Avalanche in the context of "Mount Everest"

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.

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.