Investigating Ice Sheets
Ice sheets gain and lose mass constantly. They gain mass through snow that accumulated on top of them, which slowly turns to firn and then solid ice over time. Gravity acting on the mass of ice causes the ice to gradually flow downhill towards the coast in a process known as plastic flow. Once it reaches the coast, the ice continues to flow over the ocean, creating an ice shelf. Icebergs calve off the end of the ice shelf into the ocean, where they eventually melt. The grounding line - the last point of an ice sheet that rests on continental bedrock before the ice starts to flow over water to form an ice shelf - is an interesting place for scientists to study because it can influence how quickly the ice flows from the ice sheet onto the ice shelf.
