The Long History of The Eruption of Mount Semeru

On Saturday afternoon (4/12), Mount Semeru in east Java province experienced a hot cloud fall. Volcanic material observed at 15.20 WIB leads to Besuk Kobokan, Sapiturang Village, Pronojiwo Subdistrict, Lumajang. Semeru has a long history of eruptions recorded in 1818.

Records of eruptions recorded from 1818 to 1913 do not have much documented information. Then in 1941-1942 recorded volcanic activity with a long duration.

The Center for Volcanology and Geological Hazard Mitigation (PVMBG) said lava melting occurred in the period 21 September 1941 to February 1942. At that time the eruption reached the eastern slope with an altitude of 1,400 to 1,775 meters. Volcanic material to hoard Bantengan irrigation posts.

Furthermore, several volcanic activity was recorded consecutively in 1945, 1946, 1947, 1950, 1951, 1952, 1953, 1954, 1955 – 1957, 1958, 1959, 1960.

Not stopping here, Mount Semeru is one of the active volcanoes that continue its volcanic activity. As on December 1, 1977, the lava fall produced a hot cloud fall with a distance of up to 10 km in Besuk Kembar.

The volume of observed volcanic material deposits reached 6.4 million m3. Hot clouds also point towards the Besuk Kobokan region. Rice fields, bridges and homes were damaged.

Volcanic activity continued and was recorded from 1978 to 1989.

PVMBG also recorded volcanic activity of Mount Semeru in 1990, 1992, 1994, 2002, 2004, 2005, 2007 and 2008. In 2008, there were several eruptions, namely between May 15 and May 22, 2008.

Observed on May 22, 2008, four hot cloud fall that leads to the Besuk Kobokan region with a launch distance of 2,500 meters.

According to PVMBG data, mount Semeru’s activity is in the Jonggring Seloko crater.

This crater is on the southeast side of mahameru peak. While the character of the eruption, Mount Semeru is volcanic and strombolian type that occurs 3-4 times every hour.

Vulcanian eruption characters are explosive eruptions that can destroy the dome and tongue of lava that has been formed before.

Meanwhile, the character of strombolian eruptions usually occurs the formation of friends and new lava tongues.

Currently Mount Semeru is at level II status or ‘alert’ with the following recommendations.

First, the public, visitors or tourists do not move within a radius of 1 km from the crater or peak of Mount Semeru and a distance of 5 Km in the direction of the crater opening in the southeast – south sector, and be aware of hot clouds of fall, lava and lava fall along the flow of rivers or valleys that flow at the top of Mount Semeru.

The radius and distance of these recommendations will be evaluated continuously for anticipation in case of symptoms of a change in the threat of danger.

Second, people stay away or do not move in areas affected by hot cloud material because currently the temperature is still high.

Third, it is necessary to watch out for potential slides along the valley of the Besuk Kobokan hot cloud path.

Fourth, be aware of the threat of lava in the flow of rivers or valleys that flow on Mount Semeru, considering the amount of volcanic material that has been formed.

Related to the development of the eruption of Mount Semeru, BNPB urges citizens to remain vigilant and alert by paying attention to the recommendations issued by PVMBG.

BNPB continues to monitor and coordinate with the local BPBD in handling the eruption emergency.