November 22, 2024

Intense Explosions at Mount Semeru – One Year After Unleashing Deadly Eruption

Landsat 9 Satellite picture of Mount Semeru in Indonesia on December 4, 2022.
Intense explosions at the top sent avalanches of ash and mud racing down the southeastern flank of the Indonesian volcano.
In early December 2022, the tallest and most active volcano on Java erupted once again, simply one year after Indonesias Mount Semeru released a damaging, lethal eruption. Late on December 3, a series of explosions from the summit crater expelled gas and ash that, according to the Darwin Volcanic Ash Advisory Center, increased as high as 6,100 meters (20,000 feet) at times. Extreme activity continued throughout the night into the next day.
On December 4, 2022, the Operational Land Imager-2 (OLI-2) on Landsat 9 recorded this natural-color satellite picture of a volcanic plume streaming from Semeru at about 9:30 a.m. regional time (02:30 Universal Time). Volcanic plumes typically consist of ash and a mixture of volcanic gases, including water vapor, carbon dioxide, sulfur dioxide, hydrogen sulfide, and hydrogen halides. In this case, an imposing convective cloud, maybe drawing energy from the heat of the eruption, has actually obscured parts of the plume. Diffuse ash slightly darkens the big clouds shadow (directly to its west) and the underlying landscape farther to the west in this broader variation of the image (listed below).

On December 4, 2022, the Operational Land Imager-2 (OLI-2) on Landsat 9 recorded this natural-color satellite image of a volcanic plume streaming from Semeru at about 9:30 a.m. local time (02:30 Universal Time). The eruption on December 3– 4 produced several of these circulations, consisting of one that reached a length of 19 kilometers (12 miles), according to the Indonesian National Board for Disaster Management (BNPM).
On December 4, 2022, the Center for Volcanology and Geological Hazard Mitigation (PVMBG) raised the status of the eruption from 3 (“siaga,” or “alert”) to 4 (“awas,” or “caution”), the greatest on the 1-4 scale.

Landsat 9 Satellite picture of Mount Semeru in Indonesia on December 4, 2022.
Listed below and to the east of the large convective cloud is what appears to be the edge of a pyroclastic circulation moving down a river channel on the mountains southeastern flank. These rippling avalanches of superheated ash, tephra, soil, and other debris race at high speeds and can ruin most things in their path. The eruption on December 3– 4 produced numerous of these flows, consisting of one that reached a length of 19 kilometers (12 miles), according to the Indonesian National Board for Disaster Management (BNPM).
Given that heavy rains preceded the event, the pyroclastic flows most likely combined with rainwater and morphed into muddy lahars as they rushed down the mountain. The circulations damaged a bridge and buried homes as much as their rooftops, according to the Associated Press.
The eruption has required nearly 2,000 people from their homes. On December 4, 2022, the Center for Volcanology and Geological Hazard Mitigation (PVMBG) raised the status of the eruption from 3 (“siaga,” or “alert”) to 4 (“awas,” or “caution”), the greatest on the 1-4 scale. The PVMBG prompted people to remain at least 5 kilometers (3 miles) far from the summit and at least 500 meters (1,600 feet) from the Besuk Kobokan river channel.
NASA Earth Observatory image by Joshua Stevens, utilizing Landsat information from the U.S. Geological Survey.