The Krakatoa Eruption ¹

Abstract

THE inquiry, instituted in consequence of a Government resolution of October 4, 1883, into tne nature, the extent, and the consequences of the volcanic eruptions of Krakatoa, has led to various remarkable results of which a short account is given here. A detailed report is in course of preparation, but will not appear for some months, as the making of numerous illustrative maps and plates will take much time. The inquiry did not extend solely to the islands of the Straits of Sunda, but also to the coast countries of the Lampong districts, Bantam and Batavia, which were partly or entirely destroyed. In the Straits of Sunda the islands of Merak, Toppershoedje, Dwars in den Weg (Thwart the Way), Seboekoe, Sebesi, Lagoendi, Krakatoa, Taboean, Prince's Island, the Monnikrotsen (the Monk's Rocks), and Meeuwen Island (Mew's Island), were visited; further, the coast-strip from Ketimbang to Kalianda, and inland as far as Kesoegihan, besides the foot of the Radja Bassa; the coast of Hoeroen to Telok Betong, and the environs of the capital; the southern part of Semangka Bay (the northern part was inaccessible through pumice-stone), the kampoengs Tampang and Blimbing, near the Vlakken Hoek, Java's First Point (Java Head), and the coasts of Tjiringin and Anjer to Merak. The voyage, which lasted seventeen days, was made by the hopperbarge (small steamer) Kediri, commander 't Hoen, given for the inquiry by the temporary chief of the Batayian Harbour Works. About the causes of eruptions there is usually not much to be said, yet in this case something has been ascertained. Krakatoa, namely, lies with a few other volcanoes on a rent or fissure in the crust of the earth which runs across the Straits of Sunda, and of which I indicated the probable existence for the first time three years ago. Along such a fissure little shiftings of the earth's crust are possible, by which a pressure is exercised upon the molten substances below the crust. It is also possible that along such a rent—however tightly closed by the neighbouring stone-layers—the water may more easily than elsewhere flow to the regions under the earth. If this water comes in contact with the molten substances, steam at high temperature and high pressure is formed, and this steam may be considered as the chief motor of most, if not all, volcanic eruptions.