# Would sea level rise if ice has more volume than sea water?

Curiosity Science Other Sciences Would sea level rise if ice has more volume than sea water?

• If ice contains more volume than water, why would sea-level rise if globalised fields melt?

– Asked by Chris Bright via the ask a science question page.

• I understand where you are coming from.

Density is the mass of a substance per unit volume.

$$\rho = \frac{m}{V}$$

And you are right about the volume. The volume of water increases when it freezes due to its molecular structure. But as the mass is constant the ice becomes less dense when compared to liquid water. This is why ice floats on water.

But the sea levels do not rise when sea ice melts. Because they are formed in the sea and it’s just a phase change and no additional mass is added, hence no displacement.

It is the glacial ice and ice sheets that rise the sea levels when they melt—as they are not in the ocean in the first place. The glaciers and ice sheets are part of the continental land and when they melt and flow into the ocean, they add extra water—freshwater—into the ocean. This increases sea levels around the world.

In addition to this, as the Earth gets warmer, water itself expands thermally and contributes to the rise of ocean levels.