Yearly. They look at slices generated by compressed layers of snowfall. Thick layer = cold year. They look at more stuff but that's roughly how it works.
edit: not sure why you're downvoted. It's a good question.
Also the composition of captured gasses dissolved in the ice help us see what the atmosphere was like back then
It's a really cool field to look into NGL
not sure why you're downvoted. It's a good question.
The herd acts in mysterious ways... one would have thought we left those practices in the R-site...
Yearly. They look at slices generated by compressed layers of snowfall. Thick layer = cold year. They look at more stuff but that's roughly how it works.
edit: not sure why you're downvoted. It's a good question.
Also the composition of captured gasses dissolved in the ice help us see what the atmosphere was like back then
It's a really cool field to look into NGL
The herd acts in mysterious ways... one would have thought we left those practices in the R-site...