Mount Raung Rises Status So Alert

Map of Mount Raung disaster-prone areas. (ANTARA/HO-PVMBG)

JAKARTA - The Center for Volcanology and Geological Hazard Mitigation (PVMBG) raised the threat status of Mount Raung in East Java from level I or normal to level II or alert due to increased volcanic activity.

"The potential danger of Mount Raung that may occur at this time is in the form of accumulation of high concentration volcanic gas at the bottom of the crater," said PVMBG Head Hendra Gunawan as quoted by ANTARA, Tuesday, December 19.

Based on instrumental observations made by PVMBG, there were 168 earthquake gusts, 8 local tectonic earthquakes, 75 distant tectonic earthquakes, and continuous tremors with an amplitude of 0.5 to 6 millimeters in the period 1 to 18 December 2023.

According to historical records, the eruption of Mount Raung produces pyroclastic flow, pyroclastic fall, and anesic lava flow to basaltics.

Meanwhile, when there is no eruption, the activity is in the form of gas gusts at the bottom of the crater.

From July 2020 to October 2020, the series of eruptions produced ash-sized rock material whose distribution was limited around the crater of the peak of Mount Raung.

From January 2021 to February 2021, there was a black ash and brownish eruption accompanied by lava flow at the bottom of the crater.

According to PVMBG records, the last eruption of Mount Raung was in the form of an ash eruption that occurred on July 27, 2022.

Hendra explained that visual observations on December 1 -17, 2023 showed that the height of the gas gust column during that period fluctuated and showed a maximum value that had increased from the previous period, which was a maximum of 500 meters from above the peak.

On December 18, 2023, there was an increase in crater smoke gusts and reached an altitude of 1,000 meters above the peak.

"The increase in crater gusts is estimated to be triggered by a local tectonic earthquake with a magnitude of 2.6 at 19.02 WIB, on December 18, 2023," said Hendra.

PVMBG also observed the change in the rock surface of Mount Raung. The observational results indicate that there is a process of emptying magma bags in reservoirs due to the release of fluid dominated by gas.

PVMBG urges the public and tourists not to approach the eruption center in the summit crater with a radius of three kilometers.

"The level of activity of Mount Raung will be reviewed if there are significant visual changes and seismicities," said Hendra.