This crack was really loud and caused the house to shake. I actually thought a tree had fallen on the house!
There have been many freeze/thaw cycles since November and lately the lake has been very vocal about it. Eerie, swirly ET-type noises of the water under the ice, some gurgling, the crunching of the shifting ice when it melts/freezes and the loud bangs from pressure cracks. Bang isn’t the right word. BANG is better but still not quite as shocking as the real thing. I found this site which has really good info on ice.