Ice melts where it is in contact with the ocean, mainly. Deep in the ice, there is some melting due to high pressure. When matter is compressed, its temperature goes up. That is why your bicycle pump seems warmer after you use it. There is a complicated pattern of melting and freezing where the ice slides into the ocean, so the net melt rate is not very large.
New ice looks white or clear.
The white patterns come from air that was dissolved in the water and becomes trapped in the ice when it freezes. After enough time, the air works its way out of the ice, leaving a relatively pure crystalline form of water ice. This tends to scatter blue light stronger than other colors, so the ice looks blue. Thanks for your curiosity, John Klinck Department of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Norfolk, Virginia. I've received several questions about the camera equipment I'm using.