Geomagnetic measurements were established in Antarctica in 1957 as part of the International Geophysical Year and have continued until present. Geomagnetic data have been recorded continuously but for a gap in the data from 1959 until 1963. Since 1963, the components of the earth’s magnetic field (H, D & Z) and the large variations in this field associated with the arriving charged particles which produce magnetic storms and aurora, have in principle been recorded continuously, with the quality improving as various upgrades were done. The instruments are still located at Scott Base. Because the surface volcanic rocks at Scott Base are strongly magnetised, two other sites are used for repeat measurements of the earth's magnetic field - Cape Evans (first measured by Scott’s expedition in 1911) and Lake Vanda (first measured in 1974). The magnetic field is remeasured at these sites approximately every five years.
This research project forms part of a global networks of observatory seismographs and magnetometers which provide information for the study of earthquakes and earth structure and information on the variation of the earth's geomagnetic field on global and regional scales. Three component recordings of geomagnetic field variations are made, analysed and transmitted to international databases and individual researchers as appropriate.
In the 2011/2012 season, we recorded the magnetic field at the Weir site by Lake Vanda, but the site at Astro A is now inaccessible and probably underwater, because the lake level has risen. We established a backup site called C Granite, slightly north-east of Weir, and on the same side of the Onyx River as the refuge huts. The preliminary results indicate that the vertical component, and the total strength of the field are continuing to decline as the South Magnetic Pole moves north. Final results can only be calculated when we have a longer period of magnetic data from the Scott Base observatory, to correct our results for annual changes.
In the 2016/17 season, we recorded the magnetic field and took absolute magnetic measurements at the Vanda Weir & Vanda Granite sites by Lake Vanda over a four-day time period. We also conducted a set of absolute magnetic measurements at the repeat magnetic measurement site at the Cape Evans Magnetic Hut.
In the 2022/2023 season, we only took absolute magnetic measurements at the Weir and Granite sites at Lake Vanda. The Cape Evans Magnetic Hut was not measured.
GET DATA: https://geomag.bgs.ac.uk/data_service/data/surveydata.shtml
