Search

The Intergovernmental Panel on Climate Change has documented wide-ranging changes to the world's coasts and oceans, with significant further change predicted. Impacts on coastal and underwater heritage sites, however, remain relatively poorly understood. The authors draw on 30 years of research into coastal and underwater archaeological sites to highlight some of the interrelated processes of deterioration and damage. Emphasising the need for closer collaboration between, on one hand, archaeologists and cultural resource managers and, on the other, climate and marine scientists, this article also discusses research from other disciplines that informs understanding of the complexity of the interaction of natural and anthropogenic processes and their impacts on cultural heritage. Keywords: climate change, coastal heritage, underwater cultural heritage, environment, impact, erosion, Introduction Coastal environments have long been favoured for human migration and settlement. For millennia, these locations have provided access to resources and well-connected places for exchange and defence (Dawson et [...]

Increasing pressure – such as from conflict, climate change and urbanisation – on maritime cultural heritage in the Middle East and North Africa (MENA) led to the establishment of the Maritime Endangered Archaeology (MarEA) Project in 2019. This five-year programme aims to assess rapidly and comprehensively the vulnerability of maritime and coastal heritage in the MENA region and assist in its management in the face of the aforementioned challenges. The two case studies discussed in this article highlight some of the main aspects of MarEA's current work in North Africa by focusing on two different aspects of the methodological approach used: first, the generalised but comprehensive damage and threat assessment, as applied to all sites, and demonstrated for the historic port of Suakin (Sudan); second, site-specific shoreline change assessment for the purpose of assessing the impact of coastal erosion, as demonstrated for the World Heritage Site of Sabratha (Libya). [ABSTRACT FROM AUTHOR]

Recent global projections of climate change highlight alarming rates of flooding and erosion on the coastlines of the Middle East and North Africa (MENA). Though there are indisputable links between climate change and the deterioration of maritime cultural heritage (particularly coastal archaeology), deterioration is often the result of multiple compounding factors, central among which are anthropogenic landscape alterations. In this article the authors attempt to disentangle these factors at a small scale, using the Gaza Strip, Libya, and Oman as case studies. They examine the impact of accelerating coastal erosion, flooding, and increasing frequency of tropical cyclones to question predominant discussions on the impact of climate change on heritage. They emphasize methods and practices for the identification of sites that can expand and refine climate change research (often reliant on data from the twentieth and twenty-first centuries) through the long-term perspective archaeology is uniquely placed to offer. [ABSTRACT FROM AUTHOR]

Coastal erosion in Cyrenaica (Eastern Libya) represents a major problem for archaeology and heritage management. The area is rich in archaeological sites, often understudied or not fully documented, but also has extensive stretches of vulnerable eroding coastline. This study demonstrates the extent and impact of erosion via shoreline change assessment at two spatial scales. Firstly, wide area assessment using shorelines extracted from a time-series of medium-resolution Landsat imagery. Secondly, site-specific assessment using recent and historic Very High Resolution (VHR) satellite imagery. In both cases, extracted shorelines at different timesteps were compared using the Digital Shoreline Analysis System (DSAS) tool to quantify rates and magnitudes of shoreline movement. The results show extensive zones of erosion at and around the key ancient harbour sites of Apollonia, Ptolemais and Tocra. They also suggest increased rates of coastal retreat in recent years, which is likely linked to anthropogenic actions such as sand mining and urbanization. Forecasts based on present-day shoreline change rates, coupled with ground-level documentation of the vulnerable shorelines is used to identify archaeological features and structures which will likely be progressively damaged or destroyed over the next 20 years. The ability to actively protect archaeological sites is unclear, but there is a clear need for mitigation in the form of enhanced awareness of environmental problems (e.g. caused by sand mining) and more intensive survey/documentation of sites and areas which will be lost in the coming years. [ABSTRACT FROM AUTHOR]

Climate change threatens coastal archaeology through storm flooding (extreme sea-level: ESL), long-term sea-level rise (SLR) and coastal erosion. Many regions, like the Middle East and North Africa (MENA), lack key baseline evidence. We present initial results from a climate change threat assessment of MENA's coastal heritage using the Maritime Endangered Archaeology inventory: a geospatial database of MENA maritime archaeological sites incorporating a disturbance/ threat assessment. It informs two analyses of past disturbance and future threat: (1) using the integral threat/disturbance assessment, and (2) geospatial extraction of information from external coastal change models. Analysis suggests <5% of documented coastal sites are definitely affected by coastal erosion but up to 34% could also have experienced past flooding, erosion, or storm action. Climate change-related threats will increase over the 21st Century and accelerate post-2050 if carbon emissions remain high. SLR and ESL could impact 14–25% of sites by 2050 and 18–34% by 2100. Over 30% to 40% of sites could be impacted by erosion by 2050 and 2100 respectively. Whilst documentation is ongoing and there remain modeling uncertainties, this approach provides a means to redress the absence of baseline data on climate change threats to coastal cultural heritage in MENA. [ABSTRACT FROM AUTHOR]

Urbanisation, comprising development, land reclamation and population growth along coastal margins, continues to place significant pressure on the maritime cultural heritage (MCH), particularly in the Middle East and North Africa (MENA) region. Thus, there is a growing need for ascertaining the extent of the affected MCH resource and its condition. One such assessment is being undertaken by the Maritime Endangered Archaeology (MarEA) project, which is generating a unique informed database of the maritime resource in the MENA region. Through a regional overview combined with focused assessment on two case studies – Marsa Matruh (Egypt) and Bahrain – this paper demonstrates the threat urbanisation poses and the damage it has inflicted on MCH. The analyses and documentation that MarEA produces via remote sensing, desk-based and field-based assessments, constitutes a valuable resource that, at the very least, exists in digital perpetuity. It establishes a record that can be drawn upon to formulate targeted strategies and initiatives inclusive of the maritime cultural heritage resource. [ABSTRACT FROM AUTHOR]

The Middle East and North Africa have witnessed a surfeit of geospatial data collection projects, resulting in big databases with powerful deductive capacities. Despite the valuable insights and expansive evidentiary record offered by those databases, emphasis on anthropogenic threats to cultural heritage, combined with a limited integration of local perspectives, have raised important questions on the ethical and epistemological dimensions of big data. This paper contextualizes maritime cultural heritage (MCH) in those debates through the lens of the Maritime Endangered Archaeology in the Middle East and North Africa project (MarEA). MarEA is developing a unique for the region database for MCH designed to amalgamate a baseline record emphasizing spatial location, state of preservation, and vulnerability. This record will form a stepping stone toward finer-grained research on MCH and its interdisciplinary intersections. It is also developed as an information resource to facilitate local collaborators in prioritizing site monitoring and developing documentation, management, and mitigation strategies. [ABSTRACT FROM AUTHOR]

Shipwrecks are an integral part of our maritime archaeological landscape and are associated with diverse societal and cultural interests, yielding significant management challenges. Coupled hydrodynamic and geomorphological processes significantly impact the effective in situ preservation of these fragile sites. In this study, we assess sediment budget change and hydrodynamic triggers at metal‐hulled shipwrecks lost between 1875 and 1918, all located in the tidally dominated Irish Sea at depths between 26 and 84 m. This is conducted using time‐lapse, multibeam echosounder surveys at multiannual, annual, and weekly time steps, supported by sediment grain‐size analysis, modeled ocean currents, and shallow seismic data. Results indicate significant changes at all time steps for sites located in sand‐dominated environments, whereas the seabed around shipwrecks settled in multimodal sediments shows virtually no change outside of measurement errors (±30 cm). Variability in geomorphic change is attributed to local environmental factors, including bed shear stress, sediment supply, and spatial barriers to scour. We demonstrate that individual wrecks in similar shelf sea regions can be in very different equilibrium states, which has critical implications for the in situ management of underwater cultural heritage. [ABSTRACT FROM AUTHOR]

Increasing evidence indicates that ongoing and future climate change impacts, such as enhanced coastal erosion driven by intensified storms and sea-level rise, will be destructive or problematic for coastal archaeological heritage. Approaches to this problem range from broad-scale GIS-based vulnerability assessments to site-scale monitoring and survey. In all cases, the approach chosen should be based on the best-available data on the local historic environment and pattern of coastal change. Therefore, this paper will demonstrate how such data can be successively acquired and enhanced using an integrated approach that builds on and refines a previously conducted broadscale vulnerability assessment. This approach was adopted in the study region (Northern Ireland) owing to a lack of coherent and upto-date information on shoreline change. This approach incorporated the GIS-based Digital Shoreline Analysis System (DSAS) to quantify and analyze local shoreline change. DSAS is a software extension for ESRI ArcGIS which allows calculation of rate-of-change statistics using past shorelines identified from georeferenced historic maps and vertical aerial imagery. Additionally, a field survey was conducted to assess the condition of recorded sites, and identify unrecorded ones. Results revealed a more complex pattern of shoreline change in the study area (Magilligan Foreland, Lough Foyle) than previously anticipated, with zones of significant erosion interspersed with areas of stability or advance. Fifty-one new sites ranging from the prehistoric period to the Second World War were also identified. The new information was used to develop a priority classification based on site significance, condition and risk level which improved significantly on the uniform classification of the original broad-scale assessment. [ABSTRACT FROM AUTHOR]

Inland waterways, such as rivers and lakes have been foci of human settlement and use for millennia. However, underwater archaeological prospection or survey in these environments is often hindered by poor or no-visibility conditions. While this can be overcome using a range of well-established geophysical techniques, their application in inland waterways seems comparatively less common than in offshore environments. Possible reasons include the logistical challenges of surveying shallow confined, often inaccessible and uncharted waters coupled with a wider lack of awareness of the submerged archaeological potential of inland waterways. This paper demonstrates one method by which the logistical challenge can be circumvented, specifically the use of low-cost acoustic systems which combine a single-beam echo sounder and sidescan sonar. These systems have appeared within the last decade and are smaller and cheaper than their survey-grade counterparts. Although developed for the sport fishing community, as shown here, they can also be used for archaeological purposes. Their effectiveness for archaeological prospection is illustrated via three case studies from lacustrine and riverine settings in Northern Ireland and by reference to object detection and bathymetric mapping. The data presented indicate that the low-cost systems are capable of collecting data that is sufficient for archaeological purposes but they are best suited to shallow confined waters where their disadvantages (limited range and depth of operation, reduced image quality) are minimized. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper reports on the first systematic attempt to conduct archaeological survey and excavation for submerged prehistory on the island of Ireland. Fieldwork was conducted in two small bays where Early Mesolithic flint artefacts washed ashore hinted at the presence of a submerged assemblage. Methods employed include non-intrusive survey, hand coring and excavation. Together, these allowed identification of the artefact source, albeit reworked, in one bay and an early Holocene peat in the other. Though the subtidal assemblage is reworked and relatively small, it is significant in an Irish context and more widely illustrates the potential preservation of prehistoric sites and palaeo-landscapes in high-energy settings. [ABSTRACT FROM AUTHOR]

We present early to Mid-Holocene paleo-geographic reconstructions for the Ramore Head area (Northern Ireland). This coastal area is characterized by Mesolithic occupation (c. 10-6 ka) and preserved early-Mid-Holocene peats both on- and offshore. This paper improves on previous reconstructions by employing a backstripping methodology, which removes accumulated recent deposits from identified buried paleo-landsurfaces instead of using modern topography as an analogue to the past landscape. Paleo-landsurfaces are identified offshore from seismic profiles supplemented by cores, and onshore through legacy borehole records. The paleo-landsurface can be traced offshore to depths of −2 to −19 m and is buried by <5 m of modern sediment. It extends onshore under the coastal town of Portrush and is buried <2.5-10 m below modern ground level. The identified paleo-landsurface is combined with sea-level curves from recent Glacio-Isostatic-Adjustment models to reconstruct marine transgression during the early-Mid-Holocene. Comparison is also made with reconstructions based on modern topography. Together, the identified paleo-landsurfaces and revised reconstructions can assist future site prospection on- and offshore and delimit high-potential areas for heritage management. Revised reconstructions also allow placement of extant archaeology into a more accurate context of landscape change and help develop insights into local-scale site location patterns. [ABSTRACT FROM AUTHOR]

This paper will present research on the vulnerability mapping of coastal archaeological sites currently being undertaken in Northern Ireland. The ultimate aim of this research is improve current predictions of where archaeological sites and landscapes will be at risk in the future from coastal erosion. The initial stage of this approach uses a suite of oblique aerial photographs to construct a baseline of eroding locations and coastal geomorphology. The erosion baseline can then be integrated with existing historic environment records to obtain a coarse first-pass archaeological vulnerability assessment. Subsequent stages can then use this assessment to prioritize future mitigation such as field surveys or monitoring exercises, or conduct further refinements of vulnerability classifications by incorporating information on site type and positioning on a local scale. [ABSTRACT FROM AUTHOR]

Coastal archaeological heritage is potentially vulnerable to increased erosion resulting from predicted future sea-level rise and increased storminess. As all sites cannot be protected, it is essential that heritage managers know which sites and landscapes are most at risk so they can prioritize resources and decision-making most effectively. One method of doing so is through desk-based modeling of coastal vulnerability. This article outlines the advantages and limitations of such an approach and demonstrates the application of a desk-based model to case studies from Newfoundland's coast. The rate of future sea-level rise around Newfoundland is complicated by its glacio-isostatic recovery since the last ice age. The first step therefore in this assessment is to combine output from glacio-isostatic adjustment models with appropriate rates of global eustatic sea-level rise. Next, these data are integrated with existing information on coastal characteristics (topography, surficial geology, erosion rates) to assess coastal sensitivity to sea-level rise. Finally, overlay of known archaeological sites identifies those locations at greatest risk from destructive coastal changes. The results demonstrate the effectiveness of such models for regional-scale analyses but caution against the use of low resolution data to generate site-specific predictions. [ABSTRACT FROM PUBLISHER]

Two new 14C dates from a bed of compact inter-tidal peat at Mill Strand, Portrush, are reported and discussed in relation to two previously obtained ages from peat at Dhu Varren, a short distance inland. The date from the top of the Mill Strand peat is statistically inseparable from that of the peat top at Dhu Varren. Together these dates indicate the cessation of peat growth occurred ~6950-6550 cal. BP as a result of sand deposition associated with sea-level rise. However, dated samples from deeper within the respective stratigraphies are not compatible. Their respective ages in relation to their elevations pose a problem of interpretation. [ABSTRACT FROM PUBLISHER]

This paper outlines work currently being undertaken to reconstruct submerged archaeological landscapes off the north coast of Ireland. This research uses the recently-completed Joint Irish Bathymetric Survey (JIBS), which has provided full-coverage high-resolution multibeam bathymetric data for the sea-bed off the north coast. This data has been examined for evidence of past sea-level change and been used to produce palaeo-geographic reconstructions of the past landscape, which in turn have facilitated the identification of ten areas of high archaeological potential. The results presented here will form the basis of a future programme of archaeological survey and prospection. © 2010 The Authors [ABSTRACT FROM AUTHOR]

This paper describes Phase 1 of the project 'Archaeological Applications of the Joint Irish Bathymetric Survey (JIBS) Data', analysing bathymetric and backscatter data derived from multibeam surveys off the north coast of Ireland. In particular, the usability of the data for shipwreck detection, identification and site characterization is explored. In Phase 1, the data was screened for anomalous sea-bed features, which were subsequently described, catalogued and categorized according to their archaeological potential and cross-referenced against existing records. A planned second phase of this project will examine each anomaly in greater detail together with the local and regional hydrodynamic conditions. © 2010 The Authors [ABSTRACT FROM AUTHOR]

The large number of historic metal-hulled shipwrecks on the seabed is a major consideration for the marine environment, heritage management and spatial planning. Their stability is driven by linked hydro- and sediment-dynamics, which in turn influence chemical corrosion and biological encrustation. The dynamism at underwater sites is frequently expressed in elaborate patterns of depositional and erosional features developed due to seabed scour. These settings are complex, due to the variable morphologies of the wrecks, and diverse types of seabed geology and geomorphology. Not only are the flow patterns and geomorphic changes at shipwreck sites not fully understood, but how these influence the wreck structures remains under-researched. Here we combine high-resolution multibeam echosounder, ocean current and sediment data with 3D Computational Fluid Dynamics (CFD) to investigate interrelations between hydro- and sediment-dynamics and the deterioration of two complex, fully submerged tidally-influenced shipwrecks. Intricate patterns of wake and horseshoe vortices are observed, and modelled wall shear stresses predict geomorphic changes recorded in 4-year and one-week interval difference models. Moreover, substantial damage is detected on the wrecks, correlated with areas of elevated wall shear stress and pressure in CFD simulations. The combined approach aids site management and provides analogies for offshore engineering. • The sheer number of metal shipwrecks on the seabed creates perplexing management challenges. • Their structures significantly influence, and are influenced by, the local hydro- and sediment-dynamic settings. • Computational fluid dynamics and difference modelling using bathymetric data provide new insights into wreck deterioration. • Intricate patterns of simulated flows and wall shear stresses correspond to the areas of sediment erosion and deposition. [ABSTRACT FROM AUTHOR]