For those of you who may not be aware, there is a fantastic thing in the geobloggosphere known as The Accretionary Wedge. Every month or so, someone hosts a specific topic. Geobloggers are invited to contribute, and the submissions over that month are then collated on the hosts blog.
I’ve been meaning to join in for a while, but never quite got there for one reason or another. This month it’s happening.
The topic, hosted over at Knowledge-flocs, is the relationship between Geology, life and civilisation. Or, in the words of Cat herself:
How has life or civilisation been affected by geology or how has geology been affected by life?
There are, within the field of geology, so many examples of this that it is difficult to pick any one. Everything about our society has in some what been influenced by geology, whether a single event such as a devastating earthquake, to the economic wealth of particular areas driven by events in the geological past, through to migration patterns being impacted by mountains, oceans and rivers – all constrained by geological events and behaviours.
The one that occurred to me immediately, however is a a single, one-off event. Had it not happened almost exactly where it did, at exactly the time it did (at least on a geological time scale), the world now would almost certainly be a completely different place.
To set the scene, we first must consider that much of world history for the last 2000 years has been dominated by European nations. Global colonisation (actually, mostly recolonisation) was driven by the great European powers throughout the Age of Exploration. This, after centuries of pan-European infighting, invasion, and intrigue.
These European powerhouses all grew from a similar background, with a long history of pan-continental trade and communication. Much of this grew off the back of the Roman conquest of Europe, which in turn owed much to the Greek civilisation.
So how did we get to a point with such dominant European city-states, which could lead to the Roman Empire? Let’s go back in time a bit.
Prior to the Iron Age we largely have disparate local communities, with limited trade and communication. Through the Bronze Age (~3200 – 600 BC) we see a much more complex set of civilisations develop. Farming becomes well developed, allowing cities to flourish. We city-state civilisations develop in Africa, the Mediterranean, and the Persian plateau.
These states build on pre-existing trade routes, which in turn enables strong civilisations to grow in wealth, power and influence. We start to see the development of kingdoms, and from there our early European history takes shape.
So how does all of this relate to a geological event? Well, at some point between 1627 and 1600 BC, the volcano of Santorini erupted.
The eruption itself was significant, ejecting about 60 cubic kilometers of magma into the Aegean skies in a period of perhaps a few days. As that magma was jetted from the chamber, the dissolved gases within it came out of solution allowing the otherwise glassy shards to bubble into pumice, bulking the total volume of ejected tephra to about 100 cubic kilometers. That puts the eruption at about 4 times the volume of Krakatau in 1883, and makes it the fourth largest eruption in recorded human history.
That in itself is significant, but we’re still basing our history on the success of the Greek and Roman empires – what effect did this eruption have?
What the Santorini eruption did is completely devastate the Minoan civilisation. Based on the island of Crete, the Minoans were a remarkably advanced civilisation. Their cities had stone paving, sewerage, and not only were their buildings multi-storey, but also display considerable earthquake resilience (not entirely surprising when you consider where they lived).
The Minoans operated one of the main trade networks across the Aegean, with routes connecting the Northern and Western Mediterranean with areas as remote as Kush and Afghanistan. They were instrumental in the tin trade, essential for the smelting of the Bronze which defined the age. They appear to have built almost their entire empire on the basis of trade. They developed complex written languages, and produced impressive works of art and architecture.
When Santorini erupted it put an end to the Minoan civilisation. The trade fleet is believed to have been wrecked by the resulting tsunami, and many of its port towns and cities destroyed. The tephra fallout is likely to have made the Aegean difficult if not impossible to navigate for weeks or months, and volcanic ash and pumice will have blanketed everything.
However, without the fall of this mighty trade empire, there might never have been the window of opportunity for the Greek – and subsequently Roman civilisations to grow. That’s not to say the Minoans would still be going strong today – the nature of civilisations is to rise and fall. The question is whether under different pressures and timescales - in an environment with so many different city-states looking for power and influence – an entirely different history might have developed.
Following the Santorini eruption, the Myceanean civilisation – more into war and conquest than the trade-reliant Minoans – started to exert their influence over the Aegean. After a few hundred years the Myceanean civilisation ground to a halt, and the city-states of Greece eventually formed the ancient Greek civilisation we are all familiar with.
So, I think it’s fair to say that without that one-off cataclysmic eruption, we almost certainly would not have seen the same pattern of growth and development in ancient Europe, which in turn could not have spawned the same nations across the continent for the next 3500 years, which in turn means I almost certainly wouldn’t be sat here typing this.