Glacier on the porch

The geology books say that glacier ice comes from snow, packing down into ice. It's happening on my porch as I write. I had 25 inches (real inches, measured with a yardstick) Sunday when the snow stopped falling. That has settled over the past few days. It's only 18 inches today. That's all compression and settling of the light powder snow, it ain't melting, it hasn't been warm enough to melt.