Tundra Types

1. Tundra can cover many diverse terrains: mountain ranges and peaks, glaciers and ice sheets, island archipelagos, fjords, glassland plateaus, river valleys, forests, as well as areas with grasses, sedges, mosses, and lichens for vegetation.

2. Tundra falls within three domains: polar tundra, subpolar tundra, and alpine tundra, progressing from cold regions featuring mostly treeless permafrost, such as ice sheets, sea ice, and glaciers, often with high winds and scant vegetation, to cold regions with some permafrost but also boreal forest, taiga, peat bog, and one or more warmer seasons, and finally to cold regions of high altitude (on summits, slopes, and ridges), treeless but without permafrost.

Tundra Cycles

1. Tundra cycles largely revolve around glacial accumulation, glacial retreat and subsequent flooding, and the intermediary freeze-thaw cycles associated with that.

Tundra Formation & Ecological Succession

1. Permafrost limits tundra’s biodiversity capacity. Primary ecological succession in tundra usually begins after glacial retreat, where pioneers like mosses, lichen, algae, and fungi form habitats near melted ice. In particular, lichen form on bare rock, cracking it and mixing in upon death, creating a proto-soil. And in these rock cracks, wind-blown moss can take hold, potentially followed by grasses, and in less polar regions, shrubs or trees.

2. The high soil moisture around snow patches can also support distinct vegetation habitats. Secondary succession can occur after avalanches and mudslides.

Snow Phases

1. Snow can progress from neve (snow fields), to firn, to glaciers. What does that look like? Young, granular snow which partially melts, refreezes, and compacts, densifies across seasons to recrystallize as snowflakes, then compacts further under snowpack. Snow patches persist longer than other seasonal snow cover, supporting distinctive vegetation. Eventually, glaciers solidify, which constantly move under their own mass. Alternately, on snow patches, cores of ice, snow, or firn covered by depositional materials can also form dirt cones, the start of crevasses or hollows.

Landform Expanses

1. Following an Ice Age, freeze-thaw erosion cycles can create strandflat erosion surfaces on coastal seabed, with mountains on one side and protected waters on another, or else stone runs where stable boulders sort along slopes or fields. Freeze-thaw cycles and wind can also support unique vegetation in rockfall deposit fellfields. Also, subsurface frost weathering can create blockfields as boulders or blocks break down.

2. After glacial retreats, unconsolidated rock, gravel, boulders, and powder can accumulate as a moraine, including depositional ridges.

3. Seasonal glacier motion and icefall can create ogives, waves of alternating crests and valleys of dark and light ice bands.

4. Among wetlands like peat bog, permafrost plateaus can emerge as palsas coalesce, sometimes with seasonal pools. Permafrost thaw can also create irregular surfaces, thermokarsts, with marshy hollows and small hummocks.

Iceform Expanses

1. Successive freezes and flows of groundwater can create sheet-like masses of layered ice (afeis). On a larger scale, ice shelves, sheets, tongues, or continental glaciers, can form. Large areas of interconnected glaciers, mountainous ice fields, can form too. These contrast with sea ice, including drift ice from wind and sea current, and ice fastened to coastlines, sea floors, or grounded icebergs.

2. Steep-sided valleys can form valley glaciers, bowl-shaped valleys on mountainsides can fill with cirque glaciers, and valley glaciers which spill out onto flat plains can form piedmont glacier lobes. Likewise, rock glaciers can arise as angular rock debris freezes in ice or overlays former glaciers.

3. Glacial influences from long ago over soluble rock landscapes like limestone can form glaciokarsts with underground drainage systems of sinkholes and caves.

4. Glaciers with rapid flows and crevassed surfaces can form icefalls, waterfalls of ice. The intersecting crevasses can form seracs, glacial columns.

5. Snowstorms can sculpt mounds into snowdrift dunes. And at high altitudes, low dew point along can form elongated, thin blades of hardened snow or ice (penitentes).

Patterned Ground

1. Frost weathering and freeze-thaw cycles can create lines of stones, vegetation, and soil along steps and slopes (sorted stripes). It can also create mounds: small circular mounds of soil (frost boils), low mounds with tall concentric ridges and gradual ice lenses (palsa) or mounds of earth-covered ice (pingo). Or, in permafrost, create raised landforms like lithalsas. Permafrost and seasonal frost can also create polygonal patterns of raised stone rings.

2. On snow surfaces in frozen lakes or polar regions, a combination of wind erosion, snow saltation, and deposition can form sharp irregular grooves and ridges (sastrugi).

3. Slope failure and sedimentation from differential downhill flow can form tongue-shaped landforms (solifluction lobes). Other flows – glaciers passing over bedrock – can create asymmetric rockforms (sheepbacks).

Protrusions

1. When glaciers erode parallel U-shaped valley, or glacial cirques erode toward one another, narrow rock ridges emerge (arete). Where three or more glaciers diverge from a central point, a sharp pyramidal peak forms. Frost and wind tear can create steep, rocky, rough, and bare ridges (bratschen). Snow itself can create overhangs on ridges or crests or gully sides (snow cornice).

2. Glacial action can transfer exotic rocks (glacial erratics), and act on unconsolidated sediment or ground moraine to create elongated hills (drumlin). It can also allow for rocky exposures (rognon and nunatak) atop ice.

Depressions

1. Shear stress in glaciers can create deep cracks or fissures (crevasse), including gaps between a rock face and adjacent glacier or snowfield (marginal cleft). Between ice walls, this manifests as mountain cleft.

2. Glaciers and ice sheets can have vertical and circular well-like shafts (moulin), or else horizontal outlets (glacial caves).

3. Snowmelt can form dense, honeycombed, bowl-shaped depressions (suncups), earthen hollows (nirvation hollows), and in valley amphitheaters, snowmelt can form lakes, ponds, or pools (tarn), often with glacial debris dams below.

Hoarfrost & Rime

1. On branches or poles, frost can form tiny ice spikes (advection frost) or ice crystals (air hoarfrost). On long-stemmed plants in the cold season, tiny floral-shaped iceforms (frost flowers) can arise. On dead wood, hair ice, resembling fine, silky hair, can occur.

2. On already frozen surfaces, fern-like ice crystals (surface hoarfrost) can form. Fragile white soft rime can also deposit on the outer surface of objects as fog or mist freezes. When hoarfrost forms on a snow surface and breaks apart, balls of fine frost can form tumble-weed like structures (yukimarimo).

3. In glacial crevasses, crevasse hoarfrost can form. Similarly, depth hoarfrost arises in cavities beneath surface banks of dry snow, creating steps and faceted hollows. Conversely, where subterranean water surfaces from capillary action, needle-like ice columns (needle ice) can arise.

Tundra Phenomena

1. In high-latitudes, natural aerial light displays called aurora can take place.

2. Severe snowstorms with sustained winds can manifest as blizzards, including ground blizzards, where wind picks up loose ground snow. When snow falls on a glacier, compresses, and joins it, blue ice can form.

3. Avalanches or snowslides can occur when a weaker snow layer breaks, causing a slab to side down a steep slope until a massive impact.