Alaska is lucky to avoid disasters after landslides and tsunamis. What about next time? |Alaska

tScientists, tourism operators and agent officials said he triggered a landslide in the early August 10, a close call because the risk of such events is apparently increasing due to climate change.

“It’s a historic event,” said Dennis Staley, a scientist with the U.S. Slide Geological Survey, which took place in the Tracy Arm Fjord, 50 miles (80 kilometers) south of Juneau.

“I feel like we dodged a bullet,” he continued, and there were reports that no one was injured in a destination where more than 500,000 annual tourists could be seen.

Staley studies Alaska’s mountain hazards, including popular tourist areas. Tracy Arm is a narrow 30-mile (48 km) fjord with thousands of feet of water shrouded above its transparent walls. It ends on the surface of the South Saw Glacier. The enticing scenery is part of Towns National Forest, attracting kayakers, rowers and stable cruisers. But the channel was apparently empty at 5.30 am on Sunday, August 10, when there was no warning of the huge debris of the fjord wall collapsed.

Staley says now Precise size of slides. However, by analyzing its seismic signals, he and others estimated that up to 100m cubic meters of rock (or more) fell near the surface of the South Saw ice platform. It throws an incredible 1,400 feet (425 meters) on the other side of the fjord, which could make it one of the largest waves of this kind ever. Staley can see its effect on trees and brushes in satellite images and aerial photos.

A few seconds later, the tsunami estimated to be as high as 100 feet (30 meters) high in the entrance, stripping the forest and brushes from any shore. Thirty miles away, the waves were still 15 feet (5 meters) high as it expanded toward the remote port island, and within inches of the tent, Sasha Calvey and two other kayakers were camped.

Kayakers scramble to find that half of their equipment had been washed away. One kayak hangs from the bluff, the other hangs from a tree, one third waving in a quarter-mile ocean. Kavey said the water was still chaotic for hours.

Although they had to be rescued, ending a 78-day expedition from Washington State, Calvi knew they were lucky. If the tsunami occurred only three hours ago and the tide level was 10 feet higher, it might not survive.

Jeffrey and Christine Smith plan to fix their 65-foot tour boat, David B The David B, to stay overnight in Tracy’s arm. But the rainy weather caused them to anchor about 45 miles away. On the morning of the slide, they saw the water rise 10 feet along the coast near the anchorage.

“We’ve always felt a little fatal,” Christine Smith said after learning they missed the narrowness of the slides.

The landslide took place just hours on Juneau’s sightseeing boat and a National Geographic Tourist boat, each with the capacity of more than 100 passengers, and planned to visit Tracy Arm. Less than 24 hours ago, two cruise ships carrying thousands of passengers visited the area. Another cruise ship was arranged the next day.

Staley and others were amazed by luck, the weather was bad, the early morning timing and the trend was clearly intended to prevent casualties. In another luck, a portion of the slide landed on the South Saw Glacier. Staley said the tsunami could have been even bigger if its full weight had hit the water.

But some geologists fear that luck may run out. In Alaska and elsewhere, landslides near retreat glaciers appear to be increasing. One possible reason is that glacier ice hundreds of feet thick may help support the gables above them. Scientists debate whether similar rapid glacier retreats are taking place in Tracy Arm and globally Possible “laid off” Mountains are used to carry out mountains by removing support ice that has been around for hundreds of years.

Climate change has also melted high altitudes around the world. When permanent freeze-thaw is explained, changes in pressure, temperature and hydrology can lead to instability within steep slopes. Scientists believe Thaw permafrost Earlier this summer, huge landslides and glacier collapses caused by huge overwhelming and glacier collapses.

Staley stressed that it is too early to say what caused the Tracy Arm Slide.

“We have to be careful,” he said. “We can’t really be sure what triggered the event.”

Michael West, a state seismologist who directed the Alaska Earthquake Center in Fairbanks, agreed to be too early to determine the triggers of the slide, which he called “shockingly huge.” But he said it is worth noting that in recent years, such and other tsunami-causing landslides have occurred near retreating glaciers. He said it would be reasonable to explore other factors such as the idea of ​​how much permafrost is released and melted in Tracy Arm and the recent rainfall in the region.

exist In 2015, the slope Near a retreating glacier in Taan Fiord in southeast Alaska, 630 feet of water were sent to the nearby slope. A 2024 landslide near Prince William Sound, 500 miles northwest of Tracy Arm, caused a small tsunami.

Last summer, Large slope slide In addition to the retreating Pederson Glacier at Kenai Fjord National Park near Seward, Alaska, triggering waves estimated at 60-180 feet.

Scientists’ recent discoveries Weakerone hour southeast of Anchorage. If it fails, it could trigger a tsunami at Portage Lake that could hit the nearby Chugach National Forest Visitor Center, which sees up to 1,000 people a day in the summer, researchers say.

They are still monitoring 3,000 feet Barry’s arm unstable slope The entrance was in Prince William’s voice. If it fails, modeling shows that it can trigger a tsunami that is comparable to that in Tracy Arm. The Barry Arm and the surrounding waters are also popular among crew members, kayaking, cruise ships, etc.

Since the discovery of Barry Arm instability in 2020, scientists have installed high-tech equipment on the hills to track precipitation, slope movement and other conditions. They hope this work will improve understanding of the links between landslides, glaciers and climate change.

Although Tracy Arm does not have this instrument, West says Barry Arm 250 earthquake stations Near Alaska.

“It’s a new capability,” West said, explaining that scientists spent several days finding the 2015 Taan Fiord slideshow. But using the new method, they determined the location of the Tracy Arm shortly after the ships in the area were picked up.

“But that’s where it gets crazy,” West continued.

He said a review of the earthquake monitoring sites showed that an earthquake “pop up” occurred at the Tracy Arm site about 24 hours before the slide, and hundreds of small signals could detect 100 miles. They suddenly ended with a slide.

“Not every landslide does this,” West said, hoping to study the phenomenon to better understand possible warning signs.