It is a kettle lake which was formed when a large block of ice broke off the glacier creating a depression which filled with melt water.
(It; is; a kettle lake which was formed) (a kettle lake; was formed; T:when a large block of ice broke off the glacier) (a large block of ice; broke off; the glacier creating a depression) (the glacier; creating; a depression which filled with melt water) (a depression; filled; with melt water)
It a kettle lake a large block of ice the glacier a depression
is was formed broke off creating filled
a kettle lake which was formed
T:when a large block of ice broke off the glacier
the glacier creating a depression
a depression which filled with melt water
with melt water