Avalanche in the context of Snow pack

A natural disaster is the very harmful impact on a society or community brought by natural phenomenon or hazard. Some examples of natural hazards include avalanches, droughts, earthquakes, floods, heat waves, landslides - including submarine landslides, tropical cyclones, volcanic activity and wildfires. Additional natural hazards include blizzards, dust storms, firestorms, hails, ice storms, sinkholes, thunderstorms, tornadoes and tsunamis.

A natural disaster can cause loss of life or damage property. It typically causes economic damage. How bad the damage is depends on how well people are prepared for disasters and how strong the buildings, roads, and other structures are.

The National Snow and Ice Data Center (NSIDC) is a United States information and referral center in support of polar and cryospheric research. NSIDC archives and distributes digital and analog snow and ice data and also maintains information about snow cover, avalanches, glaciers, ice sheets, freshwater ice, sea ice, ground ice, permafrost, atmospheric ice, paleoglaciology, and ice cores.

NSIDC is part of the University of Colorado Boulder Cooperative Institute for Research in Environmental Sciences (CIRES), and is affiliated with the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information through a cooperative agreement. NSIDC serves as one of twelve Distributed Active Archive Centers funded by the National Aeronautics and Space Administration to archive and distribute data from NASA's past and current satellites and field measurement programs. NSIDC also supports the National Science Foundation through the Exchange For Local Observations and Knowledge of the Arctic (ELOKA) and other scientific research grants. NSIDC is also a member of the ICSU World Data System. sujit Serreze is the director of NSIDC.

Mount Everest (known locally as Sagarmāthā in Nepal and Qomolangma in Tibet) is Earth's highest mountain above sea level. It lies in the Mahalangur Himal sub-range of the Himalayas and marks part of the China–Nepal border at its summit. Its height was most recently measured in 2020 by Chinese and Nepali authorities as 8,848.86 m (29,031 ft 8+1⁄2 in).

Mount Everest attracts many climbers, including highly experienced mountaineers. There are two main climbing routes, one approaching the summit from the southeast in Nepal (known as the standard route) and the other from the north in Tibet. While not posing substantial technical climbing challenges on the standard route, Everest presents dangers such as altitude sickness, weather, and wind, as well as hazards from avalanches and the Khumbu Icefall. As of May 2024, 340 people have died on Everest. Over 200 bodies remain on the mountain and have not been removed due to the dangerous conditions.

A disaster is an event that causes serious harm to people, buildings, economies, or the environment, and the affected community cannot handle it alone. Natural disasters like avalanches, floods, earthquakes, and wildfires are caused by natural hazards. Human-made disasters like oil spills, terrorist attacks and power outages are caused by people. Nowadays, it is hard to separate natural and human-made disasters because human actions can make natural disasters worse. Climate change also affects how often disasters due to extreme weather hazards happen.

Disasters usually hit people in developing countries harder than people in wealthy countries. Over 95% of deaths from disasters happen in low-income countries, and those countries lose a lot more money compared to richer countries. For example, the damage from natural disasters is 20 times greater in developing countries than in industrialized countries. This is because low-income countries often do not have well-built buildings or good plans to handle emergencies.

Snowpack is an accumulation of snow that compresses with time and melts seasonally, often at high elevation or high latitude. Snowpacks are an important water resource that feed streams and rivers as they melt, sometimes leading to flooding. Snowpacks provide water to down-slope communities for drinking and agriculture. High-latitude or high-elevation snowpacks contribute mass to glaciers in their accumulation zones, where annual snow deposition exceeds annual melting.

Assessing the formation and stability of snowpacks is important in the study and prediction of avalanches. Scientists study the physical properties of snow under different conditions and their evolution, and more specifically snow metamorphism, snow hydrology (that is, the contribution of snow melt to catchment hydrology), the evolution of snow cover with climate change and its effect on the ice–albedo feedback and hydrology, both on the ground and by using remote sensing. Snow is also studied in a more global context of impact on animal habitats and plant succession. An important effort is put into snow classification, both as a hydrometeor and on the ground.

Backcountry skiing (US), also called off-piste (Europe), alpine touring, freeriding or out-of-area, is skiing in the backcountry on unmarked or unpatrolled areas either inside or outside a ski resort's boundaries. This contrasts with alpine skiing, which is typically done on groomed trails benefiting from a ski patrol. Unlike ski touring, backcountry skiing can – and often does – include the use of ski lifts including snowcats and helicopters. Recent improvements in equipment have increased the popularity of the sport. As the sport does confront the individual practicing it with the dangers of natural, unprepared alpine terrain like avalanches, it is generally recommended to carry standard safety equipment and to learn beforehand how to behave safely under such conditions.

A landslide dam or barrier lake is the natural damming of a river by some kind of landslide, such as a debris flow, rock avalanche or volcanic eruption. If the damming landslide is caused by an earthquake, it may also be called a quake lake. Some landslide dams are as high as the largest existing artificial dam.

In the afternoon of 25 April 2015, a 7.8 moment magnitude earthquake struck Nepal and surrounding countries. Tremors from the quake triggered an avalanche from Pumori into Base Camp on Mount Everest. At least 22 people were killed, surpassing the toll of an avalanche that occurred in 2014 as the deadliest disaster on the mountain.

A glacial lake outburst flood (GLOF) is a type of outburst flood caused by the failure of a dam containing a glacial lake. An event similar to a GLOF, where a body of water contained by a glacier melts or overflows the glacier, is called a jökulhlaup. The dam can consist of glacier ice or a terminal moraine. Failure can happen due to erosion, a buildup of water pressure, an avalanche of rock or heavy snow, an earthquake or cryoseism, volcanic eruptions under the ice, or massive displacement of water in a glacial lake when a large portion of an adjacent glacier collapses into it.

Increasing glacial melting because of climate change, alongside other environmental effects of climate change (i.e. permafrost melting) mean that regions with glaciers are likely to see increased flooding risks from GLOFs. This is especially true in the Himalayas where geologies are more active.

Mountain warfare or alpine warfare is warfare in mountains or similarly rough terrain. The term encompasses military operations affected by the terrain, hazards, and factors of combat and movement through rough terrain, as well as the strategies and tactics used by military forces in these situations and environments.

Mountain ranges are of strategic importance since they often act as a natural border and may also be the origin of a water source such as the Golan Heights. Attacking a prepared enemy position in mountain terrain generally requires a greater ratio of attacking soldiers to defending soldiers than a war conducted on level ground. Mountains present natural hazards such as lightning, strong gusts of wind, rockfalls, avalanches, snowpacks, ice, extreme cold, and glaciers with their crevasses; in these ways, it can be similar to cold-weather warfare. The generally uneven terrain and the slow pace of troop and material movements are additional threats to combatants. Movement, reinforcements, and medical evacuation up and down steep slopes and areas in which even pack animals cannot reach involves an enormous exertion of energy.

Snezhnika (Bulgarian: Снежника 'the snow patch') is a glacieret in the Pirin Mountains of Bulgaria, a remnant of the former Vihren Glacier. The glacieret lies at an elevation between 2,425 m (7,956 ft) and 2,480 m (8,140 ft) in the deep Golemiya Kazan cirque at the steep northern foot of Vihren (2,914 m (9,560 ft)), Pirin's highest summit. Due to the relatively easy access and its location along a popular hiking trail, Snezhnika is Bulgaria's most famous glacieret. Snezhnika has an average area of 0.01 km (0.0039 sq mi) and in 2006 it had a volume of 30,000 m (1,100,000 cu ft).

Snezhnika's size varies in length from 70 to 100 metres (west to east) and in width from 40 to 90 metres (north to south). Its firn is 8–11 m thick at the base and its snow cover, which is mostly fed by avalanche snow, can be as deep as 20 metres in March and April. Snezhnika's latitude of 41°46′09″ N makes it the southernmost glacial mass in Europe; the nearby Banski Suhodol Glacier below Koncheto, although larger, is slightly to the north.

Over 405 people have died attempting to reach—or return from—the summit of Mount Everest which, at 8,848.86 m (29,031 ft 8+1⁄2 in), is Earth's highest mountain and a particularly desirable peak for mountaineers. This makes Everest the mountain with the most deaths, although it does not have the highest death rate which is defined as the number of deaths for each person who successfully summits the mountain. The most recent years without known deaths on the mountain are 1977, in which only two people reached the summit, and 2020, when permits were suspended by Nepal because of the COVID-19 pandemic.

Deaths have been attributed to avalanches, falls, serac collapse, exposure, frostbite, or health problems related to conditions on the mountain. Not all bodies have been located, so details on those deaths are not available.

Ablation zone or ablation area refers to the low-altitude area of a glacier or ice sheet below firn with a net loss in ice mass. This loss can result from melting, sublimation, evaporation, ice calving, aeolian processes like blowing snow, avalanche, and any other ablation. The equilibrium line altitude (ELA) or snow line separates the ablation zone from the higher-altitude accumulation zone. The ablation zone often contains meltwater features such as supraglacial lakes, englacial streams, and subglacial lakes. Sediments dropped in the ablation zone forming small mounds or hillocks are called kames. Kame and kettle hole topography is useful in identifying an ablation zone of a glacier. The seasonally melting glacier deposits much sediment at its fringes in the ablation area. Ablation constitutes a key part of the glacier mass balance.

The amount of snow and ice gained in the accumulation zone and the amount of snow and ice lost in the ablation zone determine glacier mass balance. Often mass balance measurements are made in the ablation zone using snow stakes.

Mount Kusatsu-Shirane (草津白根山, Kusatsu Shirane-san) is a 2,165 m (7,103 ft) active stratovolcano in Kusatsu, Gunma, Japan. It is called Kusatsu Shirane to differentiate it from the Mount Nikkō-Shirane on the other side of Gunma Prefecture. The summit of Kusatsu-Shirane volcano, located immediately north of Asama volcano, consists of a series of overlapping pyroclastic cones and three crater lakes. The largest of these is Yu-gama, an acidic emerald green lake with rafts of yellow sulfur sometimes seen floating on its surface.

On January 23, 2018, a minor phreatic eruption of the volcano occurred. One person was killed, and others were injured in an avalanche triggered by the eruption. The next day, new activity forced police to suspend search operations. One month after the eruption, it was announced by prefectural officials that only the summit of the volcano was off limits to the public.