Glaciers are melting all over the world due to global warming. Scientists are looking for ways to predict and evaluate this process. It turned out that when it melts, the air “stuck” there comes out of the ice – and this process can be heard.
The air trapped under the surface of the glacier turns into a compressed mixture of ice and bubbles, the pressure in which increases the closer the glacier ends. There are also very ancient bubbles – they are under pressure of almost 20 atmospheres, and they also make sounds, opening when the ice melts.
Scientists have found that the intensity of the sound made by the end of a glacier increases as the temperature rises. And this is logical: the glacier melts faster in warmer water, releasing more bubbles and more “noise” into the ocean. However, as the recorder moved away from the glacier, the sound pattern changed.
Moreover, acoustic stress differs from glacier to glacier and increases at different levels. That is, the sound is influenced by several parameters: the geometry of the glacier-ocean boundary, the temperature and salt composition of the underwater sound channels, and the presence of floating ice.
It turns out that recording underwater sounds emitted by the end of a glacier during melting is a way to track the state of glaciers and the amount of ice loss. And also – to determine how the water temperature affects this.
In the future, scientists want to establish a network of stations, for example, near Greenland and Svalbard, in order to record underwater sounds and monitor the stability of glaciers.