I figure they first needed Inge Lehmann to figure out that there was an inner core, outer core, and mantle which she didn’t do until 1933, eight years after she started doing seismology. And it took three years before she published it which brings us to 1936. It was accepted fairly quickly but then came the war. And after the war seismology was really big on listening to nukes. Sixties makes sense.
I figure they first needed Inge Lehmann to figure out that there was an inner core, outer core, and mantle which she didn’t do until 1933, eight years after she started doing seismology. And it took three years before she published it which brings us to 1936. It was accepted fairly quickly but then came the war. And after the war seismology was really big on listening to nukes. Sixties makes sense.
Inge Lehmann - https://en.wikipedia.org/wiki/Inge_Lehmann