Rock Debris Covering Glaciers Offers More Protection from Climate Change
With the rapidly changing climatic patterns and global warming, glaciers are melting at a fast pace. A new study has revealed that the blanket of rock debris covering glaciers can offer more protection from climate change, literally slowing the glacier melts. This factor has been long ignored in models of glacier melt and sea-level rise but is not considered significant.
The study was conducted by Northumbria University and was published in Nature Geoscience. As the glaciers melt, their neighboring mountain slopes become uncovered and weather-beaten rock debris slides down to gather on glacier surfaces to form a protective layer. This layer, which can be many meters thick, reduces the rate at which the ice melts.
The researchers found and corrected key errors within the Randolph Glacier Inventory, which is a global inventory of glacier outlines, providing a base for many studies.
The research team from Northumbria University’s Department of Geography and Environmental Sciences and the Swiss Federal Research Institute WSL spent three years examining and manually verifying more than 923,000 square kilometers of glaciers across the world, using the Landsat imagery.
The analyses reveal that debris cover glaciers on global and individual levels as well and created the world’s first baseline dataset of glaciers in their present state. It was discovered that over 29,000 square kilometers of the world’s mountain glacier area is covered in rock debris, which is roughly an area equivalent to 500 Manhattan Islands.
Lead researcher Sam Herreid who took on the study for his Ph.D. at Northumbria University,
The structure of the debris cover of each glacier is unique and sensitive to climate, but until now, global glacier models have omitted debris cover from their forecasts of how glaciers respond to a changing climate. We now know that debris cover is present on almost half of Earth’s glaciers, with 7.3% of the world’s total mountain glacier area being debris covered.
The team also developed a way to analyze how the world’s debris-covered glaciers will evolve over the coming years. By comparing the many conditions of glaciers present on Earth today, from those considered to be ‘young’ and icy in Greenland, to ‘old’ and rock covered in the Himalayas, the researchers were able to put together an abstract timeline which they believe summarizes how a glacier might evolve in the future.