Until the 1946 Aleutian Islands earthquake, tsunamis were a much described but poorly understood phenomenon. The earthquake caused a tsunami that killed 159 people in Hawaii, as waves ranging as high as 130 feet spread out across the Pacific.
‘A group of geophysicists waiting to go out to a nuclear test site were on Hawaii when the huge wave arrived,’ says Richard Hamblyn, whose recent book Tsunami looks at the culture and science behind the destructive waves. What the scientists saw that day improved tsunami science and led to the creation of the Pacific Tsunami Warning Center (PTWC) in 1949.
‘When I went to the PTWC I asked the scientists, “Would you like to see a tsunami in real life?” They all said, “Yes, absolutely”,’ says Hamblyn. His visit took place three weeks before the 2004 Boxing Day tsunami. ‘They wanted to see the waves, but certainly not the consequences,’ he adds.
Before the 2004 tsunami, the PTWC had managed several successful evacuations, according to Hamblyn. But there was a blind spot. No adequate warning system had been set up for the Indian Ocean, although this has now been resolved. A warning system using 25 seismographs was switched on in 2006. ‘I hadn’t realised how frequent tsunamis were in the past,’ says Hamblyn. ‘No shoreline on Earth is immune to tsunamis.’
Even Britain has been hit by tsunamis, albeit a long time ago.
Between 6225–6170 BCE, an underwater landslide off the Norwegian coast caused a tsunami in the North Sea that hit Scotland. The Storegga Slides – three in total – are among the largest landslides ever recorded. ‘There were an unknown number of casualties in Scotland,’ says Hamblyn. The slides happened long before records began, but even now tsunami evidence is readable in the coastline.
Hamblyn points out that there is a hypothesis that the 1607 Bristol Channel flood was caused by a tsunami, but adds that it’s contentious. Some scientists believe the flood was due to an earthquake in the Irish Sea, but others argue for a storm surge. ‘Historical accounts say the skies were clear, although this does not rule out a storm surge,’ he says.
Tsunami means ‘harbour wave’ in Japanese, and the wave is intrinsic to the archipelago’s culture. ‘There is very little of Japanese culture that does not reflect seismic instability in the islands. It’s a geophysically aware culture,’ says Hamblyn.
Katsushika Hokusai’s woodblock print The Great Wave off Kanagawa is often misidentified as showing a tsunami, according to Hamblyn. The image shows a wave threatening to inundate a small fishing boat, but it is not a tsunami. This hasn’t stopped the image being taken up to represent tsunamis in wider culture – even the UN’s International Tsunami Information Center borrows the image for its website.
A more obscure tsunami image is an 1867 engraving from the Illustrated London News. It shows Royal Mail paddle steamer La Plata riding out a tsunami off St Thomas Island in the Caribbean. ‘It was quite a feat of seamanship,’ says Hamblyn. The image went on to inspire the poster for George Clooney’s 2000 film The Perfect Storm, which shows a small fishing boat climbing an enormous wave. Again, The Perfect Storm’s wave was no tsunami – it’s a storm wave from the 1991 Halloween Nor’easter.
The 2011 Tōhoku earthquake and tsunami has changed Japan’s culture, says Hamblyn. ‘The tsunami did the damage and not the earthquake, and it destroyed Japan’s cultural image of itself as a disaster prepared society,’ he says.
With around 10,000 miles of concrete sea wall around Japan’s coast there was a perception before 2011 that the country was well protected from tsunamis. This meant people tended to ignore the tsunami warning sirens in 2011.
Now Japan must improve preparedness, as technological solutions are probably too costly. ‘Increasing the height of the sea walls is economically unviable, and it’s impossible to surround a country with a sea wall,’ says Hamblyn.
Cultural reactions to tsunamis also influence survival rates, according to Hamblyn. ‘In areas with high rates of socio-economic change there can be a problem when migrants without a cultural coastal background are caught in a tsunami,’ he says.
When a tsunami hit Samoa in 2009,most people were killed by the second wave because they returned home to collect possessions, says Hamblyn. ‘People need to listen to their own folklore because that will tell them what to do.’