A GLOF is a glacial lake outburst flood. At the end of the Little Ice Age in the 1880’s, glaciers around the world began stagnating and receding as the planet warmed, and they are still receding to this day. As these glaciers recede, water melts and pools, forming glacial lakes. These lakes are retained by material called a moraine, which acts as a natural dam holding back millions of cubic meters of water as these lakes grow. Floods happen when this moraine breaks, or is overtaken by water. The most common trigger for these floods is an ice avalanche when ice falls from above the lake and causes a surge wave to rush over the moraine. Other causes include earthquakes, and terminal moraine collapse. Glacial lake outburst floods are extremely dangerous to communities living downstream, because all that water rushes down super fast, and can take out bridges, and even whole villages even 100km downstream.
Interdisciplinary approaches to studying GLOFs:
Dr. Alton Byers doesn’t just rely on models, measurements and remote sensing to study glacial lakes. He takes an interdisciplinary approach incorporating the best of the social and physical sciences. For example in his most recent article about glacial lakes in Kanchenjunga in Nepal, the scientific record of GLOF’s seemed like it must be missing something, with only one flood recorded in the last 40 years whereas in other regions there were many. His team went into the area and interviewed local people, finding that not only was there the one GLOF on record from 1980, but also 6 other major GLOFs remembered by community members in the area. They were then able to use remote sensing to verify the oral testimony, and the different methods of research supported each other.
What are some ways to minimize the danger from GLOFs?
The Peruvian Example
Peru is an excellent example of some of the ways you can reduce the risk of dangerous glacial lakes. In the 1940s, the country experienced a series of disastrous GLOFs that killed 10,000 over the course of the decade. Since then, the Peruvians have done a survey of all of the different potentially dangerous glacial lakes in the Cordillera Blanca, and have started developing methods for reducing and eliminating the danger. Among these methods, they have drained around 30 dangerous lakes using everything from digging a trench to drain a little lake, to developing a sophisticated multi-million dollar system of tunnels that can lower the level of a lake at will.
Early Warning Systems
Draining glacial lakes is not always possible or practical, especially in areas of the Himalayas where you can’t build roads for easy access. Another method of mitigating the danger of GLOFs is through early warning systems to notify downstream communities if a lake is near bursting. These have been introduced across the Himalayas in Bhutan, Sikkim, Tebet, Nepal, India, and Pakistan, but unfortunately haven’t been the most successful yet. One of the reasons is because there are multiple studies assessing the danger of various glacial lakes, and none of them seem to agree on which are most likely to burst. It is really difficult to predict which lakes might flood, and when. Another more pressing issue with the early warning systems that have been installed is that often local people are not informed. They’re not told about this system. They don’t even know what it sounds like when it goes off, and if it goes off and they know it's from the early warning system, they don’t know what to do. So clearly there is more work to be done in awareness building and involving local communities.
How have different countries collaborated in researching GLOFs?
Dr. Byers has led dozens of international expeditions to the Himalayas and Peru with scientists from around the world to facilitate south-south collaboration and exchange or valuable information about GLOFs. On these expeditions, scientists get to see the glacial lakes for themselves, and learn from the experiences of other parts of the world in managing their risk.
When draining GLOFs, is there any opportunity to capture freshwater so that it is not lost?
Research is starting to turn in the direction of looking at glacial lakes not only as potential hazards, but also as freshwater resources and reservoirs. The glaciers might be lost, but now much of that glacier is in the form of freshwater. In a time when climate change is negatively impacting freshwater supplies, it seems to make sense to figure out ways to preserve these freshwater supplies as reservoirs as opposed to trying to drain them, and this is the direction in which future research is heading.