Which process forms kettle lakes in previously glaciated terrain?

Which process forms kettle lakes in previously glaciated terrain?

• A. Glacial moraines damming streams
• B. Melted ice blocks left after the glacier retreated
• C. Subglacial volcanism forming ponds
• D. Sea-level rise creating basins

Answer: (B)

Kettle lakes form when chunks of ice become buried in sediment as a glacier retreats, and then melt, leaving behind a hollow that fills with water. In glaciated landscapes, large blocks of ice can become embedded in outwash plains or morainic material. When those ice blocks melt, they leave depressions—often bowl- or kettle-shaped—in the ground. If water from meltwater or rainfall collects in that hollow, a kettle lake results. This differs from moraines damming streams, which can create lakes by blocking a valley or channel, but those lakes form from dammed flow rather than a isolated ice block melting to create a basin. Subglacial volcanism is not the typical mechanism in postglacial landscapes for forming kettle lakes, and sea-level rise creates basins in coastal zones rather than the inland, buried-ice depressions that define kettle lakes.

Kettle lakes form when chunks of ice become buried in sediment as a glacier retreats, and then melt, leaving behind a hollow that fills with water. In glaciated landscapes, large blocks of ice can become embedded in outwash plains or morainic material. When those ice blocks melt, they leave depressions—often bowl- or kettle-shaped—in the ground. If water from meltwater or rainfall collects in that hollow, a kettle lake results.

This differs from moraines damming streams, which can create lakes by blocking a valley or channel, but those lakes form from dammed flow rather than a isolated ice block melting to create a basin. Subglacial volcanism is not the typical mechanism in postglacial landscapes for forming kettle lakes, and sea-level rise creates basins in coastal zones rather than the inland, buried-ice depressions that define kettle lakes.