[mass noun] The magnetic properties of the earth as a whole.
- ‘These papers all dealt with the current theories on terrestrial magnetism, including Poisson's ideas, absolute measure for magnetic force and an empirical definition of terrestrial magnetism.’
- ‘If a small magnet impairs their reception of the Earth's magnetism or the area has a natural disturbance of the terrestrial magnetism, pigeons get disoriented and cannot find the way back on long distances.’
- ‘He had also agreed to collect data on terrestrial magnetism for Gauss on this trip.’
- ‘In the opinion of the author, the difficulties which stand in the way of basing terrestrial magnetism on electric currents inside the earth are insurmountable.’
- ‘In forming any theory of the cause of terrestrial magnetism, the first question that arises is whether we are to consider the near coincidence of the geographical with the magnetic axis as accidental or significant.’
- ‘The effort to do so was classically Humboldtian, repeating in its protagonists' ultimate frustration Edward Sabine's earlier ‘crusade’ to explain terrestrial magnetism in terms of meteorological as well as astronomical phenomena.’
- ‘Between 1913 and 1919 he published another important series of papers, this time on terrestrial magnetism which we comment on below.’