Re: Does ice have a specific melting rate?

The basic answer to your title question is "No."

How fast ice melts will depend on many different factors. It mostly comes down to how fast heat can be transported to the ice to accomplish the melting. That rate (per unit surface area) is usually expressed as a temperature difference (difference between ice temperature and temperature of surroundings) times a "heat transfer coefficient." The heat transfer coefficient can depend on a lot of things, like the thermal conductivity of whatever is surrounding the ice, whether the surroundings are moving (to transfer heat by convection), specific details of the surface, and I'm probably forgetting a few things.

Let's look at the two pieces with regard to your question. For the temperature difference, if you have ice "in its own water" they will both be at zero degrees Celsius, so in principle the temperature difference is zero and there will be no melting. That is why you can keep ice water for a long time in an insulated container like a thermos without significant melting. In other situations, there might be a higher temperature someplace (like outside a glass that you've poured ice water into) to provide a driving force for melting.

With regard to the heat transfer coefficient, liquid water conducts heat much better than air, so ice sitting in liquid would have a higher heat transfer coefficient than ice in air. That is why ice will melt much faster if dropped into warm water than it will in warm air. But another important factor is convection -- if the surroundings are moving there will be much more heat transfer. That is why a warm wind will make ice and snow melt faster than if it is sitting in still air, and similarly running warm water over ice will melt it faster than putting it in stagnant warm water.

Dr. Allan H. Harvey
"Don't blame the government for what I say, or vice-versa."