The picture above is air bubbles, trapped in ice of frozen O'Dell Lake in the high Cascade Mountains of Oregon. Climatologists love these sorts of things, as they represent a sample of the Earth's atmosphere from a long time ago:
Far from mute, frozen bubbles can tell many interesting tales, especially if they are in glaciers and ice sheets. Climatologists take deep cores of ice around the world. Then in special laboratory conditions they slice segments of the core and study the composition of the air bubbles trapped within. The deeper the core, the further back in time the slices represent, so they can reconstruct prehistoric climates and track changes in atmospheric conditions.