The world famous Edinburgh International Festival has kicked off, beginning three weeks of the best the arts world has to offer. The Fringe Festival has countless alternative, weird, and wacky events happening all over the city, and the Edinburgh International Book Festival is underway. Throughout the Book Festival we’ll be bringing you sneak peeks of our authors’ talks and backstage debriefs so that, even if you can’t make it to Edinburgh this year, you won’t miss out on all the action.
By Bill McGuire
If it’s August, it must be Edinburgh. Doing the rounds of the UK’s book festivals is always great fun, but the Edinburgh International Book Festival is almost inevitably the annual highlight. While the book festival is exciting in its own right, this is in large part because the Edinburgh Festival and Fringe are in full spate, packing this great city with visitors from far and wide, and with acts and events that boggle even the most unflappable mind. Where else can you stroll down a street of 10-storey high rises more than 300 years old to watch a unicyclist juggling blindfolded or an entertainer whose speciality is popping his joints and rearranging his limbs into unlikely and somewhat unsettling configurations? Away from the Royal Mile, however, the book festival is located in the calmer setting of Charlotte Square, in the so-called ‘new town’, where it is the English language and not elements of the human body that are manipulated.
My visit to the festival this year formed part of a tour to linked to my new book, Waking the Giant, which has previously taken me to London, Keswick, Aberystwyth, Liverpool, Hay-on-Wye, and coincidentally Edinburgh (for the Science Festival earlier in the year). This time, with 8-year old son, Fraser, in tow, I was booked to do a joint gig with lauded environmental journalist Fred Pearce, a stalwart contributor to the Guardian and New Scientist, and prolific author. Putting the two of us together was a smart move, given that we have new books out that address different disturbing environmental issues. I have a feeling, however, that the combination might have made for a somewhat depressing hour for an audience who, nevertheless, looked pretty chipper at the end. While Fred examined the devastating consequences for indigenous populations of the wholesale buying up of prime African farmland by foreign states, my focus was how climate change has before and may well again trigger earthquakes, tsunamis, and volcanic eruptions.
If this is the first time you have heard about this possibility, your reaction will probably be the same as most people’s: “He must be mad.” Surprisingly, however, the idea isn’t even new and we have a huge amount of evidence for past changes in our world’s climate eliciting a potentially hazardous response from the solid Earth. “But how can this possibly be the case?” I hear you say. Surely climate change is confined to the atmosphere, with perhaps the oceans involved too. What has the ground we walk and live upon got to do with it? The best way to find out is to head back to the transition from icehouse to greenhouse that followed the end of the last ice age. As the world warmed dramatically between about 18,000 and 5,000 years ago, rapid melting of the great continental ice sheets that covered much of Europe and North America resulted in the decanting of a staggering 52 million cubic kilometres of water from the land and into the oceans.
At high latitudes, particularly across Scandinavia and Canada, the removal of the colossal weight of an icy carapace up to three km thick liberated active faults beneath, which ruptured violently to release the accumulated strain of many thousands of years of imprisonment in the form of huge earthquakes. In northern Norway and Sweden, magnitude eight quakes as large as those we see today within the Pacific ‘Ring of Fire’ shook the region. Around 8,000 years ago, one of these great seismic events seems to have provided the trigger for the Storegga Slide — a monumental submarine landslide that cascaded off the Norwegian continental shelf and into the North Atlantic, spawning a giant tsunami that battered the region’s coastlines, including those of the Shetland Isles and mainland Scotland. As the one km-thick ice cover across Iceland progressively vanished, molten magma incarcerated beneath was able to force its way to the surface, leading to a ‘volcano storm’ that saw eruptive activity climb by more than 50 times.
Even far from the poles the Earth shifted. As meltwater from the vanishing ice sheets poured into the ocean basins, so water levels rose by 130m; the added weight bent ocean margins across the planet. In response, magma was squeezed upwards to explode forth from the many volcanoes that occupy coastal and island locations, while faults such as California’s San Andreas, reacted by rupturing more frequently to produce earthquakes.
Well, this all sounds pretty reasonable, but what has it to do with us right now, you might ask? Quite a bit in fact. Worryingly, climate change due to human activities is driving the loss of ice in Alaska that is already garnering a rise in earthquake activity, while thawing permafrost means that giant landslides are becoming increasingly common in mountainous regions around the world. So far there has been no global burst of volcanic or seismic activity as sea levels driven by contemporary global warming continue to climb, but if we continue to pump out greenhouse gases at current rates, it might only be a matter of time before the restless giant beneath our feet wakes once again. Be afraid. Be very afraid!
Bill McGuire is an academic, science writer, and broadcaster. He is currently Professor of Geophysical and Climate Hazards at UCL. Bill was a member of the UK Government Natural Hazard Working Group established in January 2005, in the wake of the Indian Ocean tsunami, and in 2010 a member of the Science Advisory Group in Emergencies (SAGE) addressing the Icelandic volcanic ash problem. He was also a contributing author on the recent Intergovernmental Panel on Climate Change (IPPC) report on extreme events. His books include Waking the Giant: How a changing climate triggers earthquakes, tsunamis, and volcanoes, Surviving Armageddon: Solutions for a Threatened Planet, and Seven Years to Save the Planet. Read his previous blog posts: “Climate change: causing volcanoes to go pop” and “Will climate change cause earthquakes?”
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