Verbeek, in his report on the eruption, predicted that any new activity would manifest itself in the region which had been between Perboewatan and Danan. This prediction came true on 29 December 1927, when evidence of a submarine eruption was seen in this area (an earlier event in the same area had been reported in June 1927). A new island volcano, named Anak Krakatau or Child of Krakatoa rose above the waterline a few days later. The eruptions were initially of pumice and ash, and that island and the two islands that followed were quickly eroded away by the sea. Eventually a fourth island named Anak Krakatau broke water in August 1930, and produced lava flows faster than the waves could erode them. Of considerable interest to volcanologists, this has been the subject of extensive study.
Volcanic activity at Anak Krakatau
Anak Krakatau has grown at an average rate of five inches (13 cm) per week since the 1950s. This equates to an average growth of 6.8 metres per year. The island is still active, 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, with occasional much larger explosions.
The eruption in April 2008 saw hot gases, rocks, and lava released. Scientists monitoring the volcano have warned people to stay out of a 3 km zone around the island. There are several videos of Krakatoa uploaded onto YouTube showing recent footage of it erupting, and inside its crater filmed at the edge of the volcano rim.
On 6 May 2009 the Volcanological Survey of Indonesia raised the eruption alert status of Anak Krakatau to Level Orange.
James Reynolds posted footage to YouTube from as recently as November 1, 2010 showing some spectacular eruptions, and NASA has released satellite imagery of the recent activity.
An eruption in 2008
The islands have become a major case study of island biogeography and founder populations in an ecosystem being built from the ground up in an environment virtually cleaned.
The islands had been little studied or biologically surveyed before the 1883 catastrophe—only two pre-1883 biological collections are known: one of plant specimens and the other part of a shell collection. From descriptions and drawings made by the HMS Discovery, the flora appears to have been representative of a typical Javan tropical climax forest. The pre-1883 fauna is virtually unknown but was probably typical of the smaller islands in the area.
From a biological perspective, the Krakatau problem refers to the question of whether the islands were completely sterilized by the 1883 eruption or whether some indigenous life survived. When the first researchers reached the islands in May 1884, the only living thing they found was a spider in a crevice on the south side of Rakata. Life quickly recolonized the islands, however; Verbeek's visit in October 1884 found grass shoots already growing. The eastern side of the island has been extensively vegetated by trees and shrubs, presumably brought there as seeds washed up by ocean currents or carried in birds' droppings (or brought by natives and scientific investigators). It is, however, in a somewhat fragile position, and the vegetated area has been badly damaged by recent eruptions.
A German, Johann Handl, obtained a permit to mine pumice in October 1916. His lease of 8.7 square kilometres (3.4 sq mi) (basically the eastern half of the island), was to be for 30 years. He occupied the south slope of Rakata from 1915 to 1917, when he left due to "violation of the terms of the lease." (According to Winchester, Handl arrived in 1917 and stayed there for four years.) Handl built a house and planted a garden with "4 European families and about 30 coolies". It is his party that is believed to have inadvertently introduced the black rat to the island. Handl found unburned wood below the 1883 ash deposits while digging, and fresh water was found below 18 feet (5.5 m).