It's what stimulated ice-core sampling. Before it, 60 years ago, science knew much, much less about climate, let alone climate history. (Plate tectonics was just coming into vogue!) IGY stimulated evidenciary techniques that forced a drastic revision of what we 'knew' before it.
https://en.wikipedia.org/wiki/International_Geophysical_Year
It's what stimulated ice-core sampling. Before it, 60 years ago, science knew much, much less about climate, let alone climate history. (Plate tectonics was just coming into vogue!) IGY stimulated evidenciary techniques that forced a drastic revision of what we 'knew' before it.