Krakatoa

Long ago, a giant eruption broke up the old island.

Later, a new volcano grew out of the sea. It is called Anak Krakatau.

Krakatau has erupted again and again for thousands of years: geologists count 57 eruptive periods in the last 11,700 years. In 1883, an enormous eruption destroyed the island.

About fifty years later, a new island pushed up out of the sea in the same place. It is called Anak Krakatau, 'child of Krakatau'.

According to NASA's Earth Observatory, geologists recognize 57 eruptive periods at Krakatau since the beginning of the Holocene. The explosive eruption of 1883, one of the most destructive volcanic events in modern history, obliterated the island; about fifty years later Anak Krakatau emerged from the sea in its place.

UNESCO describes the islands as a showcase of ongoing geological processes since 1883, where volcanic activity, the surrounding sea and the succession of vegetation together form the landscape.

Anak Krakatau still erupts often.

Sometimes it sends up clouds of ash and steam.

Anak Krakatau is one of the volcanoes NASA watched closely with its Earth Observing-1 satellite. In the summer and fall of 2010, it erupted hundreds of times a day.

In December 2018, during a strong eruption, part of the volcano's southwest side collapsed, and NASA's satellite images later showed that its crater area had become a lake. From May 2021, it had many small eruptions, and in late November 2023 its ash plumes rose up to 1,000 meters above the vent.

In 2010, Krakatau erupted hundreds of times a day through the summer and fall, and it was one of 100 volcanoes that NASA's Earth Observing-1 satellite monitored automatically through the Volcano SensorWeb. On 22 December 2018 it erupted and partially collapsed; NASA's ASTER instrument showed on 13 January 2019 that the crater area had closed to become a lake and that ash falls had destroyed the island's forest.

The eruptive period that began in May 2021 brought frequent but generally mild Strombolian blasts, with material lofted a few hundred meters and small lava flows occasionally reaching the sea; from 26 November 2023, Indonesia's Center for Volcanology and Geological Hazard Mitigation reported stronger explosions with plumes up to 1,000 m.

After eruptions, plants slowly grow back on the islands.

In this photo, green trees grow beside the dark volcano.

UNESCO says the Krakatau islands show how plants come back step by step after volcanic eruptions. The island, the sea around it, its plants and its eruptions together make a landscape UNESCO calls one of exceptional beauty.

The islands are part of Ujung Kulon National Park, a World Heritage site that also protects the last important home of the critically endangered Javan rhinoceros on nearby Java.

UNESCO's criterion (vii) for Ujung Kulon highlights the combination of Krakatau's physical features with the surrounding sea, natural vegetation, the succession of vegetation and volcanic activity. The World Heritage property (78,525 ha, inscribed 1991 under criteria vii and x) also includes the Ujung Kulon peninsula, the best and most extensive lowland forest remaining on Java, and is the last and most important natural habitat of the critically endangered Javan rhinoceros (Rhinoceros sondaicus).

After the December 2018 eruption, NASA's satellite images showed the forest on Anak Krakatau destroyed by ash falls.

An active volcano can be dangerous. Stay far away when it erupts.

Always do what the volcano experts say.

When Anak Krakatau grew more restless in late 2023, Indonesia's volcano center warned people to stay at least 5 kilometers from the crater. Volcano experts set these safe distances, and visitors should always follow them.

Ash from the volcano can also be a danger to airplanes, so an ash advisory center in Darwin, Australia, sends warnings to pilots.

During the heightened unrest of late 2023, Indonesia's Center for Volcanology and Geological Hazard Mitigation warned the public to stay at least 5 km (3 miles) from the crater, and the Volcanic Ash Advisory Center in Darwin, Australia, issued multiple warnings to aviation about ash in the area.

PlayOwl's own advice: before any visit near an active volcano, check the current official alert level and exclusion zone, and never go closer than the authorities allow.