After a quick thaw and an inch of rain, these holes -- most (but not all) surrounded by radial cracks -- appeared overnight in the ice. There is nothing above the ice to drop things on it, much less things of the weight, or dropped with the force, necessary to punch through the ice and cause the surrounding stress pattern. Any theories are welcome including the correct one. I have come up with a few possibilities:
1) Santa missed
2) We are being bombed by Smithfield in preparation for a ground invasion (see also: http://www.pbase.com/jason_daniel_anderson/image/90238330 )
3) I know nothing about the behavior of large superficial ice layers and this phenomenon is mildly interesting, but unremarkable
While #3 seems to be the most likely explanation, in accordance with the Sept. 2002 revision of the National Security Strategy of the United States -- http://www.pbase.com/jason_daniel_anderson/image/86727872 -- we have commenced a preemptive attack against Smithfield pending any evidence, real or imagined, of #2.