evidence: Sea ice does not simply grow and melt in one place. Sea ice is almost continually in motion, except in coastal regions where ice grows out from, and stays attached to, the shore like fast ice. The motion of ice results from a balance of forces defined by Newton's Second Law: [...] In contrast to the Arctic, the Antarctic has no surrounding land boundary for the northward flowing sea ice to run into, so the ice flows northward until it melts in warmer oceans and air temperatures. Because of this, Antarctic sea ice is younger and thinner, on average, than ice in the Arctic. Most sea ice in the Antarctic is less than a year old. [...] - Sea ice melts during the summer, and the surface temperature increases to the freezing point. Melting sea ice is difficult to distinguish from the surrounding ocean that is also near the freezing point.