stuðlum

Stuðlum is a term primarily used in Iceland to refer to columns of basalt rock. These formations are typically hexagonal or polygonal in shape, though they can also exhibit other polygonal forms. They are created when thick lava flows cool and contract. As the lava cools from the top down and sides inward, stress builds up. This stress is then released through fracturing, which typically results in vertical columns. The most common number of sides for these columns is six, but variations exist.

The geological phenomenon that produces stuðlum is known as columnar jointing. This process is not unique to Iceland and can be observed in basalt formations around the world. In Iceland, however, these formations are particularly prominent and have become a significant feature of the landscape. Iconic examples include Reynisfjara beach near Vík í Mýrdal, where large basalt columns line the shore, and Svartifoss waterfall in Skaftafell, where the columns create a dramatic backdrop to the falling water. The formation of stuðlum is a testament to the powerful geological forces that shaped Iceland, a land shaped by volcanic activity. These striking natural structures are of great interest to geologists and tourists alike.