BPBD Lumajang Appeals to Residents to Be Aware of Semeru's Secondary Eruption

LUMAJANG - The Regional Disaster Management Agency (BPBD) Lumajang appealed to residents to be aware of the secondary eruption of Mount Semeru when heavy rain hit the slopes of Mount Semeru on Sunday afternoon.

"Secondary eruptions occurred along the Kali Wedok Besuk Kobokan River Basin (DAS), while those downstream did not have an impact on the activities of residents," said the Head of the BPBD Lumajang Isnugroho when confirmed in the local district, Antara, Sunday, January 11.

The secondary eruption was a thick white smoke that occurred when rainwater met the hot volcanic material from the eruption along the Besuk Kobokan River, causing limited visibility.

According to him, the secondary eruption in the south of the monitoring post leads to the east of the Perak Gladak Bridge, so his party appeals to the public to remain vigilant against the potential of secondary eruptions during the cold lava flood of Mount Semeru.

Secondary eruptions usually occur outside the center of volcanic activity, namely the Kobokan River, which now houses a pile of hot cloud material with a moderate temperature.

Based on the records of the Semeru Mountain Observation Post, the lava flood tremor was recorded on the seismograph as one flood tremor earthquake with an amplitude of 35 millimeters and a quake duration of 6120 seconds.

"We also appeal to the public who are around the river banks to increase vigilance when there is a flash flood, and sand miners must stop their activities," he said.

The flood of Mount Semeru's rain lahar from the upstream flows into the Besuk Kobokan River and Lanang River which are in Supiturang Village, Pronojiwo District, Lumajang Regency.

Isnugroho said the status of Mount Semeru was still on alert, so the public should not carry out any activities in the southeast sector along Besuk Kobokan, as far as 13 km from the peak (center of the eruption).

"Outside this distance, the public does not carry out activities at a distance of 500 meters from the river bank (river border) along Besuk Kobokan because they have the potential to be hit by the expansion of the hot cloud and lava flow up to a distance of 17 km from the peak," he said.

The public is prohibited from carrying out activities within a radius of five kilometers from the crater / peak of Mount Semeru because they are prone to the danger of stone throwing (pijar).

The public must also be aware of the potential for hot clouds, lava ejection, and lahar along the river/valley flows upstream of the Semeru Volcano peak, especially along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as the potential for lahar in small rivers which are tributaries of Besuk Kobokan.

Meanwhile, the Meteorology, Climatology and Geophysics Agency (BMKG) issued an early warning in the Gunung Semeru area and its surroundings stating that there was moderate to heavy rain at 17.10 WIB.

"The rain occurred in the Pronojiwo area in Lumajang Regency and Ampelgading in Malang Regency which is the slope of Mount Semeru until 19.10 WIB," said Head of the BMKG Station Juanda, Taufiq Hermawan in his written report.

"So the ship was given permission to sail," he said.

He explained the potential impacts to be wary of rain lahar floods, flash floods, floods and landslides in the Lumajang Regency area which includes Pronojiwo, Pasrujambe, and Candipuro sub-districts, while the Malang Regency area occurred in Ampelgading sub-district.