The freezing and thawing of the normally frozen parts of Earth comprising the cryosphere can help regulate the planet’s normal function or wreak havoc on weather and communities around the world. Consider permafrost ground, which is soil that is continuously frozen for two or more years. The permafrost in the normally frozen Arctic holds one-third of Earth’s soil carbon, trapping and keeping it out of the atmosphere. But when Arctic temperatures warm and thaw its permafrost, carbon is released into the already carbon-burdened atmosphere, altering Earth’s carbon cycle and further amplifying global climate change.

Glaciers, ice sheets and shelves, sea ice, and, of course, snow also freeze and thaw in expected, unpredictable, beneficial or hazardous ways. For instance, the predictable freezing of rivers in Alaska can create quick transportation networks for people to dogsled or snowmobile on, but an unseasonable thaw and ice breakup can produce unforeseen open-water dangers for travelers.

NASA has a host of data for studying freezing and thawing in the cryosphere that can provide researchers and planners with information to understand how these important processes maintain or disrupt the healthy balance of the natural and human world.