The Paroxysmal Eruption of Ruang Volcano, Indonesia Heruningtyas Desi Purnamasari1,2, Sulistiyani1, Yasa Suparman1, Nugraha Kartadinata1, Sofyan Primulyana1, Asep Saepuloh2, Mirzam Abdurrachman2, Hadi P. Wijaya1, Hendra Gunawan3
1 Center for Volcanology and Geological Hazard Mitigation (CVGHM), Geological Agency, Ministry of Energy and Mineral Resources, Indonesia
2 Mineral and Coal Engineering and Environment, Directorate General of Mineral and Coal, Ministry of Energy and Mineral Resources, Indonesia
3 Geological Engineering, Faculty of Earth Sciences and Technology, Bandung Institute of Technology, Indonesia
Abstract
Ruang is an active volcano located on Ruang Island, the northern side of Sulawesi Island, Indonesia. Based on the eruptive history, Ruang volcano erupted in 1871 with the activity of a landslide at the summit that generated a tsunami on Tagulandang and Buhias Island. After 150 years, Ruang volcano erupted again on April 17 and 30, 2024. There was a significant increase in seismic activity before the eruptions, such as two tectonic earthquakes on April 9 and 14, 2024, which were felt by volcano observers at the Ruang Volcano Observatory on Tagulandang Island. On April 11, five deep volcano-tectonic (VTA) earthquakes were recorded which then increased drastically to 146 VTA earthquakes on April 16. The first eruption occurred on April 16 at 10:00 local time. The people at Ruang Island reported the felt earthquakes and rumbling sounds, so on April 16, 900 people evacuated from Ruang Volcano Island to Tagulandang Island.
On April 17 01.08 local time, there was a paroxysmal eruption with the eruption plume reaching more than 2,500 meters. The eruption continues with the vibrations felt and a rumbling sound heard from Tagulandang Island. On April 29, the earthquakes were felt by the people within a radius of 6 km from the summit of Ruang volcano. On April 30, a paroxysmal eruption took place with the eruption plume reaching more than 5,000 meters above the summit. The explosions, pyroclastic flow, and incandescent lava ejection took place from 01.15 to 05.30 local time. The entire island of Ruang was hit by thick deposits of hot clouds, volcanic ashes, and gravel.
Thick volcanic ash rain took place on the west side of the volcano and paralyzed the operation of Sam Ratulangi Airport in Manado, North Sulawesi and even reached Kalimantan Island. Based on the field survey after the eruption, the ejection of incandescent rocks with a diameter of 4 cm was spread up to a distance of 8 km from the summit, 5 cm diameter rocks were found to a distance of 7 km from the summit, and 6 cm diameter rocks were found at a distance of 5 km from the center of the activity. After these 2 major eruptions, the activity of Ruang Volcano gradually returned to normal. The eruptions were paroxysmal, but due to proper crisis management, good cooperation and coordination between stakeholders, there were no fatalities during this disaster.
Keywords: Ruang volcano, paroxysmal eruption, Indonesia
Topic: Interdisciplinary Earth Science and Technology
