Tsunami on Java and Sumatra 2018

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Sunda Strait , strait between Sumatra and Java, where Krakatau is located
The most important settlement centers on Sundastraße

A tsunami hit the coasts of the Indonesian islands of Java , Sumatra and a number of other smaller islands in the Sunda Strait on December 22, 2018 without warning . The tsunami was triggered when the volcanic flank of Anak Krakatau slid into the sea.

According to the National Agency for Disaster Control, there were 437 dead, 14,059 injured, 33,719 homeless (displaced persons) as well as 2,752 destroyed houses and 510 ships. The district of Pandeglang on the southwestern tip of Java was hardest hit; 290 people died there alone. However, Serang and Südlampung (Lampung Selatan) on the opposite side of Sumatra were also badly affected.

trigger

The Anak Krakatau is one of 76 active volcanoes in Indonesia and is the island in the Sunda Strait, on which it is located, its name. In 1883, Krakatau was the site of one of the largest eruptions in historical times, in which the island was largely destroyed and the new volcano formed as a result.

The volcano erupted twice between 2016 and 2018, and a new eruption phase of the volcano began in mid-2018. On September 22, 2018 there was an increasing sequence of eruptions ( paroxysm ), during which thermal radiation of approx. 3400 megawatts and volcanic ash at an altitude of up to 2300 meters were measured. On December 22nd at 9:03 p.m. local time, an outbreak occurred with a three-kilometer-high ash cloud, which also affected international air traffic.

The eruption phase up to the collapse of the volcanic flank lasted 175 days. From June 2018 until the collapse, 25.5 million m³ of deposits built up on the volcano, corresponding to 54 million tons (with an average density of 2110 kg / m³).

As early as January 2018, the volcano's southwest and southern flanks were slowly subsiding and moving west, about 4 mm per month. At the end of June 2018, the deformation accelerated noticeably, by around 10 mm per month. Only 115 s before the collapse, the seismic stations recorded an earthquake with a magnitude of ML = 2-3. An estimated 45–60% of the flank had failed (around 100 million m³, excluding the submerged collapse volume).

Tsunami

The regions affected and the number of victims

The collapse of the volcanic flank of Anak Krakatau, which lasted only about 2 minutes, reduced the height of the volcano from 320  m to 120  m .

The landslide triggered a tsunami, which around 24 minutes later flooded the coastal regions of the islands of Java and Sumatra on the Sunda Strait. In the seaside resort of Pantai Tanjung Lesung ( Banten province ), a three-meter-high wave hit the beach when the Indonesian boy band Seventeen gave a concert. A mobile phone video documents the moment when the wave hit the stage from behind. There were more than a hundred dead here alone. The spring tide caused by the full moon additionally strengthened the rising water. The wave of the tsunami was comparatively low and did not get far into the interior of the islands. The Indonesian Civil Protection had declared that there was “no tsunami threat” when the first waves hit land.

The Indonesian authorities feared a second tsunami and warned against staying on beaches and near the coast. However, there was no second wave.

consequences

Destruction on a beach in Banten

The National Agency for Disaster Management (BNPB) of Indonesia announced that 33,719 people had lost their homes (displaced) due to the tsunami (especially in the provinces of Banten and Lampung ). 437 dead and over 14,059 injured were registered by the authorities. More than 2,752 houses, many hotels and market stalls as well as 510 boats and ships were destroyed. Rescue teams were deployed in the administrative districts of Pandeglang, Serang, Südlampung, Pesawaran and Tenggamus . 290 people died in Pandeglang on Java alone.

At first it was unclear why the tsunami early warning system did not report any danger. Observers criticized the fact that the existing tsunami early warning system was not working or was not working properly and was only aimed at earthquakes, but not also at underwater landslides and volcanic eruptions. The Australian broadcaster ABC reported that the system had stopped working since 2012.

Reactions

Soldiers rescue victims and clean up

Indonesia's President Joko Widodo ordered immediate rescue measures by the BNPB, the Ministry of Social Affairs and the Indonesian Armed Forces. An emergency was declared for the Pandeglang region for two weeks and for South Lampung for one week. The BPPT research vessel Baruna Jaya was commissioned with the state agency BMKG to carry out the bathymetric exploration of the seabed around the volcano, a tsunami warning for events triggered by volcanoes.

Web links

Commons : Tsunami on Java and Sumatra 2018  - Collection of images, videos and audio files

Individual evidence

  1. ↑ a b Sutopo Purwo Nugroho Number of injured in Indonesia tsunami surges to over 14,000 , The Star Online. Asean Plus, December 31, 2018, accessed October 13, 2019.
  2. ↑ Philipp Hummel: Early warning signs of the fatal collapse of the Krakatau volcano , with images of the collapsed volcano, GFZ German Research Center for Geosciences, October 2, 2019, accessed on October 13, 2019.
  3. ^ Indonesia's Sunda Strait tsunami: What we know | News | Al Jazeera. Retrieved December 25, 2018 .
  4. ↑ Rescue workers are looking for more survivors in the pouring rain , deutschlandfunk.de, published and accessed on December 26, 2018
  5. ↑ Pacific Ring of Fire: Why Indonesia is hit by tsunamis so often . In: Spiegel Online . December 23, 2018 ( spiegel.de [accessed December 25, 2018]).
  6. ↑ tagesschau.de: After the tsunami: Why is Indonesia so endangered? Retrieved December 25, 2018 .
  7. ↑ Lisa Martin: What caused the tsunami in Indonesia and why was there no warning? In: The Guardian . December 24, 2018, ISSN  0261-3077 ( theguardian.com [accessed December 25, 2018]).
  8. ↑ Ruth Brown: This is why Indonesia's tsunami warning failed. In: New York Post. December 24, 2018, accessed December 25, 2018 .
  9. ↑ Flights rerouted as volcano alert raised . In: BBC News . December 27, 2018 ( bbc.com [accessed December 27, 2018]).
  10. ↑ Indonesia: At least 429 dead from a tsunami. Retrieved December 25, 2018 .
  11. ↑ a b c Thomas R. Walter: Complex hazard cascade culminating in the Anak Krakatau sector collapse , GFZ German Research Center for Geosciences, Earthquake and Volcano Physics Section, October 1, 2019, accessed on October 11, 2019.
  12. ↑ Die Welt: Number of dead after the tsunami rises , December 24, 2018 , accessed on December 28, 2018.
  13. ^ A b Deutsche Welle (www.dw.com): More than 400 tsunami victims recovered | DW | December 25, 2018. Retrieved December 25, 2018 (German).
  14. ↑ Indonesia tsunami death toll rises . In: BBC News . December 25, 2018 ( bbc.com [accessed December 25, 2018]).
  15. ↑ The Jakarta Post: Sunda Strait tsunami death toll hits 429, Navy discovers bodies at sea. Accessed December 25, 2018 .
  16. ↑ ABC News: Indonesia's tsunami early warning system has been broken since 2012, official says. December 25, 2018, accessed December 25, 2018 .
  17. ↑ Indonesia to investigate origins of 'silent' Sunda Strait tsunami after volcano collapse , The Jakarta Post , Marguerite Afra Sapiie, December 25, 2018.