Linguistic note: Colloquial Bedoui names in common use; no confirmed cartographic standard. Translation: “The shoulder and the armpit.” Name origin: A tall, knife-edged ridge (al-ketif, “the shoulder”) running parallel to a deep, narrow trench (al-ʿibt, “the armpit”). The pair lies in the highlands north of the Combs and is used as a local landmark by surface nomads.
Al-ketif y al-ʿibt typifies Samūm’s fissure country: a near-vertical escarpment casting hard shade into a gorge that is often less than 100 m wide yet over 1 km deep. One of tens of thousands of shrinkage and wind-erosion cracks that rift the planet’s crust. These chasms act as heat sinks and wildlife refuges; rare seeps collect in grottoes, feeding short streams that sheet into mist long before reaching the floor. The local microclimate produces strong daily updrafts as gradients of air are forced down the narrow trench and becomes trapped and deflected over the uneven sides and floor.
From the ridge crest, the Combs are visible to the south—nine grey domes, each ~800 m above the desert—with the mirror fields of the spaceport to the west. To the east stands the spire of Quoath, beside extensive Poatag agricultural fields. Nearer the Combs, construction crews have built thousands of solar collectors high on the mountain’s sunward flank to maximize the planet’s long insolation cycle. The light is routed via fiber-optic trunks, providing light for the city and feeding its underground hydroponic centers.
During the heat phase, al-ʿibt works like a bellows. Updrafts form where the trench bends or where boulder chokes constrict the airflow.
As with many places in the Combs, bioengineered ageal/lichen films cause rock faces that glow blue. around a tunnel mouth in the shaded bend of al-ʿibt. Separate research notes that engineered algal films of Nüüdelchid lineage and later adapted on Sangay are used on Samūm to provide low-energy passage lighting and oxygenation, and can be activated by specific stimuli (including electric fields). The gorge observations are consistent with other reports of successful feralization of bioengineered plants and animals on the surface of Samūm.
Rockfall from thermal stress, sudden gust fronts, long fall potential with limited protection, glare/black-shadow alternation, and disorientation in the trench’s lightless bends are the main risks. During the heat phase, updrafts can be strong but intermittent.
The Combs (subterranean city), Quoath (spire and historic battlefield), Poatag (bio-engineered plant and fiber), Samūm (planetary climatology and day-length).