What: When we first arrived at the Thrust Fault, looking north to Apple Tree Bay it appeared as though the bay hadn't frozen entirely on the other side of the bay. In the picture above you can notice the thin strip of darker area that's reflecting the houses and trees in it. I've often noticed this effect when looking across the lake at NY, where the thin strip of land closest to the lake often appears twice as thick, as though in reflection. I'd always kind of unthinkingly attributed this to simply being a reflection of the horizon in the water.
But when we climbed up to the top of the point and changed our perspective, it became quite clear that the bay was indeed completely frozen over and the "reflection" wasn't simply a reflection (the surface of the ice is super rough and not reflective. What was it then?
I had also noticed a thin rippling effect in the air while looking out across the lake. It reminded me of my childhood in Southern California. I loved watching those heat waves dance up off the pavement - the phenomenon of a distorted horizon when looking down a long road in the middle of the desert. As a child I remember seeing the ripples on the road, but I don't remember the reflective quality. I was more than surprised to see those with mid-day temperatures hovering around 0.
The refraction occurs only at shallow angles, so as soon as we changed our vantage by going up to the point (as in the photo above), the mirage disappeared and we were left wondering when the rest of the lake would freeze over already!!