Seafloor Mapping Used for Erosion Control Project
The survey vessel is an inflatable craft with the GeoSwath Plus Compact sonar head installed on a retractable pole, together with peripheral sensors, motion reference unit, GPS and sound velocity probe. The splash protected deck unit is powered by batteries and operated via a ruggedized laptop. Alfred Wegener Institute for Polar and Marine Research. (Photo credit: S. Weege)
This bathymetry map of Pauline Cove on Herschel Island, Yukon Territory, Canada, serves as a baseline for long-time studies. The area was chosen as the natural laboratory for coastal erosion processes in permafrost regions. Note the dredge marks caused b
Bathymetry data showing the trenching for a water intake pipeline for a local fish farm in a port in northern Spain. The bathymetry data forms the basis for route planning environmental studies.
Side Scan data are used for seafloor classification, showing distinct rock outcrops, different substrates and marine vegetation, which was verified by ground sampling.
The Alfred Wegener Institute for Polar and Marine Research (AWI) in Germany began a coastal permafrost erosion research project (COPER), funded by the Helmholz Association and the institute, at Herschel Island in Canada. The research project looks to describe and quantify the erosion and related carbon release by using air- and space-born methods together with field research.
A stark seasonal contrast characterizes coastal dynamics on the Arctic coasts. During the winter, the coast is protected from wave erosion by sea and landfast ice. Without ice, the coast is exposed to mechanical and thermal processes with high erosion rates. Many climate change models indicate that the Arctic region will experience disproportionate warming in the coming decades, which will further increase the rate of coastal erosion and also liberate vast quantities of carbon stored in permafrost. The carbon released from the permafrost might contribute further to the climate’s warming trend.
Herschel Island in the Beaufort Sea, Yukon Territory, Canada, was selected as a natural laboratory for the long-term field study.
AWI chose the Kongsberg Geoacoustics GeoSwath Plus compact system for the seafloor mapping. The system delivers high resolution bathymetry with coverage of up to 12 times the water depth in this shallow water environment and co-registered geo-referenced side scan data, which can be used for detailed seafloor classification.
In the 2012 field season, data were collected in a 3.1 square kilometer area of Pauline Cove in depths of one to 17 meters (about three to 56 feet) in five short survey days. This dataset represents a baseline, to which future surveys can be compared. Future expeditions are planned to re-survey and expand the area to other parts of the island. The remote location makes it necessary to airlift in all equipment and personnel. The survey was carried with an inflatable craft, with the splash protected (IP54) system installed in a portable installation and powered by 24-volt battery.
CIS (Centre for submarine investigation) also purchased one of the first Kongsberg GeoSwath systems in 2004 and has recently upgraded it to the latest specifications. CIS was founded in 1987 as an environment consultancy company and has since then added services from seafloor mapping to chemical and biological analysis to cover the full range of techniques to prospect and investigate marine systems. It has carried out hundreds of privately and publicly funded projects from dredging monitoring to full environmental impact assessment, engineering and monitoring studies.
CIS carried out a project in a port in northern Spain to install a trenched pipeline for water intake for a local fish farm. CIS carried out the planning, environmental impact studies and monitoring.
Spain has been strongly affected by financial crisis with decreasing private investment and stalled public funding. Small companies in the marine survey sector are diversifying, collaborating and opening new markets, adapting technology and systems, and doing research and development, often in collaboration with academic partners, like the University of Vigo. The HidroBoya and a water quality monitoring system are examples of successful developments by the spin out company Hercules Control S.L. The company has also widened its geographic market from its home base of Santiago de Compostela, Galicia, Spain to work around Spain, Portugal, Northern Africa and South America.