The longer it ages the denser, saltier and sourer it becomes. Saltier water can also become colder without freezing. In this process, the water becomes saltier and denser. It is also used as a sweeter substitute for saltier yellow soybean paste. Seawater almost always gets more dense if it gets "either" slightly colder "or" slightly saltier. Southern varieties are saltier and more pungent. The ULSW eddies erode rapidly as they mix laterally with this warmer saltier water. The spread of the bacteria is more prevalent in warmer and saltier ocean waters. Cooler and saltier waters lie to its east. Meanwhile, sea ice starts reforming, so the surface waters also get saltier, hence very dense. The eastern water is saltier because of its proximity to Mediterranean Water. Qanats transfer freshwater from the mountain plateau to the lower-lying plains with saltier soil. By 1975, the upper water layer was saltier than the lower layer.