Why don't the Baltic and North Seas mix? | Yahoo Answers
http://imgur.com/gallery/lCPDX I found this picture online and was hoping someone could explain it to me. It shows were the Baltic and North Seas meet but don't mix. All the websites say it is because they have different densities but that doesn't make sense to me. If I pour a glass of more dense salt water in to less dense fresh water, they will surely mix even though they have different densities. Could someone enlighten me as to what else is at play here? Thanks!