Scientists warned on Thursday that a catastrophic tsunami is most likely to happen because of climate change increasing the risk of a massive landslide in an Alaskan fjord. A glacier that supports a steep, mile-long slope along one flank in Prince William Sound is slowly retreating due to warmer temperatures.
According to the New York Times, only one-third of the slope is left now, and an earthquake or prolonged heavy rain or even a heatwave could trigger a landslide.
Tsunami-inducing Landslides
According to the researchers, a sudden, huge collapse is possible within a year and is likely within two decades. After being briefed on the findings, the Department of Natural Resources of Alaska issued a statement on Thursday afternoon.
They cautioned everyone that "an increasingly likely landslide could generate a wave with devastating effects on fishermen and recreationalists."
A computer modeling showed that a collapse of the slope could cause a tsunami that would start at several hundred feet high. Upon reaching Whittier, a town at the head of another fjord 30 miles away, the tsunami could still be 30 feet tall and will even cause an extensive destruction.
Although the findings are still yet to be reviewed, Anna Liljedahl, an Alaska-based hydrologist with the Woods Hole Research Center in Massachusetts, believes that the people should know. The researchers hope that a budget will be available for near-real-time monitoring of the slope to serve as a warning device if a landslide and tsunami should occur.
Granting Alaska rarely have tsunami-induced landslides, it is not new for them. The most famous event occurred on July 9, 1958, in Lituya Bay on Alaska's southeast coast. A nearby earthquake caused 4 million cubic yards of rock to slide 2,000 feet into the narrow bay.
At that time, the tsunami reached a maximum height of 1,720 feet - the highest tsunami ever documented - based on the scouring of vegetation on a hillside opposite the slide. The wave swamped several fishing boats and ended up killing two people.
Back in 2015, a landslide at Taan Fjord in Yakutat, Alaska, produced a tsunami roughly 600 feet high. Additionally, a landslide in 2017 at the west coast in Greenland created a wave of more than 300 feet tall that destroyed much of the neighboring fishing village and killed four people.
Those previous landslides may have caused great waves, but a slide at the Barry Arm would potentially be much bigger in energy and would be in a whole different class than the researchers ever studied, said Dr. Hig Higman.
Potential Hazard at Barry Arm
Dr. Higman's sister, an artist, Valisa Higman, told her brother that the slope seems to have a fracture. Dr. Higman then studied the satellite imagery and confirmed that the slope has indeed been sliding over time. According to his analysis, between 2009 and 2015, about 600 feet moved downhill, leaving a scar to the slope.
Chunli Dai, a researcher at Ohio State, said that there is a connection between the sliding movement of the slope and the melting of the nearby Barry Glacier. According to her, it is similar to what she has observed in many parts of the world that climate change has caused the permafrost to thaw.
But Higman disagreed, saying that Alaska is an earthquake-prone area, and a violent shaking could cause a slope. For example, the 1964 Alaska earthquake caused a tsunami that damaged Whittier.
