Saturday, September 06, 2008

Historic volcano eruption

It was 125 years ago this week that one of the greatest natural disasters in the recorded history of earth occurred. The events of Aug. 26-27, 1883, were felt planet-wide for years following.To begin the account, though, we must back up a few months to the early morning of May 20, 1883. It was on that day that the captain of a German warship in the Indian Ocean reported seeing a cloud of dust and ash rising some 36,000 feet above the small Indonesian island of Krakatau.

During the next two months, numerous vessels, both commercial and chartered sightseeing ships, reported similar occurrences.And, it wasn’t just clouds. Along with the visual display came deep rumblings and explosive noises.That such geologic activity would be going on was not surprising, really. There are over 130 active volcanoes in the Indonesian island chain - the majority along the crest of the chain’s two largest islands, Java and Sumatra.

Krakatau lay in the Sunda Straits, a passage between those two islands.The island of Krakatau, as it existed then, was composed of three volcanoes run together.But that was to change.Just before 1 p.m. on Sunday, Aug. 26, 1883, a deafening, explosive blast occurred, accompanied by a roiling cloud of dense, black debris that burst from the island in a cloud that quickly rose over 80,000 feet into the air - nearly three times the height of an average thunderstorm.

Over the next few hours, that cloud would continue to rise until it reached a height of nearly 120,000 feet - or over 22 miles - into the upper stratosphere.As the day wore on, the intensity of the eruptions increased, and the villagers living in costal communities of nearby western Sumatra and Java, and other nearby islands, were battered with huge waves caused by lava flows.But that was just a taste of what was still to come.

Beginning at about 5:30 a.m. on Monday, Aug. 27, 1883, a series of at least four huge blasts preceded one unimaginable one that ripped Krakatau apart. That explosion was so massive it was heard as far away as Sri Lanka and Australia, a distance of some 3,000 miles.The force of that massive explosion plunged nearly two thirds of Krakatau - almost nine square miles in area - from a height of 1,500 feet above the level of the sea to a depth of over 800 feet beneath the waves, in an undersea crater nearly four miles across.

That blast generated massive tidal waves over 130 feet tall that inundated coastlines all along the Sunda Straits, stripping away all vegetation and washing thousands of people out to sea.

Eyewitness accounts recorded the destruction. From a passenger on board a ship that was lucky enough to survive the onslaught of the wave due to the heroic efforts of its captain, came this stark assessment: “There, where an instant before had lain the town of Telok Betong, nothing remained but the open sea.”Ash and debris from the eruption fell as far as 1,500 miles away from what once was Krakatau.

Small particles remained suspended in the upper atmosphere for years, causing spectacular sunsets and exotic colors in the sky, as well as halos around the sun and moon.Sulfur dioxide from the eruption combined with water vapor in the upper stratosphere to form acid droplets that formed a shield capable of reflecting enough sunlight to cause global temperatures to drop by several degrees.No one knows how many lost their lives in that eruption, but two weeks afterward, one traveler described what he saw this way: “Thousands of corpses of human beings and also the carcasses of animals still await burial ...

They lie in knots and entangled masses, impossible to unravel.”In 1927, a small volcano rose above the waves where Krakatau once was. It was named Anak Krakatau, or Child of Krakatoa. Since its formation, Anak Krakatau had had nearly yearly eruptions, but fortunately, none on the scale of that blast of 125 years ago this week.

Brian K. Finnicum is editor of The News Observer. He can be reached at 706-632-2019 or by e-mail at brian@thenewsobserver.com .

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