• heeplr@feddit.de
      30·
      1 year ago

      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.

      • Gormadt@lemmy.blahaj.zone
        24·
        1 year ago

        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

      • Siegfried@lemmy.world
        4·
        1 year ago

        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…