Arctic global warming, page-66

SCIENCE
Water is different from other solids/liquids.

Water contracts in volume as it cools,
BUT at about 4degC it starts to expand.

This is why ice floats on water, and
lakes, streams do not freeze from the bottom, killing all aquatic life.

(The 'about' is not a lack of knowledge, as dissolved salts and suspensions alter temperature horizon).

This is why when sea ice melts, the level is static.

Ice on land IS different.