Glaciers are essentially giant rivers of ice that are formed over eons as fallen snow is compressed into layers of ice. Glaciers are found on about 10 percent of Earth's land area, with most of them found in the Arctic and Antarctica regions, but some occurring high up on mountains, even in tropical areas. Glacial ice makes up the ice sheets that cover Antarctica and Greenland, with glaciers flowing out to sea, where their ends float on the water as ice shelves. Eventually pieces of the ice shelves break off, or calve, to form icebergs. The movement of glaciers scours the underlying rock, and a glacier's movement can be affected by climate change, with worries that global warming could cause substantial glacial melt and impact global sea levels. For the latest news on glacier research and stunning views of these rivers of ice, see below.
Winter is when Arctic sea ice reaches its peak extent, but this year it could set a record seasonal low.
Isolated glaciers can store liquid water in their upper layers for years, similar to firn aquifers found in Greenland.
The eruption of volcanoes buried beneath Iceland's glacier may have triggered a series of megafloods that carved a giant canyon in a period of days, new research suggests.
Iceberg calving events have distinctive sounds that could help scientists pinpoint how much ice is vanishing and contributing to sea level rise.
The rise and fall of sea level during the past million years matches up with valleys and ridges on the seafloor, suggesting a link between underwater eruptions and ice ages, two new studies find.
Melting glaciers pose another threat beyond sea level rise. They will dump massive amounts of organic carbon into the world's oceans, altering ecosystems.
The vast ice sheet covering Greenland could melt more quickly in the future than existing models predict, new research suggests.
The most recent major ice age on Earth might have begun with the buildup of ice sheets in Antarctica, researchers say.
Scientists suspect Antarctica's shrinking glaciers are melting from the bottom up, and a fleet of robot ocean gliders may help explain why.
Ice-penetrating radar has uncovered a previously unknown ice-covered trench, and other detailed terrain, in the bedrock hidden beneath two massive, bluish glaciers in Greenland and Antarctica.
Three NASA science missions traveled the Alaskan way in summer 2014, soaring above Arctic sea ice, piloting over permafrost and gliding past mountain glaciers.
Improved climate models suggests melting in Antarctica will be worse this century than we had realized.
The steady melt of glacial ice around the world is largely due to man-made factors, such as greenhouse-gas emissions and aerosols, a new study finds.
New images from NASA's Earth Observatory reveal the turquoise melt ponds in the Arctic that form every summer.