Volcanic activity after the eruption of Samalas Volcano continued inside the crater resulting in the formation of two volcanic cones which are Rombongan Mt with a height of 2110 m amsl and Barujari Mt which is an active volcano with a height of 2376 m amsl and is growing up. Following eruption recorded in history was in the year 1944, 1966, 1994, 2004, 2009 and 2010.
The cone of RombonganMountainwas the source of eruption in 25-30 December 1944 preceded by earthquake and bluster followed by blowing thick smoke and ash fall.
The cone of Barujari has middle crater and side crater. Middle crater of it is now about 170 x 200 meter width. This crater is the center of eruption that produces lava flow in 1966 and 1994. The side crater was formed in the cone’s northern slope during 1 October 2004 eruption. Consecutive eruptions happened with an interval of 5 to 160 minutes producing thich ash with the height of 300-800 meter. The crater is also center of eruption, which produces lava flow in 2004, 2009 and 2010.
The type of 1944 eruption is andesite-basalt with the spread to north and west and about 73.2 million m3 in volume.
Lava from 1966 is basalt, overflowed to the east then spread to north and south with about 6.6 million m3 in volume while lava from 1994 eruption went to the west with about 25.4 million m3 in volume.
The lava from side crater of Barujari Mt came from the eruption in 2004, 2009 and 2010. The width of lava spread from 2009 eruption reaches 650.000 m2. This resulted in reducting the lake’s surface area of 460.000 m2.