Mt Merapi, located near Yogyakarta, is one of the most active volcanoes on earth. It is one of some 500 volcanoes in Indonesia, from which at least 129 are active, aptly giving this archipelago the name: the Ring of Fire. Despite its frequent eruptions, Mt. Merapi is very central to the lives of the Javanese people and kings. For through its eruptions Merapi spews lava, ash and minerals to the surrounding areas. These provide nutrients for the soil, making this one of the most fertile areas in the world, and consequently the most densely populated.
This majestic, perfectly cone-shaped volcano, with its peak at 2,911 meters above sea level, has also determined the lives of kings and realms. In the early 11th Century, the once mighty ancient empire of Mataram mysteriously disappeared, and power suddenly shifted to East Java. Scientists surmise that a violent eruption of Merapi in 1006 AD was the ruin of the empire.
This massive eruption also buried the nearby Borobudur temple in ash. More recently in the 20th century, a destructive eruption in 1930 claimed 1300 lives. Today Merapi still erupts intermittently, but the people here have befriended the mountain and accept its rumblings and coughs as part of normal natural phenomena.
The Merapi volcano plays an important part in the accepted cosmos of the Javanese sultans. The Keraton of Yogyakarta faces the mountain in one direct line. Merapi is also guarded by spiritual “guards” who give offerings to the mountain.
Merapi is the youngest in a group of volcanoes in southern Java. It is situated at a subduction zone, where the Indo-Australian Plate is subducting under the Eurasian Plate. It is one of at least 129 active volcanoes in Indonesia, part of the volcano is located in the Southeastern part of the Pacific Ring of Fire–a section of fault lines stretching from the Western Hemisphere through Japan and South East Asia..
Stratigraphic analysis reveals that eruptions in the Merapi area began about 400,000 years ago, and from then until about 10,000 years ago, eruptions were typically effusive, and the out flowing lava emitted was basaltic. Since then, eruptions have become more explosive, with viscous andesitic lavas often generating lava domes. Dome collapse has often generated pyroclastic flows, and larger explosions, which have resulted in eruption columns, have also generated pyroclastic flows through column collapse.