From mountain glacier to ocean deep. Welcome back, Outlander, for Part 1 of a 3 Part cheatsheet overview of my larger 16 entry Mythic Ecology Series, a series on how learning real-world landscape features can enrich fantasy worldbuilding and storytelling for Dungeon Masters, Game Masters, and fiction writers. This post covers waterforms: the coasts, wetlands, lakes, rivers, deep sea, and tundra. Part 2 will cover landforms, and Part 3 will cover ambience. Enjoy!
How do you use this stuff in practice? Check out the tools and tips in the “Worldbuilding” and “Mapping Tools & Guides” sections of my free D&D 5e resources compilation. These tips help flesh out details for Dice Drop Maps really well too, a popular method of rolling worlds.
What else? I also highly recommend using DonJon’s free D&D 5e Bestiary, which has all the 5e Monster Manual, Volo’s, and Mordenkainen’s monsters sortable by environment; the ones relevant to this entry include the “Arctic”, “Coastal”, “Swamp”, and “Underwater” habitats.
Special thanks to my Patron Adam Roder for helping make this post possible.
PART 1: COASTAL WORLDBUILDING SUMMARY
NOTE: All terms covered in depth with visuals and narrative functions in my Coastal Worldbuilding post.
Coastal Cycles – Currents, Tides, Vortexes, Waves
1. Coasts have many currents, with the tidal cycle of flood, high, ebb, and low tide, transitioning through slack tides, being particularly influential, and which sometimes results in storm surge or reverse storm surge. Tides gradually erode landforms. Ocean currents more broadly determine the continuous background movement of the sea and how waves and wind and related phenomena impact things like temperature and salinity, as well as shoreline configurations.
2. Powerful underwater disturbances can on occasion form tidal waves, whereas powerful storm systems can produce tropical cyclones. Weaker storm systems can produce rotational currents like waterspouts. Other rotational current phenomena include fog-sucking steam devils, and whirlpools.
3. More localized currents include undertow and rip currents along the near shore and surf zone, more shallow and stationary tide pool habitats deposited by nearby waters.
Coast Formation & Ecological Succession
1. Rivers, glacial melt, shoreline erosion, and marine organisms can deposit sediment, which moves onshore by wave, tide, and wind currents, forming beaches.
2. Coastal dunes can show normal grassland to woodland progression. Habitats span from off-shore sandbars to submerged beach, intertidal beach, and upper beach, to primary dunes and inter-dune meadows, and potentially to shrub zones, shrub forests, and maritime climax forests.
3. Coral reefs form when swimming hard coral larvae attach to hard submerged surfaces like rock and edges of islands or continents and form symbiotic relations with algae, secreting calcium carbonate. The bodies and activity of algae, seaweed, sponges, and mollusks adds to reef structures, as does sediment. Reefs progress toward fringing, barrier, or atoll states.
Horizontal Coastal Landforms
1. Beaches form from wind and wave action, erosion and deposition, and can feature sand, gravel, shingle, pebbles, cobblestone, boulders, driftwood, and shells.
2. Pockets can form between headlands, and headlands can feature terraces.
3. Isthmuses, shoals (sandbars), and tombolos connect lands separated by expanses of water, and clusters of tombolos can form enclosures called lagoons.
Indents & Inlets
1. Bodies of recessed coastal waters can form larger inlets like bays and gulfs and sounds, smaller inlets like coves, narrow inlets like fjords and geos, wider inlets like bights, or branching inlets like rias.
2. Narrow indents like blowholes, sea caves, and surge channels arise from water erosion on smaller scales.
Islands & Reefs
1. Waves, wind, and tides can form ridges and dunes which become barrier beaches or islands, allowing wetlands to form.
2. Durable underwater landmasses called islands or isles, and islets, protrude above the water line. Unconnected groups of islands become arcs or archipelagos, or if connected, tidal islands and tied islands. Includes less habitable ones, such as desert islands, icebergs, skerries, and vanishing islands.
3. Underwater chains of rocks, corals, or sand where corals and algae aggregate form reefs, which, with islands can encircle lagoons to for m atolls, or if attached to a shore, a fringing reef, and table reefs if attached to continental shelf. Abovewater, this forms a cay (key).
Vertical Coastal Landforms
1. Beaches can have tall ridges or cliffs, sometimes very steep, typically formed of rock; headlands and capes refer to the larger ones.
2. Tidal erosion beneath can create sea arches, and that erosion can also create sea stacks.
PART 2: WETLANDS WOLRDBUILDING SUMMARY
1. Wetlands progress based on uneven influx of minerals and nutrients, acidity, salt, sediment, and seasonal dryness or wetness.
Wetlands Formation & Ecological Succession
1. Primary succession progresses from rocky shores of pioneer plants on bedrock, boulders, and stones, to unconsolidated shore of loose matter, manifesting beaches, bars, flats, salt flats, pans, salt pans, inland saline flats, or alkali flats. Both phases have irregular or seasonal flooding.
2. From there emerge moss and lichen cover in saturated waters with few trees, shrubs, and emergent waterplants, forming mires. This progresses into emergent wetlands where standing, rooted, herbaceous waterplants form marshes, meadows, fen, prairie potholes, and slough.
3. Next, the scrub and shrub phase bears woody vegetation, especially shrubs or small or stunted trees, forming shrub swamps, shrub carr, bogs, and pocosin, with varying flooding. This progresses into forested wetlands as an overstory, understory, and herbaceous layer all solidify, creating mangroves, swamps, hammocks, heads, and bottoms, often with heavier flooding.
Mires, Marshes, and Swamps
1. Mire wetlands form with short or submerged vegetation, including bogs and fen. Bogs have high acidity from rainfall, whereas fen, beside lakes or streams, have neutral to alkaline character.
2. Marsh wetlands have taller herbaceous plants, can possess saltwater, brackish, or freshwater, and have neutral to alkaline character.
3. Swamp wetlands have full shrubs and trees.
Mires – Bogs & Fen
1. Some mires, called dambo, have grasses, rushes, and sedges, contrasting against nearby woodlands.
2. On hills or mountains, shallow pine forest bogs called missen can form, whereas on upland flats, moorland can form.
3. In boreal and arctic regions, sphagnum moss, sedge peat, and decomposing humus can form muskegs.
4. Near streams and floodplains, standing water can create pocosin habitats.
5. Along wetter valleys or raised areas or acidic lake edges, quaking bogs form, or in drier and warmer ones, valley recesses can fill with peat, forming valley bogs.
1. High rainfall in wet hollows and undulating expanses forms blanket bogs.
2. Many bogs form at montane or alpine levels, including plateau bogs, hilside bogs on mountain passes, saddle bogs, summit and crest bogs.
3. On tundra margins, palsa bogs form with tall concentric ridges and limited peat. Also with limited peat in colder environments: honeycomb-patterned polygonal bogs. And seasonal freezing and thawing can create string bogs.
4. Lens shaped bogs with uneven shallow, wet depressions form as plateau and kermi bogs.
Marshes & Mudflats
1. Inundated rushes and sedges form marshes near rivers, coasts, and estuaries which flood from adjacent estuaries, seas, or oceans.
2. Low-lying areas can become mudflats, key habitat for migratory birds, or else with stream or river deposition, may become callows or backswamp.
3. Non-tidal, freshwater marsh habitats have little to no peat. Tidal, brackish salt marshes have dense stands of salt-tolerant plants.
4. Wet-meadows form where marshes fluctuate between brief inundation and longer saturation, sustaining sedges, rushes, and grasses. In valley bottoms, these form alkaline, spongy, wet meadows with mats of thick sod (cienegas).
1. Swamps form as woody shrubs and reeds accumulate in permanently waterlogged ground. Carr refers to where reedy swamps transition into forests.
2. Near rivers or lakes, forests can permanently flood, forming igapo and varzea.
3. Where coastal barriers guard from strong waves, mangrove swamps form, featuring distinct shrubs and small trees in saline or brackish water, and fine sediment, often highly organic.
4. Tropical moist forests where waterlogged soil prevents dead leaves and wood from decomposing fully create the thick layers of a peat swamp forest.
1. Between coastal sand dunes, wind and water can form interdunal ponds. Near lakes, alternating narrow sandy ridges and saturated depressions form ridges and swales, prime migratory bird habitat.
2. On a peatland or bog’s perimeter, water from adjacent uplands can collect and flow slowly around a mass of peat. There a lagg and moat can form, with shrubs and murky water.
3. Stones and coarse sediment which collect in hollows can swirl in pothole eddies, eventually becoming mires. Other pools include vernal pools, temporary pools devoid of fish. Very large pools can become pock marks or grady ponds.
4. Within salt marshes, depressions can create salt pannes and pools, supporting bug life.
5. Near larger bodies of water, riverine side-channels, sporadically-filled inlets, or former rivermouths, stagnant or seasonal flowing water of swamps or shallow lakes can form a slough.
NOTE: All terms covered in depth with visuals and narrative functions in my Wetlands Worldbuilding post.
PART 3: LAKES WORLDBUILDING SUMMARY
Lake, Pond, Puddle, Loch
1. Lakes form as large bodies of water filling up localized basins, apart from other outlets. Smaller ones become ponds, and even smaller ones puddles.
1. Lakes vary by content and behavior, drainage basin or catchment area, inflow or outflow, nutrient and oxygen profile, pH, and sedimentation.
Lake Formation & Ecological Succession
1. Lake water can develop from filled depressions from craters or glacial recessions, or glacial outwashes into basins. As birds deposit seeds in ponds, microhabitats arise. Pondweed, plankton, and other submerged vegetation eventually emerge, and eventually the outside edges grow lush. Layers of bottom decay slowly raise the pond floor. If emergents grow across this expanse and reeds or sedges flourish, marshes develop, and if trees take root, swamp develops. If the pond dries out, a forest or grassland may emerge.
2. As lakes age, their biological productivity increases due to higher nutrient contents, the water muddies and develops aquatic plants and algae, oxygen levels decrease, and fauna multiply, but eventually algae blooms may overtake the waters, causing suffocation.
Lake Categories By Origin
1. Crust deformation via faulting, tilting, folding, and warping creates tectonic lakes. Volcanic craters or calderas can create volcanic lakes. Other crater lakes may arise from meteorite or asteroid impact.
2. Glacial action and continental ice sheets can form glacial lakes, including through direct contact with ice, glacially carved rock basins and depressions, morainic movement and outwash, and glacial drift. Glacial dams can create stratifications of ice and water (epishelf lakes), narrow finger lake water bodies in valleys and tarn mountain lakes in high valley amphitheaters, or proglacial lakes. Subglacial lakes also exist, beneath ice caps or sheets.
3. Fluvial lakes arise from running water, or when tributary sediment blocks a river, or the reverse. Blocked estuaries and uneven beach ridges can create shoreline lakes. Alongside a river, broad but shallow waters can form a mere. In valleys, meandering rivers can form crescent-shaped oxbow lakes. If streambeds have a deep recession, they can form plunge pool waterfalls, feeding stream pools.
4. In karst landscapes made of limestone, solution lakes can form as underground basins fill after bedrock dissolution, with groundwater filling cavities and sinkholes to become karst ponds or lakes.
5. In valleys, mudflows, rockslides, or screes can block sections, creating landslide lakes. Similarly, when wind-blown sand dams a basin in arid locales, aeolian lakes can form.
6. Plant and animal action can create landforms like vegetation dams, coral lakes, or beaver dams.
Acidic, Soda, Salt Lakes
1. In igneous or metamorphic landscapes, peat bogs, arid environments, or volcanic craters, acid lakes can form. In contrast, in arid or semi-arid areas associated with tectonic rifts, soda lakes can form. Arid environments can also form salt lakes, as evaporation leaves salt behind, but they also exist in the Deep Sea.
1. Basins or depressions where their water body evaporated away can form dry lakes (playa, clay pan), alkali flats, and salt flats (salt pans). Especially wet seasons can partially and intermittently restore playa lakes to shallow depth.
2. Karst fields can create seasonal lakes; seasonal lakes in arid regions can form as vlei. In contrast to seasonality, elsewhere, shrunken lakes can also form, diminishing to a stable point from a previous level, possibly dividing too.
3. As incoming sediment from plains fills a lake, fertile plains, wetlands, or deserts can form.
NOTE: All terms covered in depth with visuals and narrative functions in my Lakes Worldbuilding post.
PART 4: RIVERS WORLDBUILDING SUMMARY
River Definition & Behavior
1. Any natural flowing freshwater watercourse flowing toward an ocean, sea, lake, or other river can constitute a river, even if it dries before arrival. They fill as precipitation collects in drainage basins from surface runoff, groundwater recharge, springs, ice or snowmelt.
2. All rivers have sources, courses, and mouths, with a streambed between banks, and larger ones have floodplains. Smaller rivers include streams, creeks, brooks, rivulets, and rills.
3. Rivers tend to flow down mountains, through valleys or depressions, and along plains, often creating canyons or gorges.
1. Streams vary by gradient, substrate composition, riparian vegetation and woody debris, sediment supply, and discharge.
River Formation & Ecological Succession
1. Rainwater, as well as melting snow and ice (such as from glaciers) can expand tiny mountain streams and springs into rivers, and they can join together as confluences as they flow downhill, eroding rock and carving valleys. At lower ground, they widen and wind, usually emptying out toward the sea, potentially with distributary branches.
2. Rivers may age through stages, progressing from steep gradient, few tributaries, and swift flow, toward reduced steepness, many tributaries, and free flow, and finally toward low gradient, and dependence on floodplains.
3. River ecological succession resembles that of lakes (and thus grasslands and woodlands) in some ways, but can feature more frequent disturbances, which cause frequent erosion or sedimentation, often leading to secondary succession.
Springs – Inputs
1. Moist or wet spots where underground aquifers reach the surface as groundwater form seepage springs, whereas tubular springs flow from underwater caverns with subterranean rivers.
2. As water discharge from faults, joints, or fissures flows across voids or weaknesses in bedrock, fracture springs form.
Basic Spring Types
1. Streams can manifest as small and shallow brooks, or larger creeks.
2. Between ridges or shoreline bars or thin stretches of river floodplain, narrow channels called runnels may form.
3. Where a stream or river flows into a larger stream, main stem river, or lake, a tributary forms. If joined, they become confluences. Greater conglomerations can become yazoo stream systems. If branching away as forks, they become distributaries, which create river deltas.
Special Color Types
1. Clearwater and whitewater rivers have contrasts in suspended sediment, pH, and hue.
2. Blackwater rivers move slowly through swamps, with fewer nutrients and dark stains from decaying vegetation.
1. Alluvial rivers self-form in minimally consolidated sediment, eroding banks and depositing material on bars and floodplains, whereas bedrock rivers form when a stream cuts through its sediment into the underlying bedrock. Many rivers mix the two.
Low Gradient Channels
1. On alluvial plains with densely vegetated banks, interconnected multithread channel belts arise as anastomosed rivers. In more tectonically active areas, unstable multithread streams arise as braided rivers.
2. Toward the end of a river system, singlethreaded and winding streams arise as meandering rivers, which create cut bank erosion and point bars, sometimes cutting down to the bedrock as entrenched meanders. Diversions called anabranches may exit the main channel but rejoin downstream. More rarely, in gravelly environments, singlethreaded streams can form unstable, constrained, straight rivers.
High Gradient Channels
1. Migrating pools and transverse bars can form riffle pools, whereas pools that span channels and have boulder or cobble steps can form step-pools.
2. Relatively deep river beds with high water velocity and turbulence can form rapids, and at knickpoints, such as steep channels where boulders and cobbles dominate, cascades may form.
1. Dry creeks which have flow after rain manifest as arroyos or wadi, whereas ephemeral rivers more broadly may flow occasionally, or dry out for years at a time.
2. Tidal rivers’ flow and level comes cyclically from the tides, whereas winterbournes vary cyclically by season, drying out in summer. The higher flow can create torrents.
Springs – Outputs
1. Near volcanic regions, geysers may form as intermittent, turbulent springs which discharge water and steam. Geothermal heat may instead produce hot springs.
2. Around sedimentary rock, particularly limestone, karst springs may form aside cave systems, and mineral springs with dissolved salts, sulfur, or other compounds may form as well. Cavern flow patterns can also create rhythmic springs.
Deltas, Splays, Fans
1. Streams can deposit sediment into fan- or cone-shaped alluvial fans, create new floodplains through crevasse splays as they burst natural levees. Their silt deposition can create river delta landforms at river mouths.
2. Braided streams from melting glaciers can form fan-shaped outwash fans. Glacial meltwater can also create long winding ridges of sand and gravel called eskers, or kame delta landforms as sediment deposits stratify after entering proglacial lakes.
More River Elements
1. Rivers can form tiny riverine islands and towheads, or small whirlpool eddies. Rivers don’t always fit properly, leading to overfit and underfit streams. During high discharge, streams can create floodplains, with elongated terraces flanking the sides of these floodplains and river valleys. They can leave behind sandstone ridges, called exhumed river channels, as they erode mudstone away, or sometimes even create cylindrical riverbed depressions (rock-cut basins).
2. Along hills, wide and shallow chalk streams with clear, alkaline waters may form.
3. Connected to open sea, partially enclosed water bodies called estuaries may form, where streams of brackish water flow or converge. As streams instead connect to land, riparian habitat zones form.
5. Along mountain ranges, streams can create shut-ins, complexes of pools, rivulets, rapids, and plunge pools, typically confined to a narrow valley or canyon, with a river valley widening out both above and below.
NOTE: All terms covered in depth with visuals and narrative functions in my Rivers Worldbuilding post.
PART 5: DEEP SEA WORLDBUILDING SUMMARY
Deep Sea Cycles
1. Deep Sea cycles depend on many factors: the tides, underwater plate tectonics and volcanic activity, deep sea earthquakes, vents and seeps, and marine organism behavior, including finite detritus habitats.
2. The Deep Water Cycle covers interactions between ocean water and the mantle, and currents here determine density gradients from surface heat and freshwater fluxes. These currents flow into ocean basins, and allow for upwelling and nutrient exchanges.
Deep Sea Ecological Succession
1. Along hydrothermal vents, microbes subsist off of nutrient-rich waters, which can progress toward a state where new microbe types to dominate which don’t require the vents’ heat, instead feeding off the vents’ of iron and sulfur deposits.
2. Whale fall and jelly fall habitats gradually diminish as scavengers consume the finite detritus over several decades.
Deep Sea Zones
1. The Deep Sea has four zones with minimal or no light: the Twilight, Midnight and Lower Midnight, and Ultra-Abyssal Zones, featuring bioluminescent and transparent and sometimes eyeless creatures. As depth increases, the cold, pressure, and darkness increase, chemical conditions harshen. Extremophile or whale or jelly fall communities become more common.
Deep Sea Adaptations
1. Deep Sea creatures exhibit many rare adaptations and traits, such as chemosynthesis, transparency or reflectivity, stark black or red coloration, bioluminescence, gigantism, rapid growth or longer lifespan, or pronounced mouths and teeth.
Protrusions & Slopes
1. Seamount slopes, often extinct volcanoes, form denser Deep Sea habitats of cold-water corals, sponges, sea anemones, and sea fans. Seamounts with flat, eroded summits which sink backa below sea level manifest as tablemounts. Near subfloor hotspots, chains of seamounts become aseismic ridges.
2. Turbidity currents can allow large-scale sediment deposition to produce abyssal fans.
3. The seafloor (abyssal plain) has many ridges and bumps (abyssal hills). Larger ones manifest as oceanic ridges, underwater mountain systems from tectonic spread and magmatic activity.
1. Tectonic spreading of the seafloor and lower oceanic crust melt leads to large, flat, smooth surfaces on the deep ocean floor, called abyssal plain. Volcanic activity can create oceanic plateaus, raised and relatively flat submarine platforms with steep sides above the seafloor. Some seafloor also functions as geological basins.
1. Submarine mountain ridges may have steep-sided openings, called oceanic gaps or rifts. Submarine valleys may have submarine canyons, serving as channels for erosive turbidity currents across the seafloor.
2. Long and narrow depressions of the seafloor called oceanic trenches appear among convergent plate margins. Oceanic troughs, more gently sloping depressions of a shallower, shorter, narrower character, also exist.
1. Because of volcanic activity, tectonic spread, ocean basin activity, and hotspots on the seafloor, various seafloor fissures can issue geothermically-boiling water, potentially forming rock and mineral ore deposits and sustaining extremophile communities.
2. Black smokers form as black, chimney-like structures emitting hot clouds of black sulfides as superheated subcrust water rises and dissolves minerals that react with the colder ocean above. Similarly, lighter-hued minerals and lower temperature plumes farther from their heat source can manifest as white smokers.
1. Lake-like seepages of hydrocarbons, called cold seeps or cold vents, can appear on the ocean floor, cooler than hydrothermal vents but warmer than surrounding sea water and sustaining carbonate rock formations and reefs.
2. This can appear as brine pools arising from salt tectonics, or clathrate hydrates which trap gases or polar molecules in ice. Or as petroleum seeps which expel liquid or gaseous hydrocarbons along fractures and fissures and rocks via rapid fluid expansion or sedimentation, or seabed craters called pockmarks, also caused by fluid eruption. Finally, mud and slurries and water and gases can combine with subterranean mineral deposits to form submarine mud volcanoes.
Special Habitats and Groups
1. There exist organisms specially adapted to aggregating in the harsh environments of seamounts, hydrothermal vents, and cold seeps, and other localized deep sea habitats.
2. Around hydrogen sulfide or geothermal vents, bacterial mats and clam beds can form.
3. Around mineral-rich hydrothermal vents specifically, swarms of crabs can form living mounds, as can deep sea mussels. Also, deepwater coral can cluster on nearby hard or raised deep sea landforms into patches, banks, piles, thickets, or groves. Here sea anemone and stalked barnacles can also cluster, and shrimp can swarm.
4. In Deep Sea volcanic craters, eels can aggregate in seethings.
5. Around cold seeps, tubeworms can aggregate into bushes or even fields.
6. As the carcasses of whales or jellies fall to the farthest depths, this detritus can create complex localized ecosystems called whale falls and jelly falls, persisting for decades due to extreme conditions.
Deep Sea Phenomena
1. Hotspots, hydrothermal vents, and tectonic motion near mid-ocean ridges can fuel Deep Sea volcanism, leading to seafloor lava flow. Sometimes this forms ruin-like lava arches, or pillow lava structures.
2. Submarine earthquakes also occur, from plate tectonics, often leading to tsunamis.
NOTE: All terms covered in depth with visuals and narrative functions in my Deep Sea Worldbuilding post.
PART 6: TUNDRA WORLDBUILDING SUMMARY
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.
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.
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.
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.
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).
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).
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.
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.
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.
- NOTE: All terms covered in depth with visuals and narrative functions in my Tundra Worldbuilding Post.
I look forward to continuing this summary series, and I have some greater ambitions for developing Mythic Ecology into worldbuilding web tools. Give this a share if you liked it, and let me know in the comments if you have any feedback. I publish new posts on alternating Tuesdays. In the meantime, I post D&D memes and writing updates over on my site’s Facebook Page. Also, if you want to keep up-to-date on all my posts, check out my Newsletter Sign-Up to receive email notifications when I release new posts. A big thanks as always to my Patrons on Patreon, helping keep this project going: Adam, Alexander, Anthony, Benjamin, Chris, Eric & Jones, Evan, Geoff, Jason, KRR, Rudy, and Tom. Thanks for your support!