Množina: kettle holes
Pit or depression formed when a block of ice from a receding glacier becomes isolated and buried in glacial debris (till). As the block melts the till collapses to form a hollow, which may become filled with water to form a kettle lake or pond. Kettle holes range from 5 m/15 ft to 13 km/8 mi in diameter, and may exceed 33 m/100 ft in depth.