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27/09

It’s this fault’s fault

Our aim has always been to drive as close to fault lines as possible. Little did we really appreciate at the time that this would guarantee us such a spectacular journey. Fault lines often manifest themselves as beautiful mountains ranges or calm valleys, creating an enticing environment in which to live.

In fact in Greece, the fault lines that riddle the country are partly responsible for creating the 15,000 km of beautiful coastline that us Brits love so much, as well as the numerous mountain ranges that are now dotted with ski resorts enabling you to enjoy a morning of skiing and that same afternoon a relaxing swim in the sea.

This beautiful landscape makes it easy to forget the sheer scale and speed at which the geography is at work here – except for in a few dramatic locations where one gets a stark reminder of what’s really going on beneath the surface.

We visited a number of active fault lines within the Alkyonides Gulf, one of which was responsible for triggering a major earthquake in Athens in 1981. Here you get a real sense of how the earth’s crust really can move – this seemingly innocuous slab of rock (and the 12 km of rock you can’t see beneath the soil) moved over a metre in under a second back in 1981, triggering the quake in Athens. This is clearly evidenced by the band of rock just above the soil that is a different colour to the rest of the scarp – it having been exposed to the air for less time than the rest of the rock.

Just above the first band, you can make out a second band which was an earthquake prior to 1981, thought to have occurred about 400 years ago. This rock face was Ioannis’s favourite fault scarp – as it clearly tells the story of two earthquakes, revealing the history of the fault, how often it ruptures, what level of displacement is involved – all of which is invaluable for earthquake geologists trying working out the recurrence interval of a fault.

Further along we visited the beautiful town of Sparta, which soberingly sits just beneath the Sparta Fault, an active fault which is being closely monitored. It was a daunting propsect to see every day life being carried out within such close proximity to an active fault line.

Further along yet another fault we came across a house, knowingly built directly on the fault line itself, just because the view was so spectacular.

The house sits precariously on the loose sedimentary deposits brought down by the alluvial fan adjacent to it. Even without the fault line’s presence, this is little more than shifting gravel. Yes, the view was great, but was it that great?

Finally, on our way home we came across this rock that shows an indirect benefit of being near fault lines. Along this fault line, with each event in time, land on one side was being uplifted, creating more of Greece’s lovely beaches. Now that’s something everyone’s got to love.

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