Late Quaternary glacier equilibrium line altitudes (ELA) in the mountains of Iran

Abstract

Climate change in the late Quaternary period led to the displacement of the equilibrium line altitudes (ELAs) of glaciers in the mountainous regions of Iran. Considering the extent of Iran in different latitudes and its terrains, the effect of the direction of terrains and latitudes on the formation of a glacier and hence on the ELAs cannot be ignored. In order to estimate ELAs of the Quaternary and investigate the effect of the above-mentioned factors on the difference of the ELAs (∆ELAs), the Quaternary glacier cirques were identified in different parts of Iran’s terrains. The ELA is estimated using cirque-floor altitude and terminus-to-head altitude ratio (THAR) methods. The results indicate that in general, estimation of ELA using AAR is more consistent with cirque-floor altitude in Iran’s terrains. The maximum estimated Quaternary ELA is 3098 m in the southern part of Central Iran, and the minimum ELA is 2033 m in Talesh Mountains in Alborz terrain. The ∆ELA of Iran’s terrains is 1065 m. This elevation varied from 2030 to 3100 m.