‘The crack of doom’

Within 20 years around the turn of the 20th century occurred two of the most devastating and, to the local populations as well as experts of the fledgling science of volcanology, most surprising eruptions of modern times.

First, on Aug. 27, 1883, Krakatoa blew up the entire 2,600-foot mountainous island upon which it sat in the Sunda Strait between the great islands of Sumatra and Java in the Indonesian archipelago. The four major explosions of that day generated tsunamis that killed more than 36,000 people and were so strong that they swept around Africa and were even, in a ripple, noted in Europe thousands of miles distant. The sound was heard more than 3,000 miles away, and barometers of air pressure showed a shock wave circled the world seven times.

Then, on May 8, 1902, Mt. Pelee on the French-owned Caribbean island of Martinique expelled a glowing cloud of incandescent gases that skipped along the top of canyons lying in the four miles between it and the city of St. Pierre, hitting the municipality broadside and killing 29,533 inhabitants, leaving just two survivors. It was the first time the scientific community became aware of the possibility of pyroclastic flows, since recognized as one of the most immediately fatal volcanic effects. The explosion at Mt. Pelee was not as violent as the one at Krakatoa, but its fatal results were nearly as severe.

These two great calamities were not related to one another, but both had certain common traits. Plate tectonics were unknown at the time, but both eruptions occurred in subduction zones, near where one great tectonic plate was diving under another. Subduction is now recognized as a primary cause of volcanic activity. Both volcanoes also had fooled humanity into thinking they were not particularly dangerous, because there had been eruptions in the centuries before of both that did not amount to much, and when the new volcanism occurred, observers were certain it would follow the earlier pattern. This lulled them into a complacency that magnified the disaster.

The volcano may blow itself apart, as Krakatoa did, and it may sink into long quiet, as both Krakatoa and Pelee have done, but they do come back. And, in 1927, just 44 years after Krakatoa blew up, a new version, Anak Krakatoa, broke the sea’s surface and began to rebuild on the same spot.

Simon Winchester has in “Krakatoa: The Day the World Exploded: August 27, 1883,”written an exhaustive and often exciting account of the Krakatoa events. In particular, it is outstanding in describing the sequence of events from 1:06 p.m., the moment of the first great explosion, on Aug. 26, 1883, to the immediate aftermath of the climactic blast of 10:02 a.m. the following day.

That moment has become known as “the crack of doom,” which, as the author declares, “is still said to be the most violent explosion ever recorded and experienced by modern man.” But is Krakatoa, as the book jacket declares, “the earth’s most dangerous volcano?” Probably not, because it lies 80 miles from Jakarta, now the capital of Indonesia, and even on the day of the events of 120 years ago, when Jakarta was Batavia, the capital of the Dutch East Indies, it did not suffer much destruction from the comparatively far away eruption.

The world’s most dangerous volcanoes, as recognized by the United Nations, are the ones like Vesuvius, near Naples, Italy, or Galeras, near Pasto, Colombia, which are within a very few miles of heavily populated cities, or Rainier, a little more distant from the Seattle-Tacoma metropolitan area, which nonetheless has the altitude to send mudflows known as lahars into cities miles away. Among the greatest number of fatalities caused by a volcano in recent years were the lahar depredations of the Nevado del Ruiz volcano in Colombia in 1985, in which 23,000 died when a canyon below the volcano was hit by a mudflow with the consistency of wet cement studded with tree parts and other debris.

The question of what is most dangerous is subject to argument, however, because tsunamis, generated by the kind of sudden displacement of seawater that occurred at Krakatoa, can travel thousands of miles at speeds of up to 500 mph and then do vast damage depending on how they come ashore. This happened, for example, at Hilo, Hawaii, in 1946. As Winchester points out, however, the narrow confines of the Sunda Strait may mean that the distant impact of tsunamis that originate there is somewhat blunted.

Along the adjacent shores of Sumatra and Java, the tsunamis were, according to the author, going only about 60 mph. Still, the run up, the distance inland the tsunamis went, was severe. And in one of the most impressive of this volume’s illustrations, a sizable gunboat is shown stranded a mile and a half inland by one of the waves. “Hunks of rusting iron remained in the jungle until the 1980s,” the author notes.

Winchester does a good job of pointing out that the waves, as frequently is the case with destructive tsunamis, came in stages and that in some instances people were killed when, thinking that the worst was over, they came down to the shore to look at the damage from the first wave only to be swept away by the second. This phenomenon also occurred in Del Norte County in Northern California in 1964, when a tsunami from the huge Alaska quake struck Crescent City, killing 12.

Winchester is at his most vivid, though, when describing the devastation that Krakatoa wrought.

“Which wave was it that killed the vast majority of those thirty-six thousand who were lost?” Winchester asks.

“Was it ‘the low range of hills rising out of the sea’ that was seen, chillingly, by that elderly Dutch pilot in Anjer at dawn? ‘The sight of those receding waters haunts me still,’ he was to write later, since for him this was the killer wave, without doubt. ‘As I clung to the palm tree ... there floated past the dead bodies of many a friend and neighbour. Only a mere handful of the population escaped. Houses and trees were completely destroyed, and scarcely a trace remains of where the once busy, thriving town originally stood....

“Or was it perhaps the wave that struck Merak at 9:00 a.m. -- the wave that drowned all but two of the town’s 2,700 inhabitants? An accountant named Pechler who somehow survived by running before it, climbing farther and farther uphill until he was beyond range, certainly would imagine this tsunami to be immeasurably vast: It destroyed stone buildings that stood on top of a hill later measured at 115 feet high....”

The author certainly enhances the attraction of this book with sections devoted to the phenomena of volcanoes in general and the plate tectonics that lies behind so many of them. Indeed, his recounting of the story of the German explorer and meteorologist Alfred Lothar Wegener, who visualized drifting continents and plate tectonics well in advance of other scientists, is a high point of his book. And he is exhaustive, as when he notes how the awful 1969 movie “Krakatoa, East of Java” was grossly misnamed, Krakatoa being west of Java.

Nonetheless, he sometimes exaggerates, as when he seeks to connect the eruption at Krakatoa with stirrings of anti-colonialism that led, decades later, and not until after the Japanese conquest during World War II, to the independence of Indonesia from the Dutch. He writes entertainingly, however, of Islam in Indonesia, a more relaxed form than can be found in more fundamentalist locales in the Middle East.

This is a major work in the fecund literature of disasters, so it is disappointing that there are not better maps of the area affected by the Krakatoa eruption. Some places mentioned frequently in the book are either not shown at all or are shown in a manner that makes them indecipherable. On the other hand, there is an outstanding map of Asia, the Indian Ocean and Australia that shows the extent of the areas where the sound of the Krakatoa eruption was heard, and there is a remarkable graph showing the pressure waves from Krakatoa’s major explosions, “measured -- until it blows off scale -- at the Batavia gasworks.”

The book’s bibliography of other volcano works unfortunately omits the outstanding 1969 account of the Pelee eruption by Gordon Thomas and Max Morgan-Witts, “The Day the World Ended.” Since Winchester portrays Krakatoa as the most dangerous volcano, he may not wish to give the reader too substantial a cross-reference to a book about one possibly even more dangerous.