A melting Alaska glacier could trigger an unprecedented ‘mega-tsunami,’ scientists have warned.
The concerned experts claim the catastrophic event could even happen within the next 12 months if melting ice triggers a landslide of unstable rocks. If it’s not that soon, they think the ‘mega-tsunami’ is likely to happen within the next two decades.
Scientists warned about the potential disaster in May. They wrote an open letter to the Alaska Department of Natural Resources (ADNR). They’re worried about an area called Prince William Sound along the south coast of Alaska in the US. This region has seen glacier retreat, which has led to instability on the slopes of a mountain in Barry Arm above the Barry Glacier.
The scientists wrote: “We, a group of scientists with expertise in climate change, landslides, and tsunami hazards, have identified an unstable mountain slope above the toe of Barry Glacier in Barry Arm, 60 miles east of Anchorage, that has the potential to fail and generate a tsunami. This tsunami could impact areas frequented by tourists, fishing vessels, and hunters (potentially hundreds of people at one time). We believe that it is possible that this landslide-generated tsunami will happen within the next year, and likely within 20 years.”
Satellite images have shown how melting ice on the glacier has left a large rocky area exposed. It could mean a slow-moving landslide is already taking place, but if a large part of the mountain slope gave way it could have dire consequences.
Prince William Sound is a remote area. However, its surrounding waters are often frequented by boats, including cruise ships.
The researchers said: “Landslides have set off giant waves elsewhere in Alaska and Greenland during the past decade. In Taan Fiord (Icy Bay, Alaska), a landslide that began moving slowly decades ago suddenly failed in October 2015. The resulting tsunami reached elevations of 633 feet near the landslide, and 35 feet 15 miles away. At Karrat Fiord, west Greenland, a landslide in June 2017 similarly produced a tsunami that killed four people and destroyed a large portion of the town of Nuugaatsiaq, 20 miles away. Surviving villagers still have not returned because a nearby slope is deforming and threatening to fail. The unstable slope in Barry Arm is much bigger than either of these examples, and thus has the potential to produce a larger tsunami that could have impacts throughout Prince William Sound.”
A 1958 landslide in the region resulted in what is often referred to as the tallest tsunami wave in modern times. It was said to have reached 1,720 feet tall and the impact was compared to an atomic bomb by eye-witnesses.
Geophysicist Chunli Dai from the Ohio State University told NASA’s Earth Observatory: “It was hard to believe the numbers at first. Based on the elevation of the deposit above the water, the volume of land that was slipping, and the angle of the slope, we calculated that a collapse would release 16 times more debris and 11 times more energy than Alaska’s 1958 Lituya Bay landslide and mega-tsunami.”
Since the release of the open letter earlier this year, further analysis has noted little change. Ongoing monitoring will continue so that scientists can spot warning signs of a landslide and subsequent tsunami before it happens.
These scientists have predicted that the tsunami could cause issues over 10 miles away, so a pre-warning could save lives.