Bubbles are seen locked in the ice on Lake Nukabira in the town of Kamishihoro, in Japan's northernmost prefecture of Hokkaido, on Jan. 22, 2019. The natural phenomenon is the product of gas gushing out from the bottom of the lake and being captured in disc-shapes near the surface by the freezing water. Mitsuru Kawada, the head of Higashitaisetsu Nature Guide Centre in the town, said, "Ice bubbles can usually only be seen for a short time (because of snow cover). There is little snow this year, and I think it's the first time in several decades that they've been visible for so long."
(Japanese original by Taichi Kaizuka, Hokkaido Photo Group)