Mount Kelut is one of the most active volcanoes on the island of Java, in today’s Indonesia. During 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, Kelut 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.
Mount Kelut is one of the most dangerous volcanoes, 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.
The danger is caused by just how often the restless volcano keeps going off. The danger of Kelut’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 Mount Kelut’s crater lake, resulting in devastating lahars, or mud flows. By the time things quieted down, about 10,000 people had been killed. Kelut then 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 Kelut exploded yet once again, in another devastating eruption. An estimated 38 million cubic meters of boiling water and steam blew up from Kelut’s crater lake, and caused massive flows of hot mud, or lahars. The mud traveled 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 authority 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 Kelut’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 Kelut erupted, which happened in 1951, there was too little water in the crater lake to form massive flood flows, thus averting what would have been another Kelut disaster.
The drainage tunnels were destroyed in that 1951 eruption, however, and were not immediately rebuilt. When Kelut 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.
22. The “Minor” Eruption That Killed Tens of Thousands
Colombia’s Nevado del Ruiz, located about 75 miles northwest of Bogota, is a typical stratovolcano. Those are made of multiple layers, or strata, of hardened lava, pumice (volcanic debris), tephra (dust), and ash. What is atypical about Nevado del Ruiz is that it is located by a river valley, which makes its eruptions produce flows known as “lahars”. Those are mud flows made of a slurry of volcanic debris, rocks, and water.
The lahar flows are particularly powerful in Nevado del Rio’s case because it is located high up in the Andes, and its top is covered with a glacier. That is, a lot of frozen water just waiting to come down in an eruption as an avalanche and flow of snow, melted water, and debris. On November 13th, 1985, after lying dormant for seven decades, Nevado del Ruiz awoke from its slumber and became active. It was a minor eruption, far as volcanoes go, but it produced a massive and massively devastating lahar. Tens of thousands died in the ensuing disaster.
As lava erupted from Nevado del Ruiz, it melted the mountain’s glaciers, turning them into torrents of water. The result was four huge lahars of mudslides, landslides, and volcanic debris, racing down the mountainside at 30 miles an hour, and picking up speed as they reached and were channeled into mountain gullies.
The mud and debris flow struck nearby settlements, causing particular devastation in the town of Armero. There, about 20,000 of the town’s 29,000 population were killed in what came to be known as the Armero tragedy. Thousands more died in nearby towns and villages. The haunting images of one victim, in particular, 13-year-old Omayara Sanchez and the fight to save her life, circulated around the world and was televised live. She was trapped in the mud and debris for days as rescuers frantically tried to free her, before she died of exposure on live TV.
The Nevado del Ruiz Eruption killed about 25,000 people. That made it the 20th century’s second deadliest volcanic eruption, exceeded only by that of Mount Pelee. Sadly, the massive casualties could have easily been avoided: volcanologists had detected clear signs of an impending eruption two months before it happened, and warned the authorities of the impending disaster.
The location of Nevado del Ruiz by a river valley made the risk of lahars obvious. That, coupled with the glaciers atop the volcano which would supercharge such lahars in case of an eruption, made the dangers to Armero and its surroundings even clearer. Volcanologists and seismologists from multiple organizations warned the Colombian government to evacuate Armero, but were ignored.
Lisbon was celebrating All Saints Day on the morning of November 1st, 1755, when the festivities were cut short, just as they began, by a natural disaster. At the time, the Portuguese capitol was one of Europe’s wealthiest cities and busiest seaports. It was almost totally demolished by a powerful earthquake, with a magnitude of about a 9.0 on the Richter Scale. The shocks were felt as far away as Finland, North Africa, and the Caribbean.
Striking around 9:40 AM, the Lisbon Earthquake caused fissures nearly 20 feet deep to open in the city’s streets. Because of the religious festival, a significant percentage of the population were gathered in churches and cathedrals when the tremors began. Thousands were crushed to death as the houses of worship collapsed atop them. As the tremors subsided, another danger arose when fires erupted around the city, first individually, then joining together until most of Lisbon was a giant inferno.
The shaken and terrified survivors of the Lisbon Earthquake sought to escape the conflagration and collapsing buildings by rushing toward the harbor district. There, the large open squares of the royal palace promised safety from both flames and falling debris. Once they got there, the good people of Lisbon were further alarmed when they encountered the incongruous sight: a harbor without water, with ships resting on a dried seabed.
Gathering in the drying silt of the harbor’s bottom, they were led by priests in fervent prayers. They begged God’s mercy and forgiveness of whatever sins had occasioned such divine wrath. Many were still praying and beseeching God’s mercy in the harbor when the sea returned with a vengeance in the form of a tsunami, with a wall of water 40 feet high, and drowned them.
The Lisbon Earthquake killed about 60,000 people in the city. Total deaths in the region as a whole are estimated to have been around 100,000 or more, plus many more injured. The calamity occurred as the Enlightenment was getting into full swing, and inspired significant philosophical discourse and exchanges that furthered the development of theodicy, or the question of how a just and good God could allow what happened in Lisbon to take place.
The thorniest theodicy question was why God had sent an earthquake to crush His worshipers by the thousands in cathedrals and churches as they gathered in prayer to celebrate All Saints Day and glorify His name. The question was compounded and made thornier yet by His subsequent sending of a tsunami to drown the survivors who had been praying for His mercy in Lisbon’s harbor.
Mount Vesuvius’ eruption around noon on August 24th, 79 AD, was antiquity’s most famous disaster, and one of Europe’s most powerful volcanic explosions. Vesuvius blew its top with a force 100,000 times greater than that of the Hiroshima and Nagasaki atomic bombs, and the eruption tossed deadly debris mixed with a cloud of poisonous gasses over 20 miles up into the air. 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. It raced down Vesuvius’ side to devastate the surrounding region and destroy nearby towns, of which Pompeii and Herculaneum are the best known.
Pliny the Younger, a Roman author and magistrate, was 15 miles away at Cape Misenum, visiting his uncle, Pliny the Elder – a Roman admiral who would lose his life during rescue efforts. History is deeply indebted to Pliny’s detailed description of the events he saw and those told him by first-hand witnesses, which provide the best written and most thorough narrative of the event.
Mount Vesuvius had experienced tremors for days in August of 79 AD, but they were not unusual. Then, around noon on August 24th, a cloud appeared atop Vesuvius. About an hour later, the volcano erupted and ash began to fall on Pompeii, 6 miles away. By 2 PM, pumice, or volcanic debris, began to fall with the ash. At 5 PM, sunlight had been completely blocked and 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, the volcano was spewing a hot deadly column over 20 miles up into the air. Simultaneously, lava flowed down its side in six major surges, as Vesuvius 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, turning them into ovens and killing any who had not yet escaped or had not already suffocated from the fine ash.
14. A Calamity for Contemporaries, a Blessing for Historians
About 1500 bodies were found in Pompeii and Herculaneum when they were unearthed centuries later. They were recovered from but a small area that was impacted by the volcano’s eruption, and extrapolating to the surrounding regions, total casualties are estimated to have been in the tens of thousands.
The towns of Pompeii and Herculaneum, whose populations at the time numbered about 20,000, were buried beneath up to 20 feet of volcanic ash and pumice. Tragic and terrifying as that was, the ash deposits did a remarkably effective job of preserving those towns nearly entire. That afforded future historians and scholars an unrivaled snapshot of 1st century AD Roman architecture, city planning, urban infrastructure, and town life in general.
Few cities have been as unlucky as Coringa, India. Until 1839, it was a bustling Bay of Bengal port city, near the mouth of the Godavari River on India’s east coast. It had a population numbering in the hundreds of thousands, and a harbor that hosted thousands of ships annually, busily loading and unloading goods and produce.
Today, Coringa is a tiny village near the coast, of no distinction or note, and with a population of no more than a few thousand. The drastic decline in fortunes was caused by a pair of devastating cyclones, one in 1789, and an even more destructive one fifty years later, in 1839.
After centuries of prosperity, Coringa’s fortunes took a hit in 1789. In December of that, a storm that came to be called The Great Coringa Cyclone developed in the Bay of Bengal – fairly late in the cyclone season. It produced severe storm-tide conditions, and witnesses described a succession of three giant waves striking Coringa. The first storm tide drove ashore all the ships in anchorage. The second and third waves, even bigger than the first, flowed inland to inundate with salt water the fertile fields of the Godavari River’s delta. Coringa was almost completely destroyed, and around 20,000 people were killed.
Naming the 1789 disaster “The Great Coringa Cyclone” was akin to those who named the 1914 – 1918 global war “The Great War”, little knowing that an even greater calamity would soon follow. Those who named the 1789 storm did not suspect that an even bigger and far more devastating cyclone would strike Coringa within a lifetime.
By 1839, half a century after “The Great Coringa Cyclone”, the city had recovered from the 1789 disaster, rebuilt, and was more prosperous, populous, and bustling than ever. Then, on November 25th, 1839, again unusually late in the Bay of Bengal’s cyclone season, a monstrous cyclone struck Coringa, and brought with it a 40-foot storm surge. The extensive damage of the earlier 1789 cyclone paled in comparison to this one, which wholly destroyed the city of Coringa, wrecked all ships in the harbor and carried their wreckage miles inland, and killed over 300,000 people.
This time the damage was so extensive that the few survivors made no effort to rebuild. Most upped stakes and scattered to pursue their lives elsewhere, putting distance between themselves and what was thought to be a cursed city. The few who remained, some of whom were old enough to have experienced both devastating cyclones during their lifetimes, abandoned the coast altogether and rebuilt their community miles inland.
The 1783 Laki Eruption was not exactly one of history’s most powerful volcanic events. It was not a massive and violent eruption like Vesuvius or Krakatoa or Tambora. It did not look anything like what most people imagine when picturing a volcano going off with a bang, blowing its top, and releasing a massive amount of energy in a dramatic explosion. There were no fires reaching to the heavens, or rivers of lava rushing down the volcano’s sides.
Indeed, the Laki Eruption was not even a single explosive event. Instead, it was eight months of rumblings, interspersed by relatively small eruptions from time to time, with lava slowly seeping out of the side every now and then, while the volcano steadily spewed sulfuric dioxide gasses. Laki was not a vigorous and energetic volcano, but a tired and lazy one, steadily farting gasses for months before it finally subsided and went quiet. Nonetheless, Laki was the deadliest volcanic eruption in human history.
The Laki Eruption’s deadliness was a result of its steady gas releases during its eight months of rumbling and periodic small explosions. Massive amounts of gasses, including fluorine and over 120 million tons of sundry sulfuric dioxides, were released into the air. They produced fog and haze as far away as Syria. The fluorine settled on Iceland’s grass, which gave grazing animals fluoride poisoning and killed most of the island’s livestock. The loss of livestock in turn caused a quarter of Iceland’s human population to starve to death.
But Iceland was and remains sparsely populated, so the death of a quarter of its population did not make Laki history’s deadliest eruption. The impact was beyond Iceland, where the eruption led to a decline in temperatures in the northern hemisphere. Winter temperatures in the US, for example, dropped 10 degrees Fahrenheit in 1783, and remained below normal for several years afterward. Laki’s deadliest impact was not in the US or North America, either, however.
The Laki Eruption’s deadliest impact was in Europe and the northern hemisphere southeast of Iceland. The summer of 1783 had been a particularly hot one, and a rare high-pressure zone formed over Iceland that year, which caused winds to blow to the southeast. Thus, when Laki began spewing prodigious amounts of sulfuric dioxide into the sky, they were carried by the winds from Iceland in a southeasterly direction.
Wherever those winds arrived, they brought misery with them. Laki’s gasses caused crop failures in Europe, drought in North Africa and India, Japan’s worst famine, as well as a historic famine in Egypt, a sixth of whose population starved to death in 1784. It is estimated that the Laki Eruption and its aftermath caused the deaths of an estimated six million people, making it the deadliest volcanic eruption in human history. It also illustrated how low energy but large volume eruptions over an extended period can have a greater impact than massive explosive eruptions.
The city of Antioch in the Roman province of Syria, modern Antakya in Turkey, was rocked by an extremely intense earthquake on December 13th, 115 AD. The upheaval caused widespread devastation and high loss of life in the region, destroying not only Antioch, but also the nearby city of Apamea, and inflicting significant damage upon Beirut as well.
The tremors also triggered a tsunami that slammed into the eastern Mediterranean coast. It caused extensive damage as far south as the seaport of Caesarea in the Roman province of Palestine, whose harbor was wrecked by the wall of water. It is estimated that about 260,000 people lost their lives, with many more injured and/or made homeless. Emperor Trajan was in the city at the time, and he barely survived the disaster.
In 115 AD, Antioch was a flourishing and economically vibrant Greco-Roman city on the Orontes River. It was the Roman Empire’s third-biggest metropolis after Rome and Alexandria. The city owed its success to its location at the closest terminus of the Persian Royal Road, which linked the Mediterranean with Mesopotamia and Persia.
That made Antioch a trading center and entrepot for goods between the Roman and Persian worlds. Unfortunately, Antioch’s location had the misfortune of being near the junction of three tectonic plates – the African, Anatolian, and Arabian – whose friction made the region particularly susceptible to large earthquakes.
5. Tossing People and Trees in the Air Like Water Drops Shaken Off a Wet Dog
As described by the Roman historian Cassius Dio, the Antioch Earthquake was preceded by a loud and bellowing roar. Then the ground started to violently vibrate and shake, tossing people and entire trees up into the air as if they were water drops shaken off a wet dog’s fur.
Entire buildings were lifted off the ground, then violently slammed back to earth. Many were killed or injured by falling debris, and many more by buildings collapsing atop and burying them. The aftershocks, which continued for days, killed and injured many of those who had survived the first day’s tremors.
When the earthquake struck Antioch, the Roman emperor Trajan and his chief deputy and successor, the future emperor Hadrian, were wintering in the city, overseeing preparations for a military campaign against Parthia. Because Antioch served as headquarters for the war against Parthia, the city and the surrounding region were even more crowded than usual. The presence of legions encamped nearby, as well as the camp followers and other civilians engaged in support activities for the Roman army, swelled Antioch’s population.
Trajan managed to escape via a window from the building in which he had been housed, and was fortunate to suffer only light injuries. As buildings and debris kept falling due to aftershocks, the emperor and his entourage relocated to the open hippodrome, or race track, where they erected tents and set up house. His deputy Hadrian also escaped with only slight injuries. Both oversaw the recovery and rebuilding process, which was begun by Trajan, and after his death in 117, was continued and completed by his successor, Hadrian.
Sometime between 1642 – 1540 BC, Santorini in today’s Greece experienced one of the most powerful volcanic eruptions in recorded history. It was about four times as powerful as the gigantic Krakatoa eruption of 1883. The explosion sundered the island of Thera, and wiped out the flourishing Minoan settlement of nearby Akrotiri and surrounding islands.
Known as the Minoan Eruption of Thera, the event 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, the Minoan Eruption was one of history’s most impactful natural disasters, with consequences not only to its own era, but 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 Minoan Eruption produced powerful tsunamis. They struck and devastated Crete, contributing to the decline of its Minoan civilization, and paving the way for its 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.
The Minoan Eruption weakened Crete and its Minoan civilization sufficiently to create a power vacuum in the Aegean. The emerging Mycenaeans filled it in mainland Greece. They 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 focused not on trade with Egypt and the Levant, but 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, and the trajectory of their civilization when it flourished centuries later, long after the Mycenaeans had themselves disappeared. The Greeks ended up with civilization and culture distinct from Egypt and the eastern Mediterranean, rather than becoming an extension and outpost of those civilizations. That had knock-on effects on western civilization, which 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 Minoan Eruption of the second millennium BC.
Where Did We Find This Stuff? Some Sources and Further Reading