Mount Merapi Erupts Again, Let’s Get To Know More About Mount Merapi

PUBLISHED,- Yesterday, when the sun began to slip from overhead, the volcano showed its activity. The mountain, which is on the border of DI Yogyakarta and Central Java, erupted on Sunday (6/2/2022) at 15.12 WIB, spewing hot clouds from inside the crater reaching a height of 600 meters.

Based on the monitoring of the Center for Volcanology and Geological Hazard Mitigation (PVMBG) of the Ministry of Energy and Mineral Resources, the ash column of Mount Merapi was observed to be gray with moderate to thick intensity to the southwest. This eruption was recorded on a seismograph with a maximum amplitude of 47 mm and a duration of 129 seconds.

PVMBG informs that the current potential danger is in the form of lava avalanches and hot clouds in the south-southwest sector covering the Boyong River for a maximum of 5 km. Then, Bedog River, Krasak, Bebeng as far as a maximum of 7 km. Furthermore, in the southeast sector, it covers the Woro River for a maximum of 3 km and the Gendol River for 5 km. Meanwhile, the ejection of volcanic material in the event of an explosive eruption can reach a radius of 3 km from the summit.

The public is advised not to carry out any activities in potential hazard areas. Not only that, PVMBG also asked the public to anticipate disturbances caused by volcanic ash from the eruption of Mount Merapi and to be aware of the dangers of lahars, especially when it rains.

Mount Merapi, which erupted yesterday, is one of the southernmost volcanoes of the straight line of volcanoes in Central Java from north to south, namely Ungaran-Telomoyo-Merbabu-Merapi. This lineament is a fault associated with fractures due to tectonic activity that preceded volcanism in Central Java. This volcanism activity shifts from north to south, where Mount Merapi appears the youngest.

Some of us must remember the devastating eruption of Mount Merapi in 2010. On October 25, 2010 Merapi’s status was declared ‘Careful’ (Level IV), with conditions that would soon erupt, or a critical condition that could lead to disaster at any time. On October 26, 2010 at 17:02 WIB, the first explosive eruption occurred accompanied by hot clouds and booms. On November 3, 2010 there was a series of hot clouds. An increasing trend in RSAM data between 3 – 4 November 2010 shows a process of growth of the lava dome which reaches a volume of 3.5 million m3. On November 5, 2010, the lava dome was destroyed which produced hot clouds as far as 15 km to K. Gendol. This eruption is the largest eruption. The death toll from the 2010 eruption of Mount Merapi was 347 people (BNPB). The most victims were in Sleman Regency, namely 246 people. Followed by Magelang Regency 52 people, Klaten 29 people, and Boyolali 10 people. Meanwhile, the refugees reached 410,388 people (BNPB).

Before the eruption that occurred in 2010, there were several records of volcanic eruptions, including in the period 3000 – 250 years ago there were approximately 33 eruptions, of which 7 were major eruptions. These data indicate that a major eruption occurs once in 150-500 years.

In the period of the 19th century (1768, 1822, 1849, 1872) and the 20th century, 1930-1931. The 19th century eruptions were much larger than the 20th century eruptions, where hot clouds reached 20 km from the summit. The possibility of a major eruption occurs once in 100 years.

The eruption of Mount Merapi is characterized by the release of magma to the surface forming a lava dome in the middle of an active crater around the summit. The emergence of new lava is usually accompanied by the destruction of the old lava which blocks the flow, resulting in lava avalanches. New lava that reaches the surface forms a dome that can grow larger. The growth of the lava dome is proportional to the magma flow rate which varies up to hundreds of thousands of cubic meters per day. Lava domes that grow in the crater and enlarge causing instability. The unstable lava dome is pushed by gas pressure from within, causing some of the landslides to form, resulting in hot clouds. Hot clouds will flow to a lower place along the river valley. The flow speed reaches 60-100 km / h and will stop when the energy of motion runs out. This hot cloud is referred to as the “Merapi Type” which is the main threat.

Since the flow of hot clouds is the main hazard, development should be based on the existing volcanic disaster risk map. Residents who live in river valleys around the hot clouds of Mount Merapi are expected to always be alert and alert. (LS)