A huge glacier in Alaska could be the cause of a devastating tsunami in the area, warn American geologists in the scientific journal Geophysical Research Letters. In recent years, the glacier over the Barry Arm River has receded very quickly, becoming unstable, scientists say.
Due to the rapid retreat, its slopes lose support, and at some point, this can lead to a huge landslide. If this happens, it could cause a “mega-tsunami”.
“If the slope falls all at once, it will be catastrophic,” said Bretwood Higman, co-author of the study. The team’s analysis tested several different models. One of them shows that the tsunami can move at 145 km/h and be 10 meters high when it reaches the nearby town of Whittier.
“It was hard to believe the numbers. We calculated that the landslide could release 16 times more debris and 11 times more energy than the 1958 landslide and megatsunami in Alaska,” said the team leader.
This event was caused by a magnitude 7.8 earthquake and is considered to be the third-highest wave in history, carrying trees 524 meters high on the slopes of the Lituya Bay.
The tsunami in Barry Arm will not be so high, but it can be dangerous because there is a population nearby, while Lituya is a remote area. The landslide over Barry Arm can be caused by various factors – earthquakes, heavy rain, and others.
Scientists give the example that in 2017 a similar phenomenon caused a small tsunami in western Greenland and killed 4 people. That is why they are already working on warning systems that can save people some time if a landslide starts.
The problem is serious, as satellites have detected renewed movement on the slope, which has moved of about 20 cm in the period from 9 to 24 October this year. This is its first movement after the period 2009-2015 when it moved a total of 182 meters. That is why a warning has been issued to people and vessels to avoid this area.