Laboratory icebergs melt down and flip out

Icebergs that melt and capsize are complicated, dynamic systems. Studying these phenomena in nature can be challenging, as data is typically limited to isolated events and evaluation of environmental parameters is difficult. Small-scale laboratory experiments reduce the system to its fundamental components, allowing us to better understand the physical mechanisms at play and investigate the fascinating dynamics that lie beneath the water's surface. In our lab, we study the dynamics of a free-floating cylinder of ice submerged in room-temperature freshwater. First, the ice locks into place and melts faster below the waterline due to the differential melt rates of ice in air and water. This causes the ice to become increasingly gravitationally unstable until it abruptly rotates and locks into a new stable configuration. These ``capsize" events persist for the duration of our experiments, as the water's surface carves the ice faces into quasipolygonal form. We model this simplified system of laboratory-scale ``icebergs" to provide insight into the fundamental coupled dynamics of melting, shape change, and capsizing.