The eruption of Sileri Crater in Dieng tourism area in Central Java on Sunday (2/7) was quite shocking because it happened suddenly in a safe tourism destination area. The high number of victims was due to the high number of tourists in this area at that time. In order to prevent similar incidents, a volcanology expert from UGM, Dr. Sandy Budi Wibowo, said the tourism management need assistance to enhance the safety standard in this area.
“The management is not supposed to be blamed, but they need to be assisted in enhancing the safety over there,” said Sandy on Tuesday (4/7).
Sandy said the point of this problem is the spatial aspect related to volcanoes. If this spatial criterion is fulfilled, according to the expert, tourists will be safe from this kind of danger in the future.
Regarding the disaster, Sandy said that volcano activity is difficult to be predicted and can happen suddenly.
“This disaster is categorised into phreatic eruption which is usually not accompanied by phenomenons that can be detected by a volcanic sensor such as the seismic sensor,” he added.
This phreatic eruption happened because the magma indirectly heats the water around it, both in the crater and groundwater, thus creating superheated steam. According to Sandy, this eruption process actually did not happen in the surface.
“This eruption which was not accompanied by the movement of magma to the surface can only be recognized during the eruption, not before it happens. It is different with the magmatic eruption which is signed by the rise of magma to the Earth surface that causes vibration before the eruption, or a phreatomagmatic eruption which involves direct contact between magma and water in the Earth surface so it can be detected visually,” said Sandy.
Despite its small scale, Sandy said this eruption has a quite hazardous effect because it contains poisonous, high-temperature, and high-pressure volcanic gases such as H2O, CO2, SO2, H2S, etc. Moreover, in a crater with lake, this eruption can trigger the primary lahar or rapid flow from upstream to downstream and contain a mixture of volcanic materials and water.
“Visually, this lahar looks like mud or cement mix for buildings,” said Sandy.
In the near future, Sandy recommend starting implementing the prohibition zone around the craters with different radius based on the eruption characteristic in each zone. This is not supposed to reduce the comfort of the tourists to do sightseeing in the craters of Dieng,” he added.
Sandy also emphasized the importance of concern as well as cooperation from many parties to make a better safety standard and prevent casualties if there is a similar incident in the future. Although the current technology cannot estimate the eruption scale in the future, all we can do is monitoring the evolution of the volcano in real-time and watching its trend from time to time as well as preparing facilities to evacuate the society if needed.
“Narrow road and many vehicles would make it difficult to evacuate in case of an eruption. Widening of roads, parking management, and provision of evacuation routes are necessary. Education towards tourists is also considered necessary. After all those things have been done to the fullest, insurance may be implemented to help reduce the loss,” said Sandy.