We tend to think of gravity as a uniform force, but there are actually subtle - and very informative - differences in gravity depending on exactly where you are on earth.
In all likelihood the gravity we're experiencing here at Radio New Zealand in Wellington is not exactly the same as the gravity you're experiencing wherever you are reading this.
Gary Wilson, from the University of Otago, was in Antarctica recently as part of a team finding out about the geology and oceanography of the new site for the next ANDRILL drilling project, which collects deep sediment cores to provide insights into past climates.
Alison Ballance joined Gary Wilson at McMurdo Station as he was calibrating his gravity meter to find out how you measure gravity, and what it can tell us about the composition of the earth beneath our feet.