Читать книгу The End is Always Near - Dan Carlin - Страница 15

First, let’s step out of our timeline to the year 1815, when the Mount Tambora volcano erupted in what’s now part of Indonesia. It is the only eruption in the last thousand years that merits a 7 out of a maximum 8 rating on the Volcanic Explosivity Index (VEI).[30] It caused tsunamis and earthquakes, darkened the skies, and unleashed enough ash to cover a one-hundred-square-mile area to a depth of twelve feet. The effect on global climate was profound—1816 was known as “the year without summer.” And, among other things, it was thought to have brought on famine.

There have only been a handful of volcanic eruptions to reach that high on the VEI since humans began keeping a written record of their history. One happened near the end of the Bronze Age, in the eastern Mediterranean, in an area that was right at the heart of the whole Mediterranean Bronze Age world.

Today, the location of the volcano is actually the Greek island of Santorini, but the ancient Greeks called the island Thera. Like Tambora, the Thera eruption was one of the most powerful volcanic events in human history; unlike Tambora, we have no surviving contemporary accounts of it. Scientists can find the evidence of its eruption all over the region, but they can’t yet pinpoint the year it happened. If they could, it would become a specific marker that would help date other events.[31] Experts can get close to a date, within a century or so—usually between about 1630 and 1500 BCE—but while that’s a tiny margin of error when compared with the intervening thousands of years, it’s still enough to muddy this investigation. Since the fall of the Bronze Age is usually dated to around 1200 BCE or so, the later the eruption is dated, the more likely it is to have had an effect on the catastrophe.[32]

Experts argue about most things connected to the Thera eruption. In addition to the dating, the amount of damage done to the surrounding areas is in question. If it somehow played a role in the downfall of that age, how did it do so? Tsunamis are one proposed vector of destruction. That one or multiple tsunamis were generated by the eruption seems universally accepted, but disagreements occur over their size and what sort of damage they would have caused. Most of the Thera volcano’s tsunamis would have been created by the quick addition of massive amounts of material into the sea, which generates waves that can reach enormous heights (the same way that a glacier’s calving produces large waves).[33] These waves, known as megatsunamis, are quite different from the more familiar seismic variety of tsunami. Whereas the seismic tsunamis are almost too small to be noticed while moving through the open sea, and they explode in height only when they approach land, megatsunamis start at maximum height upon generation and lose force and height as they move across miles of water. Seismic tsunamis are often preceded by a strange receding of the beach tide, only to have the water roar back later, but megatsunamis are more like rogue waves—they can come out of nowhere.

The reason waves matter is that one of the theories about how a volcano might be tied to the end of the Bronze Age argues that the tsunamis may have decimated the coastal areas of nearby states. Ships in port would be damaged by a tsunami of any sort, but a megatsunami could also have wreaked havoc on ships in the open sea. A huge wall of water speeding across the ocean might sink anything in its path.[34]

The island of Crete, the heart and soul of the powerful maritime Minoan state, was close to Thera and is often thought to have been a likely victim of the volcano’s explosion.[35] If the ships, facilities, and perhaps settlements and coastal population of Crete were badly damaged or destroyed by the sea, the resulting effect on the economy of the region might have been huge.

It’s also been suggested that widespread damage on a large scale might have weakened the Minoans in a way that made them a tempting target for geopolitical predators in their region. Sometime between about 1450 and 1370 BCE, most of the great palaces from the heyday of the Minoans were destroyed, and eventually the area and culture was taken over by the Mycenaeans.[36] But if the Minoan state declined around 1400 BCE or so, that’s still two or more centuries removed from the other parts of the collapse manifesting. It’s possible that the volcano and the resulting tsunami might have been responsible for this, a chain reaction of events that destabilized what had been a stable system, but that would constitute a long lag time between cause and effect.

The other natural disaster that gets brought into the conversation about the end of the Bronze Age is earthquakes. There’s overlap here, because the Thera eruption may have sparked or been preceded by earthquakes, and these might have contributed to the damage spawned by the volcano. And earthquakes are also one of the primary causes of tsunamis.

There’s no doubt that earthquakes were a relatively regular ancient visitor to this very seismically active region. Damage from earthquakes in ancient times (sometimes including crushed bodies found where they fell) has been discovered in structures all over the eastern Mediterranean and western Asia. In fact, there seem to have been several big earthquakes dated to around the time of the Bronze Age’s end, and lots of important cities in that area show earthquake damage. In the age before stabilized buildings and modern construction, and when open fires were common, the damage done by earthquakes may have been worse than what we’d find today. Certainly, the ability to deal with an earthquake’s aftermath is better in modern times. An earthquake and a resulting tsunami that killed fifty thousand people today would be much easier for us to clean up and recover from than it would have been for a Bronze Age society.

Yet the evidence points often to rebuilding after the historical quakes, which shows that such events weren’t totally fatal and that the affected society could continue. But it doesn’t necessarily mean that population, prosperity, or geopolitical power and influence would return to predisaster levels.

A single phenomenon (such as earthquakes, droughts, volcanoes, or tsunamis) can explain why a particular city or area suffered damage, but it can’t by itself explain why the entire Mediterranean and west Asian region was affected by something at the end of the Bronze Age. Just because there may have been a volcano on an Aegean island that erupted and caused tsunamis, why did Babylon and Assyria, located in landlocked modern-day Iraq, have problems?