How do ice shelves form where glacial ice reaches the ocean?

Ice shelves are thick, floating masses of ice that form when glaciers or continental ice sheets extend outward from land into sheltered coastal waters.123

These structures are created and sustained by the following processes:

• Glacial Flow: Driven by the pressure of ice flowing outward from the center of a continent, glacial tongues move seaward at rates typically ranging from 0.3 to 2.6 km per year.13
• Attachment: In areas without strong currents, the ice may become partially grounded on the sea bottom, attaching itself to rocks or islands.1
• Accretion: The shelves are built up and maintained over time through the accumulation of snowfall.1
• Grounding Line: The transition zone where the floating ice shelf meets the ice resting directly on bedrock is known as the grounding line.3

Once formed, these shelves act as a continuous extension of the land-based ice mass, though their forward growth is eventually limited by sea currents and the eventual fracturing of the ice front into icebergs.13