Manipulating trapped air bubbles in ice for message storage in cold regions

Message storage using documents and telecommunications encounters high energy consumption and a short life cycle in cold regions. Easily available low temperature and water have created the history-recording glaciers. Inspired by the naturally occurring bubbles in glaciers, we elucidate the underlying physics governing them and develop an ice-based message storage method. The formation process of trapped air bubbles is controlled by the heat and mass transfer during freezing. We identify four ice regions based on the bubbles’ distribution and determine the critical freezing rate between the bubble and clear ice regions at 2.87 μm/s. Manipulating the bubble layer by varying the freezing rate successfully utilizes Morse, binary, and ternary codes to store messages. These findings reveal the underlying physics of the trapped air bubble formations, and the intermittent growth of bubble layers also provides the potential for incorporating artificial intelligence into material solidification, glacier analysis, and gas exploration.