Rifting

Manifestation

Deep underground in Ûnduleah lie many lava lakes. Some are small lakes that settle in depressions of the cave systems. Some come through porous rocks and create massive, localised, contained lava bubbles.
During the cold Iridir winters the ground frost forms so deep that they reach these lavabubbles. This added pressure from the expanding ice cold rocks above the lava creates such immense pressures that builds and builds until something must give. Usually that something is the frozen rock above.
When this breaking point is reached the ground violently tears open to release the pressure. Rocks, lava, steam and other minerals and resources are with no small force launched into the air and rain down in the surrounding area.
After the dust has settled a thin, long, deep jagged cut is left in the ground, through which the heat from the remaining lava lake emanates to the surface. Stable lava lakes create stable rift fissures that are a perfect area for the dwarves to spend the cold Iridir winters. Moving lavalakes however cause regular new rifting events making living around these places extremely dangerous.

Visual sketch

by nicemustangart

Localization

Rifting happens over underground lava lakes. Stable lava lakes create stable permanent rift fissures that emit useable heat. Moving lavalakes cause regular recurring rifting events.

Uses

Settleement

Rifts over stable lavalakes emanate heat from the remaining lava. This heat is too hot to stand directly above the fissure for too long, but not so hot that it melts the rocks anymore. This means that sitting near a stable rift fissure during cold weather is like sitting around a cozy campfire. Which is why these areas are where most of the dwarves clans settled before the The Silver Rain . The bigger dwarven settlements even built elaborate structures around these rifts with valves and pumps to direct the hot air to where they need it such as towards kitchens when cooking or central halls during feasts.

Resources

The immense pressure and temperature differences in the rocks above the lava bubbles create unique materials depending on the type of rocks. One of the most wanted materials is shimmerscale rock: a relatively hard but especially beautiful yet rare rock that is used to create jewellery and other decorative objects. It is so rare that daring fortune seekers, called rift hunters, sometimes go to active rifting valleys to wait for new rifting events so that they can be the first to gather any potential shimmerscale rocks.