AN aeromagnetic survey to map Southland’s buried geological features is scheduled to be completed this summer.
Aeromagnetic surveying is a common type of geophysical survey carried out using a magnetometer aboard an aircraft.
The survey is being carried out by Venture Southland (VS) on behalf of Southland’s four regional councils – the Invercargill City, Southland District, Gore District and Environment Southland.
A VS spokesman said the Southland survey was part of a nationwide government initiative following the then Energy and Resource Minister Simon Bridges’ announcement in December 2014 of a plan to invest $8 million to obtain and analyse new aeromagnetic data.
Aeromagnetic survey sheds light on buried geological features
THE Southland survey, carried out from small fixed-wing aircraft and helicopters, began after a visit to the region by representatives of New Zealand Petroleum and Minerals in February 2015, the spokesman said.
New Zealand Petroleum and Minerals provided funding for some Southland areas to be surveyed, including “a significant portion” of the Clutha and Gore districts and the Western and Northern Southland areas, the spokesman said. However, the four councils agreed to extend the survey area at an estimated cost of $686,000.
VS completed surveying the southern Southland area during the summer of 2016, he said.
VS general manager for business and strategic projects Steve Canny said unlike New Zealand Petroleum and Minerals, VS and the four councils had little interest in using survey data to explore options for mining or other extractive industries.
“We’re focusing on agriculture and how we can better manage our region’s resources. We’re interested in water, geological structure and soil nutrients. We have a lesser interest in minerals. We have a highly productive region, it’s producing food, crops, and generally from an economic point of view this is much better than extractive industries because [farming] has a recurring benefit compared with mineral extraction, which tends to only work in areas where there’s no other industry present”, he said.
The survey was also useful for locating fault lines and planning for civil defence emergencies. The survey had revealed there were no major fault lines in or around the Invercargill city vicinity, he said.
Early results also indicated the soil in Western Southland was rich in potassium, and this knowledge would help farmers better manage their applications of nutrients, he said.
Mr Canny said the last area to be surveyed – roughly following the route of State Highway 6 from Tuatapere to Queenstown – was scheduled to start in late November or early December, depending on weather conditions.