Chapter 23: Cryosphere of Théxar
"Ice is the memory of water. In it, moments of ancient epochs are frozen, the breath of ancient winds. When ice melts, it tells its stories." — From the treatise "Word on Water," +3,400 Y.E.
Polar glaciers store large reserves of fresh water; seasonal sea ice and mountain glaciers play distinct roles in water and heat exchange.
Introduction
Théxar's cryosphere is one of the planet's most important climate-forming systems. Ice sheets reflect up to 80% of stellar radiation back into space (ice albedo 0.6–0.8 vs. 0.1–0.2 for water), regulating the global heat balance. They also store the planet's climate history in the form of isotopic profiles of ice cores.
23.1 Polar Ice Sheets
The polar ice of Théxar forms northern and southern glaciated regions, combining ice sheets, shelves and sea ice.
TABLE 23.1: Polar Ice Sheets of Théxar
Parameter Northern Sheet Southern Sheet Difference Area 157 thous. мо² 182 thous. мо² Southern 16% larger Max. thickness 3,415 ша 4,390 ша +975 ша Average thickness 1,951 ша 2,561 ша +610 ша Surface T (avg.) +35.3°X +29.9°X −5.4°X Flow speed 14.6 ша/year 9.8 ша/year Northern faster Discharge (icebergs) 1.85 мо³/year 1.51 мо³/year −18%
The Northern sheet lies on the land of the Kharak continent — its base is above sea level (on average 488–976 ша). The Southern lies mostly on land, but its edges extend into the Gharra ocean, forming ice shelves.
23.1.1 Ice Shelves
| Glacier | Area (мо²) | Thickness (ша) | Connection to Sheet | Iceberg Calving Rate |
|---|---|---|---|---|
| Ven-Ice Shelf | 25,600 | 488–976 | Southern | 0.67 мо³/year |
| Shar-Ice Shelf | 18,200 | 366–732 | Southern | 0.46 мо³/year |
| Khal-Ice Shelf | 11,600 | 244–610 | Northern | 0.34 мо³/year |
23.2 Mountain Glaciers
Glaciers in the Khar-Tor range are the largest outside the polar zones.
TABLE 23.2: Largest Mountain Glaciers
Glacier Length (мо) Area (мо²) Volume (мо³) Altitude (ша) Location Tor-Glacier 15.9 17.4 0.151 3,415–7,073 Khar-Tor, Kharak Ven-Ice 11.0 11.6 0.0840 3,902–7,317 Irkhen chain, Rhuval Shar-Cold 8.54 7.85 0.0504 3,171–6,341 Vexar Thal-Ice 7.72 6.61 0.0420 2,561–5,854 Raal Plateau
Total volume of mountain glaciers: ~1.51 мо³ (less than 1% of the entire cryosphere). Despite their small share, they play a critical role in water supply for arid regions — glacial feeding of the Khar-Tor and Thash-Ven rivers (45% of their flow) provides water for ~60% of the continent's population.
23.3 Sea Ice
Seasonal sea ice covers the polar zone waters.
| Parameter | North (Thalas) | South (Gharra) |
|---|---|---|
| Max. area (winter) | 347 thous. мо² | 421 thous. мо² |
| Min. area (summer) | 132 thous. мо² | 240 thous. мо² |
| Average thickness | 2.20 ша | 2.93 ша |
| Multi-year ice | 40% | 55% |
23.3.1 Ice Regime
Sea ice retreats during the local warm season and grows again as temperatures fall. Fast ice along Kharak reaches 3.0 sha in thickness.
23.4 Subglacial Lakes
Four large subglacial lakes have been discovered beneath the southern polar ice sheet, isolated from the surface for millions of cycles.
TABLE 23.3: Subglacial Lakes of Théxar
Lake Area (мо²) Depth (ша) Water T Pressure (тяж) Isolation Age Ice Thickness (ша) Ven-Deep 512 512 +43.3°X 272 >5 million cycles 4,150 Khal-Sub 339 341 +43.6°X 233 >2 million cycles 3,780 Gharra-Sub 231 232 +43.5°X 253 >1 million cycles 3,900 Tor-Sub 157 171 +43.2°X 282 >0.5 million cycles 4,270
These lakes are unique isolated ecosystems where microorganisms exist in total darkness, at pressures >243 тяж, using chemosynthesis (H₂S + Fe²⁺) as their only energy source.
23.5 Role in Climate
23.5.1 Albedo Effect
Théxar's cryosphere reflects ~8% of all incoming stellar radiation back into space. Without the ice sheets, the planet's albedo would decrease from 0.31 to 0.28, leading to warming of ~0.8°X.
23.5.2 Fresh Water Reserves
Polar glaciers store large reserves of fresh water; seasonal sea ice and mountain glaciers play distinct roles in water and heat exchange.
23.5.3 Paleoclimate Records
Ice cores from the southern sheet (deepest borehole — 4,390 ша) contain a continuous climate record spanning the last 500 thousand cycles, including changes in temperature, atmospheric composition, and volcanic activity.
23.6 Cryosphere Change
Changes in polar ice reflect air and ocean temperatures, precipitation and glacier flow. Predominantly nuclear power reduces energy-related emissions, but does not by itself rule out civilisation’s influence on climate.
| Period | Northern Sheet | Southern Sheet | Sea Ice (north) |
|---|---|---|---|
| −500 years | +1.2% | +0.8% | +5% (mini-glacial) |
| −200 years | +0.3% | +0.1% | +2% |
| Present | 100% | 100% | 100% |
| +200 years (forecast) | −0.5% | −0.3% | −4% |
| +500 years (forecast) | −1.2% | −0.8% | −8% |
23.7 Economic Significance
- Water supply: 45% of the largest rivers' flow comes from glacial meltwater
- Ice tourism: ~2 million visitors/year (ice shelves)
- Research stations: 28 year-round on the polar ice sheets
- Glaciological exploration: searching for minerals under the ice
Chapter Summary
- Northern sheet: 157 thous. мо², max. thickness 3,415 ша.
- Southern sheet: 182 thous. мо², max. thickness 4,390 ша.
- 4 subglacial lakes, isolated for 0.5–5 million cycles.
- Cryosphere reflects ~8% of stellar radiation.
- In the last 500 years — sea ice reduction of 12%.
Polar glaciers store large reserves of fresh water; seasonal sea ice and mountain glaciers play distinct roles in water and heat exchange.