'Rakata' (2667 ft) is a
stratovolcano on the
Indonesian island of
Krakatoa (Indonesian: Krakatau) in the
Sunda Strait between the islands of
Sumatra and
Java. It is the largest, and southernmost, of three volcanoes that formed the
island Krakatoa (the others being
Danan and
Perboewatan) and the only one not totally destroyed in the eruption of
1883. Rakata did lose its northern half in that eruption, leaving just its southern half. The exposed cliff is quite striking visually, partially of a large exposed
dike in the middle.
Name
For the origin of the name, see
Krakatau
Because the words 'Rakata' and 'Krakatau' are the same in Indonesian, both names are used interchangeably; leading to confusion in languages which distinguish between the two words. In geological usage, Krakatau is the island and Rakata is the main volcanic cone on the island. But Krakatau is also used for the volcanic edifice as a whole, including all four islands (
Krakatau,
Anak Krakatau,
Verlaten and
Lang).
Eruptions
There are no dated reports of eruptions from Rakata until the 1883
catastrophe, although tentative datings have been made from dating ash deposits left.
1883
Rakata seems to have played a comparatively minor role in the eruption of 1883; reports seem to indicate it started erupting ('steaming') in late July, compared to Perboewatan starting in May and Danan in June. However, it is more proper to realize that all of the eruptive centers of Krakatau have a common source and that we are talking about particular cones of the same volcano, rather than separate volcanoes.
In his reconstruction of the catastrophe,
R. D. M. Verbeek has Rakata's northern half destroyed along with the central part of the island in the largest explosion, at 10:02 am, August 27. Verbeek surmised that unlike Danan and Perboewatan, Rakata was not directly above the magma chamber, being connected only by a fissure which lay along the cleavage line of the caldera. However, examining the cliff from the air indicates two arcs, the second of which seems to be due to later (post-1883) landslides of unstable cliff material.
The remmant of Rakata grew rather considerably in area due to falling pumice. However, most of the increased area (largely to the west and southeast) was washed away within several years by wave action.
Later Activity
Subsequent activity of Krakatoa seems to be limited to the area that had been between Danan and Perboewatan, where Anak Krakatoa has arisen, starting in 1927. Rakata cone seems to be extinct.
References
Furneaux, Rupert (1964) Krakatoa
See also
★
List of volcanoes in Indonesia