Flooding caused by bursting glacial lakes has led to more than 12,000 deaths, and scientists warn they represent an increasing threat.
Glacial lakes are formed when meltwater from glaciers form bodies of water with ice acting as a dam. Lakes could then overflow or breach the barrier if they become too full leading to disastrous flooding called glacial lake outburst floods (GLOF). Yet scientists told The Guardian that some glacial lakes cause more worry than others.
Adam Emmer, a geographer at the University of Graz in Austria, told The Guardian the two key ingredients in this type of disaster are the GLOF itself and a vulnerable population.
“The ones we’re concerned about are the very steep mountain valleys in the Andes and in the Himalayas, where you have glaciers retreating up into their steep valleys with lots of opportunity for bits of mountainside to fall off into lakes.”
At least 1,348 glacial outburst floods have occurred globally, according to a 2016 study.
Rising temperatures contribute to the so-called outburst floods. But other factors, including earthquakes, avalanches and rainfall could lead to a catastrophe.
“Population expansion along the potential GLOF paths and lack of building development regulations may be even more important driver of GLOF risk, especially in developing countries,” Emmer said.
Scientists expect GLOF to occur more frequently in the coming decades and into the 22nd century, according to the outlet.
Central Asia, South America, the European Alps, Iceland and Scandinavia are among the regions most affected by GLOFs, according to the 2016 study. The study’s authors noted that South America and central Asia are the most likely to experience substantial deaths and damage to infrastructure.
Meanwhile, 70 percent of the Earth’s tropical glaciers are found in the Peruvian Andes, The Guardian reported. The worst outburst flood in the region killed at least 1,800 in 1941. Peru began implementing hazard mitigation and warning systems around the 1950s.
Emmer said the biggest challenge in disaster mitigation in the region is “communicating the risk and risk reduction measures to local communities and making them trust and accept it.”
Arun Shrestha, a climate change specialist at the International Centre for Integrated Mountain Development, told The Guardian that GLOF’s also present a “big challenge for Nepal.” Up to 35 GLOF events have been recorded in the country, according to Shrestha. Shrestha added that GLOF’s threatening Nepal exist outside of the country and cooperation with neighboring China is essential for disaster prevention.
“It’s very important that Nepal talks with China and tries to address those issues,” Shrestha said. “Those lakes cannot be ignored, but for that, a bilateral diplomatic effort is required. With climate change, and infrastructure and settlements changing quite rapidly, I think the risk is growing every day.”
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