Avalanches

Stunning footage of a Utah avalanche cloud descending a mountain slope has gone viral and been viewed more than 2 million times. The footage, shared by the Utah Avalanche Center, shows the avalanche raining down from the "Middle Finger" on Mount Timpanogos, which is in the city of Provo area, as skiers watch in awe. The footage was reshared to several platforms, including In the video, a huge powdered cloud can be seen making its way down from the mountain, making a loud rumbling sound. "What the heck, bro," a man can be heard saying in the video. "That's one of the biggest avalanches I've ever seen in real life." A friend just shared this with me. Avalanche at A skier standing next to the person filming can be seen backing away as the cloud gets close and closer. "Dude, I hope nobody's down on the hill," the man can then be heard saying. The cloud continues to come closer to the people standing on the slope. "Here it comes," the man says. The cloud then engulfs the camera. Nobody was injured during the avalanche. The Utah Avalanche Center said on Read more • New ocean within Africa could take millions of years to form • Why is California's snowpack so high? • Poisonous plant sting gives woman pain worse than childbirth: "Unbearable" They tend to occur in the same areas often, as the conditions will continue to repeat themselves on certain mountainsides. Avalanches kill over 150 people annually, according to the National Weather Service. They can be sudden, meaning they ar...

Luckily, wet avalanches usually don't last forever because over time, days or weeks of percolating meltwater, all the layers in the snow disappear, and the snow becomes homogenous and dense, turning into a stable summer-like snowpack. Typically, this cycle of instability maturing into stability occurs first on the south-facing slopes in early spring, then progresses to the east and west-facing slopes in mid-spring, and finally, by late spring, the upper elevation north facing slopes go through a wet avalanche cycle. Finally, glide avalanches occur regularly in spring as the entire snowpack slides slowly on the ground like a glacier until they suddenly release into a full-depth avalanche. These occur periodically on steep rock slabs and occasionally on steep grassy slopes. Notorious glide avalanche locations include Stairs Gulch or the rock slabs in Broads Fork, which you should always avoid in spring. Avoid crossing under any slopes with telltale glide cracks in the snowpack. Remember, they come down randomly, even at night. We almost always get winter-like snow storms well in the Spring. Treat each storm just like you would in winter. Avalanches can occur within the new snow typically from 1) low-density layers deposited during the storm, 2) high precipitation intensity during a storm, and 3) from wind slabs created during the storm. It's easy to test the new snow as you travel by jumping on small test slopes to see if they avalanche or dig down with your hand to see how ...

During an avalanche, a mass of snow, rock, ice, soil, and other material slides swiftly down a mountainside. Avalanches of rocks or soil are often called landslides. Snowslides, the most common kind of avalanche, can sweep downhill faster than the fastest skier. A snowavalanche begins when an unstable mass of snow breaks away from a slope. The snow picks up speed as it moves downhill, producing a river of snow and a cloud of icy particles that rises high into the air. The moving mass picks up even more snow as it rushes downhill. A large, fully developed avalanche can weigh as much as a million tons. It can travel faster than 320 kilometers per hour (200 miles per hour). Avalanches occur as layers in a snowpack slide off. A snowpack is simply layers of snow that build up in an area, such as the side of a mountain. In winter, repeated snowfalls build a snowpack dozens of meters thick. The layers vary in thickness and texture. The bonds between the layers of a snowpack may be weak. Melted snow that refreezes may cause a slick coating of ice to form on the surface of a layer. A new snowfall may not stick to this slippery layer, and it may slide off. During spring thaw, melted snow can seep through a snowpack, making the surface of a lower layer slippery. Added weight or vibration can easily send the top layers of a snowpack hurtling downhill. Sluffs and Slabs There are two main types of snowavalanches—sluffs and slabs. Sluff avalanches occur when the weak layer of a snowpack ...

• Article • • 11 May 2021 Climate drivers of large magnitude snow avalanche years in the U.S. northern Rocky Mountains • ORCID: orcid.org/0000-0001-7624-0455 • ORCID: orcid.org/0000-0002-6014-1425 • • ORCID: orcid.org/0000-0001-6194-3596 • … • Show authors Scientific Reports volume 11, Article number: 10032 ( 2021) Large magnitude snow avalanches pose a hazard to humans and infrastructure worldwide. Analyzing the spatiotemporal behavior of avalanches and the contributory climate factors is important for understanding historical variability in climate-avalanche relationships as well as improving avalanche forecasting. We used established dendrochronological methods to develop a long-term (1867–2019) regional avalanche chronology for the Rocky Mountains of northwest Montana using tree-rings from 647 trees exhibiting 2134 avalanche-related growth disturbances. We then used principal component analysis and a generalized linear autoregressive moving average model to examine avalanche-climate relationships. Historically, large magnitude regional avalanche years were characterized by stormy winters with positive snowpack anomalies, with avalanche years over recent decades increasingly influenced by warmer temperatures and a shallow snowpack. The amount of snowpack across the region, represented by the first principal component, is shown to be directly related to avalanche probability. Coincident with warming and regional snowpack reductions, a decline of ~ 14% (~ 2% per decade) i...

avalanche, Large mass of material, such as snow or rock debris, that moves rapidly down a mountain slope, sweeping everything in its path. Avalanches begin when a mass of material overcomes the frictional resistance of the sloping surface, often after the material’s foundation has been weakened by rains or the snow has been partially melted by a warm, dry wind. Other weather conditions that can lead to avalanches are heavy snowfall and high winds. A common method of avalanche control consists of detonating explosives in the upper reaches of avalanche zones, which intentionally causes the snow to slide before accumulations have become very great.

1 of4 As much as 40 feet of snow covers Highway 395 along Mono Lake, the product of a series of avalanches in the eastern Sierra in late February. Caltrans District 9 2 of4 The avalanches north of Lee Vining (Mono County) dropped more than 2,000 feet down the snowy slopes of the Sierra in February. Caltrans District 9 3 of4 Highway 395, north of Lee Vining (Mono County), remains buried in snow from a series of avalanches in late February. Caltrans District 9 4 of4 Avalanches near Lee Vining have closed Highway 395, the main north-south artery on the eastern side of the Sierra. Provided by Inyo County Sheriff • • • • If it was just another avalanche, residents of California’s Sierra Nevada might yawn. Winters in the mountains are chock full of But last month’s avalanche just north of the town of Lee Vining, on the Sierra’s east side, was different. It buried a portion of a major U.S. highway, cut off a string of small communities heavily reliant on one another and stranded food deliveries, mail and even people. For weeks, road crews have been struggling with how to get rid of it. Live storm map: Technically a series of avalanches, the sprawling icy mass tumbled down more than 2,000 feet, splintering into several slides before crossing Highway 395 around Feb. 25. Snow now sits as thick as 40 feet and spans, on and off, across nearly three miles of road along the shores of Mono Lake. The avalanches carried with it trees, power lines and fences designed to catch rocks. Now Pla...