Ice and snow

A mass of snow sliding or flowing down a slope, burying people, roads and buildings.

Also: snow slide

A winter snowpack far below normal that cuts spring meltwater for rivers, hydropower and irrigation.

Rain falling on a snowpack so that it melts and releases water quickly, adding to runoff and flood peaks.

A sudden release of water from a lake held back by a glacier or moraine, sending a flood and debris wave down the valley.

Also: GLOF

A large part of a glacier or hanging ice breaking away and rushing down the valley as an ice and rock avalanche.

Also: ice avalanche, hanging glacier break-off

Sustained shrinking of mountain glaciers that first raises and later cuts dry-season river flow and destabilises slopes.

Also: glacier retreat

Net loss of ice from the great ice sheets, driving long-term sea-level rise and changes in ocean circulation.

Warming of frozen ground that weakens foundations, collapses slopes, releases greenhouse gases and reshapes drainage.

Also: thermokarst

Rapid break-up of a floating ice shelf when meltwater fractures it or warm water thins it, letting the glaciers it held back flow faster into the sea.

Also: ice-shelf collapse, hydrofracture

A sudden flood of meltwater released from beneath a glacier, often by volcanic heat, that sweeps away bridges, roads and land downstream.

Also: jokulhlaup, glacial volcanic flood

A glacier advancing many times faster than normal for months to years, overrunning land and damming rivers to create outburst flood risk.

Also: surging glacier

Collapse and retreat of slopes as ice-rich permafrost thaws, flowing mud and debris into rivers and undermining roads, pipelines and buildings.

Also: retrogressive thaw slump, active-layer detachment

Acceleration and breakdown of ice-cemented rock glaciers as mountain permafrost warms, feeding debris flows and rockfall onto mountain infrastructure.

Also: rock glacier acceleration, creeping permafrost failure

Sea ice that closes shipping lanes, crushes hulls and platforms and cuts off coastal communities.

Also: pack ice

Icebergs or large floes drifting into shipping lanes, ports and offshore platforms.

Also: icebergs, ice flow

Shrinking polar ice cover that exposes coasts, shifts weather patterns and opens new shipping and security risks.

Later freeze-up, earlier break-up and thinner ice on lakes and rivers that cut off winter roads and travel and raise drowning risk for northern communities.

Also: ice road failure, shorter ice season

Wind or current driving lake or sea ice onto shore, where it piles up and crushes buildings, docks and shoreline structures.

Also: ice push, ice pile-up