An eruption began at this highly active volcano in Indonesia in early February. Numerous villages are found on the flanks of the volcano and at the level of the coastline, all within 5 kilometers of the summit, and are endangered by lava flows, fiery clouds and mudslides. But these risks are accepted by these Indonesians for whom the volcano is part of their life…
With about ten eruptions since the beginning of the century, lasting from a few weeks to sometimes several years, this volcano is one of the most active in Indonesia. The inhabitants of Siau, a modest isolated island between the Philippine archipelago to the north and Indonesian Sulawesi to the south, are therefore used to seeing red at the top of the volcano!
living with danger
The islanders were therefore not particularly surprised when this new eruption began on February 8, from the southernmost summit of the two which constitute the summit zone of the volcano. The lava overflows from the small crater there and forms lava flows on the high sides of the volcano, mainly towards the southwest. As the slope is steep, these lava flows continuously crumble and thus generate avalanches of blocks which, as they rebound, break and spread in multiple directions.
Consequently, these avalanches impact the entire southwestern quarter of the volcano, even if these blocks accumulate mainly on either side of an old relief to the south-west of the southern crater. But these more or less cooled rock piles are very unstable and also end up collapsing, thus generating other avalanches which, depending on their intensity, form fiery clouds. These extremely dangerous clouds of gas and ash typically reach 1 kilometer in length, their front stopping about 1.5 kilometers from the first villages…
The volcano for habit
Due to their location near the active zone, the few families from two villages were evacuated at the start of the eruption. The access ban has been lifted for at least one of these villages, but apart from these few evacuees and the ashes that sometimes dusted the area, the eruption had very little impact on island life. Indeed, these inhabitants live by accepting the risks associated with the volcano, like this farmer of nutmeg (an important crop on this island) who explains that at the start of the eruption, he was walking for two hours to check that the lava flow did not descend towards his farm and this, twice a day…
In addition to the fiery clouds, two other main risks are listed for this volcano. The lava flows can flow into the various ravines of the volcanic massif, to areas far from the summit. This is how in 2019, the lava reached the sea north of the volcano, cutting the road that goes around it, which still disrupts the lives of the inhabitants of the fishing villages in the area today. Finally, the eruptive activity also recharges the gullies with materials that can be remobilized by the rains, in a few days or in several years, to form mudslides. These are very destructive and sometimes wash away pieces of road.
Life is thus on Siau, with a frequent volcanic spectacle, but which is not without danger.
- Thanks to Sylvain Chermette, manager of the 80 Jours Voyages agency, who allows me to use these photos free of charge, thus illustrating this article nicely. From time to time, he organizes “express eruption” stays, as for the Karangetang recently…
