Indonesia Raises Mount Anak Krakatau Status to Standby Level - Photo: Privacy

JAKARTA (TheInsiderStories) – Meteorology Climatology and Geophysics Agency raised the eruption status of Mount Anak Krakatau to Standby level (Level III) with the dangerous zone expanded from 2 kilometers to 5 kilometers.

At a press conference at the Ministry of Energy and Mineral Resources (MEMR) office in Jakarta, today (12/27), the secretary of the agency Antonius Ratdomopurbo, said that the status improvement was based on observations and analysis of visual and instrumental data until Dec. 27, 2018 at 05:00 a.m. local time.

Besides the continuing eruption, there is a continuous tremor with an amplitude of 8-32 millimeters (dominant 25 millimeters), and an audible banging sound. For this, its recommends that people not carry out activities on the coast at a 500 meter radius to 1 kilometer from the coast in anticipation of a subsequent tsunami.

The tsunami that was raised underwater landslides due to mountain eruption. Based on the agency data, the mountain is active again and enters the eruption phase from July 2018.

The next eruption is strombolian eruptions, which are eruptions accompanied by the ejection of incandescent lava and dominant incandescent lava flows to the southeast. Fluctuating ongoing eruptions.

Today there was a small scale eruption recorded, in comparison to the eruptions of the September-October 2018 period. The results of the analysis of satellite imagery are known as the west-southwest slope flank collapse and avalanches entering the sea. This possibility triggered the recent tsunami.

If this is the case then the volume discharge of magma released increases and the crater hole enlarges. There may be a new crater hole that is close to the sea level. Since then the eruption took place without a pause. Eruption sound are heard several times per minute.

Meanwhile, the authority does not yet know the cause of the 64-hectare avalanche (the size of a soccer field or hotel) that collapsed from the mountain. The landslide can cause large water ripples that trigger high waves. The biggest landslide occurred in 1883 when the mountain erupted.

Even though it has monitoring equipment, it is only for monitoring the vibration of volcanic earthquakes, while other devices are assisted by the geology agency. However, the equipment near the mountain was damaged due to the impact of the eruption, so now it only relies on equipment far from the island next to it. The team also has problems to approach the location because of the weather.

Based on satellite photos, on Dec. 26 there was a known surtseyan type eruption, namely lava or magma flow which is suspected to have came from direct contact with sea water. This hot cloud has resulted in rain of ash.

The volcanic ash is spread in several regions, namely in Cilegon, Anyer and Serang. The distribution of volcanic dust leads to southwest-west with a height reaching more than 10 kilometers.

At present the mountain has the highest elevation of 338 meters from the sea level (measurements in September 2018). The eruption character is a magmatic eruption in the form of a weak explosive eruption and an effusive eruption in the form of lava flow.

In 2016, there was a small eruption, then in 2017 a strombolian eruption. But since June 29, 2018, the mountain has again issued an eruption until Dec. 22 in the form of a strombolian eruption.

From the data of Citra Sentinel, actually from Dec. 11 and Dec. 23, it can be seen that some of the slopes of the West to South sector appear to have experienced landslides which are shown from the comparison of images before and after the tsunami event. In that period there was a continuous tremor with amplitude 08-31 mm, dominant 25 mm.

At present there is fog from the main craters to gray to black with thin to thick high intensity around 200-1,500 meters from the top of the mountain.

On the other hand, Director General of Civil Aviation, Polana B. Pramesti has inspected air transportation infrastructure facilities and prepared airports for the distribution of humanitarian aid and flight operations that could be affected by the eruption, mainly due to high flight activities during the Christmas and New Year holidays 2019.

“Coinciding with the Christmas holidays and welcoming the 2019 New Year and school children’s holidays, air transportation modes are in great demand by the public to go on vacation. For this reason, it is necessary to continue to coordinate and be ready when things happen that disrupt flight activities,” he said.

Indeed, flight activities with the Jakarta-Lampung route are still normal and unaffected by mountain eruptions. But the authorities continues to monitor the activities of the mountain in order to anticipate unexpected problems.

Written by Daniel Deha, Email: theinsiderstories@gmail.com