In the Patagonian town of El Chaltén, Argentina, authorities and scientists are intensifying efforts to prepare for the risk of a glacial lake outburst flood (Glof) following increased evidence of glacial instability and recent catastrophic events elsewhere. The concern centers on Laguna Torre, a glacial lake fed by the Torre glacier, whose retreat and associated slope destabilization could trigger a sudden and destructive flood reaching the town within minutes.

Geologist Daniela Schmidt, who studies the region at the University of Buenos Aires, highlighted the increasing threat based on comparisons with recent disasters, including the deadly flash floods in Nepal in August 2023. The Nepal event, caused by the collapse of glacier ice and rock, illustrated the potential magnitude such floods can reach and prompted renewed urgency in assessing similar risks at Laguna Torre. Schmidt’s models estimate that if the northern slope of Cerro Solo—a granite peak adjacent to the lake—were to collapse, it could release between 8 million and 13 million cubic meters of material into the lake. This could generate a wave up to 5.8 meters high traveling across Laguna Torre at 20 meters per second, inundating the Fitz Roy River and reaching El Chaltén in roughly 20 minutes or less.

Local authorities, including Los Glaciares National Park and the municipal government, have been collaborating with scientific institutions to develop Argentina’s first Glof early-warning system and evacuation protocols. Monitoring stations equipped with cameras, sensors, and emergency buoys are planned to provide alerts via sirens, SMS, and email. However, implementation has faced delays due to funding shortfalls, with estimates for the necessary technology reaching approximately $220,000—exceeding current budgets.

The risk is compounded by ongoing glacial retreat, with the Torre glacier shrinking by 4 square kilometers and thinning by 60-70 meters from 1952 to 2023. This retreat has led to increased rockfall and slope movement, some of which double in speed during heavy rainfall or high temperatures. Additionally, new measurements indicate Laguna Torre’s depth has increased to over 220 meters, raising concerns about the volume of water that could be displaced in a sudden collapse. Authorities have started practical mitigation steps, including dredging the Fitz Roy River channel and clearing the riverbed beneath the town’s vital access bridge.

The potential impact extends beyond flooding, threatening critical infrastructure such as gas and power plants, homes, and schools located near the riverbanks. In the event of a flood, especially during the summer tourist season when the population swells with visitors, El Chaltén could become isolated, with over 27,000 people stranded. Currently, there is limited public awareness: signage indicating evacuation routes is absent, and hotels generally do not inform guests about the hazard.

Local leaders acknowledge the tension between addressing the risk and protecting the town’s tourism-based economy. Some community members express concern that widespread discussion of the flood threat might deter visitors, who are vital to livelihoods in the area. Nonetheless, officials like Enrique Rivero, El Chaltén’s secretary of government, stress the importance of preparing for a worst-case scenario, emphasizing that while the exact timing of such an event cannot be predicted, it remains inevitable.

The situation in El Chaltén reflects a broader challenge as climate change accelerates glacial retreat and destabilizes mountainous regions worldwide. The recent glacier collapse in the Swiss Alps serves as a sobering example of the suddenness and severity of such disasters. Researchers and local authorities hope current efforts will improve readiness and mitigate potential losses, prioritizing the safety of both residents and visitors amid a rapidly evolving landscape.