[TigersEye]

when the solid part above the surface of the scotch melts the level of liquid in the glass will rise

No it won't.

Why does ice melting not change the water level in a container?

[chiller]

The simpler explanation for we science dummies: A large protuding ice cube weighs more and displaces or pushes surrounding water higher in the glass (or ocean). As the ice melts, the cube weights less, and displaces less. = no change.

An iceberg supported by land, dumped into the ocean (not physically possible) would raise sea levels, but it's a damn big ocean, so ocean rise would be barely measurable even by satellite. Bergs attached but not supported by land won't make a difference.