Dasht-e Kavir

Dasht-e Kavir, salt desert in north central Iran. Beginning about 50 km (30 mi) west of the city of Qom, the Dasht-e Kavir extends eastward about 290 km (180 mi) through Iran’s northern Semnān province to the eastern Khorāsān province. Its greatest extent from north to south is about 190 km (120 mi), and its total area is about 54,400 sq km (21,000 sq mi). The Dasht-e Kavir consists of one large and several small basins situated within a mountainous area. Most of the basins are located at an elevation of about 900 m (3,000 ft). The surrounding mountain peaks range between about 1,500 and 1,800 m (5,000 and 6,000 ft) above sea level. A few large sand dunes are found along the desert’s southern edges.

The desert’s Persian name, kavir, signifies a saline swamp or a muddy expanse of land topped by a hard crust of crystallized salt. The weight of a human or a large animal traversing the crust, which is about 10 to 100 mm (0.5 to 4 in) thick, can cause it to break, causing those who fall through to become trapped in the briny quagmire below the surface. Because of this dangerous feature, people rarely attempt to cross the Dasht-e Kavir, and existing rail and road routes pass no closer than its northern rim.

In the summer temperatures are very hot, and the Dasht-e Kavir usually receives no precipitation. In the winter temperatures are still hot in the daytime, but freezing at night. The Dasht-e Kavir receives several inches of precipitation in the winter, and much of the kavir basin may be covered with water for weeks at a time. Despite the winter moisture, the Dasht-e Kavir is too salty for vegetation to grow. Other than the rare appearance of a variety of salt-resistant scrub, the desert is barren. Due to the lack of fresh water, the impossibility of agriculture, and the absence of vegetation for livestock, there are no settlements in the Dasht-e Kavir. Much of the desert remains unexplored.