How can a low bulge on flat ground indicate an underground salt dome?

A low bulge on flat ground can indicate an underground salt dome because the salt core, which acts as a mobile and relatively plastic material, exerts upward pressure on the overlying sedimentary strata.12

As the salt flows upward from a parent bed, it creates a dome or anticline structure by pushing the surrounding rock layers toward the surface. This process of uplift causes the strata to arch over the salt mass, resulting in a visible topographic high or bulge at the surface. Because salt is less dense than many consolidated rocks, it is gravitationally unstable when buried, leading it to rise like cream toward the surface. This upward growth often continues alongside the deposition of additional strata, allowing the salt mass to maintain its position near the surface and create the characteristic domed appearance.132