The eruption of the tiny Indonesian island of Krakatoa stands even today as a milestone. It was, says science writer Simon Winchester, the “greatest detonation, the loudest sound, the most devastating volcanic event in modern recorded human history.” The eruption may ultimately have been responsible for the deaths of tens of millions of people and resulted in climatic, historical, and social consequences so far-reaching that many are still felt today. The island’s very name has become a byword for catastrophe.
Winchester traces Europeans’ first knowledge of Krakatoa’s nature to a secondhand report from Johan Vilhelm Vogel of the Dutch East India Company. While traveling on the ship de Zijp in 1681, the official witnessed a “burned and barren” island in place of the once-verdant “Craketovv,” as he spelled it, that lay in the Sunda Strait between the much larger islands of Java and Sumatra. In May of the preceding year, the ship’s captain told him, the crew had experienced an earthquake and an enormous crash, had smelled sulfur, and had scooped up pumicelike stones floating on the surface of the sea—all in the vicinity of Krakatoa.
More important to Winchester’s story is British naturalist and writer Alfred Russel Wallace, who identified a kind of natural division, still known as Wallace’s Line, running from northeast to southwest through the seventeen thousand islands of Indonesia. Having spent many years in the region collecting and preserving zoological specimens, Wallace had come to realize that animal life found west of this line differed dramatically from that found east of it. West of the line were apes and monkeys, tigers and elephants, and many other animals at least moderately familiar to Wallace and his fellow Europeans. None of these were found east of the line, where instead there dwelt kangaroos and wombats and the even stranger duck-billed platypus. Perhaps most remarkable of all, some of the islands thus divided are only a few miles apart.
Without knowing it, Wallace had stumbled upon evidence of what is recognized today as a collision between vast tectonic plates, an event that, however slow, can have catastrophic consequences—as the eruption of Krakatoa illustrates. Winchester introduces another scientist, Alfred Lothar Wegener, who was the first to put forward the theory of continental drift, which posits that over the ages the great landmasses have migrated, or drifted, to their present positions. Rejected during his lifetime as a crank, Wegener is recognized today as a key figure in the development of modern geology.
The zones where tectonic plates meet are known as subduction zones, and in Indonesia, where the Indo-Australian and Eurasian plates meet, the tracks of the zones largely follow Wallace’s Line. Although Krakatoa is west of that line, it lies between one of the world’s most volcanically unstable pairs of islands, Java and Sumatra.
Among Winchester’s most intriguing pages are those he devotes to Ancient Krakatoa, a much larger island that scientists suggest existed some sixty thousand years ago. The volcano may have exploded as many as eleven times since then, says Winchester. Possible dates for “recent” eruptions include the years 416, 535, and 1680, and Winchester discusses each possibility in turn. A Dutch print in the book may well represent the 1680 eruption, although the evidence is tantalizing rather than conclusive.
Like a practiced writer of suspense, Winchester paces his story. He explores many byways and indulges in many asides, but these are preludes to his treatment of the great eruption of 1883. In a chapter titled “The Unchaining of the Gates of Hell” he records the first ominous tremors that would lead to the cataclysm. On May 10 a lighthouse keeper on Java noted that his structure “suddenly seemed to shift on its foundations. The sea outside whitened, appeared to freeze briefly . . . , became uncannily smooth like a mirror, shivered slightly, and then returned to its usual sickly...
(The entire section is 1641 words.)