Tine Missiaen - Academia.edu (original) (raw)

Papers by Tine Missiaen

Research paper thumbnail of Coastal management : guide for using archaeology, palaeoenvironments, history and art

Coastal managers face an ongoing battle to moderate impacts from the sea in the face of a changin... more Coastal managers face an ongoing battle to moderate impacts from the sea in the face of a changing climate and pressures from human use of the coastal zone. The challenges that lie ahead are forecast to increase while resources are being forced to go further. This document quantifies the value of under-used coastal indicators that can be applied as tools to inform long term patterns of coastal change. In addition, it provides instruments to communicate past change effectively, model areas under threat and interpret progressive coastal trends. • To develop additional tools for decision making in coastal management. When tough coastal management decisions are required to determine levels of future risk, science based evidence is necessary to support these decisions. The project has analysed scientific data within archives to provide evidence of long-term coastal adaptation. • To extract data from under-used sources from archaeology, art, maps, charts and photographs. It was realised that data from archaeology, heritage features, art, photographs, maps and charts can provide both qualitative and quantitative information on coastal evolution and reactions to climate change spanning from the past decade to many thousands of millennia. The potential of these datasets were not being used to support understanding of long-term coastal change. • To demonstrate the value of archaeological, historic and artistic resources to understanding long-term coastal change. Study of this data allows understanding and modelling of past changes on the coast and human interactions with these processes. This knowledge can be used to plan for current and future changes in the face of increased coastal erosion, flooding and coastal instability. • The project was delivered between 2011 and 2014. • Project partners from the United Kingdom, France, Belgium and the Netherlands were involved, representing large parts of the coast of the Channel-Southern North Sea area. • The project was part funded by the European Regional Development Fund through the Interreg IVA 2 Seas Programme. • Data research-using local, regional and national sources of information on geology, geomorphology, archaeology, history, art, maps, charts and photographs. Using existing data enables maximum value to be extracted from available resources. Records consulted included heritage, environmental and geological databases, documentary archives, archaeological collections, online sources, art galleries, private art collections and publications. • Ranking approach-developed four complementary methods for assessing the data sources for their potential to inform on coastal change. The ranking systems were: 1) archaeological and palaeoenvironmental evidence; 2) artistic depictions; 3) maps and charts; and 4) historic photographs. The ranking enabled sites of highest potential to inform on coastal change to be identified, this helped target sites for more detailed field investigations. It also demonstrated where sites or areas of the coast were represented within several of the available data sources. • Fieldwork-a range of archaeological and palaeoenvironmental fieldwork approaches were taken to extract primary data from high potential sites. Site visits to areas shown within artistic depictions gathered information on current coastal conditions. Working in the intertidal and marine zones enabled techniques to be used to gather data from exposed and buried archaeological and palaeoenvironmental remains. Survey ranged from 'low-tech' drawn records in the intertidal zone and by divers underwater, through to the application of technology deployed from boats to image buried sites and landscapes. More intrusive investigation included a range of augering to collect samples through to larger archaeological excavations. Selected fieldwork case studies are presented in the report.

Research paper thumbnail of Shallow marine acoustic imaging in environmental investigations

Research paper thumbnail of Le Paardenmarkt, une décharge de munitions de la 1ère GM devant la côte belge

Background: Drug addiction is one of the main concerns of mental and social damages in current ce... more Background: Drug addiction is one of the main concerns of mental and social damages in current century with unpleasant consequences for affected person. The present study aims to compare the attention functions in heroin abusers compared with normal controls. Methods: The method of current research was causative-comparative with two groups of heroin abusers and normal individuals. Therefore, 30 men consumers of heroin and 30 normal individuals were selected using convenience sampling. The substance users were selected from addiction treatment center in Gonabab city. The normal group included 30 normal individuals matched in terms of age, sex and education with the first group. The data were collected using Stroop test, Spatial Cueing and Change Detection. Data were analyzed using multivariate analysis through SPSS v.19 software. Results: The outcomes of multivariate analysis showed that significant difference was between attention functions in group of heroin abusers with normal individuals (p<0.0001). Conclusion: Heroin abuse has undesired adverse effects on attention function in heroin abusers. Attention dysfunction affects on the everyday life of the individual and his activities. It is recommended that desirable treatment strategy is designed for heroin abusers for remove and reduce the deficit of attention.

Research paper thumbnail of Prehistorische fossielen en verdronken landschappen in het Belgisch deel van de Noordzee

Research paper thumbnail of De Noordzeebodem: ooit een dichtbevolkt rivierenlandschap

Probeer het je voor te stellen. Je staat op de zeedijk en tuurt over die eindeloze, golvende Noor... more Probeer het je voor te stellen. Je staat op de zeedijk en tuurt over die eindeloze, golvende Noordzeevlakte. Waar nu enkel water te zien is, strekte zich heel lang geleden een landschap uit van brede, vruchtbare valleien en imposante riviersystemen. Een landschap bevolkt door grote kudden planteneters (mammoeten, bizons, paarden), roofdieren (lynx, wolf, sabeltand) en jawel, mensen! Een deel van dit gebied had zelfs een naam: Doggerland.

Research paper thumbnail of A continuum of knowledge from measurements to modelling to explore the future of our seabed resources, Belgian part of the North Sea

Research paper thumbnail of Modeling Holocene landscape wettening in the Lower Scheldt basin in relation to its prehistoric occupation

Research paper thumbnail of Interactive management of marine resources in the southern North Sea, a long-term perspective

Management of geological resources is based, ideally, on information on the quality and quantity ... more Management of geological resources is based, ideally, on information on the quality and quantity of surface and subsurface litho-stratigraphical properties. Increasingly, these data become available for the offshore domain, though the integration into manageable and user-friendly applications is still at its infancy. Building on expertise from on-land data mining, we are now in the phase of creating 3D voxel models allowing for multi-criteria resource volume calculations. The underlying data are subdued to uncertainty modelling, a necessary step to produce data products with confidence limits. Anticipating on the dynamic nature of the marine environment, voxel models are coupled to environmental impact models that calculate resource depletion and regeneration under various scenarios, and using geological boundary conditions. In combination with foreseen impacts on fauna and flora, mining thresholds can be defined. Integration into a decision-support system allows for easy querying a...

Research paper thumbnail of Introducing data and model uncertainty into the new 3D voxel model of the Belgian part of the North Sea

One of the major challenges in creating geological models is to be able to prove how ’realistic’ ... more One of the major challenges in creating geological models is to be able to prove how ’realistic’ these models are. Since the 3D voxel model developed within TILES (Belspo project on ‘Transnational and Integrated Long-term Marine Exploitation Strategies’) will form the basis of a decision support system that will ‘guide’ the sand extraction in the Belgian part of the North Sea for the coming years, it is crucial to integrate estimates of uncertainties into the model. Two major categories of uncertainties are being quantified: database related uncertainties (e.g., core density) and interpolation-related uncertainties. The latter are quantified by calculating entropy (i.e. entropy of a voxel is a single value ranging from 0 to 1 that can be calculated from each of the probabilities of lithological class. An entropy value of 0 means that there is no uncertainty, whereas a value of 1 indicates that all lithological classes have the same probability thus higher uncertainty.) on the lithoc...

Research paper thumbnail of GISP : Geophysical In Situ Probe

Research paper thumbnail of Development of a Tube Wave System for Obtaining in Situ Geotechnical Parameters in Shallow Marine Environments

Research paper thumbnail of Acute aquatic toxicity of arsenic-based chemical warfare agents to Daphnia magna

Research paper thumbnail of Exploration of submerged Mesolithic landscapes around the Brown Bank, southern North Sea

Research paper thumbnail of Archaeological prospection of the nearshore and intertidal area using ultra-high resolution marine acoustic techniques: Results from a test study on the Belgian coast at Ostend-Raversijde

Geoarchaeology, 2017

The coastal site of Ostend-Raversijde in Belgium is known for its archaeological artifacts, mainl... more The coastal site of Ostend-Raversijde in Belgium is known for its archaeological artifacts, mainly from Roman and medieval times. In recent years, detailed geophysical and geotechnical investigations have been carried out here to test the efficiency of these techniques for geoarchaeological prospection of the subtidal and intertidal zone. Very high-resolution 2D subbottom profiling using a parametric echosounder evidenced a highly complex system of paleogullies and tidal channels, some of which can be linked to the medieval peninsula Testerep and the drowned settlement of Walraversijde. For the first time marine seismic and terrestrial electromagnetic induction (EMI) data were fully integrated in the same intertidal area. The parametric echosounder proved a highly effective tool to map the (partly excavated) peat layers and submerged landscape in high detail, even in extremely shallow water. Using a novel multitransducer parametric echosounder (SES-2000 Quattro), unique 3D imaging of the peat exploitation pattern was possible with unprecedented detail (submeter level). This sets a new standard for shallow water research and opens important new perspectives for geoarchaeological studies in nearshore areas.

Research paper thumbnail of How subsurface voxel modelling and uncertainty analysis contribute to habitat-change prediction and monitoring

Research paper thumbnail of Building a 4D Voxel-Based Decision Support System for a Sustainable Management of Marine Geological Resources

Oceanographic and Marine Cross-Domain Data Management for Sustainable Development

For sustainable management of marine geological resources, a geological knowledge base is being b... more For sustainable management of marine geological resources, a geological knowledge base is being built for the Belgian and southern Netherlands part of the North Sea. Voxel models of the subsurface are used for predictions on sand and gravel quantities and qualities, to ensure long-term resource use. The voxels are filled with geological data from boreholes and seismic lines, but other information can be added also. The geology provides boundary conditions needed to run environmental impact models that calculate resource depletion and regeneration under various scenarios of aggregate extraction. Such analyses are important in monitoring progress towards good environmental status, as outlined in the Marine Strategy Framework Directive. By including uncertainty, data products can be generated with confidence limits, which is critical for assessing the significance of changes in the habitat or in any other resource-relevant parameter. All of the information is integrated into a cross-do...

Research paper thumbnail of Exploring Integrated Geophysics and Geotechnics as a Paleolandscape Reconstruction Tool: Archaeological Prospection of (Prehistoric) Sites Buried Deeply below the Scheldt Polders (NW Belgium)

Archaeological Prospection, 2016

During extensive construction works in Antwerp harbour, well preserved Late Glacial dune formatio... more During extensive construction works in Antwerp harbour, well preserved Late Glacial dune formations were discovered buried deeply below the Scheldt polders and covered by peat, organic matter (OM) rich clays and marine clayey to sandy sediments. First, coring based archaeological prospection strategies for evaluating prehistoric occupation levels in wetland landscapes are reviewed. Next, a more effective approach including near surface geophysical and geotechnical techniques is proposed and tested in Doelpolder Noord. The results indicate that high resolution electromagnetic induction survey at multiple coil spacing provides a suitable approximation of the prehistoric landscape variability but is challenged by variations in groundwater brackishness. Gridded cone penetration tests provide a solution in such cases and serve as an excellent interpretation tool for the conductivity data in general. Due to the required effort, electrical resistance imaging and shear wave land seismics were judged inefficient. Finally, a small dune with indications of paleosol conservation and estimated suitability for Final Palaeolithic to Early Neolithic occupation is sampled by Dutch hand augering and Sonic Drill Aqualock coring. Archaeological indicators for prehistoric occupation such as burnt bone and flint fragments were retrieved from these samples after sieving.

Research paper thumbnail of Chemical munitions off the Belgian coast : an evaluation study

Research paper thumbnail of Technical article: A new 3D seismic acquisition system for very high and ultra high resolution shallow water studies

First Break, 2002

give the system a full wingspan of 14 m and provide spatial control for the spread of eight dual-... more give the system a full wingspan of 14 m and provide spatial control for the spread of eight dual-channel streamers. The streamers are 7.5 m long, with a channel spacing of 2 m and two hydrophones per channel (hydrophone spacing of 0.25 m). The streamers are towed a few metres behind the modules, the distance depending on the desired offset. The surface-towed frames are kept under air pressure (± 0.5 bar), which allows convenient deployment and recovery by inflation and deflation. The inflatable frames are made of flexible hose of 10 cm diameter. Each frame consists of two lengthwise floats connected by three crosswise floats, the latter curving upwards in order to reduce contact with the water (Fig. 1). Their form has been pre-shaped to increase the rigidity of the frames. The use of a modular system allows the dimensions of the acquisition system to be varied, by simply increasing or decreasing the number of modules and streamers. The central RIB has a catamaran structure to ensure optimum stability at sea, and it is wide enough to allow ample storage of the modular frames. Furthermore, the positioning antenna can be placed on it. The antenna is normally installed on the rear of the boat, near the source and streamers, in order to reduce relative positioning errors to a minimum. The source (IKB SEISTEC, a wide-band electrodynamic boomer with a dominant frequency of 23 kHz) is towed closely behind the RIB. The system is typically deployed from small-to mediumsized vessels, preferably with an A-frame or small crane. All components are folded within the RIB, and once deployed at the correct distance behind the vessel the modules are inflated. A central rope fixed to the RIB is used for towing with additional lines attached to the module tips, ensuring a good array layout. After the survey, the modules are deflated and rolled (with the streamers) inside the RIB, which is placed on the deck of the vessel. In protected waters (harbour areas, rivers, canals and lakes) and in the absence of strong currents, the system can also be used autonomously. To this end the central RIB is converted into a survey vessel unit with twin engines and a

Research paper thumbnail of Intertidal landscape response time to dike breaching and stepwise re-embankment: A combined historical and geomorphological study

Research paper thumbnail of Coastal management : guide for using archaeology, palaeoenvironments, history and art

Coastal managers face an ongoing battle to moderate impacts from the sea in the face of a changin... more Coastal managers face an ongoing battle to moderate impacts from the sea in the face of a changing climate and pressures from human use of the coastal zone. The challenges that lie ahead are forecast to increase while resources are being forced to go further. This document quantifies the value of under-used coastal indicators that can be applied as tools to inform long term patterns of coastal change. In addition, it provides instruments to communicate past change effectively, model areas under threat and interpret progressive coastal trends. • To develop additional tools for decision making in coastal management. When tough coastal management decisions are required to determine levels of future risk, science based evidence is necessary to support these decisions. The project has analysed scientific data within archives to provide evidence of long-term coastal adaptation. • To extract data from under-used sources from archaeology, art, maps, charts and photographs. It was realised that data from archaeology, heritage features, art, photographs, maps and charts can provide both qualitative and quantitative information on coastal evolution and reactions to climate change spanning from the past decade to many thousands of millennia. The potential of these datasets were not being used to support understanding of long-term coastal change. • To demonstrate the value of archaeological, historic and artistic resources to understanding long-term coastal change. Study of this data allows understanding and modelling of past changes on the coast and human interactions with these processes. This knowledge can be used to plan for current and future changes in the face of increased coastal erosion, flooding and coastal instability. • The project was delivered between 2011 and 2014. • Project partners from the United Kingdom, France, Belgium and the Netherlands were involved, representing large parts of the coast of the Channel-Southern North Sea area. • The project was part funded by the European Regional Development Fund through the Interreg IVA 2 Seas Programme. • Data research-using local, regional and national sources of information on geology, geomorphology, archaeology, history, art, maps, charts and photographs. Using existing data enables maximum value to be extracted from available resources. Records consulted included heritage, environmental and geological databases, documentary archives, archaeological collections, online sources, art galleries, private art collections and publications. • Ranking approach-developed four complementary methods for assessing the data sources for their potential to inform on coastal change. The ranking systems were: 1) archaeological and palaeoenvironmental evidence; 2) artistic depictions; 3) maps and charts; and 4) historic photographs. The ranking enabled sites of highest potential to inform on coastal change to be identified, this helped target sites for more detailed field investigations. It also demonstrated where sites or areas of the coast were represented within several of the available data sources. • Fieldwork-a range of archaeological and palaeoenvironmental fieldwork approaches were taken to extract primary data from high potential sites. Site visits to areas shown within artistic depictions gathered information on current coastal conditions. Working in the intertidal and marine zones enabled techniques to be used to gather data from exposed and buried archaeological and palaeoenvironmental remains. Survey ranged from 'low-tech' drawn records in the intertidal zone and by divers underwater, through to the application of technology deployed from boats to image buried sites and landscapes. More intrusive investigation included a range of augering to collect samples through to larger archaeological excavations. Selected fieldwork case studies are presented in the report.

Research paper thumbnail of Shallow marine acoustic imaging in environmental investigations

Research paper thumbnail of Le Paardenmarkt, une décharge de munitions de la 1ère GM devant la côte belge

Background: Drug addiction is one of the main concerns of mental and social damages in current ce... more Background: Drug addiction is one of the main concerns of mental and social damages in current century with unpleasant consequences for affected person. The present study aims to compare the attention functions in heroin abusers compared with normal controls. Methods: The method of current research was causative-comparative with two groups of heroin abusers and normal individuals. Therefore, 30 men consumers of heroin and 30 normal individuals were selected using convenience sampling. The substance users were selected from addiction treatment center in Gonabab city. The normal group included 30 normal individuals matched in terms of age, sex and education with the first group. The data were collected using Stroop test, Spatial Cueing and Change Detection. Data were analyzed using multivariate analysis through SPSS v.19 software. Results: The outcomes of multivariate analysis showed that significant difference was between attention functions in group of heroin abusers with normal individuals (p<0.0001). Conclusion: Heroin abuse has undesired adverse effects on attention function in heroin abusers. Attention dysfunction affects on the everyday life of the individual and his activities. It is recommended that desirable treatment strategy is designed for heroin abusers for remove and reduce the deficit of attention.

Research paper thumbnail of Prehistorische fossielen en verdronken landschappen in het Belgisch deel van de Noordzee

Research paper thumbnail of De Noordzeebodem: ooit een dichtbevolkt rivierenlandschap

Probeer het je voor te stellen. Je staat op de zeedijk en tuurt over die eindeloze, golvende Noor... more Probeer het je voor te stellen. Je staat op de zeedijk en tuurt over die eindeloze, golvende Noordzeevlakte. Waar nu enkel water te zien is, strekte zich heel lang geleden een landschap uit van brede, vruchtbare valleien en imposante riviersystemen. Een landschap bevolkt door grote kudden planteneters (mammoeten, bizons, paarden), roofdieren (lynx, wolf, sabeltand) en jawel, mensen! Een deel van dit gebied had zelfs een naam: Doggerland.

Research paper thumbnail of A continuum of knowledge from measurements to modelling to explore the future of our seabed resources, Belgian part of the North Sea

Research paper thumbnail of Modeling Holocene landscape wettening in the Lower Scheldt basin in relation to its prehistoric occupation

Research paper thumbnail of Interactive management of marine resources in the southern North Sea, a long-term perspective

Management of geological resources is based, ideally, on information on the quality and quantity ... more Management of geological resources is based, ideally, on information on the quality and quantity of surface and subsurface litho-stratigraphical properties. Increasingly, these data become available for the offshore domain, though the integration into manageable and user-friendly applications is still at its infancy. Building on expertise from on-land data mining, we are now in the phase of creating 3D voxel models allowing for multi-criteria resource volume calculations. The underlying data are subdued to uncertainty modelling, a necessary step to produce data products with confidence limits. Anticipating on the dynamic nature of the marine environment, voxel models are coupled to environmental impact models that calculate resource depletion and regeneration under various scenarios, and using geological boundary conditions. In combination with foreseen impacts on fauna and flora, mining thresholds can be defined. Integration into a decision-support system allows for easy querying a...

Research paper thumbnail of Introducing data and model uncertainty into the new 3D voxel model of the Belgian part of the North Sea

One of the major challenges in creating geological models is to be able to prove how ’realistic’ ... more One of the major challenges in creating geological models is to be able to prove how ’realistic’ these models are. Since the 3D voxel model developed within TILES (Belspo project on ‘Transnational and Integrated Long-term Marine Exploitation Strategies’) will form the basis of a decision support system that will ‘guide’ the sand extraction in the Belgian part of the North Sea for the coming years, it is crucial to integrate estimates of uncertainties into the model. Two major categories of uncertainties are being quantified: database related uncertainties (e.g., core density) and interpolation-related uncertainties. The latter are quantified by calculating entropy (i.e. entropy of a voxel is a single value ranging from 0 to 1 that can be calculated from each of the probabilities of lithological class. An entropy value of 0 means that there is no uncertainty, whereas a value of 1 indicates that all lithological classes have the same probability thus higher uncertainty.) on the lithoc...

Research paper thumbnail of GISP : Geophysical In Situ Probe

Research paper thumbnail of Development of a Tube Wave System for Obtaining in Situ Geotechnical Parameters in Shallow Marine Environments

Research paper thumbnail of Acute aquatic toxicity of arsenic-based chemical warfare agents to Daphnia magna

Research paper thumbnail of Exploration of submerged Mesolithic landscapes around the Brown Bank, southern North Sea

Research paper thumbnail of Archaeological prospection of the nearshore and intertidal area using ultra-high resolution marine acoustic techniques: Results from a test study on the Belgian coast at Ostend-Raversijde

Geoarchaeology, 2017

The coastal site of Ostend-Raversijde in Belgium is known for its archaeological artifacts, mainl... more The coastal site of Ostend-Raversijde in Belgium is known for its archaeological artifacts, mainly from Roman and medieval times. In recent years, detailed geophysical and geotechnical investigations have been carried out here to test the efficiency of these techniques for geoarchaeological prospection of the subtidal and intertidal zone. Very high-resolution 2D subbottom profiling using a parametric echosounder evidenced a highly complex system of paleogullies and tidal channels, some of which can be linked to the medieval peninsula Testerep and the drowned settlement of Walraversijde. For the first time marine seismic and terrestrial electromagnetic induction (EMI) data were fully integrated in the same intertidal area. The parametric echosounder proved a highly effective tool to map the (partly excavated) peat layers and submerged landscape in high detail, even in extremely shallow water. Using a novel multitransducer parametric echosounder (SES-2000 Quattro), unique 3D imaging of the peat exploitation pattern was possible with unprecedented detail (submeter level). This sets a new standard for shallow water research and opens important new perspectives for geoarchaeological studies in nearshore areas.

Research paper thumbnail of How subsurface voxel modelling and uncertainty analysis contribute to habitat-change prediction and monitoring

Research paper thumbnail of Building a 4D Voxel-Based Decision Support System for a Sustainable Management of Marine Geological Resources

Oceanographic and Marine Cross-Domain Data Management for Sustainable Development

For sustainable management of marine geological resources, a geological knowledge base is being b... more For sustainable management of marine geological resources, a geological knowledge base is being built for the Belgian and southern Netherlands part of the North Sea. Voxel models of the subsurface are used for predictions on sand and gravel quantities and qualities, to ensure long-term resource use. The voxels are filled with geological data from boreholes and seismic lines, but other information can be added also. The geology provides boundary conditions needed to run environmental impact models that calculate resource depletion and regeneration under various scenarios of aggregate extraction. Such analyses are important in monitoring progress towards good environmental status, as outlined in the Marine Strategy Framework Directive. By including uncertainty, data products can be generated with confidence limits, which is critical for assessing the significance of changes in the habitat or in any other resource-relevant parameter. All of the information is integrated into a cross-do...

Research paper thumbnail of Exploring Integrated Geophysics and Geotechnics as a Paleolandscape Reconstruction Tool: Archaeological Prospection of (Prehistoric) Sites Buried Deeply below the Scheldt Polders (NW Belgium)

Archaeological Prospection, 2016

During extensive construction works in Antwerp harbour, well preserved Late Glacial dune formatio... more During extensive construction works in Antwerp harbour, well preserved Late Glacial dune formations were discovered buried deeply below the Scheldt polders and covered by peat, organic matter (OM) rich clays and marine clayey to sandy sediments. First, coring based archaeological prospection strategies for evaluating prehistoric occupation levels in wetland landscapes are reviewed. Next, a more effective approach including near surface geophysical and geotechnical techniques is proposed and tested in Doelpolder Noord. The results indicate that high resolution electromagnetic induction survey at multiple coil spacing provides a suitable approximation of the prehistoric landscape variability but is challenged by variations in groundwater brackishness. Gridded cone penetration tests provide a solution in such cases and serve as an excellent interpretation tool for the conductivity data in general. Due to the required effort, electrical resistance imaging and shear wave land seismics were judged inefficient. Finally, a small dune with indications of paleosol conservation and estimated suitability for Final Palaeolithic to Early Neolithic occupation is sampled by Dutch hand augering and Sonic Drill Aqualock coring. Archaeological indicators for prehistoric occupation such as burnt bone and flint fragments were retrieved from these samples after sieving.

Research paper thumbnail of Chemical munitions off the Belgian coast : an evaluation study

Research paper thumbnail of Technical article: A new 3D seismic acquisition system for very high and ultra high resolution shallow water studies

First Break, 2002

give the system a full wingspan of 14 m and provide spatial control for the spread of eight dual-... more give the system a full wingspan of 14 m and provide spatial control for the spread of eight dual-channel streamers. The streamers are 7.5 m long, with a channel spacing of 2 m and two hydrophones per channel (hydrophone spacing of 0.25 m). The streamers are towed a few metres behind the modules, the distance depending on the desired offset. The surface-towed frames are kept under air pressure (± 0.5 bar), which allows convenient deployment and recovery by inflation and deflation. The inflatable frames are made of flexible hose of 10 cm diameter. Each frame consists of two lengthwise floats connected by three crosswise floats, the latter curving upwards in order to reduce contact with the water (Fig. 1). Their form has been pre-shaped to increase the rigidity of the frames. The use of a modular system allows the dimensions of the acquisition system to be varied, by simply increasing or decreasing the number of modules and streamers. The central RIB has a catamaran structure to ensure optimum stability at sea, and it is wide enough to allow ample storage of the modular frames. Furthermore, the positioning antenna can be placed on it. The antenna is normally installed on the rear of the boat, near the source and streamers, in order to reduce relative positioning errors to a minimum. The source (IKB SEISTEC, a wide-band electrodynamic boomer with a dominant frequency of 23 kHz) is towed closely behind the RIB. The system is typically deployed from small-to mediumsized vessels, preferably with an A-frame or small crane. All components are folded within the RIB, and once deployed at the correct distance behind the vessel the modules are inflated. A central rope fixed to the RIB is used for towing with additional lines attached to the module tips, ensuring a good array layout. After the survey, the modules are deflated and rolled (with the streamers) inside the RIB, which is placed on the deck of the vessel. In protected waters (harbour areas, rivers, canals and lakes) and in the absence of strong currents, the system can also be used autonomously. To this end the central RIB is converted into a survey vessel unit with twin engines and a

Research paper thumbnail of Intertidal landscape response time to dike breaching and stepwise re-embankment: A combined historical and geomorphological study