This volcano is included in stratovulkan type with characteristic explosive eruption. Like many other volcanoes in Java, Kelud formed by the subduction of the Indo-Australian continental plate against the Eurasian plate. Since the year 1300 AD, it is recorded active mountain range erupted with a relatively short distance (9-25 years), making it the volcanoes are harmful to humans. The specificity of this volcano is a crater lake (until late 2007) which makes a very liquid lava eruptions and endanger the surrounding population. Due to the activity that gave rise to the 2007 lava dome, crater lake almost gone and left a sort of puddle water. Peak-peak current is the remainder of the eruption of the past that brought down the top of the ancient. Wall on the southwest side open so complex crater collapse toward the opening. Kelud is the highest peak, positioned slightly to the northeast crater. Other peaks are the Peak Gajahmungkur on the west side and Peak Sumbing on the south side.
Since the 15th century, Kelud has claimed more than 15,000 lives. The volcanic eruption in 1586 claimed the lives of more than 10,000 inhabitants. A system to divert the lava flow has been made extensively in 1926 and still functioning until now after the eruption in 1919 claimed thousands of lives due to cold lava flood swept settlements. In the 20th century, recorded Kelud erupted in 1901, 1919 (May 1), 1951, 1966, and 1990. In 2007 the mountain was again increased its activity. This pattern brings experts volcano on 15-year cycle for this eruption.