Mount Anak Krakatau: What to know about the volcano disrupting Indonesia flights
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Mount Anak Krakatau in Indonesia has been erupting since Sept 4.
PHOTOS: TPARON/X, STARSNAP_1/X
- Mount Anak Krakatau's recent eruptions since Sept 4 have disrupted flights, closed schools, and caused eye irritation from ash spreading over 150km, affecting around 170,000 people.
- Anak Krakatau formed less than 80 years ago from the 1883 Krakatau eruption, known for the loudest sound ever recorded and deadly tsunamis.
- The volcano remains active with frequent eruptions since 1927, including a deadly 2018 collapse-triggered tsunami; current alerts show no imminent tsunami risk, says Indonesia's disaster agency.
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SINGAPORE – A series of eruptions at Indonesia’s Mount Anak Krakatau since Sept 4 has disrupted flights and daily life as volcanic ash spread more than 150km away, blanketing Jakarta and nearby areas.
Several schools in Indonesia cancelled activities on Sept 5 after students and residents reported suffering eye irritation from the ash, while fishermen scrapped their fishing trips.
Seven Indonesian airports, including two in Jakarta, remained closed on the morning of Sept 7, with about 270,000 people affected by flight cancellations.
Here are some key facts about Anak Krakatau:
Volcano emerged less than 80 years ago
Anak Krakatau lies in the Sunda Strait, which separates the islands of Sumatra and Java.
The young volcano emerged less than 80 years ago, and its crater is located south-west of the centre of the island.
It was formed along the 3,000km-long Sunda Arc, where the Australian plate sinks beneath the Eurasian plate and where earthquakes and volcanic eruptions are common, according to US space and aeronautical research agency NASA.
Formed after biggest volcanic eruption in history
Anak Krakatau, which means “child of Krakatau”, was formed after its parent, Krakatau, disappeared in one of the biggest volcanic eruptions in history more than 140 years ago.
In 1883, a two-day eruption of Krakatau from Aug 26 to 27 led to two-thirds of the island – about 23 sq km, or around five times the size of Sentosa island – sinking into the Sunda Strait.
Parent volcano’s explosions produced loudest known sound
The explosions heard from the 1883 eruption remain the loudest noise on record. The sound was heard across the Indian Ocean as far as Rodriguez Island, 4,653km to the west, and Australia, 3,450km to the east, according to NASA.
The massive eruption also generated a series of tsunamis across Sumatra and Java, which produced waves up to 30m high and led to most of the 36,000 deaths linked to the eruption.
Sporadic activity since 1927
Anak Krakatau has been the site of frequent eruptions since 1927, according to the Smithsonian Institution.
Since July 2, the volcano has been on alert level 3, the second-highest.
An eruption on July 7 sent an ash column 100m into the sky.
A man clearing volcanic ash from his car windscreen in Bogor, West Java, on Sept 6, following the eruption of Anak Krakatau.
PHOTO: AFP
2018 tsunami after partial collapse
In December 2018, a large part of Anak Krakatau collapsed following an eruption. The landslide triggered a tsunami that killed more than 400 people and injured thousands in the surrounding Java and Sumatra islands.
The volcano also lost about two-thirds of its height, down from 338m to 110m, and three-quarters of its mass. Its estimated mass after the 2018 eruption was about 50 million cubic m, or about 25 per cent its original size.
Indonesia’s national disaster management agency said on Sept 5 that there was no imminent risk of a tsunami from the recent volcanic eruptions.
