Basically Lake Michigan is located in a relatively cold climate. Its around 494 km long and 190 km at its widest and with a depth of 281 meters... From what i understand about water freezing in lakes....4 C was probably the temperature at the bottom of the lake , also winter isnt long enough for the whole lake to reach 4 C only just the bottom... What i need help with understanding is.... If during the winter months the entire lake ISNT covered with ice, but near the shore, ice does form sufficiently thick for ice fishing ...Why is that?? ....Is it because the edges are not really deep which allows for quicker freezing? ...or can you please explain why because i have no clue?? Does the lake need to absorb or lose energy for the ice to melt? how much of an energy change must the lake undergo for each gram of ice melted? ....My guess is that the lake needs to absorb energy but i an confused on the energy change....does it require 80 calories for ice to melt or does it require 80 plus 100 = 180 calories for the ice to melt into water??? Would the process of the ice melting change the temperature of the lake? Why or why not? ...I would give an answer but i dont have a clue....can you please help me understand any of these?