Anak Krakatau is one of the world's most famous volcanoes.
In 1883, the Krakatau (Krakatoa) volcano erupted in a series of four explosions that destroyed the surrounding island and killed more than 30,000 people. The eruption wreaked havoc on global weather patterns for the next five years.
Some 50 years later, the island of Anak Krakatau (Anak Krakatoa) emerged from the site of Krakatoa's fiery death.
Anak Krakatau — located east of Jakarta, Indonesia — has been active since 1927 and erupted nearly every year, according to a volcanologist-run website called Volcano Discovery, which catalogs information about volcanoes.
Anak Krakatau grew steadily each year until the partial collapse in December 2018. This is what it looked like in November 2017.
Anak Krakatau had been growing taller by an average of about 5 meters (16 feet) per year, according to EarthSky.
Satellite imagery shows what the volcano looked like after the collapse — it's as if a giant thumb pushed down on Anak Krakatau.
This image is more zoomed out than the previous one, so it also includes the islands that surround the volcano. But it's clear that, at the top of Anak Krakatau, there's now a gaping hole. The trees and wildlife that once lived there are also gone.
After the collapse, Anak Krakatau shrank to just a quarter of its original height.
It shrank from a height of 1,108 feet to 361 feet. The volcano lost two-thirds (some 100 million cubic meters) of its volume.
Anak Krakatau spewed so much ash into the air that planes had to be re-routed around the Sunda Strait area.
Anak Krakatau is still active; the collapse didn't stop its volcanic activity.
Subsequent eruptions will help to rebuild the volcano, forming a new island.
A period of high-intensity volcanic activity followed the collapse during the final weeks of December, which means the island is already rebuilding itself, according to Michigan Tech volcanologist Simon Carn.
Indonesia needs to be prepared for future tsunamis, experts say.
The December 22 tsunami came without warning.
Richard Teeuw of the University of Portsmouth told The Guardian that “the likelihood of further tsunamis in the Sunda Strait will remain high while Anak Krakatau volcano is going through its current active phase, because that might trigger further submarine landslides.”
