by Matt Kaplan
On July 21, 365 AD, the Roman historian Ammianus Marcellinus, who was living in Alexandria, wrote:
Slightly after daybreak, and heralded by a thick succession of fiercely shaken thunderbolts, the solidity of the whole earth was made to shake and shudder, and the sea was driven away, its waves were rolled back, and it disappeared, so that the abyss of the depths was uncovered and many-shaped varieties of sea-creatures were seen stuck in the slime; the great wastes of those valleys and mountains, which the very creation had dismissed beneath the vast whirlpools, at that moment, as it was given to be believed, looked up at the sun’s rays. Many ships, then, were stranded as if on dry land, and people wandered at will about the paltry remains of the waters to collect fish and the like in their hands; then the roaring sea as if insulted by its repulse rises back in turn, and through the teeming shoals dashed itself violently on islands and extensive tracts of the mainland, and flattened innumerable buildings in towns or wherever they were found. Thus in the raging conflict of the elements, the face of the earth was changed to reveal wondrous sights. For the mass of waters returning when least expected killed many thousands by drowning, and with the tides whipped up to a height as they rushed back, some ships, after the anger of the watery element had grown old, were seen to have sunk, and the bodies of people killed in shipwrecks lay there, faces up or down.
Marcellinus was witnessing a tsunami of tremendous proportions, and according to research studies of the area, it appears that the inhabitants of Crete were plagued by these disasters.
In 2007, a team of geologists led by Beth Shaw, then a researcher at the University of Cambridge, set out to determine what might have caused the ancient tsunami and whether there was still a threat of enormous waves to the region. The team’s work brought them to Crete, where they started analyzing the carbon found inside corals.
Carbon is an element that appears naturally in the environment in two common forms, carbon 12 and carbon 14. Carbon 12 is stable and, as long as it is left alone, remains carbon 12 in perpetuity. Carbon 14 initially forms as the result of cosmic rays striking it and is a radioactive material, meaning that over time it loses energy by radiating away energized particles. During their lifetimes, all animals consume both carbon 12 and carbon 14 from their environment. After they die, the amount of carbon 12 in the body remains constant but the carbon 14 loses energy and slowly degrades into carbon 12. All samples of carbon 14 shed energy at precisely the same rate and, for this reason, it is possible to look at the carbon 14 found in fossils and work out very accurate dates of animal death by comparing the amount of carbon 14 in the fossil to the amount of carbon 14 in animals that are currently alive.
What surprised the Cambridge team was that all of the algal organisms and aquatic tube worms that had been growing along the western shore of Crete suddenly died in AD 365. When they looked closer, they noticed that the ground around the fossilized organisms had marks on it that looked like a bathtub ring around the island. They realized that tectonic activity had suddenly shoved the western side of the island up and out of the Mediterranean Sea. The team’s analysis, reported in Nature Geoscience in 2008, proposed that tectonic activity pushed the western portion of Crete nearly 32 feet (10 meters) out of the water in a single powerful tectonic event. This sudden uplift quickly dried out all of the algae and worms that had been sitting happily on the seafloor and killed them, thus explaining why they all have exactly the same carbon 14 value.
Lifting that much rock out of the water would have caused a tsunami of epic proportions,29 similar to what Marcellinus described, as well as been connected to a very powerful earthquake. Yet 365 was several thousand years after the days of the Minoans and was probably just an isolated tragedy, right?
Not so. Work on the geology of the Mediterranean, conducted by Anja Scheffers at Southern Cross University in Australia and reported in Earth and Planetary Science Letters in 2008, revealed boulders along the Greek coast with shelled marine animals attached to them. Scheffers and her team realized that, because of the animals attached to them, these boulders had to have once rested beneath the waves. Yet the boulders themselves were not sitting among marine sediments. The only logical explanation was that giant waves had thrown the boulders out of the sea and onto dry land while animals were still hanging on.
When the team analyzed the carbon 14 of the fossil animals on boulders, they found that some of the boulders had been thrown out of the water in 365. This was not surprising. However, they also found evidence of tsunamis having formed in and around 6000, 1000, and 200 BC, suggesting that really big tsunamis, and the powerful earthquakes responsible for creating them, have been common phenomena along the Greek coast for the past ten thousand years.
Scheffers does not provide any evidence of powerful tsunamis between 3000 and 1100 BC, when the Minoan civilization was flourishing, but there is no need. Earthquakes half as strong as those that can send boulders flying out of the ocean terrify people living today who understand the geologic forces behind them. To the poor souls living on ancient Crete, violent shaking of the ground had to have been downright petrifying. During these episodes, buildings would have quickly crumbled, with collapsing pieces of stone and wood snapping human bones as if they were twigs. Without even the most rudimentary geology available to turn to for an explanation, there was no denying that these destructive events were the result of the Minotaur and the deafening roar was its angry bellowing as it fumed in misery deep within its shadowy labyrinth.30 But not all people of the world have come to associate earthquakes with monsters. In some places, earthquakes are viewed as indications of good deities being present.
Beyond the labyrinth
On the Hawaiian islands, where people have long been relentlessly exposed to strong earthquakes, natives worshipped the goddess Pele. Described in myths as a sensitive woman of beauty with a fierce temper, she represented both the destructive fury of volcanic eruptions and the mesmerizing enchantment of Hawaiian dance. Sure, touching her could set fire to a mortal’s skin, but she was also sensitive, loving, and emotional. Thus Pele, the fair and fiery, is a far cry from the Minotaur.
Hawaii is nowhere near a plate boundary. Indeed, the volcanic eruptions and earthquakes that are so common there are not related to plate subduction. Instead, Hawaii is the result of what geologists call a hot spot, which is a section of Earth’s mantle that is superheated and burns through to the crust, making it thin. Sometimes groundwater in this crust on continents becomes so hot that it bubbles up to form geysers and thermal pools like those seen at the hot spot that is Yellowstone National Park. Where Earth’s crust is the seafloor, the eruptions form islands of volcanic rock, as is the case with the hot spot responsible for Hawaii.
The islands that ancient Hawaiians lived on were all formed from lava released by volcanic eruptions. Islanders would have witnessed many eruptions that blanketed the land in fiery red magma. This magma, which would have been destructive and lethal at first, would then solidify and, in areas near the edges of the islands, pour out into the ocean, creating new land. In just a single human life span the magma would cool, soften with exposure to the elements, and transform into fertile soil that would rapidly become covered in verdant plants.
With volcanic eruptions so obviously tethered to the formation of their own island and the creation of life-granting soil, it hardly seems surprising that tectonics took the form of the loving, creative, and fierce Pele rather than just a destructive force to be feared. The Minoans, on the other hand, would not have seen any beneficial effects from the many earthquakes they experienced, in spite of the fact that these earthquakes were the cause of their island’s very existence. Even in the case of a major uplift event, a Cretan coastal shelf suddenly raised up and out of the water would not have become covered in lush vegetation because Crete is not a place where dense plant life readily sprouts.
Today, while Minotaurs are, thankfully, absent, portraying the Earth as a monster in the media continues to prove popular among th
ose who like a good scare. The reason, quite possibly, is because the unknowns of geology are conceptually similar to the dark shadows of the world’s jungles.
The films Volcano and Dante’s Peak portrayed heroic individuals racing against time to save the great masses from the imminent eruption of a volcano. Dante’s Peak has some credible science behind it. The story features a town in the mountains that sits next to a volcano that has not erupted for seven thousand years. Suddenly, for no apparent reason, the volcano becomes active. First, visitors to hot springs get boiled alive as the springs leap to lethal temperatures. Then, as the volcano really gets going, the acidity of water in the surrounding area spikes from all of the sulfuric gases released by nearby volcanic vents. Eventually, there is a catastrophic eruption and much Hollywood-friendly action ensues. The timeline of events in Dante’s Peak is faster than would likely be seen in the real world, but the unpredictability of the volcano and the sorts of threats an eruption might really pose are reasonable enough.
In contrast, the volcano in Volcano appears underneath the La Brea Tar Pits in Los Angeles shortly after an unexpected earthquake. Superheated steam kills people in underground tunnels, magma begins to ooze up from the ground, and fires threaten to destroy the city. Rather than run away, the protagonists arrange to “redirect” the lava out of the city and into the ocean. More terrible ideas for a film about a volcanic disaster would be challenging to come up with.
Volcanos simply do not form anywhere near as quickly as they are shown to do in the film and, as much as some may like there to be a volcano simmering below Los Angeles, no such thing exists. Moreover, tar pits do not have any known link to volcanic activity and magma, which is hot enough to melt stone, cannot be redirected around a city using lane dividers on a freeway.
Even so, as stupid as Volcano is, it and Dante’s Peak play off of real unknowns associated with when and why earthquakes and volcanic eruptions happen. Among geologists who have studied regions like Yellowstone and Hawaii extensively, there is simply no consensus on what causes these volcanic hot spots to exist. Some argue that they are the result of unusual, localized chemistries in the mantle that cause it to become superheated. But nobody is sure. And with the creation of a monster, what better place to start than with an aspect of the natural world that is barely understood? Just like the Minotaur, the volcanic eruptions in the films are beasts built from observations of geology that nobody can make sense of.
Will we see more volcanic eruptions portrayed as monsters? It is difficult to know. The Minotaur came into being in a region where earthquakes were common and explanations were few and far between. Volcano and Dante’s Peak were both produced in 1997, which, in the movie-making world where production takes ages, was a mere blink of an eye after the 1991 Mount Pinatubo eruption in Indonesia, which killed roughly eight hundred people, left a hundred thousand homeless, and was presented in live video on news channels around the world. While it is impossible to leap into the minds of the producers and screenwriters and determine what exactly inspired them to develop these films, a safe bet is that discussions of volcanic eruptions in the news were involved.
We will no doubt see many more monsters take the form of tsunamis, earthquakes, and volcanic eruptions in the years ahead, yet it would be foolish to believe that tectonic movements are required for Earth to inspire monsters. Many processes far more subtle than those associated with earthquakes have created fears that have left sturdy souls trembling in terror.
Secret in the stone
The Minotaur is not the only ancient monster to have come from fears associated with the earth. In the earliest stories from the Theogony, as told by the Greek poet Hesiod around 700 BC, Medusa is one of three daughters, known as the Gorgons, born to the sea gods Phorcys and Ceto. Further details in this early tale are lacking, but fortunately ancient art offers more, with Medusa often being portrayed with a horrible visage, snakes in her hair, fangs in her mouth, and, sometimes, wings on her back.
The playwright Euripides, who lived between 480 and 406 BC, mentions in his tragedy Orestes that merely looking at Medusa and her sisters could turn people to stone. Specifically, Orestes asks the Phrygian slave (or eunuch; translations vary), “Are you afraid of being turned to a stone, as if you had seen a Gorgon?” Euripides expected his audience to know that the Gorgons could petrify, and the allusion would have been clear. Further to this, a few hundred years later, a text that has often been attributed to Apollodorus states that Medusa and her sisters “turned to stone such as beheld them” and that “when her head had been cut off, the winged horse Pegasus sprang out of the Gorgon, and also Chrysaor [a warrior (or in some versions a flying monster) carrying a divine golden sword].”
Perseus Battling Medusa. Pitcher. ©The Trustees of the British Museum. All rights reserved.
But it is the Roman poet Ovid, born 43 BC, who goes further and presents an elaborate story describing how Medusa became a monster. Perseus, who ultimately beheads Medusa, explains: “Her beauty was far-famed, the jealous hope of many a suitor, and of all her charms her hair was loveliest; so I was told by one who claimed to have seen her. She, it’s said, was violated in Athena’s shrine by Ocean’s Lord [Poseidon]. Zeus’s daughter [Athena] turned away and covered with her shield her virgin’s eyes, and then for fitting punishment transformed the Gorgon’s lovely hair to loathsome snakes.”
This is a major change. Rather than being born a monster, Medusa is transformed into one by Athena as punishment for being raped by Poseidon.
There is no question that the early and late stories of Medusa differ significantly, but with the exception of Hesiod, who describes almost nothing at all about Medusa, one element is consistent: She always has a gaze that can petrify flesh. It is the key trait that gives her great power and makes her an object of both terror and fascination. Where did this deadly ability come from?
Some historians argue that the text attributed to Apollodorus, with its talk of Chrysaor with his golden sword and the flying horse Pegasus, is actually an ancient record of a volcanic eruption. The golden sword, they suggest, is a bright orange burst of lava and the flying horse is a chunk of rock or burst of gas being thrown up into the air. Some even go so far as to suggest that the snake attributes associated with Medusa stem from snakelike rivulets of magma coming down the side of a volcano. To a certain extent, ash and lava can cover things and make them look as if they have been turned to stone. Certainly, in the Roman town of Pompeii, which was smothered by ash from Mount Vesuvius in AD 79, humans were killed by toxic gases and covered by ash, and the details of their bodies were preserved by the solidifying ash as their bodies rotted away. There may be some truth to all of this, but fossils provide an alluring alternative explanation.
Anyone with a keen eye who walks along a streambed or next to a cliff for any significant distance stands a chance of stumbling upon a bit of fossilized material. This can take the form of something as mundane as a fossilized shell or be as impressive as a dinosaur skeleton or a human skull. As different as these fossils appear, they all have something in common: They have been transformed from their original biological materials into stone.
Today this process is well understood. When animals die, their bodies fall to the ground and, under most circumstances, other animals come and consume the remains. This starts with the soft bits of the dead animal being ripped away by predators like lions, and generalist scavengers like most vultures. Then more specialized scavengers like hyenas and bearded vultures, which are adept at cracking open bones, break apart the skeleton to suck out nutritious marrow. If the remains are not entirely destroyed by all of this activity, bacterial rot, wind, and rain will usually finish them off in a matter of weeks or months.
However, in some environments, instead of being consumed or weathered, a body that falls onto the shore of a river, next to a lake, or adjacent to a sand dune can become covered by sediment that is either flowing by in the water or being blown about by the wind. Once buried, the remains are
effectively locked away from the surface world.
This sort of burial scenario is common for animals that die by the mouth of a stream. Yet streams do not survive forever. Over time, a meandering stream can become a raging river or it can dry up completely. Such changes can happen in just a few thousand years or over the course of millions of years. Regardless of the time scale, a corpse buried by stream sediment can ultimately be exposed if the stream changes course and it begins eroding away the rock where the remains are located.
Throughout the journey from burial to eventual exposure, corpses are transformed. Flesh rots away. Bones, which are porous, are exposed to water that is traveling underground through sediment. Because groundwater is slightly acidic, it dissolves many of the materials it comes into contact with and carries these dissolved materials away. This water percolates through the many tiny holes in bones, and as it does so, the minerals in the water usually cause a buildup of silica, the primary component in sand, and eventually turn the bones to stone.31 Remarkably, in spite of the radical chemical change involved in transforming bone to stone, the fossil that is formed from the process frequently looks very similar to the original specimen. Even subtle details, like partially healed injuries sustained by an animal during its lifetime, can sometimes be seen after fossilization.
For geologists, fossilized remains offer a glimpse of life from long ago. In contrast, ancient humans finding such things must have been perplexed. The more rationally inclined, like the sixth-century BC philosopher Xenophanes, speculated that the presence of fossilized shells high up on dry land meant that the sea must have once been a lot higher, but there was no understanding of fossilization at the time. During the late 1400s, Leonardo da Vinci went further by arguing that fossil shells he had collected were organic in origin. But it would not be until the 1600s, when Robert Hooke looked into his microscope at both petrified wood and normal wood and saw that they were remarkably similar in structure, that anyone would conclude there was a natural petrification process at work.
