Geology marks Himalayas as the youngest mountain ranges on the planet formed as a result of collision between two tectonic plates, the Indo-Australian Plate and the Eurasian Plate. About 70 million years ago a continental collision or orogeny began in the Upper Cretaceous period along the convergent boundary between the Indo-Australian Plate and the Eurasian Plate and this collision led to the formation of Himalayas that stretches along the length of 2,500 km (1,550 miles). Modern theory of plate tectonic has it that the north-moving Indo-Australian Plate moved at about 15 cm/year at the time of collision. Later, this plate completely closed the Tethys Ocean as a result of which there occurred several weathering and erosion and this resulted in the formation of sediments which instead of sinking formed Himalayan ranges. At present, the Indo-Australian plate is moving at 67 mm/year and over the next 10 million years it will travel about 1,500 km into Asia. Himalayas is vulnerable to earthquakes and landslide due the ongoing under thrusting of the Indian peninsula against the Eurasian Plate.