History of Mount Batur and the First Large Eruption Occurred 29,300 Years Ago

The second major eruption occurred around 20,150 years ago, followed by the formation of several cones and domes such as Mount Payang and Mount Bunbulan. The second subsidence occurred and then formed the Batur II Caldera.

1. Mount Batur once released lava that covered Batur Village

Junghun’s journal (1850) recorded that there was an eruption and lava flow in 1849 which flowed south to Lake Batur. In 1926, the eruption of Mount Batur released lava that covered Batur Village, but did not cause any casualties. In 1963 and 1964 there was another eruption in the form of lava flowing to the west, south and southwest.

Four years later, to be precise in 1968, Mount Batur erupted in the form of a blast of incandescent volcanic material. The following year, for two days it was reported that the smell of sulfur on the surface of Lake Batur caused the color of the water to change from green to white.

The eruption period of Mount Batur generally lasts a long time (months) with relatively low or weak intensity. Meanwhile, the time between eruptions in one period lasts from several minutes or seconds to several hours. The resting time between eruptive periods is recorded as 1 to 39 years.

2. The distribution of rocks produced from Mount Batur consists of 5 periods

According to the writings of van Bemmelen (1949), it is stated that the caldera of Mount Batur is closed from all directions and is the largest and most beautiful caldera in the world. The height of the caldera embankment ranges from 1,267 meters to 2,152 meters. In Caldera I, Caldera II is formed, which is circular in shape with a diameter of approximately 7 kilometers.

Meanwhile, the base of Caldera II is located between 120 and 300 meters lower than Undak Kintamani (Base of Caldera I). There is a lake in the caldera which is shaped like a crescent moon. The lake is thought to have formed at the same time as Caldera II.

The oldest rocks exposed are the Bukit Jangkrik pyroclastic flow deposits. These rocks are exposed in the southern part. Another rock is Cempaga Lava which has an olivine basalt composition, this rock is exposed slightly in the southern part.

The young rock is the Tejakulak Lava which is exposed in the north, composed of porphyritic olivine basalt, light gray, phenocrysts (around 40 percent). It is characterized by large euhedral-subhedral olivine with subhedral plagioclase (Less than 2 mm).

3. Map of the Mount Batur disaster-prone area is divided into three units

Is Mount Batur included in a disaster-prone area? Of course yes. The map of Mount Batur’s disaster-prone areas is divided into three units, including Disaster-Prone Area III, Disaster-Prone Area II, and Disaster-Prone Area I.

Disaster Prone Area III Mount Batur is an area that is often hit by lava flows, incandescent rocks, heavy ashfall and possibly toxic gas. This area includes the peak area of ​​Mount Batur and the southeast, south, southwest, west and northwest slopes. Due to the high level of disaster vulnerability in this area, it is not permitted to build permanent settlements and tourism service businesses.

Meanwhile, the Mount Batur II disaster-prone area is an area that has the potential to be hit by heavy ashfall and the possibility of expanding lava flows and ejections of incandescent rock. This area covers the northern, northeastern and eastern feet of Mount Batur, and borders the inner caldera walls of Batur and Lake Batur.

What about the disaster-prone area I Mount Batur? This area will only be threatened by ashfall and the possibility of throwing incandescent rocks, covering the Batur Caldera area with a radius of approximately 6 kilometers from the peak of Mount Batur. Considering that the eruption level of Mount Batur was weak, in this area generally only light ash rain occurred. This area is relatively suitable for residential and business activities.