[wideminded]

I just noticed something interesting: Even a floating ice block will raise the level of the body of water it is in when it melts, if it is floating in seawater.

The volume of extra water is equal to about 2 1/2 percent of the volume of the ice block.

Weight of block = h x A x r0

Volume of fresh water from melted block = (h x A x r0)/r1

Volume of block below the water line = d x A

Volume of extra water produced when an ice block resting on the bottom melts:

h x A x r0/r1 - d x A

= ((0.9167 x h) - d) x A

Volume of extra water produced when a floating ice block melts:

= h x A x (r0/r1 - r0/r2) = h x A x (0.9167 - 0.8909) = h x A x 0.0258

So it might be possible to trick someone by having some ice floating in a glass filled with very salty water. When the ice melts the glass should overflow. (Because of surface tension you would have to make sure that there is a lot of ice.)

[wideminded]

I put ice in a glass. I fill the glass to the top. When the ice melts does the glass overflow?

I just tried the following experiment. Although the ice is not even all melted yet, it is clear that it works.

Mixed up some very salty water. Left some room in the glass. Dropped in ice cubes until the water level reached the top. Waited. The water overflowed.

(For an explanation, see #132, #134, #136.)

I previously said that a melting glacier in the ocean or ice in a glass of water could raise the water level when it melted if the ice was large and heavy enough to be resting on the bottom.

But it is also true that even if the ice is floating, as long as it is floating in salt water, it will still raise the water level a little when it melts.