Some of the oceanic changes can have dramatic influence on the marine ice sheets. Critical to understanding the response of a marine ice sheet to environmental changes is understanding the interplay of the marine ice sheet components. There are three major components, the grounded ice sheet, the ice streams, and the floating ice shelf. Ice streams are rapidly flowing rivers of ice that form in regions of convergent ice sheet flow. The more water that is under the glacier, the thicker the ice, and the steeper the ice surface, the faster the outlet glaciers can pull ice away from the ice sheets.
Ice sheets rest on a foredeepened surface.
The ice thickens from the edge to the middle of the ice sheet. The thicker the ice, the faster the ice streams pull ice from the ice sheet. This means that once the ice streams start to pull ice from the ice sheet, the ice gets thicker and thicker and the ice streams pull faster and faster. The ice has to have somewhere to go. In the case of a marine ice sheet the ice streams can pull all of the ice from the ice sheet and send it to the ocean as icebergs.