the intersection of early human development and natural environmental changes.
The findings show that climate changes probably influenced agricultural phases and that relative sea-level variations had important impacts on maritime developments. In conclusion, the findings demonstrate that human–environment interactions were significant factors in Lofoten’s
history and the authors suggest specific areas for future research.

The skeletons of teleost fishes dominate the Tithonian ichthyotaphocoenosis from the Mörnsheim Formation of Bavaria. Analysis of
skeletal distribution, deformations of the vertebral column, and evidence of benthic currents originated from the long-term accumulation
of carcasses in the plattenkalk under low sedimentation rates with evidence of prolonged exposure at the sediment-water interface. The
spatial arrangement of disarticulated skeletal elements of fishes in the Mörnsheim resulted from the decay of soft tissues at the burial
place in a calm environment. Disarticulation of some fishes as well as the convex-up arrangement of bivalve valves and ammonite aptychi
may indicate weak current activity. Unlike other plattenkalk localities, there is no conclusive evidence of mass mortality. This suggests
that the Mörnsheim Formation was subject to weak bottom currents indicating more open-marine circulation compared to the Solnhofen
Formation.