Late Quaternary sea-level change and early human societies in the central and eastern Mediterranean Basin : an interdisciplinary review

This article reviews key data and debates focused on relative sea-level changes since the Last Interglacial (approximately the last 132,000 years) in the Mediterranean Basin, and their implications for past human populations. Geological and geomorphological landscape studies are critical to archaeology. Coastal regions provide a wide range of resources to the populations that inhabit them. Coastal landscapes are increasingly the focus of scholarly discussions from the earliest exploitation of littoral resources and early hominin cognition, to the inundation of the earliest permanently settled fishing villages and eventually, formative centres of urbanisation. In the Mediterranean, these would become hubs of maritime transportation that gave rise to the roots of modern seaborne trade. As such, this article represents an original review of both the geo-scientific and archaeological data that specifically relate to sea-level changes and resulting impacts on both physical and cultural landscapes from the Palaeolithic until the emergence of the Classical periods. Our review highlights that the interdisciplinary links between coastal archaeology, geomorphology and sea-level changes are important to explain environmental impacts on coastal human societies and human migration. We review geological indicators of sea level and outline how archaeological features are commonly used as proxies for measuring past sea levels, both gradual changes and catastrophic events. We argue that coastal archaeologists should, as a part of their analyses, incorporate important sea-level concepts, such as indicative meaning. The interpretation of the indicative meaning of Roman fishtanks, for example, plays a critical role in reconstructions of late Holocene Mediterranean sea levels. We identify avenues for future work, which include the consideration of glacial isostatic adjustment (GIA) in addition to coastal tectonics to explain vertical movements of coastlines, more research on Palaeolithic island colonisation, broadening of Palaeolithic studies to include materials from the entire coastal landscape and not just coastal resources, a focus on rescue of archaeological sites under threat by coastal change, and expansion of underwater archaeological explorations in combination with submarine geomorphology. This article presents a collaborative synthesis of data, some of which have been collected and analysed by the authors, as the MEDFLOOD (MEDiterranean sea-level change and projection for future FLOODing) community, and highlights key sites, data, concepts and ongoing debates

Multiple Geographic Origins of Commensalism and Complex Dispersal History of Black Rats

The Black Rat (Rattus rattus) spread out of Asia to become one of the world's worst agricultural and urban pests, and a reservoir or vector of numerous zoonotic diseases, including the devastating plague. Despite the global scale and inestimable cost of their impacts on both human livelihoods and natural ecosystems, little is known of the global genetic diversity of Black Rats, the timing and directions of their historical dispersals, and the risks associated with contemporary movements. We surveyed mitochondrial DNA of Black Rats collected across their global range as a first step towards obtaining an historical genetic perspective on this socioeconomically important group of rodents. We found a strong phylogeographic pattern with well-differentiated lineages of Black Rats native to South Asia, the Himalayan region, southern Indochina, and northern Indochina to East Asia, and a diversification that probably commenced in the early Middle Pleistocene. We also identified two other currently recognised species of Rattus as potential derivatives of a paraphyletic R. rattus. Three of the four phylogenetic lineage units within R. rattus show clear genetic signatures of major population expansion in prehistoric times, and the distribution of particular haplogroups mirrors archaeologically and historically documented patterns of human dispersal and trade. Commensalism clearly arose multiple times in R. rattus and in widely separated geographic regions, and this may account for apparent regionalism in their associated pathogens. Our findings represent an important step towards deeper understanding the complex and influential relationship that has developed between Black Rats and humans, and invite a thorough re-examination of host-pathogen associations among Black Rats

Redox evolution and the development of oxygen minimum zones in the Eastern Mediterranean Levantine basin during the early Holocene

Oxygen Minimum Zones (OMZs) are expanding in modern oceans due to anthropogenically-driven climate and environmental change. In the Eastern Mediterranean Sea (EMS), OMZs developed in the early Holocene as a result of decreased intermediate water ventilation, increasing temperature, and increased Nile discharge and primary productivity. Here, we report benthic foraminiferal numbers (BFN) and species abundances, together with redox-sensitive trace metals (RSTM), and iron and phosphorus speciation from two sediment cores sampled at intermediate depths (1200 and 1430 m) from the SE Levantine shelf. The main aim of our study is to better understand the sequence of redox changes during sapropel S1 deposition caused by biogeochemical processes affecting the sapropel intermediate water mass. The use of benthic foraminifera indices (diversity and oxygen) together with iron speciation and RSTM (V, Mo and U) enables detailed description of the changing oxygen/redox status of the overlying water. Prior to sapropel S1 deposition at ∼10.2 ka BP, RSTM suggest that the overlying water was well oxygenated, but benthic foraminifera numbers (BFN) suggest that oxygen levels had already begun to decrease. There was then a pulse of increased export carbon from the enlarged Nile flood plume, as shown by increased BFN at the beginning of sapropel S1. Shortly after, RSTM and Fe-S systematics suggest that the water column transitioned from dysoxic to anoxic, non-sulfidic. Anoxic conditions then persisted at 1200 m depth, but RSTM and benthic foraminifera indices suggest that deeper waters at 1430 m were more likely dysoxic, until the 8.2 ka BP global cooling event. The benthic foraminifera and inorganic redox proxies then suggest a second period of anoxic, non-sulfidic conditions, with a gradual return to well ventilated waters at the end of sapropel deposition at ∼6 ka BP. There was enhanced burial of authigenic P throughout sapropel deposition, derived from the deposition and subsequent release of organic-P and iron bound-P during diagenesis. Phosphorus recycling from the sediment and in the overlying water column added reactive P to these mid-depth waters, a process which has the potential to result in a positive feedback in systems where such waters are upwelled into the photic zone. The past EMS thus represents a template which can be used to predict biogeochemical changes in settings that evolve towards anoxic, non sulfidic conditions, which may occur in some areas as modern climate and environment change causes the continued expansion of modern OMZs and hypoxic areas adjacent to modern major rivers

Publicity waves based on manipulated geoscientific data suggesting climatic trigger for majority of tsunami findings in the mediterranean – response to ‘tsunamis in the geological record: Making waves with a cautionary tale from the mediterranean’ by marriner et al. (2017)

This article is a response to the publication by Nick Marriner, David Kaniewski, Christophe Morhange, Clément Flaux, Matthieu Giaime, Matteo Vacchi and James Goff entitled “Tsunamis in the geological record: Making waves with a cautionary tale from the Mediterranean”, published in October 2017 in Science Advances. Making use of radiometric data sets published in the context of selected palaeotsunami studies by independent research groups from different countries, Marriner et al. (2017) carried out statistical and time series analyses. They compared their results with an assessment of Mediterranean storminess since the mid-Holocene that was previously published by Kaniewski et al. (2016) based on a single-core study from coastal Croatia. Marriner et al. (2017) now present “previously unrecognized” 1500-year “tsunami megacycles” which they suggest correlating with Mediterranean climate deterioration. They conclude that up to 90 % of all the ‘tsunamis’ identified in original tsunami papers used for their study are “better ascribed to periods of heightened storminess”. In this response, we show that (i) the comparison of statistical data describing storm and tsunami events presented by Marriner et al. (2017) is incorrect both from a geographical and a statistical point of view, (ii) the assumed periods of central Mediterranean storminess published by Kaniewski et al. (2016) are missing convincing geological and geochronological evidence and are statistically incorrect, (iii) the palaeotsunami data that was originally collected by different groups of authors were manipulated by Marriner et al. (2017) in a way that the resulting data set – used as a benchmark for the entire study of these authors – is wrong and inaccurate, and that (iv) Marriner et al. (2017) did not address or even negate the original sedimentological studies’ presentation of comparative tsunami versus storm deposits for the selected individual localities. Based on a thorough and detailed evaluation of the geoscientific background and the methodological approach of the studies by Kaniewski et al. (2016) and Marriner et al. (2017), we conclude that there is no serious and reliable geoscientific evidence for increased storminess in the (central) Mediterranean Sea between 3400–2550, 2000–1800, 1650–1450, 1300–900 and 400–100 cal BP. The impact of those storms in the Mediterranean, producing geological traces somewhat comparable to those caused by tsunamis, is insignificantly small. For the period 1902–2017, Mediterranean tsunamis make up 73–98 % of all combined extreme wave events (EWE) leading to coastal flooding and appeared up to 181 times deadlier than comparable storm effects. This is the reason why coastal Mediterranean research has focused on Holocene records of the tsunami hazard, while research on comparable storm effects is of lower signifi-cance. The validity of geological evidence for Mediterranean EWE and their interpretation as caused by palaeotsunami impacts thus remains untouched. Tsunamis, in most cases directly and indirectly induced by seismo-tectonics, have always been a much greater threat to Mediterranean coastal regions than comparable storm effects. ‘Tsunami megacycles’ as expressions of a 1500-year periodicity centered on the Little Ice Age, 1600 and 3100 cal BP that were correlated with questionable storm data do not exist. Cause and effect relationships work the other way round: Major tsunami events, testified by historical accounts, such as those that occurred in 1908 AD, 1755 AD, 1693 AD and 365 AD, induced numerous studies along Mediterranean coasts. These investigations resulted in a large number of publications that specifically focus on those time periods, suspected by Marriner et al. (2017) to bear signs of increased storminess, namely 200–300 BP and 1600 BP. The Mediterranean tsunami record cannot be ascribed to periods of increased storminess. On the contrary, the tsunami record as interpreted by the authors of the original papers cited by Marriner et al. (2017), is due to the outstandingly high seismo-tectonic activity of the region. Mediterranean tsunamis are mostly triggered by earthquakes or by earthquake-related secondary effects such as underwater mass movements. The study by Marriner et al. (2017) is also problematic because it includes simple basic statistical mistakes and major methodological inconsistencies. The geomorphological and sedimentary background of EWE deposits was not taken into account. The ‘broad brush’ approach used by Marriner et al. (2017) to sweep sedimentary deposits from tsunami origin into the storm bag origin, just on the basis of (false) statistics coupled with very broad and unreliable palaeoclimatic indicators and time frames, is misleading. The distortion of original data collected and interpreted by other research groups by Marriner et al. (2017) is particularly disturbing. Their publication is also bound to question in this case the effectiveness of scientific quality assurance in modern publishing commerce. Marriner et al. (2017: 7) talk down the considerable risk to human settlements and infrastructure along Mediterranean coasts in relation to tsunami and earthquake hazards. Their conclusion is not only wrong as a result of their incorrect data mining and analyses, it is also irresponsible with regard to national and international efforts of tsunami and earthquake risk mitigation