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Anak Krakatoa or Anak Krakatau (Indonesian: Anak Krakatau), is an island in a caldera[1] in the Sunda Strait situated between the islands of Java and Sumatra in the Indonesian province of Lampung. On 29 December 1927, Anak Krakatau, or "Child of Krakatoa", emerged from the caldera formed in 1883 by the explosive volcanic eruption which destroyed the island of Krakatoa. There has been sporadic eruptive activity at the site since the late 20th century, culminating with a large underwater collapse of the volcano which caused a deadly tsunami in December 2018. The island is one of several in the area which are of considerable interest to volcanologists, and the subject of extensive study.

Anak Krakatoa
Krakatoa eruption 2008.jpg
Anak Krakatoa 2008 eruption
Highest point
Elevation110 metres (360 ft)
Prominence110 m (360 ft)
ListingSpesial Ribu
Coordinates6°06′07″S 105°25′23″E / 6.102°S 105.423°E / -6.102; 105.423Coordinates: 6°06′07″S 105°25′23″E / 6.102°S 105.423°E / -6.102; 105.423
Naming
Native nameAnak Krakatau  (Indonesian)
Geography
Anak Krakatoa is located in Indonesia
Anak Krakatoa
Anak Krakatoa
Location
LocationIndonesia
Geology
Mountain typeCaldera
Last eruptionDecember 2018– January 2019
Climbing
First ascent29 December 1927

Contents

ActivityEdit

 
Volcanic activity at Anak Krakatau, 2008
 
2010: The thick brown plume of ash, steam and volcanic gas rising from Anak Krakatau in this true-colour satellite image is a common sight at the volcano.

Until its 2018 collapse, Anak Krakatau grew at an average rate of 13 cm (5.1 in) per week since the 1950s. This equates to an average growth of 6.8 m (22 ft) per year. The island remains active in January 2019, with its most recent eruptive episode having begun in 1994. Quiet periods of a few days have alternated with almost continuous Strombolian eruptions since then.

Hot gases, rocks, and lava were released in an eruption in April 2008. Scientists monitoring the volcano warned people to stay out of a 3 km (1.9 mi) zone around the island.[2]

On 6 May 2009, the Volcanological Survey of Indonesia raised the eruption alert status of Anak Krakatau to Level III.[3] An expedition to the volcano revealed that a 100 m (330 ft) wide lava dome was growing in its crater.

In January 2012, volcanologists at the University of Oregon warned that a tsunami caused by flank collapse of Anak Krakatau was likely, as it had formed on a steep slope at an edge of the big caldera formed in 1883.[4]

A new eruptive phase was observed from June 2018. On 15 October 2018, Anak Krakatau had a strong Strombolian to weak Vulcanian eruption that sent lava bombs into the water, with one almost hitting a nearby boat. The eruption was recorded on video.[5]

2018 eruptionEdit

 
Anak Krakatau in 2007

An eruption of the volcano on 22 December 2018 caused a deadly tsunami.[6] On 31 December 2018 the disaster agency stated the tsunami's death toll as 437, with 14,059 injured.[7] This makes the eruption the deadliest volcanic eruption of the 21st century.

It was believed after the December 2018 eruption that the southwest sector of the volcano, including the summit, had collapsed, triggering the tsunami. On 23 December this was confirmed by satellite data and helicopter footage, with the main conduit erupting from underwater, producing Surtseyan-style activity.[8] The volcano lost over two-thirds of its volume due to this event, and elevation above sea level was reduced from 338 m to 110 m (360 ft).[9]

Satellite radar observations showed that by 10 January 2019, the volcano had continued to evolve, with further eruptions beginning to re-model the remnant structure. The crater, which had become open to the sea immediately after the eruption, now had a complete circle of rim above sea level.[10]

See alsoEdit

ReferencesEdit

  1. ^ Volcano;
  2. ^ "Indonesia's Krakatau roars, dazzles with fireworks". Reuters India. 11 November 2007. Retrieved 10 January 2019.
  3. ^ "VSI Alert". Volcanological Survey of Indonesia. Archived from the original on 6 May 2009. Retrieved 20 March 2012.
  4. ^ Giachetti, T.; Paris, R.; Kelfoun, K.; Ontowirjo, B. (January 2012). Terry, J. P.; Goff, J. (eds.). "Tsunami Hazard Related to a Flank Collapse of Anak Krakatau Volcano, Sunda Strait, Indonesia". Natural Hazards in the Asia–Pacific Region: Recent Advances and Emerging Concepts. Special Publications. London: Geological Society. 361: 79–90. doi:10.1144/SP361.7. ISSN 0305-8719.
  5. ^ "Tour boat almost lava-bombed by erupting Indonesian volcano in stunning VIDEO". RT. Retrieved 29 October 2018.
  6. ^ "Indonesia 'Volcano Tsunami': At least 168 Dead and 745 Injured after [Anuk] Krakatoa Erupts". telegraph.co.uk. 23 December 2018. Retrieved 23 December 2018.
  7. ^ "Number of injured in Indonesia tsunami surges to over 14,000". The Star Online. Asean Plus. Retrieved 31 December 2018.
  8. ^ "22-23 Dec 2018 Eruption & Tsunami of Krakatoa - Updates". Volcano Discovery. 25 December 2018. Retrieved 26 December 2018.
  9. ^ Amos, Jonathan (29 December 2018). "Indonesian volcano's lost stature". BBC News. Retrieved 29 December 2018.
  10. ^ "Anak Krakatau: Finnish radar satellite eyes tsunami volcano". BBC News. 10 January 2019. Retrieved 10 January 2019.