Climate change also measured by the sound of glaciers
In winter, glaciers are silent. But in the summer, it turns out that they generate infrasound through calving ice and meltwater. This is an inaudible sound to humans, but is picked up by high resolution measuring instruments.
Researcher Prof. Läslo Evers, TU Delft CEG and The Royal Netherlands Meteorological Institute (KNMI), has been measuring the sound of glaciers in Greenland for 18 years and has discovered, together with a team from KNMI and researchers from Japan, that glaciers have started to make more noise in recent years. This is mainly related to the meltwater from the glaciers flowing through all kinds of cavities and channels. In recent years, the highest activity was when the water was running off of the glaciers. Variations in glacier activity were observed between different years and also on a daily basis. It is concluded that glacier infrasound monitoring is complementary to other (remote) techniques for gaining insights into glacier dynamics. And therefore insight into the changing behaviour of glaciers due to climate change.
The infrasound measurements are used to monitor the international Comprehensive Nuclear-Test-Ban Treaty (CTBT). On Greenland, the monitoring station is installed near the town of Qaanaaq. The results of are published in Geophysical Research Letters.