Ancient harbour infrastructure in the Levant: tracking the birth and rise of new forms of anthropogenic pressure

Beirut, Sidon and Tyre were major centres of maritime trade from the Bronze Age onwards. This economic prosperity generated increased pressures on the local environment, through urbanization and harbour development. Until now, however, the impact of expanding seaport infrastructure has largely been neglected and there is a paucity of data concerning the environmental stresses caused by these new forms of anthropogenic impacts. Sediment archives from Beirut, Sidon and Tyre are key to understanding human impacts in harbour areas because: (i) they lie at the heart of ancient trade networks; (ii) they encompass the emergence of early maritime infrastructure; and (iii) they enable human alterations of coastal areas to be characterized over long timescales. Here we report multivariate analyses of litho- and biostratigraphic data to probe human stressors in the context of their evolving seaport technologies. The statistical outcomes show a notable break between natural and artificial sedimentation that began during the Iron Age. Three anchorage phases can be distinguished: (i) Bronze Age proto-harbours that correspond to natural anchorages, with minor human impacts; (ii) semi-artificial Iron Age harbours, with stratigraphic evidence for artificial reinforcement of the natural endowments; and (iii) heavy human impacts leading to completely artificial Roman and Byzantine harbours

Tsunamis in the geological record: Making waves with a cautionary tale from the Mediterranean

This is the final version of the article. Available from AAAS via the DOI in this record.From 2000 to 2015, tsunamis and storms killed more than 430,000 people worldwide and affected a further >530 million, with total damages exceeding US$970 billion. These alarming trends, underscored by the tragic events of the 2004 Indian Ocean catastrophe, have fueled increased worldwide demands for assessments of past, present, and future coastal risks. Nonetheless, despite its importance for hazard mitigation, discriminating between storm and tsunami deposits in the geological record is one of the most challenging and hotly contended topics in coastal geoscience. To probe this knowledge gap, we present a 4500-year reconstruction of "tsunami" variability from the Mediterranean based on stratigraphic but not historical archives and assess it in relation to climate records and reconstructions of storminess. We elucidate evidence for previously unrecognized "tsunami megacycles" with three peaks centered on the Little Ice Age, 1600, and 3100 cal. yr B.P. (calibrated years before present). These ~1500-year cycles, strongly correlated with climate deterioration in the Mediterranean/North Atlantic, challenge up to 90% of the original tsunami attributions and suggest, by contrast, that most events are better ascribed to periods of heightened storminess. This timely and provocative finding is crucial in providing appropriately tailored assessments of coastal hazard risk in the Mediterranean and beyond.Financial support for this work was provided by Labex OT-Med (ANR-11-LABX-0061). Additional assistance was provided by the Institut Universitaire de France (CLIMSORIENT project), ANR Geomar (ANR-12-SENV- 0008-01), A*MIDEX (ANR-11-IDEX-0001-02), and Partenariat Hubert Curien PROCOPE (33361WG). J.G. benefited from a research fellowship at Chrono-environnement funded by the Région Bourgogne-Franche-Comté

Not the End of the World? Post-Classical Decline and Recovery in Rural Anatolia

Between the foundation of Constantinople as capital of the eastern half of the Roman Empire in 330 CE and its sack by the Fourth Crusade in 1204 CE, the Byzantine Empire underwent a full cycle from political-economic stability, through rural insecurity and agrarian decline, and back to renewed prosperity. These stages plausibly correspond to the phases of over-extension (K), subsequent release (Ω) and recovery (α) of the Adaptive Cycle in Socio-Ecological Systems. Here we track and partly quantify the consequences of those changes in different regions of Anatolia, firstly for rural settlement (via regional archaeological surveys) and secondly for land cover (via pollen analysis). We also examine the impact of climate changes on the agrarian system. While individual histories vary, the archaeological record shows a major demographic decline between ca .650 and ca. 900 CE in central and southwestern Anatolia, which was then a frontier zone between Byzantine and Arab armies. In these regions, and also in northwest Anatolia, century-scale trends in pollen indicate a substantial decline in the production of cereal and tree crops, and a smaller decline in pastoral activity. During the subsequent recovery (α) phase after 900 CE there was strong regional differentiation, with central Anatolia moving to a new economic system based on agro-pastoralism, while lowland areas of northern and western Anatolia returned to the cultivation of commercial crops such as olive trees. The extent of recovery in the agrarian economy was broadly predictable by the magnitude of its preceding decline, but the trajectories of recovery varied between different regions

Pollen-inferred regional vegetation patterns and demographic change in Southern Anatolia through the Holocene

Southern Anatolia is a highly significant area within the Mediterranean, particularly in terms of understanding how agriculture moved into Europe from neighbouring regions. This study uses pollen, palaeoclimate and archaeological evidence to investigate the relationships between demography and vegetation change, and to explore how the development of agriculture varied spatially. Data from 21 fossil pollen records have been transformed into forested, parkland and open vegetation types using cluster analysis. Patterns of change have been explored using non-metric multidimensional scaling (nMDS) and through analysis of indicator groups, such as an Anthropogenic Pollen Index, and Simpson’s Diversity. Settlement data, which indicate population densities, and summed radiocarbon dates for archaeological sites have been used as a proxy for demographic change. The pollen and archaeological records confirm that farming can be detected earlier in Anatolia in comparison with many other parts of the Mediterranean. Dynamics of change in grazing indicators and the OJCV (Olea, Juglans, Castanea and Vitis) index for cultivated trees appear to match cycles of population expansion and decline. Vegetation and land use change is also influenced by other factors, such as climate change. Investigating the early impacts of anthropogenic activities (e.g. woodcutting, animal herding, the use of fire and agriculture) is key to understanding how societies have modified the environment since the mid–late Holocene, despite the capacity of ecological systems to absorb recurrent disturbances. The results of this study suggest that shifting human population dynamics played an important role in shaping land cover in central and southern Anatolia

On magnetometer heading updates for inertial pedestrian navigation system

A magnetometer is often used to aid heading estimation of a low-cost Inertial Pedestrian Navigation System (IPNS) without which the latter will not be able to accurately estimate heading for more than a few seconds, even with the help of Zero Velocity Update (ZVU). Heading measurements from the magnetometer are typically integrated with gyro heading in an estimation filter such as Kalman Filter (KF) — to best estimate the true IPNS heading, resulting in a better positioning accuracy. However indoors the reliability of these measurements is often questionable because of the magnetic disturbances that can disrupt the measurements. To solve this problem, a filtering method is often used to select the best measurements. However, the importance of the frequency of these measurement updates has not been highlighted. In this paper, the impact of frequency of magnetometer updates on the overall accuracy of the navigation system is presented. The paper starts by discussing the use of a magnetometer in a low-cost IPNS. An exemplary filter to extract reliable heading measurements from the magnetometer is then described. From real field trial results, it will be shown that even if reliable heading measurements may be obtained indoors, it is still insufficient to increase the positioning accuracy of the low-cost IPNS unless it is reliable on every epoch

Pollen-inferred regional vegetation patterns and demographic change in Southern Anatolia through the Holocene

Southern Anatolia is a highly significant area within the Mediterranean, particularly in terms of understanding how agriculture moved into Europe from neighbouring regions. This study uses pollen, palaeoclimate and archaeological evidence to investigate the relationships between demography and vegetation change, and to explore how the development of agriculture varied spatially. Data from 21 fossil pollen records have been transformed into forested, parkland and open vegetation types using cluster analysis. Patterns of change have been explored using non-metric multidimensional scaling (nMDS) and through analysis of indicator groups, such as an Anthropogenic Pollen Index, and Simpson’s Diversity. Settlement data, which indicate population densities, and summed radiocarbon dates for archaeological sites have been used as a proxy for demographic change. The pollen and archaeological records confirm that farming can be detected earlier in Anatolia in comparison with many other parts of the Mediterranean. Dynamics of change in grazing indicators and the OJCV (Olea, Juglans, Castanea and Vitis) index for cultivated trees appear to match cycles of population expansion and decline. Vegetation and land use change is also influenced by other factors, such as climate change. Investigating the early impacts of anthropogenic activities (e.g. woodcutting, animal herding, the use of fire and agriculture) is key to understanding how societies have modified the environment since the mid–late Holocene, despite the capacity of ecological systems to absorb recurrent disturbances. The results of this study suggest that shifting human population dynamics played an important role in shaping land cover in central and southern Anatolia

Mediterranean landscape change during the Holocene: synthesis, comparison and regional trends in population, land cover and climate

This synthesis paper offers a comparative perspective on how seven different Mediterranean regions, from Iberia and Morocco to the Levant, have been transformed by human and natural agencies during the last ten millennia. It draws on a range of sources of data notably, 1) archaeological site surveys (n=32k) and 14C dates (n=12k) as proxies for long-term population change, 2) pollen records as a proxy for past vegetation and land cover (n=157), and 3) proxies, such as stable isotopes, from lake, cave and marine records as indicators of hydro-climate (n=47). Where possible, these data sets have been made spatially and temporally congruent in order to examine relationships between them statistically and graphically. Data have been aggregated or averaged for each region/subregion and put into 200-year time windows. Archaeo-demographic data show a clear increase at the start of Neolithic farming, followed by a series of regionally-asynchronous fluctuations in population, prior to a pan-Mediterranean Roman settlement maximum. Pollen data indicate a Late Holocene decline in %Arboreal Pollen in those regions that were initially well-wooded, but not in drier regions of the southern/eastern Mediterranean. Overall, the clearest palynological proxy for human land cover change is provided by the OJCV (tree crop) index. The cultivation of these trees in the eastern Mediterranean after 6500 Cal yr BP may have been an adaptive response to mid-Holocene climatic desiccation. These anthropogenic pollen indicators correlate more closely with trends in population than with regional hydro-climatic z-scores, implying that they reflect primarily human activities. During the mid-Holocene, most Mediterranean landscapes were transformed by a combination of climate and rural land use, but after ~3500 Cal yr BP, human actions became increasingly dominant in determining land cover. During the last 1500 years the dominant landscape trajectory in the eastern Mediterranean was markedly different to that in the central/western Mediterranean

Modelling climate and societal resilience in the Eastern Mediterranean in the last Millennium

This article analyses high-quality hydroclimate proxy records and spatial reconstructions from the Central and Eastern Mediterranean and compares them with two Earth System Model simulations (CCSM4, MPI-ESM-P) for the Crusader period in the Levant (1095–1290 CE), the Mamluk regime in Transjordan (1260–1516 CE) and the Ottoman crisis and Celâlî Rebellion(1580–1610 CE). During the three time intervals, environmental and climatic stress tested the resilience of complex societies.We find that the multidecadal precipitation and drought variations in the Central and Eastern Mediterranean cannot be explained by external forcings (solar variations, tropical volcanism); rather they were driven by internal climate dynamics. Our research emphasises the challenges, opportunities and limitations of linking proxy records, palaeoreconstructions and model simulations to better understand how climate can affect human history