A map shows where in Alaska may be at risk ... As global temperatures increase, polar ice caps and glaciers melt, and thermal expansion of seawater occurs, resulting in higher sea levels.

Two ice skaters were stranded and self-rescued from a glacier chunk that fell onto the ice in Portage Lake, Alaska, on Monday ...

A window of cold and clear weather has drawn hundreds of people to skate, bike and walk on the lake ice in recent days.

During this time, you can also purchase souvenirs from Alaska Geographic ... the snow morphs into solid ice under its own weight. Friction between the glacier and bedrock produces meltwater.