After the final aftershocks of the Jalar Earthquake a thin crack remained in the ground where some two hundred souls were crushed along with business and home. Though the gaping wound in the city remained a sore spot for years it didn’t take long for Aarelinn to recover. Several bright minds discovered that at a few major openings in Shelin, as the massive crack was dubbed, notable heat could be felt rising from below. Around 2935 AoN rudimentary mills were built which utilized the flowing air to power their wheels instead of the less reliable wind. Over time by filling in large portions of the crack with patches of a soft limestone concrete, the effective pressure was increased. The specially formulated grout was capable of sustaining the seal for many years with the expansion and contraction brought about by constant temperature changes. Today several financial groups war diplomatically over control of the heat vents and their lucrative opportunities.