Náttúruvísindi og tøkni
Vinnu Ph.d. - verkætlan
Kanningar, eftir møguligum grunnvatni, í økinum á Fútakletti á Vágoynni, til smolt-aling á landi
Stuðul úr Granskingargrunninum:
Investigation for potential groundwater in the Fútaklett area on the island of Vágar, Faroe Islands, for use in onshore smolt farming production The Faroese salmon farming company P/F Luna/Hiddenfjord, produces smolt onshore in their production facilities on Fútaklettur, on the islands of Vágar. The smolt production requires large quantities of freshwater in order to maintain current production rates and only by recycling the water taken from the nearby freshwater spring, it is possible to maintain the production available today. The company therefor aims at 1) keeping the recycled water temperatures at 12 degrees or lower, due to higher temperatures negatively effecting the fish - and 2) having larger quantities of freshwater available than at present, in case parts of the recycled water need to be replaced. Several factors affect the water temperatures in the recycling system, for example 1) the energy generated by feeding the smolt, while also pumping water into the recycling system, increases the water temperature in the long run - and 2) changing weather conditions also affect the indoor temperature in the production halls, often being too low in the winter months and too high in the summer. Today, Hiddenfjord has an active cooling system for the recycled water, using mostly electrical power from the public power company SEV. If larger amounts of freshwater (below 12 degrees) could be located, this could significantly help reduce costs generated by the cooling system used today. This PhD project will address these problems and focus on finding a suitable solution. This will be done by detailed geophysical investigations and geological mapping of the area on Fútaklettur, in order to understand the areas capacity for holding groundwater reserves. Geophysical methods will include: collection of optical, thermal and microwave satellite and UAV data, airborne electromagnetic and magnetic geophysical surveys, ground-based TDEM, multielectrode geophysics and - dependant on the interpreted results - drilling, borehole logging and groundwater sampling. Limited amounts of research have been carried out in regards to groundwater in the Faroe Islands, partly due to the countries freshwater resources coming only from a few freshwater springs and from purged surface-water collected in dammed lakes. Although, a large number of springs have been known for a long time, as reflected in e.g. numerous place names around the islands (Ólavsdóttir et al. 2015). Unfortunately, this is insufficient during dryer seasons, leading to periods of water usage restrictions in some areas. The volcanic origin of the islands, consisting mostly of basaltic rocks, has also led to the general assumption that the geology of the Faroe Islands is a restricting factor when it comes to groundwater. A couple of hundred geothermal wells (180-200m's deep), drilled for heating of private houses around the islands, although show evidence of the contrary. Water is pouring from most of the newly drilled wells, some as high as 30.000 Litres/hour (kortal.fo - pointing to the presence of some kind of subsurface aquifers. Therefore, geological investigations into the complex matter of groundwater issues in the Faroe Islands could form the basis for future use of groundwater for clean water supply as well as geothermal energy (Ólavsdóttir et al. 2015). By investigating, mapping and hopefully confirming the presence of groundwater reserves on the islands, this project will establish baseline knowledge for the Faroese research community and the country in general, and thereby contributing with useful knowledge for future applications.