Tunabreen is a small glacier in Svalbard which is unique in that four surges have been identified in its recorded history – the first in the 1920’s, the second in the 1960’s, the third in the early 2000’s, and the fourth starting in 2016 – more than any other glacier on Earth (Flink et al., 2015). The first three surges established a surge periodicity of 40 years. It was generally believed that surge cycles are of a consistent period, so a further surge of Tunabreen was not anticipated until the 2040’s. The latest surge, a few decades earlier than expected, may have come early because over years of thinning and retreat the glacier geometry has changed. Alternatively, a warmer and wetter recent climate in Svalbard may have triggered the surge early.
We are experiencing a significant growth in the availability of satellite data to monitor surges such as those in Svalbard. The European Space Agency Sentinel-1 Synthetic Aperture Radar (SAR) in particular provide a great leap forward because is can acquire images once a week, regardless of cloud cover, throughout the polar night as well as when sunlight is available at these high latitudes. The Sentinel-1 animation below shows the recent surge of Tunabreen, which is coming to an end in late 2018.
Please feel free to copy and use this animated GIF which already contains the relevant attribution to ESA.