Eruption of Mount Fuji would be a headache for us all
You know the iconic image of the bullet train speeding past Mount Fuji? Well, that train wouldn’t run if Japan’s tallest — and volcanic — mountain erupted.
Nor, come to think of it, would cars or planes. A huge eruption of Mount Fuji would rain down so much ash that it would take only three hours to bring the network of trains and highways in Tokyo — just 100km away — to a halt.
Last week Japan updated its disaster response plans for a Fuji eruption, setting out how the 800,000 people living in the vicinity of the mountain would evacuate (by foot as far as possible, to avoid the roads clogging up with cars) and how they would survive the immediate aftermath.
But the prospect of the 3,776m volcano erupting in a big way, which it hasn’t done since 1707, is not just a problem for the people living in the three provinces at the foot of the mountain.
It’s a problem for the Tokyo metropolitan region of about 30-million people. And it’s a problem for the rest of the world.
Lava flows are scary, but ash is the bigger problem. While it would take about 24 hours for lava to flow from an erupting Fuji to the shinkansen (bullet train) line, ash would almost certainly shut down the worldpioneering fast train far earlier.
Just half a millimetre of ash would force trains to stop running. One millimetre of the stuff on the roads would force cars to drive at a maximum speed of 30km/h. Five millimetres would cut their speed to 10km/h. And at 10cm the roads would become impassable.
Back in 1707 Fuji’s eruption covered Tokyo in a thick layer of ash, burying farmland. Many people starved. In 2014 the country suffered its worst volcanic disaster in more than 90 years when the 3,067m-high Mount Ontake, 200km west of Tokyo, exploded without warning, killing 63 hikers.
Of course, Japan is just one country where volcanoes pose a serious risk. Other countries flagged in a 2009 academic paper as having the highest level of volcanic hazard or vulnerability are the US, Indonesia, Ecuador, Papua New Guinea, Italy, New Zealand, Philippines, Mexico and the UK.
Activity can happen in many places, and the fallout isn’t just local. The 2010 eruption of Iceland’s Eyjafjallajökull volcano disrupted global supply chains, including the flow of what was then estimated at 10,000 tonnes of airfreight transported daily between Asia and Europe. Carmaker Nissan suspended production at two plants due to a lack of parts imported from Ireland.
The economic miracle of middle-class growth in Asia and the surge in e-commerce guarantees that the cost of any disruption to air travel and transport in the region will be far higher than in the past.
The problem for planes is that ash in a jet engine can cause it to stall. In June 1982 flight BA009, en route from Kuala Lumpur to Perth, flew into a cloud of dust and ash from the eruption of Mount Galunggung on Indonesia’s island of Java, and all four engines failed.
“Ladies and gentlemen, this is your captain speaking,” Captain Eric Moody told his passengers. “We have a small problem. All four engines have stopped. We are doing our damnedest to get them under control. I trust you are not in too much distress?” Moody and colleagues glided the 747-200 out of the cloud and were able to restart three engines, landing safely at Jakarta.