Ruang volcano in Indonesia erupted again: Highest alert level

On Tuesday night, the 725-meter-high Mountain of Fire in the Sangihe archipelago north of Sulawesi island hurled a 2,000-meter-high column of ash, smoke and rock into the sky, “accompanied by thunderous sounds and sustained tremors,” according to the national volcano monitoring agency reported. The authorities then issued the highest alert level again.

Residents within a radius of initially six and later seven kilometers around the crater were asked to immediately get to safety and wear masks. The airport in Manado, the capital of Sulawesi province, and other airports in the region were temporarily closed.

A significant increase in both very deep and shallow volcanic earthquakes has been recorded, the agency wrote. This indicates magma migration from deep reservoirs to the surface. People in the region should be careful about possible pyroclastic flows – avalanches of lava, ash and hot gases – as well as tsunamis, which could be caused by boulders falling into the sea or the collapse of the entire volcanic body.

Parts of the volcanic island threatened to collapse into the sea

There have been eruptions on Ruang since mid-April. The volcano spewed clouds of ash and rock up to 3,000 meters high several times. Air traffic in the region was partially suspended. Last week, however, the alert level was initially lowered after the Ruang calmed down somewhat.

Two weeks ago, parts of the volcanic island threatened to collapse into the sea. According to the state Center for Meteorology, Climatology and Geophysics, eruptions could cause the flanks of a volcano or, in the worst case, the entire mountain to collapse – triggering tsunamis with meter-high tidal waves and devastating consequences.

In 1871, an eruption of Ruang triggered a tsunami with waves up to 25 meters high. Around 400 people died on the neighboring island of Tagulandang, five kilometers away.

The world’s largest island state, Indonesia, lies on the so-called Pacific Ring of Fire, the most geologically active zone on earth. Earthquakes and volcanic eruptions occur frequently along this belt. There are about 130 active volcanoes in Indonesia.