Friday, September 2, 2016

The History of the World through a Volcano: Krakatoa


About five years ago, Kansas Dad and I saw something about Krakatoa in a documentary we were watching, so I added this book to my reading list. So of course, it was finally time to read it.
In the aftermath of Krakatoa's eruption, 165 villages were devastated, 36,417 people died, and uncountable thousands were injured--and almost all of them, villages and inhabitants, were victims not of the eruption directly but of the immense sea-waves that were propelled outward from the volcano by that last night of detonations.
In this book, Winchester weaves together a story of geology, plate tectonics, biology, Dutch colonialism, Javanese culture, Islamic militarists, art history, and, of course, Krakatoa.

The detonations were heard (and recorded in official reports) 2,968 miles away, on Rodriguez Island.
And the 2,968-mile span that separates Krakatoa and Rodriguez remains to this day the most prodigious distance recorded between the place where unamplified and electrically unenhanced natural sound was heard and the place where that sound originated.
It is not a book entirely friendly to Christianity, but the small slights were not too bothersome.

I had considered sharing this book with First Son, as a reward at the end of two years of geology. There is an excellent introduction to plate tectonics and description of the forces that account for the violent volcanoes found in the Indonesian islands.
Suddenly a Hadean nightmare is created miles beneath the subducted continental crust: Immense volumes of boiling, gaseous, white-hot magma, alive with bubbles, energy, and restless muscle, seethe in vaults and chambers of unimaginable size and temperature. The Promethean material searches ceaselessly for some weakened spot in the crust above it. Every so often it finds one, a crack, crevice, or fault, and then forces its way up into a holding chamber. Before long the accumulating pressure of the uprushing material becomes too great, and the temperature too high, and the proportion of dissolved gas becomes too large, and it explodes out into the open air in a vicious cannonade of destruction.
Later he explains specifically what happens when continental plates collide with oceanic plates. The oceanic crust, being heavily, is pushed under the continental crust, taking with it just the right amount of water. This water allows the rocks of the mantle to melt at a lower temperature, and decreases the density at the same time which opens a path for that partly melted rock to escape, which then melts even more rocks.
 Then, with the dissolved carbon dioxide and water vapor suddenly turning back into gas and frothing out of solution, the whole mass rushes up and out as a torrent of phenomenal explosivity into the unsuspecting open air: as a gigantic and classical subduction-zone volcano.
Over the last several years, I've read a number of descriptions of subduction-zone volcanoes with First Son and First Daughter. This book described them in a manner both more exciting and more clearly than anything I've read before. Unfortunately, it's surrounded by chapters and chapters of other topics which, while I found them interesting, First Son may not entirely enjoy.

After describing all the effects of 1883 eruption of Krakatoa, the author asks why such things happen. He answers with a description of earth's perfect placement in the universe for the development and support of life.
And then there are the volcanoes--just the right number, of just the right size, for our own good. The deep heat reservoir inside the earth is not so hot, for instance, as to cause ceaseless and unbearable volcanic activity on the surface. The amount of heat and thermal decay within the earth happens to be just perfect for allowing convection currents to form and to turn over and over in the earth's mantle, and for the solid continents that lie above them to slide about according to the complicated and beautiful mechanisms of plate tectonics.
I also rather wish the author had provided endnotes or footnotes, rather than a general bibliography. There were a few times I would have liked a bit more clarification or to look at another source for a fact, but they weren't identified that way.

If you want to learn about the eruption of Krakatoa, you can probably find more succinct descriptions in other books. If you want to delve deeply into the world of 1883, including extensive history of its development, in addition to a complete history of Krakatoa's emergence as a volcano eons before, this book is the one for you.

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