Nemrut (volcano) of the earliest trade routes. Two eruptions of Nemrut were probably witnessed by people of Urartu, an ancient state located in the eastern Turkey. These eruptions occurred c. 787 BC (period of King Menua) and c. 657 BC (period of King Rusa II), and the latter eruption might cause the sudden disappearance of the city Uaiais located 30 km east of Süphan. In the 1980s, Japanese volcanologists studied the evolution of gases inside the caldera of Nemrut. They found that the ratio of helium isotopes He/He is 1.06, which indicates volcanic activity (most of the measured helium evolved from the
Nemrut (volcano) The direction of pressure coming from the Arabian plate is gradually turning from South-North to the West-East, with a linear shift of 7.8–9 mm per year. Fumarolic activity and the presence of many hot springs are observed at the bottom of the caldera. The volcano has an elliptical shape and covers 486 km. Its center contains 377.5 km of volcanic material, mainly 0.23–1.18 million years old lava. Nemrut has a distinct caldera with an area of 46.7 km and a volume of 32.9 km; the maximum height of the edge of the caldera is above sea level (Sivritepe, on the