Rakata - The 1883 Eruption

The 1883 Eruption

Rakata seems to have played a comparatively minor role in the 1883 eruption of Krakatoa. Some reports seem to indicate it started erupting ("venting") in late July, compared to Perboewatan starting in May and Danan in June. (Furneaux mentions an unsourced report that the Peak had collapsed sometime in July.) 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. The map made by Capt. Ferzaneer from his visit on August 11 shows no eruptive "foci" from Rakata or its slopes (although there are several from the southern part of Danan), but he was not able to investigate the southern or western parts of the island due to the ash cloud blowing in that direction.

In his portrayal of the catastrophe, Rogier Verbeek depicts that Rakata's northern half was destroyed, along with the central part of the island, during the largest explosion, which occurred at 10:02 am on 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.

In surveys made a few months after the catastrophe, Rakata's height is given as 830 m, compared to 820 m before, however this may be due to inaccuracy of the earlier surveys. Verbeek reports that the cleavage was approximately at the old summit. The remnant 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.

Due to the severity of the eruption, leaving very little flora and fauna alive, Rakata has been used as a modern study on biological island colonization.