Mount Semeru erupts, bursts of hot clouds falling
The Center for Volcanology and Geological Hazard Mitigation (PVMBG) stated, based on visual observations, seismic activity on Mount Semeru was dominated by surface earthquakes before the eruption on December 4, 2021.
Then, the seismicity does not indicate an increase in the number and type of earthquakes associated with the supply of magma or fresh rock to the surface.
Based on PVMBG's visual monitoring data, during November 1-30 2021, Mount Semeru was clearly visible until it was covered in fog. Then gas gusts from the main crater are white and gray with moderate to thick intensity, about 100-600 meters from the summit.
"Eruptions still occur intermittently, resulting in a gray eruption column with a maximum height of 300 to 600m from the top of the crater/peak," said PVMBG.
Meanwhile, on December 1, 2021, a hot cloud avalanche occurred with a sliding distance of 1,700 m from the peak, or 700 m from the end of the lava flow, with a sliding direction to the southeast. After the hot cloud avalanche, lava avalanches occurred with the distance and direction of the slide not being observed.
Then on December 4, 2021 starting at 13.30 WIB, a flood vibration was recorded. Then at 14.50 WIB, hot clouds of avalanches were observed with a sliding distance of 4 km from the peak or 2 kilometers from the tip of the lava flow to the southeast or to Besuk Kobokan.
Dominated by Surface Earthquake
Meanwhile, the number and types of earthquakes recorded during November 1 to 30, 2021 were dominated by surface earthquakes. Namely in the form of earthquake eruptions with an average of 50 events per day, and earthquake avalanches on December 1 and 3, 2021, each occurring 4 times.
"Volcanic earthquakes (Deep Volcanic Earthquakes, Shallow Volcanic Earthquakes, and Tremors) which indicate magma rising to the surface are recorded in very low numbers," he explained.
The eruption of Mount Semeru on Saturday (4/12/2021), began with a lahar incident at 13.30 WIB, according to the Head of the Volcanology Center for Geological Hazard Mitigation (PVMBG) Andiani.
