Monday 4 August 2014

The Biggest Bang in Recorded History...



The Caldera from the Winery

The big bang...

It's the start of everything. Isn't it? Cosmologists would have us believe that about 14 gazzillion years ago, in one very loud instant, we went from nothing to... well if not necessarily everything, at least quite a lot of it. And who knows, they might even be right, but that's not the big bang I'm on about. My big bang is on a rather more human scale – imaginable because it happened within the span of human history. It happened only three and a half thousand years ago – hell from a cosmological perspective, we can still hear the echo!

The airport

The international airport at Santorini is insane! Not in the same way as other airports are insane. Other airports are Machiavellian masterpieces, designed to remove all sense of place and time before flying you to another place and a different time zone. While you await the chance to go through the gate you are bombarded with the opportunity to buy all the things you may have forgotten and lots of things you probably don't need. Once through the gate, the onslaught on your holiday spending money intensifies and the price of a cup of coffee trebles, but the price of Boss by Hugo Boss becomes tax free. The money haemorrhages from your wallet. And as the departure boards change with slumber inducing speeds, you wonder, having gotten up at 4am this morning and being in dire danger of nodding off, if you will have enough time to get to your gate once it has been silently announced...

The caldera from the plane


Santorini international airport is insane because it has none of that! The couple of concourse shops sell local trinkets, Coca Cola and Lays – How quaint. The waiting room were we (about 250 of us) crowded for over an hour on the way back had just about 20 seats – Genius! It is without doubt the straightest stretch of tarmac on the island and can be clearly seen as the plane banks around to approach past the mass of Profitas Ilias – the highest point on the island and one of the few parts that is not volcanic in origin. The plane bumps down and one has to wonder if the pilot only does this as a hobby and his actual area of expertise is dentistry or brick-laying. The runway shuttle bus arrives and so begins the undignified scramble to (a.) get your luggage from the overheads, (b.) get out of the plane, shouldering aside any fellow passengers like a pro-footballer (the American type), and (c.) get a seat on the shuttle bus for that 2 minute journey... For those saddo's and losers who are not prepared to take this affirmative action, there is the indignity of having to stand up on the shuttle bus! Duh!

In the airport, the customs man barely acknowledges my passport or even my presence, and then it's out of the building, into the blazing sun and the chaos of finding our rep. The reps allocate people to buses depending on their eventual destination. It's like being in the middle of one of those epic films with casts of thousands, all of whom are shouting at once – Chaotic, but with a narrative all the same – where are we going to? Perissa – on the inexpensive side of the island. The bus traverses a switchback road through whitewashed villages to to crest of the island with the mass of Profitas Ilias off to the left before similar route down the other side. Whitewashed villages turn dusty and seemingly half finished close up. Vines hunker down close to the volcanic soil. And Venician windmills march across the horizon.

Profitas Ilias from Perissa


Profitas Ilias is a crumpled piece of the basement the oldest rocks on Santorini through which all the volcanic bits burrowed to get to the surface. Looking at it from our destination, Perissa, one can see the curves of tortured meta-sediments and the slashes of the controlling faults. Close up the rocks - marbles, phylites and greywakes speak of their sedimentary origins – they were once seabed, now they are the highest oldest point on the island.


Back to the big bang

So back to that big bang. Three and a half thousand years ago, there was an Island – one of a group of islands called the Cyclides, sited a couple of hundred kilometers behind the Hellenic trench were the African plate descends below the Aegean plate. Back then it had already been the site of several violent episodes of volcanism, creating an island with an inland waterway cutting it off from the volcano in the centre. This was a thriving trading centre at the northern edge of influence of Crete's famous Minoan civilization. All this started to unravel over about 3 weeks to a month in 1650BC when the island was hit by many earthquakes and the volcano started to erupt violently. It sent plumes of smoke, rock and ash into the stratosphere in a so-called Plinian eruption. The ash settled out under gravity, blanketing the island, every road, roof, field. One of the major killers in eruptions is building collapse as ash blankets the roofs of buildings that are not designed to support the extra weight. The final cataclysmic eruption is that big bang I'm talking about. It's arguably the biggest bang in recorded history, and it may have been due to a caldera forming magma chamber collapse... It could have been a Phraetomagmatic explosion due to magmatic interaction with sea water...

The results can be seen all over the island as a thick (up to 60m thick in some places) pale ash layer (photo 4). The ash is mixed with rock fragments, pumice, volcanic bombs and even (as I found) the occasional bit of pottery. From a the water taxi, you can see how soft the ash is were it has been wind eroded into weird castles at the shoreline  and the nutrients provided by the volcanic ash produce good wine producing soils. From the inside of the caldera, the successive layers of ash, pumice and lava can be seen in their magnificence telling a tale of eruptive activity going back over half a million years – The biggest bang in recorded history may be the one that gets talked about, but it was by no means the first.

Ash deposits from the 1645BC eruption


Pumice

Volcanic Bomb


Minoan Pottery (maybe) found buried in the ash deposits


Wind sculpted ash castles 


Ghost towns

There are two ghost towns in Santorini. Akrotiri was the ancient Minoan settlement buried Pompeii style by the ash from the 1645BC eruption. It was a bustling trade centre, frozen in place for over 30 centuries. Unlike Pompeii, there are no bodies, no remains at all. It seems that the the seismic events preceding the eruptive phase was enough to make the population of a thriving town abandon it. Today it is under a climate controlled roof, viewed from carefully placed walkways and viewing points so that the complexity of Minoan culture and the enormity of the disaster which overran it can be appreciated.

The village shop at Akrotiri


The second ghost town is from 30 centuries later. Mesa Gonia (the Corner) suffered a similar set of earth tremors that caused the inhabitants to abandon it completely. Now residents are moving back, renovating and rebuilding, but they are cheek and jowl with houses long abandoned and falling into disrepair, the only people viewing them, the bus loads of tourists. Some of the houses here are actually built into the soft deposits of ash from the 1645BC eruption. The irony is as thick as the ash deposits. 

Craters and Lava domes

Nea Kameni – the current volcanic centre on Santorini is thought to be much smaller that the volcanic peak responsible for the 1645BC eruption. It has appeared on phases and stages since 197BC, with it variously poking it's head above the water in different places at different times before submerging again. The growth of the current shield volcano really took off after 1866 when the Georgios lavas spread out over a wide area. The last eruption was in 1950, but don't be fooled, Nea Kameni is only slumbering. The main crater can be accessed and viewed with ease, lying just south west of the Niki Lava dome.  A tourist path circumnavigates the rim of the crater, and holding ones hand over unassuming holes in the ground near a small cluster of seismic equipment on the south eastern crater rim betrays the heat that is not that far below.  This is the breath of the beast below...  and it's only slumbering...

Lava flows seem to be blocky affairs – the lava was very sticky dacitic, and it emerged like tooth paste, the occasional bomb being blasted pout by the pressures created. This has created a blasted landscape of black, brown and red rock, some coated in dust, others almost glassy smooth, some clearly very dense, others strangely light weight. It's a growing island on which barely anything grows. It's a land of contradictions.

The Main Crater, Nea Kameni

The Niki Lava Dome , Nea Kameni
Sunsets

Santorini is pretty boastful about its sunsets. It is as much about the location as about the actual setting of out nearest star. I have experienced more spectacular combinations of setting sun and appropriately placed clouds and pollution induced colouration in the UK. Try the Isle of Harris off the west coast of Scotland sometime. If you see it from the top of Clisham – Harris' highest peak, it takes some beating. That said, the three sunsets I experiences whilst I was there were not bad efforts. I one I was sat in a cliff top restaurant in the capitol of the island – Fira – with an enormous ice cream and a view out into the caldera before me. A strong gusty wind was whipping the sea surface into little mini tornados amid the surface chop. The view from romantic Oia (pronounced ear) lacks land reference points unless you position yourself very carefully. By about 2 hours before sunset, all the best spots have been taken and in the last half hour or so, there is a frantic scramble, seemingly by every person in town to that end of town. There must be a measurable isostatic adjustment of Santorini every sunset as large portions of the transient population all gather at one end. Does that end go down and the other go up? There's a PHD project there I think. Finally, sunset from a sail boat has everything but land, but who needs land on a sailboat. The company, the food, the Santorini wine (which is rather good by the way), that feel of continuous automatic adjustment of your stance – your sea-legs.

Sunset from Fira


Sunset from Oia


Sunset from the sail boat
Agates

Red Beach is on the shallow side of the island. No caldera view. Just down the hill from the ruins at Akrotiri. The iron rich red rocks of the Therasia Shield outcrop as high loose cliffs above a narrow shingle and sand beach and aquamarine waters. Sun worshipers arrive from the carpark at the Akrotiri end, or from the sea via the frequent water taxis. The water is clear and just the right temperature to cool off in. The general tempo of the place is relax... soak up the sun... have a cool drink... So I wander off in search of treasure! Millenia ago, silica rich fluids seeped through the red rocks, depositing silica in its most common form - quatrz, but with a twist -layer on microscopic layer with slightly different chemical contaminants, forming beautiful, intricate patterns, each one individual, each completely unique – like little tiny faberge eggs - agate. The patient obsessive, can sit in the cool of the water at the surf line and pick slivers and chips of these agates from the shingle – no two of them the same, yet all equally beautiful. I'm one such obsessive.

Red Beach

As the sun drops to the horizon, the sun worshipers start to thin out, leaving only empty coke bottles and plastic wrapping as the echoes of their presence.  The die-hard obsessive sits in the gently lapping surf excavating hand-fulls of shingle for the surf to sort and categorise.  Amid the light absorbent reds, browns and blacks of the volcanic pebbles, the occasional fleck of light reflective quartz shines like a tiny star, yearning to be found, beckoning the obsessive to take it...


Agate


Agate



Agate


Agate


Agate


Agate


Agate