Chthyilri Glacier Caves

History

Geography

Geography The Chthyilri Glacier Caves are a gargantuan, transient sub-terranean labyrinth carved entirely from living, shifting ice. In sharp contrast to the timeworn, wave-etched basalt of the Busor Sea Caves or the solid bedrock of Belth Canyon, Chthyilri is a realm of explosive geological dynamism, of hydrostatic pressure, abrasion, and the inexorable creep of gravity-a fractal maze of frigid vaults and frozen rivers constantly buckling, rupturing and reforming from within. Topography and Glaciology From the surface, the glacier itself is a forbidding landscape: a shattered plateau of packed firn and ancient blue ice, dissected by sheer crevasses and unstable seracs.

But Chthyilri’s true wonder exists only in its depths.

Topography and Glaciology

From a geological standpoint, it’s a unique entity in its own right-there is literally no stable ‘bedrock’ at play in its construction. The complex of caves is contained solely within the englacial (i.e., within the ice) and subglacial (i.e., below the ice) portions of the immense ice sheet, which rests, however distantly, upon scraped-away ancient granite. However, the walls that form the vast ice caverns themselves are, of course, made of deeply compressed glacial ice containing a dazzling display of frozen geological history-bands of tephra from ancient eruptions, air bubbles from epochs past, and dust-like ground ice. These strata function as a snapshot of the climate of the Twilight Age trapped eternally within a slowly moving glacier.

Climate and Englacial Hydrology

In the brief melt season, tremendous quantities of water accumulate on the glacier surface, before plummeting into vertical, hundreds-meter deep moulin shafts. The water then forces its way through the ice itself in a high-pressure englacial hydrological system, forcefully eroding a network of tubular tunnels via thermal abrasion. While the surface blizzards rage, the interior of the caves is relatively benign, insulated from the surface cold by the sheer mass of ice; the air here is held precariously at pressure melting point.

Inside the largest caverns, sound ricochets and reverberates, with a constant groaning, cracking, and booming from the immense pressures acting upon the ice. When conditions allow, sunlight filters through thin sections of ice, blocking reds and blues from reaching the glacial depths in the form of an ethereal glow. Traversability To navigate Chthyilri is to test the limits of both human and geological sanity.

Traversability

A map of the glacier caves is an obsolete relic from the moment it is even printed; the ice is alive and will have likely re-arranged itself significantly by the following nightfall.

Featureless ice corridors can be psychologically confusing (imagine navigating in endless mirrored halls with no distinguishing landmarks), while physical hazards-falling ice bridges, sudden crevasse openings over thin snow and catastrophic subglacial outburst floods that can inundate tunnels in seconds-are lethal. Chthyilri is a truly stunningly beautiful place, but one with a deadly and implacable embrace.

Plants

Flora Proglacial Flora (Cushion Plants and Extremophile Lithophytes)

The plants that surround the Chthyilri Glacier Caves are an exhibition of biological extremophilism, a desperate life waging a grim war against absolute zero. Unlike the relatively sheltered taiga of Chanest or the wet, fertile lands of Chreint, there is plant life here only on the proglacial foreland – the freshly-emerged, pulverized rocky edges of the receding ice. Vegetation is constrained into extreme morphological and pigment adaptations to survive lethal, sub-zero winds and the gnawing intensity of ultraviolet radiation.

They survive using a cushioning technique. Ultra-dense, low-profile, hemispherical masses of dwarf alpine shrubs and mosses can physically absorb enough geothermal heat and resist freezing wind.

In many of these species, dark red/purple anthocyanins in the foliage aggressively collect any hint of solar radiation and promote agonizingly slow, below-freezing levels of photosynthesis.

Outwash Flora (Braided Streams and Alluvial Pioneers)

The only reliable ribbons of biological productivity in Chthyilri are found on the sandur (glacial outwash plains). Glacial torrents carrying pulverized and mineral-rich glacial flour surge out of the ice, depositing vast quantities of fine sediment onto river plains. On these unstable, braid-like streams and river banks the resilient, cold-adapted plants are sedges and pioneer mosses, their interwoven roots binding the loose alluvium to stabilize them.

Because glacial outbursts can wipe out entire banks and stream beds unpredictably and frequently, vegetation must constantly recycle itself vegetatively.

Englacial Flora (Cryophytes and Cryoconite Micro-Ecosystems)

Chthyilri has the strangest plants found within the ice itself. While vascular plants cannot live within the ice sheet's depth, wherever a moulin or thin ceiling of ice has a point of light ingress, highly specialised cryophytic (ice-dwelling) plants formcommunities. These phototropic extremophiles, in the form of tiny snow algae, lichens and cyanobacteria, grow clinging to wind-blown volcanic ash particles embedded in the ice; this darkly coloured material traps ambient light, locally melting pockets of ice into liquid areas known as 'cryoconite'. Biofilms will slowly grow and spread within these ice-locked pools, streaking with red, orange or green The Ice Caves flora along their glacial-blue walls.

Seasonal Adaptations (Cryo-Dormancy and Hyper-Accelerated Phenology)

The flora lives a life of extremes - ten months buried in deep snow with an ice-crystal busting bio-antifreeze built into their cell structure, followed by a few frenetic, brief, and often-failed attempts at summer life. The ecosystem lives or dies based on the relatively brief but intense mid-year thaws, where flowers must pop out, pollinate, reproduce and die, sometimes in less than three weeks - and are liable to sudden blizzard at any time.

Animals

Fauna(Proglacial Megafauna & Alpine Predators)

Animal life on the exposed peripheries of the Chthyilri Glacier Caves is the subject of vicious thermal arithmetic, hypothermia-induced despair. In direct contrast to the sheltered residents of the Chaund Graywood, the cryophilic fauna of the proglacial foreland lives life upon a brutally exposed field. Survival demands specialized morphology – both the megaherbivores and apex predators are sheathed in hyper-dense, thermal-insulating pelage and adipose tissue to conserve core body temperature and reduce calorific expenditure.

To navigate slick, mirrored ice and granular firn snow, its species are provided with crampon-like claws and specialized, highly textured pads to prevent slipping on the treacherous glacial slopes while they hunt and forage.

Ice Cave Fauna(Englacial Obligates and Cryo-Troglobites)

Deeper within the bowels of the ice labyrinth can be found one of the stranger biologicassemblies of the Twilight Age world. In these solar-starved depths operate creatures of allochthonous genesis: cryo-troglobites. Highly-specialized ice-dwelling cavern organisms who exist in frigid, perpetually-dark, isolated conditions have been shown to exhibit extreme troglomorphic-related evolutionary adaptations, including near total depigmentation (ghostly albinism) and degenerate, sightless ocular organs. These species navigate their eternally-dark, ever-shifting ice-tunnels with finely-tuned mechanoreception, and acutely precise chemical sensing.

Because no photosynthetic activity can occur deep beneath the ice, its entirely enclosed food web consists exclusively of allochthonous food-organic de-tritus; dead invertebrates;glacial flours of whatever provenance which have washed down through meltwater-rich fissures; which have, over long periods, been processed by obligatelyblind, scavaging detritivores.

Meltwater Fauna(Subglacial Aquatics and Benthic Guilds)

MeltwaterRiversThe pressurised, frigid waters flowing through the glacier are the arteries of the ecosystem of the ice caves. Their violent, supersaturated flows harbour rheophilic aquatic species adapted to the relentless summer pressures. Highly streamlined and possessing suckered appendages (“benthic holdfasts”) designed for anchoring on stable substrates or ice walls these creatures avoid being instantaneously washed out into the open air during high flow melt conditions,and remain rooted in their rapidly moving environment to scavange particles in the super-heated flow.

Lakes Deep below the glacier exist a number of vast, pressurized subglacial lakes isolated communities of endemics(both predatory,and blind crustaceans) persist through all seasons of the year,sealed within liquid vaults hundreds of feet below miles of ancient ice.

Behaviorial Cycles(Geomorphological Instability and Cryo-Dormancy)

Animal-behavioral cycles at Chthyilri are subject not only to thermal pressures,but to violent geomorphological instability as well. In the deadly winter period most above-surfacefaunain the area enter into a state of profunda cryo-dormancy (torpor) where they retreat to sub-surface snow-caves to survive and subsist purely upon the body-fat accumulated during the better seasons.

However,the real threat to organisms occurse in the brief summer melt-season.

As the increasing volumes of meltwater swell the underground rivers the glacier'sinternal structure rapidly warps,deforms,and collapaseswithout prior warning,due to ice creep.englacial fauna cannot hold static territoriesand instead continuously migrate deeper into more-newly-formed melt-channels to follow its perpetually shifting,molten guts.

Template:Controllers