Volcanic activity of Mount Anak Krakatoa increase

By Ludya Arica Bakti
(Pakistan News & Features Services) 

The volcanic activity of Mount Anak Krakatoa located in the Sunda Strait has continued to increase. To that end, the PVMBG of the ESDM Ministry of Geology has upgraded the status of Gunung Anak Krakatau from Alert (Level II) to Standby (Level III), with the danger zone extended from 2 kilometers to 5 kilometers exclusion zone.

People and tourists are prohibited from carrying out activities within a 5 kilometer radius of the crater peak of Mount Anak Krakatau. 

This increase in Standby status (Level III) was valid starting from 6 am local time on December 27. 

There was an eruption on December 22 but it was recorded as a small scale, compared to the eruption in the period September-October 2018. 

The results of the analysis of satellite images were known as the west-southwest slope flank collapse and avalanches entered the sea. This was the possibility that triggered the tsunami. 

Since December 22 a Surtseyan type eruption was observed, namely magma which came out of direct contact with sea water which meant that the volume discharge of magma released was increased and the crater hole enlarged. There may be a new crater hole that is close to the sea level. Since then the eruption took place without a pause. Sounds of eruption sound are heard several times per minute.

At present the eruption activity was still ongoing, namely in the form of Strombolian eruptions accompanied by throws of incandescent lava and hot clouds. 

On December 26 an eruption of hot clouds was observed. This hot cloud has resulted in rain of ash. Dominant winds lead to the southwest so that volcanic ash spreads southwest to the sea. 

The presence of several layers of wind at certain elevations leading to the east caused rain of thin volcanic ash to fall in the city of Cilegon and partly in attack at around 5.15 pm December 26. This was not deemed dangerous as volcanic ash actually fertilized the soil. 

The community anticipated using masks and goggles when moving outside when it rained ash. According to another observation, the eruption of Mount Anak Krakatoa eruption was still ongoing, continuous tremor with an amplitude of 8-32 millimeters (dominant 25 millimeters), and a banging sound was heard.

Until now, the Emergency Response Team has continued to monitor the visual activities of Mount Anak Krakatoa at the Pasuruan monitoring post, Cinangka, Serang Regency. 

"All flights are diverted because Krakatoa's ash on red alert," the air traffic control agency, AirNav, said in a release. The civil aviation authority said there are no airports affected. 

The PVMBG recommended that people and tourists be prohibited from carrying out activities within a 5 km radius of the crater peak because they are dangerously affected by eruptions in the form of incandescent rocks, hot clouds and thick volcanic ash. 

Meanwhile the Meteorology Climatology and Geophysics Council (BMKG) recommended that the community 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 the eruption of Mount Anak Krakatoa. People were encouraged to remain calm and increase their awareness and they were advised to use information from PVMBG for volcano early warning and BMKG regarding tsunami early warning as an official institution. 

**The writer is a freelancer based in Indonesia