1979 eruption of Sinila crater

{{Short description|Volcanic eruption in Indonesia}}

{{Use dmy dates|date=December 2023}}

{{Infobox eruption

| name = 1979 eruption of Sinila crater

| image =

| caption =

| date = 20 February 1979

| time = nighttime

| volcano= Dieng Volcanic Complex,

| location = Central Java, Indonesia

| coordinates =

| VEI = 1{{cite gvp|vn=263200|vtab=Eruptions|title=Dieng Volcanic Complex: Eruptive History|access-date=2024-10-26}}

| impact = 175 –180{{cite news |url=https://resolver.kb.nl/resolve?urn=KBPERS01:002950020:mpeg21:a00127 |title=Al 800 doden na vulkaanuitbarsting |work=Algemeen Dagblad|date=23 February 1979 |via=Delpher |language=nl}} deaths (up to 800+ deaths have been reported)
1,000+ injured
17,000 evacuated

}}

During the night of 20 February 1979, the Sinila volcano of the Dieng Volcanic Complex erupted on the Indonesian island of Java in Central Java province. Over 175 people died, mainly due to gas poisoning in villages on the plateau near the Sinila crater.[http://www.thejakartapost.com/news/2001/02/06/fumarole-death-blamed-poor-signs.html Fumerole death blamed on poor signs'], The Jakarta Post{{cite news |url=https://resolver.kb.nl/resolve?urn=ddd:011187794:mpeg21:a0026 |title=Tientallen doden bij vulkaanuitbarsting op Sumatra |work=Vrije Stem|date=3 May 1979 |via=Delpher |language=nl}} It was the fourth Sinila eruption since 1928, and the first one since 1951.{{cite news |url=https://resolver.kb.nl/resolve?urn=ddd:010960082:mpeg21:a0002 |title=Vulkaan op Java spuwt lava en gif - 155 doden |work=Het Vrije Volk|date=21 February 1979 |via=Delpher |language=nl}}This complex sits on a subduction zone between the Australian and Eurasian plates.

File:Dieng-Plateau-Kawah-Sinela-April-2019-DJI 0595.jpg

Geological impact and toxic gas emission

The eruption started in the early morning, with three earthquakes before the initial explosion at 5 in the morning at Sinila crater. The eruption involved explosions, the expulsion of rocks and mud, intense steam and gas release, and a hot lahar that flowed over roads and farmland along a 3.5 km stretch. A new crater was created, measuring approximately 90 m in diameter and 100 m deep. A new vent, 15 meters in width, formed after a second but minor eruption at 6:45 am, in the Sigludug area. Mud and stones were expelled and a small lahar was released. During the eruption, the Sumur crater, another crater in the Dieng complex, which was initially dormant, got reactivated and started showing activity when carbon dioxide emissions began to occur.

During the eruption, toxic gases were emitted from the Sinila crater for two days. Carbon dioxide emissions continued for several months after the initial explosion. Voluminous amounts of carbon dioxide started to emerge from both the fracture and the Sigluduk crater, and sheets of the dense gas flowed down to the Batur plain. Gases were still released for several months after the explosion. These gases were sampled in early July, when they were emitted. The gas was made up of carbon dioxide, methane, and hydrogen sulfide. These craters are known for emitting toxic gases, which are dangerous for the people living nearby.

The eruption came unexpectedly as the Sinila volcano had been considered dormant for a long time.{{cite news |url=https://resolver.kb.nl/resolve?urn=ABCDDD:010826859:mpeg21:a0261 |title=Vulkaanuitbarsting op Java: 175 doden |work=Trouw|date=22 February 1979 |via=Delpher |language=nl}} The eruption followed after seven earthquakes and an explosion. Two explosions occurred within an hour of each other, causing a lahar lava flow.{{Cite web |title=Global Volcanism Program {{!}} Report on Dieng Volcanic Complex (Indonesia) — March 1979 |url=https://volcano.si.edu/showreport.cfm?doi=10.5479/si.GVP.SEAN197903-263200 |access-date=2024-09-19 |website=volcano.si.edu |language=en |doi=10.5479/si.gvp.sean197903-263200}} Next to lava, toxic gas was released which could be seen, smelled or tasted. As the eruption took place during the night, people inhaled the poisonous gases during their sleep and died. The village with the most deaths was Pucukan, where bodies were also lying on the streets.{{cite news |url=https://resolver.kb.nl/resolve?urn=KBNRC01:000026537:mpeg21:a0068 |title=Zeker 137 doden bij eruptie vulkaan op Java |work=NRC Handelsblad |date=21 February 1979 |via=Delpher |language=nl}} The rescue work was made difficult due to toxic gases and difficulty accessing the area. At some places the streets were covered by an {{convert|8|m|adj=on}} layer of lava. The worst affected village was Pekasiran, which was inaccessible due to the mud and lava.{{cite news |url=https://resolver.kb.nl/resolve?urn=ABCDDD:010841094:mpeg21:a0117 |title=Lavastroom bemoeilijkt hulpacties |work=Het Parool|date=22 February 1979 |via=Delpher |language=nl}}{{cite news |url=https://resolver.kb.nl/resolve?urn=ddd:010639588:mpeg21:a0100 |title=Reddingswerk vulkaan gaat stroef|work=Amigoe|date=23 February 1979 |via=Delpher |language=nl}}

Casualties, losses, and human response

Rescue work was also hampered due to a lack of gas masks.{{cite news |url=https://resolver.kb.nl/resolve?urn=KBNRC01:000026542:mpeg21:a0054 |title=Vulkaanramp op Java nu 180 doden|work=NRC Handelsblad|date=23 February 1979 |via=Delpher |language=nl}} Policemen, soldiers and volunteers were killed by the gases due to the absence of enough gas masks.{{cite news |url=https://resolver.kb.nl/resolve?urn=ddd:110607782:mpeg21:a0311 |title=Vulkaanramp op Midden-Java |work=De Telegraaf |date=22 February 1979 |via=Delpher |language=nl}}

A few days after the eruption, the death toll rose to 180. Some sources even stated over 800 deaths.{{cite news |url=https://resolver.kb.nl/resolve?urn=MMECAL02:180086023:mpeg21:a00018 |title=Uitbarsting |work=Nieuwe Winterswijksche Courant |date=23 February 1979 |via=Delpher| language=nl}} According to an expert, most people died due to panic after the eruption. It was later discovered that 142 people among the casualties died due to the toxic gas when they were fleeing along a trail from the village of Kepucukan towards the Batur village.{{Cite journal |last=Allard |first=P. |last2=Dajlevic |first2=D. |last3=Delarue |first3=C. |date=November 1989 |title=Origin of carbon dioxide emanation from the 1979 Dieng eruption, Indonesia: Implications for the origin of the 1986 Nyos catastrophe |url=https://linkinghub.elsevier.com/retrieve/pii/0377027389900589 |journal=Journal of Volcanology and Geothermal Research |language=en |volume=39 |issue=2-3 |pages=195–206 |doi=10.1016/0377-0273(89)90058-9|url-access=subscription }}

People went to higher ground to flee the lava but were killed by the toxic gas. Over 1,000 people were injured, and many people were hospitalized.

The toxic gas not only killed people. There was a 4-meter-wide, 40 centimeters thick gas sheet seen discharging from the Sigludug vent. The vegetation around which had already suffered damage from the eruption also showed signs of chemical destruction where the gas flowed. The chemical destruction of the gas sheet in a small valley resulted in dead birds and rodents lying on the valley bottom.{{Cite journal |last=Allard |first=P. |last2=Dajlevic |first2=D. |last3=Delarue |first3=C. |date=1989-11-01 |title=Origin of carbon dioxide emanation from the 1979 Dieng eruption, Indonesia: Implications for the origin of the 1986 Nyos catastrophe |url=https://www.sciencedirect.com/science/article/abs/pii/0377027389900589 |journal=Journal of Volcanology and Geothermal Research |series=The Lake Nyos Event and Natural CO2 Degassing, I |volume=39 |issue=2 |pages=195–206 |doi=10.1016/0377-0273(89)90058-9 |issn=0377-0273|url-access=subscription }}

The Indonesian government ordered that an area of {{convert|3|km}} around the mountain be evacuated, affecting around 17,000 people.{{Cite web |title=Report on Dieng Volcanic Complex (Indonesia) — March 1979 |url=https://volcano.si.edu/showreport.cfm?doi=10.5479/si.GVP.SEAN197903-263200 |access-date=2024-09-19 |website=volcano.si.edu |language=en |doi=10.5479/si.gvp.sean197903-263200}} President Suharto stated that around 6,000 people have evacuated by February 22nd. Evacuation efforts were hampered due to lava severing main roads, restricting access to the area.

The Sinila crater and the whole Dieng Volcanic complex is kept being watched and monitored. Most recent report indicated that 2023, the carbon dioxide emissions have decreased and the alert level for the Dieng Volcanic Complex has been lowered to 1 (on a scale of 1-4). Though the public was still warned to stay at least 500 meters away from several craters in the volcanic complex, including the Sileri Crater and the Timbang Crater. It is also told to take caution when digging the ground around the area which may result in gasses being released from the soil.{{Cite web |title=Global Volcanism Program {{!}} Dieng Volcanic Complex |url=https://volcano.si.edu/volcano.cfm?vn=263200 |access-date=2024-11-21 |website=Smithsonian Institution {{!}} Global Volcanism Program |language=en}}

See also

References