10 of History's Deadliest Volcanoes That Changed the World Forever
10 of History’s Deadliest Volcanoes That Changed the World Forever

10 of History’s Deadliest Volcanoes That Changed the World Forever

Khalid Elhassan - January 4, 2018

10 of History’s Deadliest Volcanoes That Changed the World Forever
A glowing lava dome, which formed during a 2007 Mount Kelud eruption. Natural Disasters in Indonesia

Mount Kelud Erupted Over 30 Times in the Past Millennium

Mount Kelud is one of the most active volcanoes on the island of Java, in today’s Indonesia. In the past millennium, it erupted more than 30 times. In just the 20th century, it went off four times, and its latest eruption occurred as recently as 2014. Throughout most of its history, Kelud had a massive crater, which filled with rainwater to form a beautiful lake. The lake was an attractive vacation destination, but during eruptions, the lake’s waters frequently led to devastating mud flows, or lahars. In 2007, seeping lava piled into a big mound at the center of the crater, which displaced most of the lake’s water.

Kelud’s volcano is one of the most dangerous, not only in Java, but in the entire world. Not because of massive eruptions – Kelud’s explosions are not as energetic as some historically powerful eruptions, such as Tambora or Krakatoa – but because of how often it goes off. The danger of Kelud’s frequent eruptions is made even worse by its tendency to produce deadly mud flows, because of the presence of massive amounts of water in the volcano’s crater. In 1586, an eruption emptied Kelud’s crater lake, resulting in devastating lahars, or mud flows. By the time things quieted down, about 10,000 people had been killed by the eruption and the ensuing lahars.

Mount Kelud behaved itself without major eruptions and significant devastation for over three centuries, during which the volcano’s crater refilled with water and turned into a crater lake. That period of relative peace ended on May 19th, 1919, when Kelud exploded yet once again, in another devastating eruption. An estimated 38 million cubic meters of boiling water and steam blew up from Kelud’s crater lake, and caused massive flows of hot mud, or lahars. The mud flow travelled for about 30 miles, destroying about 100 villages in its path. By the time it stopped, an estimated 5100 people had been killed.

The colonial government of the Dutch East Indies responded by creating a volcanological authorities to study and warn about future eruptions. It also launched an ambitious engineering project to avert future devastation. The authorities created a drainage system for Mount Kelud’s crater lake, to manage the hazards and potential future mud flows, in case of another eruption. Drainage tunnels were dug, which reduced the crater lake’s water level by about 150 feet, and they proved highly effective. The next time Mount Kelud erupted, which happened in 1951, there was too little water in the crater lake to form massive flood flows, and thus another major Mount Kelud disaster was averted.

The drainage tunnels were destroyed in that 1951 eruption, however, and were not immediately rebuilt. When Kelud erupted again, in 1966, the crater lake had refilled, and contained over 50 million cubic meters of water. In the resultant lahars, over 200 people were killed by the mud flows. The Indonesian authorities responded by digging a new, and deeper tunnel, which reduced the crater lake’s volume to only 1 million cubic meters of water.

10 of History’s Deadliest Volcanoes That Changed the World Forever
‘The Last Day of Pompeii’, but Karl Brulov. Google Art Project

The 79 AD Vesuvius Eruption Killed Tens of Thousands – and Contributed to Our Knowledge of Roman History

The Vesuvius eruption of August 24th, 79 AD, was one of antiquity’s most famous volcanic eruptions, and one of Europe’s most powerful volcanic explosions. Vesuvius went off with a force 100,000 times greater than that of the Hiroshima and Nagasaki atomic bombs. The eruption tossed deadly debris, mixed with a cloud of poisonous gasses, over 20 miles up into the sky. As it spewed gasses into the air, lava and hot pumice poured out of the volcano’s mouth at a rate of 1.5 million tons per second. The glowing hot material raced down Vesuvius’ side to devastate the surrounding region. Nearby towns were destroyed, of which Pompeii and Herculaneum are the best known.

Pliny the Younger, a Roman author and magistrate, was 15 miles away at Cape Misenum. He was visiting his uncle, Pliny the Elder – a Roman admiral who would lose his life during rescue efforts after the eruption. History is deeply indebted to Pliny’s detailed description of the events he saw, and those told him by first hand witnesses. His work is the best written and most thorough narrative of the disaster.

Vesuvius had been giving off tremors for days, but they were not unusual. Then, around noon on August 24th, a cloud appeared atop the volcano. About an hour later, Vesuvius erupted, and ash began to fall on Pompeii, 6 miles away. By 2PM, pumice started falling with the ash, and by 5PM sunlight had been completely blocked. Around that time, roofs in Pompeii began collapsing under the accumulating weight of ash and pumice. Panicked townspeople rushed to the harbor, seeking any ship that would take them away.

By midnight, Vesuvius was spewing a hot deadly column over 20 miles up into the air. Simultaneously, lava flowed down its side in six major surges, as the volcano vomited molten rock in a rapid flow that incinerated all that it encountered. The lava did not reach Pompeii or Herculaneum, but it sent heat waves of more than 550 degrees Fahrenheit into those towns. That turned them into ovens, and killed any who had not yet escaped or had not yet already suffocated from the fine ash. When Pompeii and Herculaneum were unearthed centuries later, about 1500 bodies were found in them. Those 1500 bodies were recovered from just one small area of the region impacted by the volcano’s eruption. Extrapolating to the surrounding regions, total casualties are estimated to have been in the tens of thousands.

Pompeii and Herculaneum, whose populations at the time numbered about 20,000, were buried under up to 20 feet of volcanic ash and pumice. While tragic and terrifying, the ash did a remarkably great job of preserving those towns. As a result, future historians got an unrivaled snapshot of 1st century AD Roman architecture, city planning, urban infrastructure, and town life in general.

10 of History’s Deadliest Volcanoes That Changed the World Forever
Ruins of the Minoan civilization, whose collapse was triggered by the Thera eruption. Science News

The Thera Eruption Shaped History and Led to Today’s World

One of the most powerful eruptions in recorded history occurred in Thera, today’s Greek island of Santorini, sometime between 1642 and 1540 BC. It was four times as powerful as the gigantic Krakatoa explosion of 1883. It sundered the island of Thera, and wiped out the flourishing Minoan settlement of nearby Arkotiri and surrounding islands. That gave rise to the legend of the vanished civilization of Atlantis, which was doomed by a natural catastrophe and swallowed by the sea. Beyond legend, however, Thera’s eruption had the greatest impact of any volcanic eruption on human history. The consequences stretched far beyond its own era, with knock on effects and a chain of causation leading directly to the world in which we live today.

In addition to the immediate devastation of Thera and surrounding islands, the eruption produced powerful tsunamis that devastated Crete. That greatly weakened Crete’s Minoan civilization, led to its decline, and put it on the path to extinction. The Minoans were the Mediterranean’s greatest naval power, as well as the dominant power of the Aegean, including what became Greece and the Greek world. A trading power, the Minoans were oriented towards Egypt and the Eastern Mediterranean, and were strongly influenced by those civilizations. While the Minoans flourished, the Aegean world in their thrall was by necessity oriented in the same direction, and strongly influenced by the Egyptian and eastern civilizations as well.

Thera’s eruption weakened Crete and the Minoans, creating a power vacuum in the Aegean. It was filled by the emerging Mycenaeans, in mainland Greece. The Myceneans went on to conquer Crete and destroy the Minoans, and became the dominant power of the Aegean. However, unlike the Minoans, the Mycenaeans’ energies were not focused on trade with Egypt and the Levant. Instead, they focused on colonizing the Aegean, the western coast of Asia Minor, the Black Sea coast, and the western Mediterranean.

That change of orientation significantly reduced Egyptian and eastern influences upon the Greeks. Thus, when the Greek world flourished centuries later, long after the Mycenaeans had themselves disappeared, it would do so as a civilization and culture distinct from those of Egypt and the eastern Mediterranean, not an extension and outpost of those civilizations. And since western civilization is founded upon that of the ancient Greeks, an argument could be made that today’s western civilization and its impact on the modern world would not exist but for the Thera eruption.