Salt doesn’t necessarily melt ice, it just lowers the freezing point of the water that composes the ice, meaning that water has to reach a lower temperature in order to freeze. My guess is that the oceans in the Arctic and Antarctic are so cold, that it negates the effect of the salt on the ice, but I’m not a scientist or anything
Salt is a solute, which when added to water (ice in this case) lowers its freezing point.
The freezing point of water is 0 degrees on Celsius scale. Addition of salt will lower its freezing point, to some negative temperature.
The geological locations where Glaciers exist, the temperatures are way below 0 degrees. So even though the freezing point of ice is lower, the temperature is still lower than the final freezing point of the salt-water solution, hence it tends to remain in the solid state.
I think you mean icebergs?
Glaciers are rivers of ice. They don’t touch salt water as a general rule, except where the river meets the sea.
Icebergs are giant hunks of ice floating in the ocean.
Salt lowers the freezing point of water, which is why it can cause ice to melt. But it does not remove the freezing point altogether. At about 28.4F, saltwater will freeze. That is the point at which salt will no longer melt ice, and that is the temperature at which icebergs can survive in saltwater.
Salt doesn’t melt ice.
It changes the freezing point of the water.
So instead of water changing from liquid to solid at 0C, that number decreases. How much it decreases depends on how much salt you add. The actual scientific concept is called “freezing point depression” and you can calculate the exact new freezing point if you know how much salt is added, but it’s not very ELI5.
The reason it seems like it melts the ice is because most places don’t maintain a constant temperature of -20C, which is relatively easy to depress water to with icemelt pellets. So, the ice then melts because it isn’t cold enough for it to stay frozen with the newly depressed freezing point.
If you try using salt to melt ice in places where it’s freakishly cold, it doesn’t really work very well.
The glaciers exist in places (the Arctic and Antarctic), which are generally freakishly cold.
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