The capital of Alaska, Juneau, has lived for hours tense since the start of annual glacial floods. Local authorities have ordered the evacuation of numerous districts in the face of a rise in waters which could reach an never recorded level, a direct consequence of global warming according to several federal agencies cited by The Guardian and by cnn. Residents located in flooding areas have received alerts enjoining them to leave immediately, while municipal teams strengthen protections with temporary barriers.
Tuesday morning, the water began to escape from the natural dam formed by the Mendenhall glacier, located about twenty kilometers north of the city. This phenomenon, called the glacial flood, occurs when rainwater and snowfall accumulate until the pressure pierces the ice bar. According to forecasts from the National Weather Service (NWS), the level of the river should exceed 4.87 meters Wednesday morning, an absolute record. The authorities hope that the recently installed emergency dikes will be able to contain at least part of the flow and protect the Mendenhall valley, where the majority of the 32,000 inhabitants of Juneau reside.
Regular floods every summer
Since 2011, these overflows have been hitting the Mendenhall valley every summer, sometimes causing significant destruction. Scientists note that the extent and frequency of these events are intensifying, in direct connection with global warming. The NOAA stresses that Alaska healed twice as fast as the rest of the United States, with an average increase of 1.7 ° C on the past century, and that the trend continues. The rapid mealing and decline in glaciers, which began in the late 1980s, directly promoted these sudden and massive floods, which now represent a recurring risk for local residents.
Our file on floods
For Rick Thoman, climatologist at Alaska Center for Climate Assessment and Policy, without climate change, such floods simply would not take place on the Mendenhall. In August 2023, a similar episode had already flooded areas previously spared, destroying homes, damaging infrastructure and causing massive erosion of the banks. Local authorities now consider these floods as a major seasonal threat. The Mendenhall glacier, a vestige of the little ice age, is now falling from 30 to 45 meters per year.
