knob and kettle (sag and swell topography) The landscape sometimes found on a recent terminal moraine complex and consisting of a hummocky mound (the ‘knob’) alternating with a depression (the ‘kettle’). The ‘kettle’ results from the melting of a block of ice enclosed in the drift.

knob and kettle(sag and swell topography) The landscape sometimes found on a recent terminal moraine complex, consisting of a hummocky mound (the ‘knob’) alternating with a depression (the ‘kettle’). The ‘kettle’ results from the melting of a block of ice enclosed in the drift.