Helicopter-borne magnetic, electromagnetic and radiometric geophysical survey in Repparfjord area, Alta and Kvalsund, Finnmark

Abstract

NGU conducted an airborne geophysical survey in Repparfjord area in September - October 2011 as a part of the MINN project. This report describes and documents the acquisition, processing and visualization of recorded datasets. The geophysical survey results reported herein are 6000 line km, covering an area of 1200 km2.The NGU modified Geotech Ltd. Hummingbird frequency domain system supplemented by optically pumped Cesium magnetometer and 1024 channels RSX-5 spectrometer was used for data acquisition.The survey was flown with 200 m line spacing, line direction 146o (North-West to South-East), and average speed 110 km\/h. The average terrain clearance of the bird was 58 m.Collected data were processed at NGU using Geosoft Oasis Montaj software. Raw total magnetic field data were corrected for diurnal variation and levelled using standard micro levelling algorithm.