First-year ice

First-year Ice
Sea ice of not more than one winter's growth, developing from young ice, and measuring 30 cm or greater. It may be subdivided as follows:

Thin First-year Ice / White Ice - First Stage 30-50 cm thick
Thin first-year Ice / White Ice - Second Stage 50-70 cm thick
Medium First-year Ice 70-120 cm thick
Thick First-year Ice Greater than 120 cm thick