Fountain in the Snow

I was amazed to find this bubbling fountain in the deep snow and don't know why it doesn't freeze over. I went back to the spot a little later in the twilight and illuminated the fountain with my flashlight. The light in the background is the residual light of the day; the moon rose a little later.

https://www.hess.photography/FineArt/i-pdHxxdG

NIKON Z 6 | NIKKOR Z 24-200mm f/4-6.3 VR
71 mm | f/8 | 4s | ISO 400
Date 2021-12-15 17:25:50