Given the increasing global temperatures, many assume that glaciers around the world are retreating and shrinking. However, 25-years-worth of satellite images compiled by a Swiss researcher suggest otherwise.
Published in the journal The Cryosphere, an open journal of the European Geosciences Union (EGU), glaciologist Dr. Frank Paul, from the University of Zurich in Switzerland, created Graphics Interchange Format (GIF) images showing 25 years of glacier movement in just one second.
Using data from NASA's Landsat satellite, he compiled images between 1990 and 2015. With Karakoram mountain range in Asia as his focus, he compressed the images into just one second taken from four regions namely Panmah, Baltoro, Shaksgam and Skamri-Sarpo Laggo.
For the first time, the images show glacier movement, shift and changes over a long period of time and at a larger scale. The satellite images have shown a new dynamic in studying glacier behavior and changes over the span of decades.
With the movement sped up by approximately 800 million times, movements of the glaciers can be easily seen. It shows that glaciers are not actually retreating not like in other parts in the world, but instead, advancing and flowing into one another.
"The surges of individual glaciers are generally out of phase, indicating a limited climatic control on their dynamics. On the other hand, nearly all other glaciers in the region are either stable or slightly advancing, indicating balanced or even positive mass budgets over the past few decades," Dr. Paul wrote in his study.
This simple method will help scientists detect glacier movement in other parts of the world using satellite images. Dr. Paul used seven to 15 false-color satellite images using colors light blue to cyan for glaciers, white for clouds, dark blue for water, green for vegetation and brown as terrain.
"I like the idea of applying an 'old-school' and very simple file format, along with freely available software, to do something that is difficult to achieve with other formats or commercial software," Dr. Paul said in a press release.
"From a scientific point of view, the key motivation for this research was to understand the highly variable behavior of the glaciers in the Karakoram. We have known about this for over 50 years, but still have a very limited scientific understanding of what is going on there," he added.
He added that the image animation shows a very 'practical way' to have a better view of glacier changes through time.
