A magnetic survey of the United States was carried out by the government in the 1950s.
A magnetic survey that is more accurate than grade 5, (see note 5).
Discovered in 1994, it is not exposed at the surface, but has been mapped by magnetic and gravimetric surveys.
It was discovered by a magnetic survey and a gravity survey.
In 1901 he began a magnetic survey of South Africa.
This included a magnetic survey, aerial photography and the production of a digital relief model.
An airborne EM and magnetic survey of the whole area was flown in the early 1970s.
A magnetic survey was conducted in 1994 by Fischer and Masero.
This included physical inspections of the site, a magnetic survey, ground resistance measurements and aerial photography.
He also took part in four eclipse expeditions, and a magnetic survey of the British Isles.