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The western Makran subduction zone is capable of producing considerable tsunami run-up heights that penetrate up to 5 km inland. In this study, we show how climate change has affected urbanization along the tsunami-prone Makran coastline during the past 35 years. To address this issue, we have employed climate data, satellite altimeter radar, geomorphology and historical shoreline changes in order to shed light on the factors leading to a decline in access to freshwater resources and also rapid urbanization. We furthermore consider the interactions between environmental changes and human-induced coastal and catchment modifications in increasing socioeconomic vulnerabilities of littoral areas. The results of this study show that agricultural and freshwater management methods along the Chabahar coastal plain date back to at least 1808 CE, when wetter climate conditions characterized the area. Severe climate changes have been pronounced since 2000. Within this context, the majority of agricultural lands have been abandoned due to increasing drought intensity and duration. Decreasing cultivation and limited access to freshwater resources have led to extensive urbanization particularly for the two cities of Konarak and Chabahar. Enhanced soil erosion, increasing summer monsoon wind speed, sea-level rise and the growing number of strong storm events are some of the climate change-related hazards for high to very high socially vulnerable zones. In addition to environmental risks, poor urban planning has increased damage to coastal infrastructures such as ports and desalination plants. Furthermore, industrial and urban growth in the northwest of the Makran could further enhance socioeconomic damage by earthquakes and tsunamis. [ABSTRACT FROM AUTHOR]

In Northern Dobrogea, north of the Dunavăţ promontory, the Roman fortress of Halmyris was founded in the late 1st century AD on a Getic settlement dating to the middle of the 1st millennium BC, probably associated with a Greek emporium of the Classical and Hellenistic periods. At the time of the foundation of Halmyris, the Danube delta had already prograded several kilometres to the east leading to the progressive retreat of the sea and the formation of a deltaic plain characterised by numerous lakes and river channels. Here, we present the results of a multiproxy study combining sedimentology and palaeoecology to (1) understand the evolution of fluvial landscapes around Halmyris since ca. 8000 years BP and (2) identify the fluvial palaeoenvironments close to the city in Getic/Greek and Roman times, in order to locate and characterise the waterfront and the harbour. Our overriding objective was to improve understanding of human-environment relations in river delta settings. We demonstrate that Halmyris, protected by the Danubian floods due to its location on a palaeo-cliff top, had direct access to the river. A secondary channel of the Saint George, flowing north of the site, has been elucidated between the 7th century BC and the 7th century AD and could have been used as a natural harbour. [ABSTRACT FROM AUTHOR]

Since the first archaeological excavations undertaken in the 1970s/1980s, Tel Akko is known to have been an important trade city from the early 2nd millennium B.C. onwards. Even if the site has been intensively excavated, no paleoenvironmental studies looking to understand coastal changes near the tell since the Bronze Age had been undertaken until recently. Our research is based on the study of sediment cores drilled at the foot of the tell and in the Old City of Akko, 1,500 m west of the tell. We validate the coastal changes, already proposed by previous studies, while clarifying the chronology of these changes. We propose that the southern anchorage was located in the river mouth of the Na'aman until the early Persian period. This anchorage shifted to the "open" western coast of the tell during the Persian period before its subsequent relocation to the rocky promontory of Akko in Hellenistic times. We attempted to locate the Hellenistic harbor of Akko by coring in the Old City, in proximity to the modern harbor. At that time, a harbor lay in a semi‐protected pocket beach at the foot of the promontory. [ABSTRACT FROM AUTHOR]

The presence of a regional-wide notch (45 to 115cm below present biological mean sea level [BMSL]) along the Adriatic coast of Croatia, at a string of sites between Zadar and Rijeka, provides evidence for a rapid but poorly constrained subsidence event(s) after Roman times. For more than a century, this geomorphological tidal level indicator has attracted rich scientific debate but many unresolved questions remain. In this paper, we present new results from Caska Bay (Pag Island) looking at notch morphology and Holocene salt-marsh stratigraphy to constrain the chronology of this crustal deformation on Pag Island. The typical salt-marsh stratigraphy comprises low to high salt-marsh muds interjected by an unconformable marine layer (which lies between -50 and -100cm BMSL) consistent with an abrupt transgression. The palaeoecological record shows an abrupt shift in assemblages across the salt-marsh mud-sand sediment contact translating abrupt coastal changes. Geochronological data constrain this event to around 1000 to 1200cal. AD. The altitude of the layer is coeval with the submerged notch attested on limestone cliffs around the bay. The U-shape of the notch profile, coupled with the sharp palaecological contacts and submerged Roman pier, implies that sea-level rise was episodic and not gradual as suggested by regional numerical models. Together, our findings shed new light on the chronology of the "enigmatic" Croatian notch on the island of Pag, and highlight the need to couple geomorphological studies of rocky coasts with high-resolution sediment records. [ABSTRACT FROM AUTHOR]

Abstract: Although it is acknowledged that there has been an exponential growth in neocatastrophist geoscience inquiry, the extent, chronology and origin of this mode have not been precisely scrutinized. In this study, we use the bibliographic research tool Scopus to explore ‘catastrophic’ words replete in the earth and planetary science literature between 1950 and 2009, assessing when, where and why catastrophism has gained new currency amongst the geoscience community. First, we elucidate an exponential rise in neocatastrophist research from the 1980s onwards. We then argue that the neocatastrophist mode came to prominence in North America during the 1960s and 1970s before being more widely espoused in Europe, essentially after 1980. We compare these trends with the EM-DAT disaster database, a worldwide catalogue that compiles more than 11,000 natural disasters stretching back to 1900. The findings imply a clear link between anthropogenically forced global change and an increase in disaster research (r2 =0.73). Finally, we attempt to explain the rise of neocatastrophism by highlighting seven non-exhaustive factors: (1) the rise of applied geoscience; (2) inherited geological epistemology; (3) disciplinary interaction and the diffusion of ideas from the planetary to earth sciences; (4) the advent of radiometric dating techniques; (5) the communications revolution; (6) webometry and the quest for high-impact geoscience; and (7) popular cultural frameworks. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents geoarchaeological results from the ancient harbour of Beirut (Lebanon). As at Sidon, knowledge of Beirut''s ancient tell has advanced significantly over the past decade, thanks namely to redevelopment of the city centre and excavations centred on the modern port. In spite of this research, understanding of the city''s coastal palaeoenvironments during antiquity is poor. Buried Iron Age harbourworks presently 300m from the sea attest to pronounced coastal changes during the past 3000 years. These processes have been significantly accentuated during the last two centuries by redevelopment of the port, which remains in use some 5000 years after its foundation. Here we elucidate the coastal stratigraphy east and west of the Bronze Age tell to yield new insights into the evolution of the Beirut seaboard, in addition to the complex history of human–environment interactions. These chronostratigraphic data are subsequently used to (1) precisely locate the main anchorage haven during antiquity; and (2) propose a chronology for its evolution. [Copyright &y& Elsevier]

Abstract: Although much has been written on the subject of ancient Mediterranean harbours, the relatively new area of harbour geoarchaeology remains dispersed in the geoscience and archaeological literature. Over a decade of research has amassed rich and varied datasets of anthropogenically forced coastal evolution, with a remarkable number of between-site analogies. This new research field also shows the rich potential of geoscience to reconcile important archaeological questions. No single publication, however, has yet drawn on these geological patterns to yield a detailed overview suitable for geoscientists and environmental archaeologists. The aim of this review article is to (1) discuss how ancient harbours have come to be preserved in the geological record; (2) expound the basic principles and palaeoenvironmental tools underpinning ancient harbour geoarchaeology; (3) outline some of the most significant research advances made; and (4) discuss a new chrono-stratigraphic model applicable to harbour sequences. [Copyright &y& Elsevier]

Abstract: Twenty-nine 14C dates of precise biological sea-level indicators from the Lebanese coast show evidence for two significant regional crustal uplift episodes during the past 6000 years. We elucidate: (1) an upper shoreline at ca. +120 to +140 cm, which lasted from ca. 6000 to 3000 BP; and (2) a lower shoreline at +80 ±40 cm, developed between the fifth century BC and the sixth century AD. These movements are associated with: (1) two major seismic crises along the Yammuneh fault and the Roum-Tripoli Thrust (RTT); and (2) subsequent seismic events on a series of second-order ENE trending dextral transpressive faults. Vertical movements affected north Lebanon, whilst the coasts of south Lebanon generally underwent crustal downlift. This is in contrast with relative stability in northern Israel, suggesting an area of stationary tectonic conditions west of the Dead Sea–Rosh Hanikra/Ras Nakoura fault. The main 14C age cluster, corresponding to the second uplift event, may have resulted from fault movements during the “Early Byzantine Tectonic Paroxysm” (EBTP), between ca. 1750 and 2000 BP. Relative sea level stabilised to present level around 1000 BP. [Copyright &y& Elsevier]

After centuries of archaeological debate, the harbors of Phoenicia's two most important city states, Tyre and Sidon, have been rediscovered, and including new geoarcheological results reveal how, where, and when they evolved after their Bronze Age foundations. The early ports lie beneath their present urban centers, and we have indentified four harbor phases. (1) During the Bronze Age, Tyre and Sidon were characterized by semi-open marine coves that served as protoharbors. (2) Biostratigraphic and lithostratigraphic data indicate the presence of early artificial basins after the first millennium B.C. (3) The harbors reached their apogees during the Greco-Roman and Byzantine periods. (4) Silting up and coastal progradation led to burial of the medieval basins, lost until now. [ABSTRACT FROM AUTHOR]

Abstract In deltaic areas, within a context of relative sea-level stability during the past 6000 years, environmental conditions have been key in mediating human settlements and the evolution of ancient harbours. The natural diversity of clastic-coast environments, in particular deltas, is central to explain the wide disparity in harbour contexts. It is, therefore, important to understand the impact of these settlements on the evolution of clastic coasts. How did ancient societies exploit and adapt to deltaic environments? Here, we detail a typology of ancient harbours on clastic coasts using a suite of multidisciplinary case studies from the Mediterranean and the Black Sea. We present the impact of different forcing agents (floods, storms, sedimentary inputs, relative sea-level (RSL) changes, dredging and harbour structures) on the geomorphological evolution of selected harbour sites, and underline the important role of coastal changes at different temporal and spatial scales. These processes affected the infrastructure and the viability of harbours to varying degrees. In deltaic contexts, our analysis differentiates five harbour types: (1) fluvial harbours, affected by floods, rapid sedimentation and river-channel changes; (2a) infilled estuarine harbours; or (2b) submerged estuarine harbours, lying at the interface between marine and fluvial processes; (3) lagoonal harbours strongly affected by sedimentary inputs; and (4) the impact of humans on harbour basins via harbour protection structures and dredging. For these harbour types, we probe the advantages and disadvantages of each geomorphological setting, in addition to the consequences of environmental pressures on human societies. [ABSTRACT FROM AUTHOR]

The present geomorphology of the Mediterranean's coasts is largely a product of an intricate long-term relationship between Nature and human societies. A cradle of ancient civilisations, the Mediterranean has seen its shores occupied by Humans since Prehistory, and is, therefore, a particularly pertinent unit of analysis. The morphotectonic context and other forcing agents (e.g., climate) shaped out a highly diversified coastal morphology and generated a sediment-supply regime potentially favourable to the formation of numerous open-coast deltas and bay-head deltas in infilled rias as sea level stabilised during the mid-Holocene. This supply of riverine sediment has also been the key agent in mediating human occupation of the Mediterranean's clastic coasts. Expressions of this relationship have been extensively archived in clastic coastal deposits, including base-level deltaic and estuarine sedimentary sinks, which comprise records to explore the interactions between geosystems and the human environment. The stratigraphic sequences in these coastal sedimentary archives comprise, in many places, a clearly identified anthropogenic signature, notably in ancient harbours, some of which underwent extremely rapid silting up due to massive sediment sourcing generated by new agricultural practices from the Neolithic onwards. Increasing human influence, especially over the last 3000 years, has been, in turn, an important driver of changes in sediment supply, strongly modulating deltaic development. Pulses of sediment supply from catchments rendered vulnerable by human perturbations during the Roman period resulted in a new cycle of inception of many other deltas and in rapid delta growth (e.g. the Ebro, the Po, the Arno and the Ombrone). Another progradation dynamic during the Little Ice Age, at a time of strong rural population growth, river discharge increases, technological developments, and urbanisation, further consolidated delta growth. Understanding the life cycle of these deltas since their initial formation is, in turn, key to unravelling the relative role of natural and anthropogenic forcing agents. Rapid climate changes are deemed to have contributed through both the stripping of landscapes rendered fragile by human activities and active fluvial sediment transport to the coast, but disentangling climate change effects from human impacts in the Mediterranean remains a challenge. The patterns of subsequent deltaic growth and delta morphodynamics reflect adaptations to pulsed sediment supply, river discharge variations, the microtidal, fetch-limited context of the Mediterranean, and direct engineering interventions. The progradation dynamic of the Roman period and Little Ice Age contrasts markedly with the situation of common coastal destabilisation over the last two centuries, particularly well documented for the last 50 years. This period has been characterised by reduced sediment flux to base-level geosystems due to catchment reforestation, retenion within reservoirs, fluvial regulation and dredging, resulting in the erosion of deltas and barrier–lagoon and beach–dune systems. Large stretches of shoreline and narrow coastal plains have been massively engineered for coastal defence and protection against erosion, but also for the construction of marinas, leisure harbours and artificial beaches, resulting in the emergence of veritable artificial seafronts. These interventions have, collectively and progressively, raised societies to a pervasive and overarching position in the geomorphic stability–instability of the Mediterranean's coasts, a situation that will be exacerbated by pressures from sea-level rise, paving the way for rampant coastal erosion and delta destruction. [ABSTRACT FROM AUTHOR]

The Nile Delta is a subsiding sedimentary basin that hosts ~66% of Egypt's population and 60% of the country's food production. Projected sea-level-rise scenarios for the coming decades have sharpened focus on the delta's potential resilience to rapid changes in accommodation space. We use chronostratigraphic data from 194 organic-rich peat and lagoon points to quantitatively reevaluate the drivers of Nile Delta surface dynamics during the Holocene. Reconstructed subsidence rates range from 0.03 to 4.5 mm/yr, and are highest in the Manzala, Burullus, Idku, and Maryut lagoons, areas that correspond to deep late Pleistocene topography infilled with compressible Holocene strata; 88% of the subsidence values are <2 mm/ yr. We suggest that during the Holocene two significant but previously underestimated contributors to changes in Nile Delta mass balance have been sediment compaction and orbitally forced changes in sediment supply. Between 8000 and 4000 calibrated (cal) 14C yr B.P., spatially averaged sedimentation rates were greater than subsidence, meaning that delta aggradation was the dominant geomorphological process at the regional scale. Since ca. 4000 cal yr B.P., a sharp climate-driven fall in Nile sediment supply, coupled with the human-induced drainage of deltaic wetlands, has rendered the depocenter more sensitive to degradation by sea-level rise and extreme flood events. [ABSTRACT FROM AUTHOR]

The mouths of the Nile Delta are sensitive coastal areas, their geomorphology primarily being mediated by relative sea-level rise and sediment supply. To further document the Holocene evolution of the Nile's Canopic mouth, a core was taken from the southern shores of Abu Qir Bay, close to the ancient Canopic channel. Core bio-sedimentology and chronostratigraphy highlight four stages of marine incursion which are juxtaposed upon the general progradation trend of the Nile coast in this area. Compiled age-depth points from sediment cores taken in Abu Qir Bay underscore two phases of negative sediment budget at the Canopic mouth: (1) a first period, between 3.5 and 2 ka cal. yr BC, probably in relation to the well-documented mid-to-late Holocene decline in Nile flow; and (2) a second phase, after 0.5 ka cal. AD, linked to a decline in Canopic sediment supply to the coastal area, and concomitant with the development of the Rashid branch. The erosion and reworking of material flattened and lowered the promontory surface by up to 4 m. The submersion of the Canopic promontory was completed by relative sea-level rise, primarily controlled by the compaction and liquefaction of unconsolidated lagoonal muds. The lowering of the Canopic mouth led to the submersion of two ancient estuarine-harbor cities, known as East-Canopus and Herakleion, whose remains lie 4–7 m below present mean sea level. It is argued that the subsidence of the two cities cannot explain their abandonment during the late 7th–early 8th century AD, taking into account the regional occupation pattern during Antiquity. Rather, the longevity of the two cities, spanning more than 13 centuries, shows that adaptation to coastal risks including erosion, subsidence and high-energy events like storms or tsunamis, was the rule. [ABSTRACT FROM AUTHOR]

Abstract: Holocene sediments from the ria of Burmarrad (western Malta) provide a record of changing geomorphology, relative sea-level rise and human impacts. Chronostratigraphic evidence attests to a fluvial-dominated upper estuarine environment between ~7500cal. BP and ~7000cal. BP, with increasing salinity linked to rising post-glacial sea level. The shift to a marine setting is dated to ~7000cal. BP, characterized by a wave-dominated coastline that accreted up until ~4000cal. BP. During the maximum marine ingression, the Burmarrad floodplain formed a vast 1.8km2 marine bay, ~3000m long by ~650m wide, whose environmental potentiality presented western Malta''s early societies with a multiplicity of coastal, terrestrial, and fluvial resources, in addition to a low-energy context favourable to the anchoring of boats. New palynological data show intensified human impact on the landscape beginning ~7300cal. BP, which is broadly consistent with the earliest archaeological traces. Western Malta was already void of a significant vegetation cover by the mid-Holocene. Rapid human-induced sedimentation means that by the Bronze Age, the palaeobay had been reduced by ~40% compared to its mid-Holocene maximum. The final morphogenetic phase constitutes fluvial silts and sands that began accreting after 2700cal. BP. During Punic/Roman times, the ria bay was ~1km2, and was flanked to the south by a well-developed deltaic plain providing fertile land for agriculture. Today, the ria is ~60% smaller than it was 7000years ago. [Copyright &y& Elsevier]

Abstract: The Nile valley accommodates the world''s longest river and shaped the development of numerous complex societies, providing a reliable source of water for farming and linking populations to sub-Saharan Africa and the Mediterranean Sea. Its fertile delta lay at the heart of ancient Egyptian civilization, however little is known of its morpho-sedimentary response to basin-wide changes in Holocene hydrology. Here, we present two well-resolved records from the Nile delta (based on ∼320 radiocarbon dates) to reconstruct the timing and rhythm of catchment-scale modifications during the past 8000 years. On the orbital timescale, we demonstrate that Nilotic hydrology and sedimentation have responded to low-latitude insolation forcing while, on sub-millennial timescales, many of the major phases of deltaic modification were mediated by climate events linked to El Niño Southern Oscillation-type (ENSO) variability. [Copyright &y& Elsevier]