Krakatoa: the Eruption that Shook the Earth to its Core

krakatoaThe eruption of Krakatau island in August 1883 was THE most deadly volcanic explosion in modern history. More than 36,000 people in over 300 coastal villages perished in the most ghastly ways imaginable. Many died of burns and suffocation from the super-heated pyroclastic blasts that blew the peaks off the island. Thousands more drowned from the 4 tsunamis that followed when the volcano collapsed into the sea.

The Indonesian island of Krakatau (Krakatoa) sits in the narrow Sunda Straits between Sumatra to the north and Java to the south. Before the 1883 eruption, the uninhabited tropical island had no less than 3 volcanic peaks: Perboewatan the most active, Danan in the middle, and Rakata the tallest. Krakatau and its two nearby islands were remnants of a previous eruption that left an undersea caldera simmering beneath the sea.

Our story however starts 3 months before. Early in the morning of 20 May 1883, an 11 kilometer high cloud of ash and pumice plumed above the silent Krakatau, the first eruption in over 2 centuries. Over the next 2 months, it would deliver similar spectacles, all of which brought churning clouds of incandescent ash to the hot tropical skies. People living in the nearby Dutch colonies on Java & Sumatra actually held parties celebrating nature’s spectacular fireworks. These awe-inspiring displays were a prelude of far worse things to come.

Celebrations would come to a tragic halt in late August.

At 12:53 pm on Sunday 26 August, the eruption’s first major blast sent a cloud of hot gas, ash and pumice 24 km into the afternoon sky! Debris from the smaller summer eruptions plugged the neck of the cone, allowing pressure to build in the magma chamber. This initial blast generated an eardrum-rupturing fusillade accompanied by a black churning cloud that quickly turned daytime into night. Villagers covered their mouths and fled into houses and huts to escape the raining storm of ash and pumice. This was but the opening salvo to a climactic eruption the next day.

The first of 4 stupendous eruptions began at 5:30 am Monday morning, climaxing in a colossal blast at 10am that literally blew Krakatau island apart. The noise was heard over 4600 km away, throughout the Indian Ocean – from Sri Lanka in the west, to Australia in the east. TWO-THIRDS of the island collapsed beneath the sea, into the now vacated magma chamber. 23 square kilometers of the island, including all of Perboewatan and Danan, fell into a caldera 6 kilometers across.

The explosive force was estimated at 200 megatons of TNT. By comparison, the 1945 atomic bomb that devastated Hiroshima was a mere 20 kilotons.. When the northern half of the island dropped beneath the ocean, it generating a series of devastating pyroclastic ash flows. Black clouds blasted across the waters of the Sundra Straits at speeds up 100 kph. Pyroclastic flows struck southern Sumatra and western Java with a vengeance, hot enough to incinerate entire villages. 1000 alone died in the Sumatra town of Ketimbang, 40 kilometers away. Dutch Controller Willem Beyerinck contemplated killing his wife and children to spare them the hidieous death of suffocation by hot ash.

Still Krakatau was not finished as the worst was yet to come.

The collapse of the island into the sea generated immense tsunamis that ravaged the coastlines. Thousands that survived burns from the hot ash were now killed by a tidal wave 120 feet tall. Completely unprepared, survivors scrambled fanatically for higher ground. Most of the closest islands, after first being overwhelmed by the pyroclastic flow, were totally submerged, stripping away all vegetation, washing people out to sea, and removing all signs of human occupation.

The steamship Berouw was carried a mile inland on Sumatra and beached in a river bed; all 28 crew members died. The Loudon was anchored in Lampong Bay, near the village of Telok Betong when the first wave approached. The ship’s captain Lindemann turned its bow to face the tsunami and the ship somehow managed to ride over the steep crest. The wave continued past them and the shocked crew watched as the waters consumed the town until nothing remained but the open sea.

All told, the explosions hurled 45 cubic kilometers of debris into the atmosphere darkening skies 440 km away. Dawn did not return over Sumatra and Java for three days. The shock wave was recorded around the globe and circled the planet seven times. Within 13 days, a layer of volcanic gas had circled the Earth, making for spectacular sunsets over Europe and the USA. Average GLOBAL temperatures were up to 1.2 degrees COOLER for the next FIVE years!

Nobody knows how many souls were washed out to sea by the tsunamis. For months, the Sunda Straits were clogged with so much debris that it looked like solid ground, peppered with decaying corpses. Relief ships were unable to reach coastal communities like Telok Betong for weeks.  The official number of dead, calculated by the Dutch East India Company was 36,417, 90 percent of which were killed by the tsunamis. Truer estimates including native populations are over 100,000 dead.

In 1927, fishermen were shocked when a column of steam began spewing from the old collapsed caldera. Krakatau had awakened after 44 years of slumber. Within weeks, a new cone appeared above sea level and within a year it grew into a small island, named Anak Krakatau, Child of Krakatau. The new peak continues to periodically erupt mildly to this day and grows on average 7 meters a year…

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